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	<id>http://nassp.space/index.php?action=history&amp;feed=atom&amp;title=Service_Module_Reaction_Control_System</id>
	<title>Service Module Reaction Control System - Revision history</title>
	<link rel="self" type="application/atom+xml" href="http://nassp.space/index.php?action=history&amp;feed=atom&amp;title=Service_Module_Reaction_Control_System"/>
	<link rel="alternate" type="text/html" href="http://nassp.space/index.php?title=Service_Module_Reaction_Control_System&amp;action=history"/>
	<updated>2026-04-21T05:08:12Z</updated>
	<subtitle>Revision history for this page on the wiki</subtitle>
	<generator>MediaWiki 1.40.1</generator>
	<entry>
		<id>http://nassp.space/index.php?title=Service_Module_Reaction_Control_System&amp;diff=1862&amp;oldid=prev</id>
		<title>imported&gt;Abr35 at 19:40, 31 May 2011</title>
		<link rel="alternate" type="text/html" href="http://nassp.space/index.php?title=Service_Module_Reaction_Control_System&amp;diff=1862&amp;oldid=prev"/>
		<updated>2011-05-31T19:40:32Z</updated>

		<summary type="html">&lt;p&gt;&lt;/p&gt;
&lt;table style=&quot;background-color: #fff; color: #202122;&quot; data-mw=&quot;interface&quot;&gt;
				&lt;col class=&quot;diff-marker&quot; /&gt;
				&lt;col class=&quot;diff-content&quot; /&gt;
				&lt;col class=&quot;diff-marker&quot; /&gt;
				&lt;col class=&quot;diff-content&quot; /&gt;
				&lt;tr class=&quot;diff-title&quot; lang=&quot;en&quot;&gt;
				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;← Older revision&lt;/td&gt;
				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;Revision as of 19:40, 31 May 2011&lt;/td&gt;
				&lt;/tr&gt;&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot; id=&quot;mw-diff-left-l19&quot;&gt;Line 19:&lt;/td&gt;
&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot;&gt;Line 19:&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;	The propellant tanks are surrounded by a helium bladder which, when filled, pressurizes the propellant tanks. Once the tanks are pressurized, they must also be opened in order for the fuel and ocidizer to mix. Each RCS quad has both a primary and a secondary propellant tank. These have individual isolation valves in between them and the engine. The controls for these valves are located below the helium isolation valves on MDC-2 {{panel label|name=2.B}} and work in exactly the same manner. These are labeled PRIM PRPLNT for the primary isolation valves and SEC PRPLNT for the secondary valves. The propellant isolation valves receive current from the either or both of the main buses by closing the circuit breakers on MDC-8 labeled SM RCS - PRPLNT ISOL {{panel label|name=8.A}}.&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;	The propellant tanks are surrounded by a helium bladder which, when filled, pressurizes the propellant tanks. Once the tanks are pressurized, they must also be opened in order for the fuel and ocidizer to mix. Each RCS quad has both a primary and a secondary propellant tank. These have individual isolation valves in between them and the engine. The controls for these valves are located below the helium isolation valves on MDC-2 {{panel label|name=2.B}} and work in exactly the same manner. These are labeled PRIM PRPLNT for the primary isolation valves and SEC PRPLNT for the secondary valves. The propellant isolation valves receive current from the either or both of the main buses by closing the circuit breakers on MDC-8 labeled SM RCS - PRPLNT ISOL {{panel label|name=8.A}}.&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;−&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;	Once the fuel isolation valves have been opened fuel can flow ahead into the quad&#039;s injector valves. Just like most rocket engines, the SM RCS consists of both Fuel (MMH) and Oxidizer (NO4) which are pumped into a combustion chamber by the injection valves, and then expelled out of the engine nozzle. The force from the resulting reaction provides attitude control. A fuel injector valve consists of two separate coils, an automatic and direct coil. The automatic coils receive commands to fire from the RJ/EC and the direct coil is commanded by the RHC. For more information on this consult the Stabilization and Control System section. The injectors are all magnetically shut and must receive commands from either the RJ/EC or the RHC to open and fire. In order for the automatic coils to function the SM RCS logic circuit breakers {{panel label|name=8.C}} on MDC-8 must be closed.&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;	Once the fuel isolation valves have been opened fuel can flow ahead into the quad&#039;s injector valves. Just like most rocket engines, the SM RCS consists of both Fuel (MMH) and Oxidizer (NO4) which are pumped into a combustion chamber by the injection valves, and then expelled out of the engine nozzle. The force from the resulting reaction provides attitude control. A fuel injector valve consists of two separate coils, an automatic and direct coil. The automatic coils receive commands to fire from the RJ/EC and the direct coil is commanded by the RHC. For more information on this consult the Stabilization and Control System section. The injectors are all magnetically shut and must receive commands from either the RJ/EC or the RHC to open and fire. In order for the automatic coils to function the SM RCS logic circuit breakers {{panel label|name=8.C}} on MDC-8 must be closed&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;. Commands to the automatic RCS coils may be inhibited by switching the RCS CMD switch on MDC-2 to the off position&lt;/ins&gt;.&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;=Engine=&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;=Engine=&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;	When an RCS engine fires, the fuel and oxidizer cross in the premix chamber first before entering the combustion chamber. This is done to ensure a steady output of force when the engine is fired and minimize transients. Being a burst from a rocket engine is a chemical reaction, the reaction builds and generates more force when the reactants mix.  As the reactants are depleted, the force exerted by the rocket also tails-off. This brief build-up and tail-off of force from the RCS rockets are referred to as their start and shut-off transients. These transients are not yet implemented in the current version of NASSP.&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;	When an RCS engine fires, the fuel and oxidizer cross in the premix chamber first before entering the combustion chamber. This is done to ensure a steady output of force when the engine is fired and minimize transients. Being a burst from a rocket engine is a chemical reaction, the reaction builds and generates more force when the reactants mix.  As the reactants are depleted, the force exerted by the rocket also tails-off. This brief build-up and tail-off of force from the RCS rockets are referred to as their start and shut-off transients. These transients are not yet implemented in the current version of NASSP.&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;

&lt;!-- diff cache key NASSP_wiki:diff::1.12:old-1861:rev-1862 --&gt;
&lt;/table&gt;</summary>
		<author><name>imported&gt;Abr35</name></author>
	</entry>
	<entry>
		<id>http://nassp.space/index.php?title=Service_Module_Reaction_Control_System&amp;diff=1861&amp;oldid=prev</id>
		<title>imported&gt;Abr35 at 17:02, 13 May 2011</title>
		<link rel="alternate" type="text/html" href="http://nassp.space/index.php?title=Service_Module_Reaction_Control_System&amp;diff=1861&amp;oldid=prev"/>
		<updated>2011-05-13T17:02:28Z</updated>

		<summary type="html">&lt;p&gt;&lt;/p&gt;
&lt;table style=&quot;background-color: #fff; color: #202122;&quot; data-mw=&quot;interface&quot;&gt;
				&lt;col class=&quot;diff-marker&quot; /&gt;
				&lt;col class=&quot;diff-content&quot; /&gt;
				&lt;col class=&quot;diff-marker&quot; /&gt;
				&lt;col class=&quot;diff-content&quot; /&gt;
				&lt;tr class=&quot;diff-title&quot; lang=&quot;en&quot;&gt;
				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;← Older revision&lt;/td&gt;
				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;Revision as of 17:02, 13 May 2011&lt;/td&gt;
				&lt;/tr&gt;&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot; id=&quot;mw-diff-left-l23&quot;&gt;Line 23:&lt;/td&gt;
&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot;&gt;Line 23:&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;	When an RCS engine fires, the fuel and oxidizer cross in the premix chamber first before entering the combustion chamber. This is done to ensure a steady output of force when the engine is fired and minimize transients. Being a burst from a rocket engine is a chemical reaction, the reaction builds and generates more force when the reactants mix.  As the reactants are depleted, the force exerted by the rocket also tails-off. This brief build-up and tail-off of force from the RCS rockets are referred to as their start and shut-off transients. These transients are not yet implemented in the current version of NASSP.&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;	When an RCS engine fires, the fuel and oxidizer cross in the premix chamber first before entering the combustion chamber. This is done to ensure a steady output of force when the engine is fired and minimize transients. Being a burst from a rocket engine is a chemical reaction, the reaction builds and generates more force when the reactants mix.  As the reactants are depleted, the force exerted by the rocket also tails-off. This brief build-up and tail-off of force from the RCS rockets are referred to as their start and shut-off transients. These transients are not yet implemented in the current version of NASSP.&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;−&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;	Each quad is heated by two SM RCS Heaters that activate and deactivate based on temperature sensors. These heaters can be given current via their SM RCS - SM RCS HEATERS circuit breakers on MDC-8 {{panel label|name=8.B}}. Normally only one of the two heaters operate at a time in each quad&lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;, and they can be configured by the &lt;/del&gt;SM RCS HEATER switches on MDC-2. The SM RCS indicator gauges on MDC-2 {{panel label|name=2.E}} also allow the astronaut to monitor package temperatures for any of the quads. From left to right this gauge displays: package temperature, helium pressure, secondary fuel pressure, and either helium temperature or fuel quantity. This fourth indicator displays one of two values, which can be selected by the SM RCS IND switch {{panel label|name=2.F}}. The rotary switch on MDC-2 {{panel label|name=2.D}} will select which package&#039;s temperature is represented on the gauge. Should temperatures in any of the quads fall too low, it&#039;s appropriate caution and warning light will illuminated and the master alarm will sound. This happens regardless of which package is currently displayed.&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;	Each quad is heated by two SM RCS Heaters that activate and deactivate based on temperature sensors. These heaters can be given current via their SM RCS - SM RCS HEATERS circuit breakers on MDC-8 {{panel label|name=8.B}}. Normally only one of the two heaters operate at a time in each quad&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;. The &lt;/ins&gt;SM RCS HEATER switches on MDC-2 &lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;determine whether the primary or secondary heaters are in use for each of the four quads&lt;/ins&gt;. The SM RCS indicator gauges on MDC-2 {{panel label|name=2.E}} also allow the astronaut to monitor package temperatures for any of the quads. From left to right this gauge displays: package temperature, helium pressure, secondary fuel pressure, and either helium temperature or fuel quantity. This fourth indicator displays one of two values, which can be selected by the SM RCS IND switch {{panel label|name=2.F}}. The rotary switch on MDC-2 {{panel label|name=2.D}} will select which package&#039;s temperature is represented on the gauge. Should temperatures in any of the quads fall too low, it&#039;s appropriate caution and warning light will illuminated and the master alarm will sound. This happens regardless of which package is currently displayed.&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;−&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;	If the SM RCS IND switch {{panel label|name=2.F}} is switched to quantity, a temperature-pressure transducer can monitor the propellant tanks and estimate the quantity of fuel remaining in each package. Remember that each quad&#039;s propellant is independent. Also remember that primary and secondary propellant tanks are independent in each quad, so if the primary tank is depleted, you must manually open the secondary isolation valve. Should the RCS quantity fall too low, the caution and warning system will alert you, just as it would for temperatures&lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;. When the switch is set to up the temperatures in the helium tank are displayed on the gauge&lt;/del&gt;.&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;	If the SM RCS IND switch {{panel label|name=2.F}} is switched to quantity, a temperature-pressure transducer can monitor the propellant tanks and estimate the quantity of fuel remaining in each package. Remember that each quad&#039;s propellant is independent. Also remember that primary and secondary propellant tanks are independent in each quad, so if the primary tank is depleted, you must manually open the secondary isolation valve. Should the RCS quantity fall too low, the caution and warning system will alert you, just as it would for temperatures.&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;[[Category:Reaction Control System (CSM)]]&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;[[Category:Reaction Control System (CSM)]]&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;

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&lt;/table&gt;</summary>
		<author><name>imported&gt;Abr35</name></author>
	</entry>
	<entry>
		<id>http://nassp.space/index.php?title=Service_Module_Reaction_Control_System&amp;diff=1860&amp;oldid=prev</id>
		<title>imported&gt;Abr35 at 17:00, 13 May 2011</title>
		<link rel="alternate" type="text/html" href="http://nassp.space/index.php?title=Service_Module_Reaction_Control_System&amp;diff=1860&amp;oldid=prev"/>
		<updated>2011-05-13T17:00:22Z</updated>

		<summary type="html">&lt;p&gt;&lt;/p&gt;
&lt;table style=&quot;background-color: #fff; color: #202122;&quot; data-mw=&quot;interface&quot;&gt;
				&lt;col class=&quot;diff-marker&quot; /&gt;
				&lt;col class=&quot;diff-content&quot; /&gt;
				&lt;col class=&quot;diff-marker&quot; /&gt;
				&lt;col class=&quot;diff-content&quot; /&gt;
				&lt;tr class=&quot;diff-title&quot; lang=&quot;en&quot;&gt;
				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;← Older revision&lt;/td&gt;
				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;Revision as of 17:00, 13 May 2011&lt;/td&gt;
				&lt;/tr&gt;&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot; id=&quot;mw-diff-left-l8&quot;&gt;Line 8:&lt;/td&gt;
&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot;&gt;Line 8:&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;	The Service Module RCS contains 16 reaction control jets grouped into clusters of four, or quads. These four quads are placed 90 degrees apart about the circumference of the service module. The quads are designated A-D clockwise with Quad A being on the top of the service module. Each quad&amp;#039;s thrusters are numbered 1 through 4. Thrusters 1 and 2 control roll and 3 and 4 control either pitch or yaw, depending on the quad.&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;	The Service Module RCS contains 16 reaction control jets grouped into clusters of four, or quads. These four quads are placed 90 degrees apart about the circumference of the service module. The quads are designated A-D clockwise with Quad A being on the top of the service module. Each quad&amp;#039;s thrusters are numbered 1 through 4. Thrusters 1 and 2 control roll and 3 and 4 control either pitch or yaw, depending on the quad.&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;−&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;	The engine nozzles on each quad are canted approximately 10 degrees away from the Service Module&#039;s skin&lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;. This is done &lt;/del&gt;to prevent damage when the rockets fire. The roll engines are offset from one another to accommodate the quad&#039;s plumbing. Each RCS quad has its own individual fuel and plumbing systems. &lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;The quads operate independently from one another&lt;/del&gt;. For example, if quad A&#039;s fuel is depleted &lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;it &lt;/del&gt;will not prevent any other quad from being used. The functions and structures of each quad &lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt; &lt;/del&gt;identical.  &lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;	The engine nozzles on each quad are canted approximately 10 degrees away from the Service Module&#039;s skin to prevent damage when the rockets fire. The roll engines are offset from one another to accommodate the quad&#039;s plumbing. Each RCS quad has its own individual fuel and plumbing systems. &lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;Each quad operates as its own independent system&lt;/ins&gt;. For example, if quad A&#039;s fuel is depleted &lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;or if the quad&#039;s plumbing is damaged, this &lt;/ins&gt;will not prevent any other quad from being used. The functions and structures of each quad &lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;are &lt;/ins&gt;identical.  &lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;=Helium=&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;=Helium=&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;[[Image:sm_rcs_2.jpg|thumb|left|Panel MDC-2]]	&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;[[Image:sm_rcs_2.jpg|thumb|left|Panel MDC-2]]	&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;−&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;Helium is used to pressurize the fuel and oxidizer tanks and allow the gasses to be expelled in zero-gravity. Each quad has two independent Helium tanks with a magnetically latched helium isolation valve. In order to allow helium pressurization of the RCS propellants, the solenoid must first be unlatched. Eight spring loaded switches on MDC-2, labeled HELIUM 1 and HELIUM 2 {{panel label|name=2.A}} control helium isolation solenoids for tanks 1 and 2 in each quads. If the square talkback indicator for a particular solenoid is barber-pole (meaning it displays white and black diagonals) the helium tank is &lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;closed&lt;/del&gt;. &lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;Switch &lt;/del&gt;one of the helium switches into the up position will energize the solenoid and open the helium tank. When it&#039;s talk back is gray the helium tank is open and helium is flowing out of the tank. Switching the helium switch down will unlatch the solenoid and it will magnetically close.&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;Helium is used to pressurize the fuel and oxidizer tanks and allow the gasses to be expelled in zero-gravity. Each quad has two independent Helium tanks with a magnetically latched helium isolation valve. In order to allow helium pressurization of the RCS propellants, the &lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;isolation valve &lt;/ins&gt;solenoid must first be unlatched. Eight spring loaded switches on MDC-2, labeled HELIUM 1 and HELIUM 2 {{panel label|name=2.A}} control helium isolation solenoids for tanks 1 and 2 in each quads. If the square talkback indicator for a particular solenoid is barber-pole (meaning it displays white and black diagonals) the helium tank is &lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;blocked from the rest of the quad&lt;/ins&gt;. &lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;Switching &lt;/ins&gt;one of the helium switches into the up position will energize the solenoid and open the helium tank. When it&#039;s talk back is gray the helium tank is open and helium is flowing out of the tank. Switching the helium switch down will unlatch the solenoid and it will magnetically close &lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;without the need for electrical impulse&lt;/ins&gt;.&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;−&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;	The helium passes through a forward flowing check valve. This valve prevents any RCS propellants from flowing backwards into the helium tanks. After the check valve, &lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;there are &lt;/del&gt;two helium regulators operating in parallel. These regulators control the flow of helium into a bladder which surrounds the RCS propellant tanks. Should one of the regulators fail, the other will increase flow to ensure proper helium pressure. Finally, the helium bladders contain a burst valve, which will relieve pressure in the helium bladders, should it rise too high.&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;	The helium passes through a forward flowing check valve. This valve prevents any RCS propellants from flowing backwards into the helium tanks. After the check valve, &lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;the helium flows through &lt;/ins&gt;two helium regulators operating in parallel. These regulators control the flow of helium into a bladder which surrounds the RCS propellant tanks. Should one of the regulators fail, the other will increase flow to ensure proper helium pressure. Finally, the helium bladders contain a burst valve, which will relieve pressure in the helium bladders, should it rise too high.&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;=Propellant=&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;=Propellant=&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;[[Image:sm_rcs_8.jpg|thumb|right|Panel MDC-8]]	&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;[[Image:sm_rcs_8.jpg|thumb|right|Panel MDC-8]]	&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;−&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;	The propellant tanks are surrounded by a helium bladder which, when filled, pressurizes the propellant tanks. Once the tanks are pressurized they must also be opened in order for the &lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;RCS &lt;/del&gt;to &lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;be operational&lt;/del&gt;. Each RCS quad has both a primary and a secondary propellant tank. These have isolation valves in between them and the engine. The controls for these valves are located below the helium isolation valves on MDC-2 {{panel label|name=2.B}} and work in exactly the same manner. These are labeled PRIM PRPLNT for the primary isolation valves and SEC PRPLNT for the secondary valves. The propellant isolation valves receive current from the either or both of the main buses by closing the circuit breakers on MDC-8 labeled SM RCS - PRPLNT ISOL {{panel label|name=8.A}}.&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;	The propellant tanks are surrounded by a helium bladder which, when filled, pressurizes the propellant tanks. Once the tanks are pressurized&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;, &lt;/ins&gt;they must also be opened in order for the &lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;fuel and ocidizer &lt;/ins&gt;to &lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;mix&lt;/ins&gt;. Each RCS quad has both a primary and a secondary propellant tank. These have &lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;individual &lt;/ins&gt;isolation valves in between them and the engine. The controls for these valves are located below the helium isolation valves on MDC-2 {{panel label|name=2.B}} and work in exactly the same manner. These are labeled PRIM PRPLNT for the primary isolation valves and SEC PRPLNT for the secondary valves. The propellant isolation valves receive current from the either or both of the main buses by closing the circuit breakers on MDC-8 labeled SM RCS - PRPLNT ISOL {{panel label|name=8.A}}.&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;−&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;	Once the fuel isolation valves have been opened fuel can flow ahead into the quad&#039;s injector valves. Just like most rocket engines, the SM RCS consists of both Fuel and Oxidizer which are pumped into a combustion chamber by the injection valves, and then expelled out of the engine nozzle. The resulting reaction provides attitude control. A fuel injector valve consists of two separate coils, an automatic and direct coil. The automatic coils receive commands to fire from the RJ/EC and the direct coil is commanded by the RHC. For more information on this consult the Stabilization and Control System section. The injectors are all magnetically shut and must receive commands from either the RJ/EC or the RHC to open and fire. In order for the automatic coils to function the SM RCS logic circuit breakers {{panel label|name=8.C}} on MDC-8 must be closed.&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;	Once the fuel isolation valves have been opened fuel can flow ahead into the quad&#039;s injector valves. Just like most rocket engines, the SM RCS consists of both Fuel &lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;(MMH) &lt;/ins&gt;and Oxidizer &lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;(NO4) &lt;/ins&gt;which are pumped into a combustion chamber by the injection valves, and then expelled out of the engine nozzle. The &lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;force from the &lt;/ins&gt;resulting reaction provides attitude control. A fuel injector valve consists of two separate coils, an automatic and direct coil. The automatic coils receive commands to fire from the RJ/EC and the direct coil is commanded by the RHC. For more information on this consult the Stabilization and Control System section. The injectors are all magnetically shut and must receive commands from either the RJ/EC or the RHC to open and fire. In order for the automatic coils to function the SM RCS logic circuit breakers {{panel label|name=8.C}} on MDC-8 must be closed.&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;=Engine=&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;=Engine=&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;−&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;	When an RCS engine fires, the fuel and oxidizer cross in the premix chamber first before entering the combustion chamber. This is done to ensure a steady output of force when the engine is fired and minimize transients. Being a burst from a rocket engine is a chemical reaction, the reaction builds and generates more force when the reactants mix.  As the reactants are depleted, the force exerted by the rocket also tails-off. This brief build-up and tail-off of force from the RCS rockets are referred to as their start and shut-off transients. These are not yet implemented in the current version of NASSP.&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;	When an RCS engine fires, the fuel and oxidizer cross in the premix chamber first before entering the combustion chamber. This is done to ensure a steady output of force when the engine is fired and minimize transients. Being a burst from a rocket engine is a chemical reaction, the reaction builds and generates more force when the reactants mix.  As the reactants are depleted, the force exerted by the rocket also tails-off. This brief build-up and tail-off of force from the RCS rockets are referred to as their start and shut-off transients. These &lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;transients &lt;/ins&gt;are not yet implemented in the current version of NASSP.&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;−&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;	Each quad is heated by two SM RCS Heaters that activate and deactivate based on temperature sensors. These heaters can be given current via their SM RCS - SM RCS HEATERS circuit breakers on MDC-8 {{panel label|name=8.B}}. Normally only one of the two heaters operate at a time in each quad, and they can be configured by the SM RCS HEATER switches on MDC-2. The SM RCS indicator gauges on MDC-2 {{panel label|name=2.E}} also allow the astronaut to monitor package temperatures for any of the quads. From left to right this gauge displays: package temperature, helium pressure, secondary fuel pressure, and either helium temperature or fuel quantity, which can be selected by the SM RCS IND switch {{panel label|name=2.&lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;f&lt;/del&gt;}}. The rotary switch on MDC-2 {{panel label|name=2.D}} will select which package&#039;s temperature is represented on the gauge. Should temperatures in any of the quads fall too low, it&#039;s appropriate caution and warning light will illuminated and the master alarm will sound. This happens regardless of which package is currently displayed.&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;	Each quad is heated by two SM RCS Heaters that activate and deactivate based on temperature sensors. These heaters can be given current via their SM RCS - SM RCS HEATERS circuit breakers on MDC-8 {{panel label|name=8.B}}. Normally only one of the two heaters operate at a time in each quad, and they can be configured by the SM RCS HEATER switches on MDC-2. The SM RCS indicator gauges on MDC-2 {{panel label|name=2.E}} also allow the astronaut to monitor package temperatures for any of the quads. From left to right this gauge displays: package temperature, helium pressure, secondary fuel pressure, and either helium temperature or fuel quantity&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;. This fourth indicator displays one of two values&lt;/ins&gt;, which can be selected by the SM RCS IND switch {{panel label|name=2.&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;F&lt;/ins&gt;}}. The rotary switch on MDC-2 {{panel label|name=2.D}} will select which package&#039;s temperature is represented on the gauge. Should temperatures in any of the quads fall too low, it&#039;s appropriate caution and warning light will illuminated and the master alarm will sound. This happens regardless of which package is currently displayed.&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;−&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;	If the SM RCS IND switch {{panel label|name=2.F}} is switched to quantity, a temperature-pressure transducer can monitor the propellant tanks and estimate the quantity of fuel remaining in each package. Remember that each quad&#039;s propellant is independent. Also remember that primary and secondary propellant tanks are independent in each quad, so if the primary tank is depleted, you must manually open the secondary isolation valve. Should the RCS quantity fall too low, the caution and warning system will alert you, just as it would for temperatures. When the switch is set &lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;top &lt;/del&gt;up the temperatures in the helium tank are displayed on the gauge.&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;	If the SM RCS IND switch {{panel label|name=2.F}} is switched to quantity, a temperature-pressure transducer can monitor the propellant tanks and estimate the quantity of fuel remaining in each package. Remember that each quad&#039;s propellant is independent. Also remember that primary and secondary propellant tanks are independent in each quad, so if the primary tank is depleted, you must manually open the secondary isolation valve. Should the RCS quantity fall too low, the caution and warning system will alert you, just as it would for temperatures. When the switch is set &lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;to &lt;/ins&gt;up the temperatures in the helium tank are displayed on the gauge.&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;[[Category:Reaction Control System (CSM)]]&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;[[Category:Reaction Control System (CSM)]]&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;

&lt;!-- diff cache key NASSP_wiki:diff::1.12:old-1859:rev-1860 --&gt;
&lt;/table&gt;</summary>
		<author><name>imported&gt;Abr35</name></author>
	</entry>
	<entry>
		<id>http://nassp.space/index.php?title=Service_Module_Reaction_Control_System&amp;diff=1859&amp;oldid=prev</id>
		<title>imported&gt;Abr35 at 21:42, 27 March 2011</title>
		<link rel="alternate" type="text/html" href="http://nassp.space/index.php?title=Service_Module_Reaction_Control_System&amp;diff=1859&amp;oldid=prev"/>
		<updated>2011-03-27T21:42:08Z</updated>

		<summary type="html">&lt;p&gt;&lt;/p&gt;
&lt;table style=&quot;background-color: #fff; color: #202122;&quot; data-mw=&quot;interface&quot;&gt;
				&lt;col class=&quot;diff-marker&quot; /&gt;
				&lt;col class=&quot;diff-content&quot; /&gt;
				&lt;col class=&quot;diff-marker&quot; /&gt;
				&lt;col class=&quot;diff-content&quot; /&gt;
				&lt;tr class=&quot;diff-title&quot; lang=&quot;en&quot;&gt;
				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;← Older revision&lt;/td&gt;
				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;Revision as of 21:42, 27 March 2011&lt;/td&gt;
				&lt;/tr&gt;&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot; id=&quot;mw-diff-left-l19&quot;&gt;Line 19:&lt;/td&gt;
&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot;&gt;Line 19:&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;	The propellant tanks are surrounded by a helium bladder which, when filled, pressurizes the propellant tanks. Once the tanks are pressurized they must also be opened in order for the RCS to be operational. Each RCS quad has both a primary and a secondary propellant tank. These have isolation valves in between them and the engine. The controls for these valves are located below the helium isolation valves on MDC-2 {{panel label|name=2.B}} and work in exactly the same manner. These are labeled PRIM PRPLNT for the primary isolation valves and SEC PRPLNT for the secondary valves. The propellant isolation valves receive current from the either or both of the main buses by closing the circuit breakers on MDC-8 labeled SM RCS - PRPLNT ISOL {{panel label|name=8.A}}.&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;	The propellant tanks are surrounded by a helium bladder which, when filled, pressurizes the propellant tanks. Once the tanks are pressurized they must also be opened in order for the RCS to be operational. Each RCS quad has both a primary and a secondary propellant tank. These have isolation valves in between them and the engine. The controls for these valves are located below the helium isolation valves on MDC-2 {{panel label|name=2.B}} and work in exactly the same manner. These are labeled PRIM PRPLNT for the primary isolation valves and SEC PRPLNT for the secondary valves. The propellant isolation valves receive current from the either or both of the main buses by closing the circuit breakers on MDC-8 labeled SM RCS - PRPLNT ISOL {{panel label|name=8.A}}.&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;−&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;	Once the fuel isolation valves have been opened fuel can flow ahead into the quad&#039;s injector valves. Just like most rocket engines, the SM RCS consists of both Fuel and Oxidizer which are pumped into a combustion chamber by the injection valves, and then expelled out of the engine nozzle. The resulting reaction provides attitude control. A fuel injector valve consists of two separate coils, an automatic and direct coil. The automatic coils receive commands to fire from the RJ/EC and the direct coil is commanded by the RHC. For more information on this consult the Stabilization and Control System section. The injectors are all magnetically shut and must receive commands from either the RJ/EC or the RHC to open and fire. In order for the automatic coils to function the SM RCS logic circuit breakers {{&lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;pnael &lt;/del&gt;label|name=8.C}} on MDC-8 must be closed.&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;	Once the fuel isolation valves have been opened fuel can flow ahead into the quad&#039;s injector valves. Just like most rocket engines, the SM RCS consists of both Fuel and Oxidizer which are pumped into a combustion chamber by the injection valves, and then expelled out of the engine nozzle. The resulting reaction provides attitude control. A fuel injector valve consists of two separate coils, an automatic and direct coil. The automatic coils receive commands to fire from the RJ/EC and the direct coil is commanded by the RHC. For more information on this consult the Stabilization and Control System section. The injectors are all magnetically shut and must receive commands from either the RJ/EC or the RHC to open and fire. In order for the automatic coils to function the SM RCS logic circuit breakers {{&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;panel &lt;/ins&gt;label|name=8.C}} on MDC-8 must be closed.&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;=Engine=&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;=Engine=&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;	When an RCS engine fires, the fuel and oxidizer cross in the premix chamber first before entering the combustion chamber. This is done to ensure a steady output of force when the engine is fired and minimize transients. Being a burst from a rocket engine is a chemical reaction, the reaction builds and generates more force when the reactants mix.  As the reactants are depleted, the force exerted by the rocket also tails-off. This brief build-up and tail-off of force from the RCS rockets are referred to as their start and shut-off transients. These are not yet implemented in the current version of NASSP.&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;	When an RCS engine fires, the fuel and oxidizer cross in the premix chamber first before entering the combustion chamber. This is done to ensure a steady output of force when the engine is fired and minimize transients. Being a burst from a rocket engine is a chemical reaction, the reaction builds and generates more force when the reactants mix.  As the reactants are depleted, the force exerted by the rocket also tails-off. This brief build-up and tail-off of force from the RCS rockets are referred to as their start and shut-off transients. These are not yet implemented in the current version of NASSP.&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;

&lt;!-- diff cache key NASSP_wiki:diff::1.12:old-1858:rev-1859 --&gt;
&lt;/table&gt;</summary>
		<author><name>imported&gt;Abr35</name></author>
	</entry>
	<entry>
		<id>http://nassp.space/index.php?title=Service_Module_Reaction_Control_System&amp;diff=1858&amp;oldid=prev</id>
		<title>imported&gt;Abr35 at 21:41, 27 March 2011</title>
		<link rel="alternate" type="text/html" href="http://nassp.space/index.php?title=Service_Module_Reaction_Control_System&amp;diff=1858&amp;oldid=prev"/>
		<updated>2011-03-27T21:41:43Z</updated>

		<summary type="html">&lt;p&gt;&lt;/p&gt;
&lt;table style=&quot;background-color: #fff; color: #202122;&quot; data-mw=&quot;interface&quot;&gt;
				&lt;col class=&quot;diff-marker&quot; /&gt;
				&lt;col class=&quot;diff-content&quot; /&gt;
				&lt;col class=&quot;diff-marker&quot; /&gt;
				&lt;col class=&quot;diff-content&quot; /&gt;
				&lt;tr class=&quot;diff-title&quot; lang=&quot;en&quot;&gt;
				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;← Older revision&lt;/td&gt;
				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;Revision as of 21:41, 27 March 2011&lt;/td&gt;
				&lt;/tr&gt;&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot; id=&quot;mw-diff-left-l19&quot;&gt;Line 19:&lt;/td&gt;
&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot;&gt;Line 19:&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;	The propellant tanks are surrounded by a helium bladder which, when filled, pressurizes the propellant tanks. Once the tanks are pressurized they must also be opened in order for the RCS to be operational. Each RCS quad has both a primary and a secondary propellant tank. These have isolation valves in between them and the engine. The controls for these valves are located below the helium isolation valves on MDC-2 {{panel label|name=2.B}} and work in exactly the same manner. These are labeled PRIM PRPLNT for the primary isolation valves and SEC PRPLNT for the secondary valves. The propellant isolation valves receive current from the either or both of the main buses by closing the circuit breakers on MDC-8 labeled SM RCS - PRPLNT ISOL {{panel label|name=8.A}}.&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;	The propellant tanks are surrounded by a helium bladder which, when filled, pressurizes the propellant tanks. Once the tanks are pressurized they must also be opened in order for the RCS to be operational. Each RCS quad has both a primary and a secondary propellant tank. These have isolation valves in between them and the engine. The controls for these valves are located below the helium isolation valves on MDC-2 {{panel label|name=2.B}} and work in exactly the same manner. These are labeled PRIM PRPLNT for the primary isolation valves and SEC PRPLNT for the secondary valves. The propellant isolation valves receive current from the either or both of the main buses by closing the circuit breakers on MDC-8 labeled SM RCS - PRPLNT ISOL {{panel label|name=8.A}}.&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;−&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;	Once the fuel isolation valves have been opened fuel can flow ahead into the quad&#039;s injector valves. Just like most rocket engines, the SM RCS consists of both Fuel and Oxidizer which are pumped into a combustion chamber by the injection valves, and then expelled out of the engine nozzle. The resulting reaction provides attitude control. A fuel injector valve consists of two separate coils, an automatic and direct coil. The automatic coils receive commands to fire from the RJ/EC and the direct coil is commanded by the RHC. For more information on this consult the Stabilization and Control System section. The injectors are all magnetically shut and must receive commands from either the RJ/EC or the RHC to open and fire.&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;	Once the fuel isolation valves have been opened fuel can flow ahead into the quad&#039;s injector valves. Just like most rocket engines, the SM RCS consists of both Fuel and Oxidizer which are pumped into a combustion chamber by the injection valves, and then expelled out of the engine nozzle. The resulting reaction provides attitude control. A fuel injector valve consists of two separate coils, an automatic and direct coil. The automatic coils receive commands to fire from the RJ/EC and the direct coil is commanded by the RHC. For more information on this consult the Stabilization and Control System section. The injectors are all magnetically shut and must receive commands from either the RJ/EC or the RHC to open and fire&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;. In order for the automatic coils to function the SM RCS logic circuit breakers {{pnael label|name=8.C}} on MDC-8 must be closed&lt;/ins&gt;.&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;=Engine=&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;=Engine=&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;−&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;	When an RCS engine fires, the fuel and oxidizer cross in the premix chamber first before entering the combustion chamber. This is done to ensure a steady output of force when the engine is fired and minimize transients. Being a burst from a rocket engine is a chemical reaction, the reaction builds and generates more force when the reactants mix.  As the reactants are depleted, the force exerted by the rocket also tails-off. This brief build-up and tail-off of force from the RCS rockets are referred to as their start and shut-off transients.  &lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;	When an RCS engine fires, the fuel and oxidizer cross in the premix chamber first before entering the combustion chamber. This is done to ensure a steady output of force when the engine is fired and minimize transients. Being a burst from a rocket engine is a chemical reaction, the reaction builds and generates more force when the reactants mix.  As the reactants are depleted, the force exerted by the rocket also tails-off. This brief build-up and tail-off of force from the RCS rockets are referred to as their start and shut-off transients&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;. These are not yet implemented in the current version of NASSP&lt;/ins&gt;.&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;	Each quad is heated by two SM RCS Heaters that activate and deactivate based on temperature sensors. These heaters can be given current via their SM RCS - SM RCS HEATERS circuit breakers on MDC-8 {{panel label|name=8.B}}. Normally only one of the two heaters operate at a time in each quad, and they can be configured by the SM RCS HEATER switches on MDC-2. The SM RCS indicator gauges on MDC-2 {{panel label|name=2.E}} also allow the astronaut to monitor package temperatures for any of the quads. From left to right this gauge displays: package temperature, helium pressure, secondary fuel pressure, and either helium temperature or fuel quantity, which can be selected by the SM RCS IND switch {{panel label|name=2.f}}. The rotary switch on MDC-2 {{panel label|name=2.D}} will select which package&amp;#039;s temperature is represented on the gauge. Should temperatures in any of the quads fall too low, it&amp;#039;s appropriate caution and warning light will illuminated and the master alarm will sound. This happens regardless of which package is currently displayed.&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;	Each quad is heated by two SM RCS Heaters that activate and deactivate based on temperature sensors. These heaters can be given current via their SM RCS - SM RCS HEATERS circuit breakers on MDC-8 {{panel label|name=8.B}}. Normally only one of the two heaters operate at a time in each quad, and they can be configured by the SM RCS HEATER switches on MDC-2. The SM RCS indicator gauges on MDC-2 {{panel label|name=2.E}} also allow the astronaut to monitor package temperatures for any of the quads. From left to right this gauge displays: package temperature, helium pressure, secondary fuel pressure, and either helium temperature or fuel quantity, which can be selected by the SM RCS IND switch {{panel label|name=2.f}}. The rotary switch on MDC-2 {{panel label|name=2.D}} will select which package&amp;#039;s temperature is represented on the gauge. Should temperatures in any of the quads fall too low, it&amp;#039;s appropriate caution and warning light will illuminated and the master alarm will sound. This happens regardless of which package is currently displayed.&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;	If the SM RCS IND switch {{panel label|name=2.F}} is switched to quantity, a temperature-pressure transducer can monitor the propellant tanks and estimate the quantity of fuel remaining in each package. Remember that each quad&amp;#039;s propellant is independent. Also remember that primary and secondary propellant tanks are independent in each quad, so if the primary tank is depleted, you must manually open the secondary isolation valve. Should the RCS quantity fall too low, the caution and warning system will alert you, just as it would for temperatures. When the switch is set top up the temperatures in the helium tank are displayed on the gauge.&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;	If the SM RCS IND switch {{panel label|name=2.F}} is switched to quantity, a temperature-pressure transducer can monitor the propellant tanks and estimate the quantity of fuel remaining in each package. Remember that each quad&amp;#039;s propellant is independent. Also remember that primary and secondary propellant tanks are independent in each quad, so if the primary tank is depleted, you must manually open the secondary isolation valve. Should the RCS quantity fall too low, the caution and warning system will alert you, just as it would for temperatures. When the switch is set top up the temperatures in the helium tank are displayed on the gauge.&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;−&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;=RCS Logic=&lt;/del&gt;&lt;/div&gt;&lt;/td&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-side-added&quot;&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;−&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;Coming...&lt;/del&gt;&lt;/div&gt;&lt;/td&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-side-added&quot;&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;−&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;&lt;/del&gt;&lt;/div&gt;&lt;/td&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-side-added&quot;&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;[[Category:Reaction Control System (CSM)]]&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;[[Category:Reaction Control System (CSM)]]&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;

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&lt;/table&gt;</summary>
		<author><name>imported&gt;Abr35</name></author>
	</entry>
	<entry>
		<id>http://nassp.space/index.php?title=Service_Module_Reaction_Control_System&amp;diff=1857&amp;oldid=prev</id>
		<title>imported&gt;Abr35 at 01:54, 19 March 2011</title>
		<link rel="alternate" type="text/html" href="http://nassp.space/index.php?title=Service_Module_Reaction_Control_System&amp;diff=1857&amp;oldid=prev"/>
		<updated>2011-03-19T01:54:13Z</updated>

		<summary type="html">&lt;p&gt;&lt;/p&gt;
&lt;table style=&quot;background-color: #fff; color: #202122;&quot; data-mw=&quot;interface&quot;&gt;
				&lt;col class=&quot;diff-marker&quot; /&gt;
				&lt;col class=&quot;diff-content&quot; /&gt;
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				&lt;tr class=&quot;diff-title&quot; lang=&quot;en&quot;&gt;
				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;← Older revision&lt;/td&gt;
				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;Revision as of 01:54, 19 March 2011&lt;/td&gt;
				&lt;/tr&gt;&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot; id=&quot;mw-diff-left-l17&quot;&gt;Line 17:&lt;/td&gt;
&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot;&gt;Line 17:&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;=Propellant=&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;=Propellant=&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;[[Image:sm_rcs_8.jpg|thumb|right|Panel MDC-8]]	&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;[[Image:sm_rcs_8.jpg|thumb|right|Panel MDC-8]]	&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;−&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;	The propellant tanks are surrounded by a helium bladder which, when filled, pressurizes the propellant tanks. Once the tanks are pressurized they must also be opened in order for the RCS to be operational. Each RCS quad has both a primary and a secondary propellant tank. These have isolation valves in between them and the engine. The controls for these valves are located below the helium isolation valves on MDC-2 {{panel label|name=2.B}} and work in exactly the same manner. These are labeled PRIM PRPLNT for the primary isolation valves and SEC PRPLNT for the secondary valves. The propellant isolation valves receive current from the either or both of the main buses by closing the circuit breakers on MDC-8 labeled SM RCS - PRPLNT ISOL.&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;	The propellant tanks are surrounded by a helium bladder which, when filled, pressurizes the propellant tanks. Once the tanks are pressurized they must also be opened in order for the RCS to be operational. Each RCS quad has both a primary and a secondary propellant tank. These have isolation valves in between them and the engine. The controls for these valves are located below the helium isolation valves on MDC-2 {{panel label|name=2.B}} and work in exactly the same manner. These are labeled PRIM PRPLNT for the primary isolation valves and SEC PRPLNT for the secondary valves. The propellant isolation valves receive current from the either or both of the main buses by closing the circuit breakers on MDC-8 labeled SM RCS - PRPLNT ISOL &lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;{{panel label|name=8.A}}&lt;/ins&gt;.&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;	Once the fuel isolation valves have been opened fuel can flow ahead into the quad&amp;#039;s injector valves. Just like most rocket engines, the SM RCS consists of both Fuel and Oxidizer which are pumped into a combustion chamber by the injection valves, and then expelled out of the engine nozzle. The resulting reaction provides attitude control. A fuel injector valve consists of two separate coils, an automatic and direct coil. The automatic coils receive commands to fire from the RJ/EC and the direct coil is commanded by the RHC. For more information on this consult the Stabilization and Control System section. The injectors are all magnetically shut and must receive commands from either the RJ/EC or the RHC to open and fire.&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;	Once the fuel isolation valves have been opened fuel can flow ahead into the quad&amp;#039;s injector valves. Just like most rocket engines, the SM RCS consists of both Fuel and Oxidizer which are pumped into a combustion chamber by the injection valves, and then expelled out of the engine nozzle. The resulting reaction provides attitude control. A fuel injector valve consists of two separate coils, an automatic and direct coil. The automatic coils receive commands to fire from the RJ/EC and the direct coil is commanded by the RHC. For more information on this consult the Stabilization and Control System section. The injectors are all magnetically shut and must receive commands from either the RJ/EC or the RHC to open and fire.&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot; id=&quot;mw-diff-left-l23&quot;&gt;Line 23:&lt;/td&gt;
&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot;&gt;Line 23:&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;	When an RCS engine fires, the fuel and oxidizer cross in the premix chamber first before entering the combustion chamber. This is done to ensure a steady output of force when the engine is fired and minimize transients. Being a burst from a rocket engine is a chemical reaction, the reaction builds and generates more force when the reactants mix.  As the reactants are depleted, the force exerted by the rocket also tails-off. This brief build-up and tail-off of force from the RCS rockets are referred to as their start and shut-off transients.  &lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;	When an RCS engine fires, the fuel and oxidizer cross in the premix chamber first before entering the combustion chamber. This is done to ensure a steady output of force when the engine is fired and minimize transients. Being a burst from a rocket engine is a chemical reaction, the reaction builds and generates more force when the reactants mix.  As the reactants are depleted, the force exerted by the rocket also tails-off. This brief build-up and tail-off of force from the RCS rockets are referred to as their start and shut-off transients.  &lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;−&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;	Each quad is heated by two SM RCS Heaters that activate and deactivate based on temperature sensors. These heaters can be given current via their SM RCS - SM RCS HEATERS circuit breakers on MDC-8. Normally only one of the two heaters operate at a time in each quad, and they can be configured by the SM RCS HEATER switches on MDC-2. The SM RCS indicator gauges on MDC-2 {{panel label|name=2.E}} also allow the astronaut to monitor package temperatures for any of the quads. From left to right this gauge displays: package temperature, helium pressure, secondary fuel pressure, and either helium temperature or fuel quantity, which can be selected by the SM RCS IND switch {{panel label|name=2.f}}. The rotary switch on MDC-2 {{panel label|name=2.D}} will select which package&#039;s temperature is represented on the gauge. Should temperatures in any of the quads fall too low, it&#039;s appropriate caution and warning light will illuminated and the master alarm will sound. This happens regardless of which package is currently displayed.&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;	Each quad is heated by two SM RCS Heaters that activate and deactivate based on temperature sensors. These heaters can be given current via their SM RCS - SM RCS HEATERS circuit breakers on MDC-8 &lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;{{panel label|name=8.B}}&lt;/ins&gt;. Normally only one of the two heaters operate at a time in each quad, and they can be configured by the SM RCS HEATER switches on MDC-2. The SM RCS indicator gauges on MDC-2 {{panel label|name=2.E}} also allow the astronaut to monitor package temperatures for any of the quads. From left to right this gauge displays: package temperature, helium pressure, secondary fuel pressure, and either helium temperature or fuel quantity, which can be selected by the SM RCS IND switch {{panel label|name=2.f}}. The rotary switch on MDC-2 {{panel label|name=2.D}} will select which package&#039;s temperature is represented on the gauge. Should temperatures in any of the quads fall too low, it&#039;s appropriate caution and warning light will illuminated and the master alarm will sound. This happens regardless of which package is currently displayed.&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;	If the SM RCS IND switch {{panel label|name=2.F}} is switched to quantity, a temperature-pressure transducer can monitor the propellant tanks and estimate the quantity of fuel remaining in each package. Remember that each quad&amp;#039;s propellant is independent. Also remember that primary and secondary propellant tanks are independent in each quad, so if the primary tank is depleted, you must manually open the secondary isolation valve. Should the RCS quantity fall too low, the caution and warning system will alert you, just as it would for temperatures. When the switch is set top up the temperatures in the helium tank are displayed on the gauge.&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;	If the SM RCS IND switch {{panel label|name=2.F}} is switched to quantity, a temperature-pressure transducer can monitor the propellant tanks and estimate the quantity of fuel remaining in each package. Remember that each quad&amp;#039;s propellant is independent. Also remember that primary and secondary propellant tanks are independent in each quad, so if the primary tank is depleted, you must manually open the secondary isolation valve. Should the RCS quantity fall too low, the caution and warning system will alert you, just as it would for temperatures. When the switch is set top up the temperatures in the helium tank are displayed on the gauge.&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;

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&lt;/table&gt;</summary>
		<author><name>imported&gt;Abr35</name></author>
	</entry>
	<entry>
		<id>http://nassp.space/index.php?title=Service_Module_Reaction_Control_System&amp;diff=1856&amp;oldid=prev</id>
		<title>imported&gt;Abr35 at 01:52, 19 March 2011</title>
		<link rel="alternate" type="text/html" href="http://nassp.space/index.php?title=Service_Module_Reaction_Control_System&amp;diff=1856&amp;oldid=prev"/>
		<updated>2011-03-19T01:52:12Z</updated>

		<summary type="html">&lt;p&gt;&lt;/p&gt;
&lt;table style=&quot;background-color: #fff; color: #202122;&quot; data-mw=&quot;interface&quot;&gt;
				&lt;col class=&quot;diff-marker&quot; /&gt;
				&lt;col class=&quot;diff-content&quot; /&gt;
				&lt;col class=&quot;diff-marker&quot; /&gt;
				&lt;col class=&quot;diff-content&quot; /&gt;
				&lt;tr class=&quot;diff-title&quot; lang=&quot;en&quot;&gt;
				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;← Older revision&lt;/td&gt;
				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;Revision as of 01:52, 19 March 2011&lt;/td&gt;
				&lt;/tr&gt;&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot; id=&quot;mw-diff-left-l16&quot;&gt;Line 16:&lt;/td&gt;
&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot;&gt;Line 16:&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;	The helium passes through a forward flowing check valve. This valve prevents any RCS propellants from flowing backwards into the helium tanks. After the check valve, there are two helium regulators operating in parallel. These regulators control the flow of helium into a bladder which surrounds the RCS propellant tanks. Should one of the regulators fail, the other will increase flow to ensure proper helium pressure. Finally, the helium bladders contain a burst valve, which will relieve pressure in the helium bladders, should it rise too high.&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;	The helium passes through a forward flowing check valve. This valve prevents any RCS propellants from flowing backwards into the helium tanks. After the check valve, there are two helium regulators operating in parallel. These regulators control the flow of helium into a bladder which surrounds the RCS propellant tanks. Should one of the regulators fail, the other will increase flow to ensure proper helium pressure. Finally, the helium bladders contain a burst valve, which will relieve pressure in the helium bladders, should it rise too high.&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;=Propellant=&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;=Propellant=&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-side-deleted&quot;&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;[[Image:sm_rcs_8.jpg|thumb|right|Panel MDC-8]]	&lt;/ins&gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;	The propellant tanks are surrounded by a helium bladder which, when filled, pressurizes the propellant tanks. Once the tanks are pressurized they must also be opened in order for the RCS to be operational. Each RCS quad has both a primary and a secondary propellant tank. These have isolation valves in between them and the engine. The controls for these valves are located below the helium isolation valves on MDC-2 {{panel label|name=2.B}} and work in exactly the same manner. These are labeled PRIM PRPLNT for the primary isolation valves and SEC PRPLNT for the secondary valves. The propellant isolation valves receive current from the either or both of the main buses by closing the circuit breakers on MDC-8 labeled SM RCS - PRPLNT ISOL.&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;	The propellant tanks are surrounded by a helium bladder which, when filled, pressurizes the propellant tanks. Once the tanks are pressurized they must also be opened in order for the RCS to be operational. Each RCS quad has both a primary and a secondary propellant tank. These have isolation valves in between them and the engine. The controls for these valves are located below the helium isolation valves on MDC-2 {{panel label|name=2.B}} and work in exactly the same manner. These are labeled PRIM PRPLNT for the primary isolation valves and SEC PRPLNT for the secondary valves. The propellant isolation valves receive current from the either or both of the main buses by closing the circuit breakers on MDC-8 labeled SM RCS - PRPLNT ISOL.&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot; id=&quot;mw-diff-left-l25&quot;&gt;Line 25:&lt;/td&gt;
&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot;&gt;Line 26:&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;	If the SM RCS IND switch {{panel label|name=2.F}} is switched to quantity, a temperature-pressure transducer can monitor the propellant tanks and estimate the quantity of fuel remaining in each package. Remember that each quad&amp;#039;s propellant is independent. Also remember that primary and secondary propellant tanks are independent in each quad, so if the primary tank is depleted, you must manually open the secondary isolation valve. Should the RCS quantity fall too low, the caution and warning system will alert you, just as it would for temperatures. When the switch is set top up the temperatures in the helium tank are displayed on the gauge.&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;	If the SM RCS IND switch {{panel label|name=2.F}} is switched to quantity, a temperature-pressure transducer can monitor the propellant tanks and estimate the quantity of fuel remaining in each package. Remember that each quad&amp;#039;s propellant is independent. Also remember that primary and secondary propellant tanks are independent in each quad, so if the primary tank is depleted, you must manually open the secondary isolation valve. Should the RCS quantity fall too low, the caution and warning system will alert you, just as it would for temperatures. When the switch is set top up the temperatures in the helium tank are displayed on the gauge.&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;−&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt; &lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;=RCS Logic=&lt;/ins&gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-side-deleted&quot;&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;Coming...&lt;/ins&gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;/tr&gt;

&lt;!-- diff cache key NASSP_wiki:diff::1.12:old-1855:rev-1856 --&gt;
&lt;/table&gt;</summary>
		<author><name>imported&gt;Abr35</name></author>
	</entry>
	<entry>
		<id>http://nassp.space/index.php?title=Service_Module_Reaction_Control_System&amp;diff=1855&amp;oldid=prev</id>
		<title>imported&gt;Abr35 at 21:42, 18 March 2011</title>
		<link rel="alternate" type="text/html" href="http://nassp.space/index.php?title=Service_Module_Reaction_Control_System&amp;diff=1855&amp;oldid=prev"/>
		<updated>2011-03-18T21:42:48Z</updated>

		<summary type="html">&lt;p&gt;&lt;/p&gt;
&lt;table style=&quot;background-color: #fff; color: #202122;&quot; data-mw=&quot;interface&quot;&gt;
				&lt;col class=&quot;diff-marker&quot; /&gt;
				&lt;col class=&quot;diff-content&quot; /&gt;
				&lt;col class=&quot;diff-marker&quot; /&gt;
				&lt;col class=&quot;diff-content&quot; /&gt;
				&lt;tr class=&quot;diff-title&quot; lang=&quot;en&quot;&gt;
				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;← Older revision&lt;/td&gt;
				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;Revision as of 21:42, 18 March 2011&lt;/td&gt;
				&lt;/tr&gt;&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot; id=&quot;mw-diff-left-l12&quot;&gt;Line 12:&lt;/td&gt;
&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot;&gt;Line 12:&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;=Helium=&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;=Helium=&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;[[Image:sm_rcs_2.jpg|thumb|left|Panel MDC-2]]	&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;[[Image:sm_rcs_2.jpg|thumb|left|Panel MDC-2]]	&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;−&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;Helium is used to pressurize the fuel and oxidizer tanks and allow the gasses to be expelled in zero-gravity. Each quad has two independent Helium tanks with a magnetically latched helium isolation valve. In order to allow helium pressurization of the RCS propellants, the solenoid must first be unlatched. Eight spring loaded switches on MDC-2 {{panel label|name=2.A}} control helium isolation solenoids for tanks 1 and 2 in each quads. If the square talkback indicator for a particular solenoid is barber-pole (meaning it displays white and black diagonals) the helium tank is closed. Switch one of the helium switches into the up position will energize the solenoid and open the helium tank. When it&#039;s talk back is gray the helium tank is open and helium is flowing out of the tank. Switching the helium switch down will unlatch the solenoid and it will magnetically close.&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;Helium is used to pressurize the fuel and oxidizer tanks and allow the gasses to be expelled in zero-gravity. Each quad has two independent Helium tanks with a magnetically latched helium isolation valve. In order to allow helium pressurization of the RCS propellants, the solenoid must first be unlatched. Eight spring loaded switches on MDC-&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;2, labeled HELIUM 1 and HELIUM &lt;/ins&gt;2 {{panel label|name=2.A}} control helium isolation solenoids for tanks 1 and 2 in each quads. If the square talkback indicator for a particular solenoid is barber-pole (meaning it displays white and black diagonals) the helium tank is closed. Switch one of the helium switches into the up position will energize the solenoid and open the helium tank. When it&#039;s talk back is gray the helium tank is open and helium is flowing out of the tank. Switching the helium switch down will unlatch the solenoid and it will magnetically close.&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;	The helium passes through a forward flowing check valve. This valve prevents any RCS propellants from flowing backwards into the helium tanks. After the check valve, there are two helium regulators operating in parallel. These regulators control the flow of helium into a bladder which surrounds the RCS propellant tanks. Should one of the regulators fail, the other will increase flow to ensure proper helium pressure. Finally, the helium bladders contain a burst valve, which will relieve pressure in the helium bladders, should it rise too high.&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;	The helium passes through a forward flowing check valve. This valve prevents any RCS propellants from flowing backwards into the helium tanks. After the check valve, there are two helium regulators operating in parallel. These regulators control the flow of helium into a bladder which surrounds the RCS propellant tanks. Should one of the regulators fail, the other will increase flow to ensure proper helium pressure. Finally, the helium bladders contain a burst valve, which will relieve pressure in the helium bladders, should it rise too high.&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;=Propellant=&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;=Propellant=&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;−&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;	The propellant tanks are surrounded by a helium bladder which, when filled, pressurizes the propellant tanks. Once the tanks are pressurized they must also be opened in order for the RCS to be operational. Each RCS quad has both a primary and a secondary propellant tank. These have isolation valves in between them and the engine. The controls for these valves are located below the helium isolation valves on MDC-2 {{panel label|name=2.B}} and work in exactly the same manner. The propellant isolation valves receive current from the main buses by closing the circuit breakers on MDC-8.&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;	The propellant tanks are surrounded by a helium bladder which, when filled, pressurizes the propellant tanks. Once the tanks are pressurized they must also be opened in order for the RCS to be operational. Each RCS quad has both a primary and a secondary propellant tank. These have isolation valves in between them and the engine. The controls for these valves are located below the helium isolation valves on MDC-2 {{panel label|name=2.B}} and work in exactly the same manner&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;. These are labeled PRIM PRPLNT for the primary isolation valves and SEC PRPLNT for the secondary valves&lt;/ins&gt;. The propellant isolation valves receive current from &lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;the either or both of &lt;/ins&gt;the main buses by closing the circuit breakers on MDC-8 &lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;labeled SM RCS - PRPLNT ISOL&lt;/ins&gt;.&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;	Once the fuel isolation valves have been opened fuel can flow ahead into the quad&amp;#039;s injector valves. Just like most rocket engines, the SM RCS consists of both Fuel and Oxidizer which are pumped into a combustion chamber by the injection valves, and then expelled out of the engine nozzle. The resulting reaction provides attitude control. A fuel injector valve consists of two separate coils, an automatic and direct coil. The automatic coils receive commands to fire from the RJ/EC and the direct coil is commanded by the RHC. For more information on this consult the Stabilization and Control System section. The injectors are all magnetically shut and must receive commands from either the RJ/EC or the RHC to open and fire.&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;	Once the fuel isolation valves have been opened fuel can flow ahead into the quad&amp;#039;s injector valves. Just like most rocket engines, the SM RCS consists of both Fuel and Oxidizer which are pumped into a combustion chamber by the injection valves, and then expelled out of the engine nozzle. The resulting reaction provides attitude control. A fuel injector valve consists of two separate coils, an automatic and direct coil. The automatic coils receive commands to fire from the RJ/EC and the direct coil is commanded by the RHC. For more information on this consult the Stabilization and Control System section. The injectors are all magnetically shut and must receive commands from either the RJ/EC or the RHC to open and fire.&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot; id=&quot;mw-diff-left-l22&quot;&gt;Line 22:&lt;/td&gt;
&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot;&gt;Line 22:&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;	When an RCS engine fires, the fuel and oxidizer cross in the premix chamber first before entering the combustion chamber. This is done to ensure a steady output of force when the engine is fired and minimize transients. Being a burst from a rocket engine is a chemical reaction, the reaction builds and generates more force when the reactants mix.  As the reactants are depleted, the force exerted by the rocket also tails-off. This brief build-up and tail-off of force from the RCS rockets are referred to as their start and shut-off transients.  &lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;	When an RCS engine fires, the fuel and oxidizer cross in the premix chamber first before entering the combustion chamber. This is done to ensure a steady output of force when the engine is fired and minimize transients. Being a burst from a rocket engine is a chemical reaction, the reaction builds and generates more force when the reactants mix.  As the reactants are depleted, the force exerted by the rocket also tails-off. This brief build-up and tail-off of force from the RCS rockets are referred to as their start and shut-off transients.  &lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;−&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;	Each quad is heated by two SM RCS Heaters that activate and deactivate based on temperature sensors. These heaters can be given current via their circuit breakers on MDC-8. Normally only one of the two heaters operate at a time in each quad, and they can be configured by the SM &lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;RC &lt;/del&gt;HEATER switches on MDC-2. The SM RCS indicator gauges on MDC-2 {{panel label|name=2.E}} also allow the astronaut to monitor package temperatures for any of the quads. From left to right this gauge displays: package temperature, helium pressure, secondary fuel pressure, and either helium temperature or fuel quantity, which can be selected by the SM RCS IND switch {{panel label|name=2.f}}. The rotary switch on MDC-2 {{panel label|name=2.D}} will select which package&#039;s temperature is represented on the gauge. Should temperatures in any of the quads fall too low, it&#039;s appropriate caution and warning light will illuminated and the master alarm will sound. This happens regardless of which package is currently displayed.&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;	Each quad is heated by two SM RCS Heaters that activate and deactivate based on temperature sensors. These heaters can be given current via their &lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;SM RCS - SM RCS HEATERS &lt;/ins&gt;circuit breakers on MDC-8. Normally only one of the two heaters operate at a time in each quad, and they can be configured by the SM &lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;RCS &lt;/ins&gt;HEATER switches on MDC-2. The SM RCS indicator gauges on MDC-2 {{panel label|name=2.E}} also allow the astronaut to monitor package temperatures for any of the quads. From left to right this gauge displays: package temperature, helium pressure, secondary fuel pressure, and either helium temperature or fuel quantity, which can be selected by the SM RCS IND switch {{panel label|name=2.f}}. The rotary switch on MDC-2 {{panel label|name=2.D}} will select which package&#039;s temperature is represented on the gauge. Should temperatures in any of the quads fall too low, it&#039;s appropriate caution and warning light will illuminated and the master alarm will sound. This happens regardless of which package is currently displayed.&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;−&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;	If &lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;the switch beneath &lt;/del&gt;the SM RCS &lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;gauge &lt;/del&gt;{{panel label|name=2.F}} is switched to quantity, a temperature-pressure transducer can monitor the propellant tanks and estimate the quantity of fuel remaining in each package. Remember that each quad&#039;s propellant is independent. Also remember that primary and secondary propellant tanks are independent in each quad, so if the primary tank is depleted, you must manually open the secondary isolation valve. Should the RCS quantity fall too low, the caution and warning system will alert you, just as it would for temperatures. When the switch is set top up the temperatures in the helium tank are displayed on the gauge.&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;	If the SM RCS &lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;IND switch &lt;/ins&gt;{{panel label|name=2.F}} is switched to quantity, a temperature-pressure transducer can monitor the propellant tanks and estimate the quantity of fuel remaining in each package. Remember that each quad&#039;s propellant is independent. Also remember that primary and secondary propellant tanks are independent in each quad, so if the primary tank is depleted, you must manually open the secondary isolation valve. Should the RCS quantity fall too low, the caution and warning system will alert you, just as it would for temperatures. When the switch is set top up the temperatures in the helium tank are displayed on the gauge.&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;/tr&gt;

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		<author><name>imported&gt;Abr35</name></author>
	</entry>
	<entry>
		<id>http://nassp.space/index.php?title=Service_Module_Reaction_Control_System&amp;diff=1854&amp;oldid=prev</id>
		<title>imported&gt;Abr35 at 19:34, 17 March 2011</title>
		<link rel="alternate" type="text/html" href="http://nassp.space/index.php?title=Service_Module_Reaction_Control_System&amp;diff=1854&amp;oldid=prev"/>
		<updated>2011-03-17T19:34:28Z</updated>

		<summary type="html">&lt;p&gt;&lt;/p&gt;
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				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;← Older revision&lt;/td&gt;
				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;Revision as of 19:34, 17 March 2011&lt;/td&gt;
				&lt;/tr&gt;&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot; id=&quot;mw-diff-left-l11&quot;&gt;Line 11:&lt;/td&gt;
&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot;&gt;Line 11:&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;=Helium=&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;=Helium=&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;−&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;[[Image:&lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;sm_rcs_2jpg&lt;/del&gt;|thumb|left|Panel MDC-2]]	&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;[[Image:&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;sm_rcs_2.jpg&lt;/ins&gt;|thumb|left|Panel MDC-2]]	&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;Helium is used to pressurize the fuel and oxidizer tanks and allow the gasses to be expelled in zero-gravity. Each quad has two independent Helium tanks with a magnetically latched helium isolation valve. In order to allow helium pressurization of the RCS propellants, the solenoid must first be unlatched. Eight spring loaded switches on MDC-2 {{panel label|name=2.A}} control helium isolation solenoids for tanks 1 and 2 in each quads. If the square talkback indicator for a particular solenoid is barber-pole (meaning it displays white and black diagonals) the helium tank is closed. Switch one of the helium switches into the up position will energize the solenoid and open the helium tank. When it&amp;#039;s talk back is gray the helium tank is open and helium is flowing out of the tank. Switching the helium switch down will unlatch the solenoid and it will magnetically close.&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;Helium is used to pressurize the fuel and oxidizer tanks and allow the gasses to be expelled in zero-gravity. Each quad has two independent Helium tanks with a magnetically latched helium isolation valve. In order to allow helium pressurization of the RCS propellants, the solenoid must first be unlatched. Eight spring loaded switches on MDC-2 {{panel label|name=2.A}} control helium isolation solenoids for tanks 1 and 2 in each quads. If the square talkback indicator for a particular solenoid is barber-pole (meaning it displays white and black diagonals) the helium tank is closed. Switch one of the helium switches into the up position will energize the solenoid and open the helium tank. When it&amp;#039;s talk back is gray the helium tank is open and helium is flowing out of the tank. Switching the helium switch down will unlatch the solenoid and it will magnetically close.&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;/tr&gt;

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&lt;/table&gt;</summary>
		<author><name>imported&gt;Abr35</name></author>
	</entry>
	<entry>
		<id>http://nassp.space/index.php?title=Service_Module_Reaction_Control_System&amp;diff=1853&amp;oldid=prev</id>
		<title>imported&gt;Abr35 at 19:34, 17 March 2011</title>
		<link rel="alternate" type="text/html" href="http://nassp.space/index.php?title=Service_Module_Reaction_Control_System&amp;diff=1853&amp;oldid=prev"/>
		<updated>2011-03-17T19:34:16Z</updated>

		<summary type="html">&lt;p&gt;&lt;/p&gt;
&lt;table style=&quot;background-color: #fff; color: #202122;&quot; data-mw=&quot;interface&quot;&gt;
				&lt;col class=&quot;diff-marker&quot; /&gt;
				&lt;col class=&quot;diff-content&quot; /&gt;
				&lt;col class=&quot;diff-marker&quot; /&gt;
				&lt;col class=&quot;diff-content&quot; /&gt;
				&lt;tr class=&quot;diff-title&quot; lang=&quot;en&quot;&gt;
				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;← Older revision&lt;/td&gt;
				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;Revision as of 19:34, 17 March 2011&lt;/td&gt;
				&lt;/tr&gt;&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot; id=&quot;mw-diff-left-l11&quot;&gt;Line 11:&lt;/td&gt;
&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot;&gt;Line 11:&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;=Helium=&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;=Helium=&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;−&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;[[Image:&lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;sm_rcs_2.jpg&lt;/del&gt;]]	&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;[[Image:&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;sm_rcs_2jpg|thumb|left|Panel MDC-2&lt;/ins&gt;]]	&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;Helium is used to pressurize the fuel and oxidizer tanks and allow the gasses to be expelled in zero-gravity. Each quad has two independent Helium tanks with a magnetically latched helium isolation valve. In order to allow helium pressurization of the RCS propellants, the solenoid must first be unlatched. Eight spring loaded switches on MDC-2 {{panel label|name=2.A}} control helium isolation solenoids for tanks 1 and 2 in each quads. If the square talkback indicator for a particular solenoid is barber-pole (meaning it displays white and black diagonals) the helium tank is closed. Switch one of the helium switches into the up position will energize the solenoid and open the helium tank. When it&amp;#039;s talk back is gray the helium tank is open and helium is flowing out of the tank. Switching the helium switch down will unlatch the solenoid and it will magnetically close.&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;Helium is used to pressurize the fuel and oxidizer tanks and allow the gasses to be expelled in zero-gravity. Each quad has two independent Helium tanks with a magnetically latched helium isolation valve. In order to allow helium pressurization of the RCS propellants, the solenoid must first be unlatched. Eight spring loaded switches on MDC-2 {{panel label|name=2.A}} control helium isolation solenoids for tanks 1 and 2 in each quads. If the square talkback indicator for a particular solenoid is barber-pole (meaning it displays white and black diagonals) the helium tank is closed. Switch one of the helium switches into the up position will energize the solenoid and open the helium tank. When it&amp;#039;s talk back is gray the helium tank is open and helium is flowing out of the tank. Switching the helium switch down will unlatch the solenoid and it will magnetically close.&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;/tr&gt;

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&lt;/table&gt;</summary>
		<author><name>imported&gt;Abr35</name></author>
	</entry>
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