Earth Landing System: Difference between revisions
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[[Image:ELSSequence.png|thumb|right|Earth Landing System sequence of events]] | [[Image:ELSSequence.png|thumb|right|Earth Landing System sequence of events]] | ||
The '''Earth Landing System''' (ELS) | The '''Earth Landing System''' (ELS) includes all equipment required to land the crew safely on Earth at the end of a mission. | ||
{{ | ==Overview== | ||
Most of the ELS hardware is installed under the forward heat shield (apex cover) at the top of the [[Command Module]]. The major components are eight parachutes (three main chutes, two drogue chutes and three pilot chutes) and the mortars used to deploy them. | |||
In addition, there is a logic controller for the automated sequencing which activates these components as required. | |||
==Controls== | |||
[[Image:ELS-control-location.jpg|right|thumb|250px|Location of main ELS controls on Panel 1]] | |||
The ELS LOGIC switch ({{Panel label|name=A}}) enables the main logic systems, without which the ELS systems cannot function. To enable, flip up the guard and then flip the switch up. | |||
The ELS AUTO switch ({{Panel label|name=B}}) enables automatic sequencing during landing. In the AUTO position the ELS will automatically jettison the apex cover and deploy the parachutes, in the MAN position you will have to perform those operations yourself. | |||
In addition to enabling the ELS, you will need to enable the [[Sequential Events Control Subsystem]] and the [[Pyros]] in order for the ELS to operate. | |||
<br clear="right"> | |||
==Manual Override== | |||
[[Image:CSMPanel-LES-guarded-pushbuttons.jpg|right|thumb|250px|Guarded pushbuttons on Panel 1]] | |||
If the automatic systems should fail to operate, then the guarded push-buttons on Panel 1 can be used to trigger the landing events instead. To use the button, first lift the guard cover, then press the button underneath. | |||
The APEX COVER JETT button ({{Panel label|name=A}}) will jettison the Apex Cover/Forward Heat-shield from the CM, allowing parachute deployment. While the cover is in place, the parachutes cannot be ejected by the mortars. | |||
The DROGUE DEPLOY button ({{Panel label|name=B}}) will deploy the drogue parachutes which slow the capsule down and stabilise it before the main parachutes are deployed. | |||
The MAIN DEPLOY button ({{Panel label|name=C}}) will deploy the main parachutes to slow the capsule to a survivable landing speed. | |||
The CM RCS He DUMP button ({{Panel label|name=D}}) will dump the Helium pressurant gas from the CM [[Reaction Control System]]. | |||
At low [[REALISM]] levels these buttons will light up when activated, at higher levels they will remain unlit, as was the case on a real Apollo flight. | |||
<br clear="right"> | |||
==Checklist== | |||
The Earth/Post-Landing checklist begins at an altitude of 50,000 feet, when the main re-entry process is complete and it is now safe to enable the ELS. | |||
Normally the crew will rely on the automatic operation, but if events do not occur correctly at the specified altitude, they will take manual control instead. | |||
[[Image:Earth-PostLanding-Checklist.png|500px]] | |||
==Notes== | |||
* Any of the automated events may fail if you have [[Random Failures]] enabled in the scenario. Be ready to use the manual procedure if the ELS does not operate automatically. | |||
* Currently the apex cover vanishes immediately when jettisoned; in reality it was pulled away from the CM by a small parachute of its own after being thrown upwards by pistons. | |||
==External Links== | ==External Links== | ||
* [http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19740003586_1974003586.pdf Apollo experience report: Earth landing system] | |||
* [http://history.nasa.gov/afj/aoh/aoh-v1-2-09-seqsys.pdf Apollo Operations Handbook: Sequential Systems] | * [http://history.nasa.gov/afj/aoh/aoh-v1-2-09-seqsys.pdf Apollo Operations Handbook: Sequential Systems] | ||
* [http://www.jdkbph.com/histdocs/apollo/Apollo%20Training%20Sequential%20Events%20Control.pdf Apollo Training Sequential Events Control] | |||
[[Category: | [[Category:Sequential Events Control Subsystem]] | ||
Latest revision as of 17:10, 15 April 2007
The Earth Landing System (ELS) includes all equipment required to land the crew safely on Earth at the end of a mission.
Overview
Most of the ELS hardware is installed under the forward heat shield (apex cover) at the top of the Command Module. The major components are eight parachutes (three main chutes, two drogue chutes and three pilot chutes) and the mortars used to deploy them.
In addition, there is a logic controller for the automated sequencing which activates these components as required.
Controls
The ELS LOGIC switch (A) enables the main logic systems, without which the ELS systems cannot function. To enable, flip up the guard and then flip the switch up.
The ELS AUTO switch (B) enables automatic sequencing during landing. In the AUTO position the ELS will automatically jettison the apex cover and deploy the parachutes, in the MAN position you will have to perform those operations yourself.
In addition to enabling the ELS, you will need to enable the Sequential Events Control Subsystem and the Pyros in order for the ELS to operate.
Manual Override
If the automatic systems should fail to operate, then the guarded push-buttons on Panel 1 can be used to trigger the landing events instead. To use the button, first lift the guard cover, then press the button underneath.
The APEX COVER JETT button (A) will jettison the Apex Cover/Forward Heat-shield from the CM, allowing parachute deployment. While the cover is in place, the parachutes cannot be ejected by the mortars.
The DROGUE DEPLOY button (B) will deploy the drogue parachutes which slow the capsule down and stabilise it before the main parachutes are deployed.
The MAIN DEPLOY button (C) will deploy the main parachutes to slow the capsule to a survivable landing speed.
The CM RCS He DUMP button (D) will dump the Helium pressurant gas from the CM Reaction Control System.
At low REALISM levels these buttons will light up when activated, at higher levels they will remain unlit, as was the case on a real Apollo flight.
Checklist
The Earth/Post-Landing checklist begins at an altitude of 50,000 feet, when the main re-entry process is complete and it is now safe to enable the ELS.
Normally the crew will rely on the automatic operation, but if events do not occur correctly at the specified altitude, they will take manual control instead.
Notes
- Any of the automated events may fail if you have Random Failures enabled in the scenario. Be ready to use the manual procedure if the ELS does not operate automatically.
- Currently the apex cover vanishes immediately when jettisoned; in reality it was pulled away from the CM by a small parachute of its own after being thrown upwards by pistons.