[16:04:40] NASSP Logging has been started by alexb_88 [16:04:42] does this need some additional presettings added in ATDP generated missions? [16:05:33] I see some launch scenarios have LVDC_VTIM, LVDC_VENTA added [16:06:46] you mean the venting? [16:07:07] the ATDP has simulated the venting from its beginning, so, no [16:07:34] my goal wasn't presettings that are perfect for NASSP as it was then. But more, using calculations as close to the real targeting as possible [16:07:51] I haven't added the calculations for the right shape of the Earth though [16:08:06] a bit of difference in drag, so not that relevant [16:08:22] right [16:09:02] I have added LVDC venting models for the missions where we have a LVOT with the numbers [16:09:22] or the listing in the case of Apollo 17 [16:09:43] otherwise it uses a default model [16:10:01] which is Apollo 17 [16:10:17] our behavior in NASSP is a bit more venting than that though [16:10:34] so might not be the best defaults [16:10:51] morning! [16:11:08] hey [16:11:23] all done with venting? :D [16:11:39] are we ever [16:11:56] at least this branch though :D [16:12:13] people are asking for the "waste water/G&N" Maneuver PAD haha [16:12:28] hahaha [16:21:26] email sent! [16:21:40] hopefully one less document for you to scan at NARA [16:22:07] I also fully expect to be told off for asking for documents in this way haha [16:22:21] but hopefully not [16:27:07] hahaha what did you request? and why would you be told off? [16:28:34] one of the two documents I had put on the list [16:28:58] former NASA employee who definitely only has this document because of working there. So maybe he isn't allowed to just share it with people asking for it. [16:29:24] and I'm sending it to the one email address I found, his current non-NASA company [16:29:40] ahhhh nice haha [16:30:02] I also said that I am getting the document likely anyway from your scanning at NARA [16:30:17] so, might as well send it? :D [16:30:32] to me [16:32:12] might as well! [17:50:15] ASTP will be the interesting for drag effects and rendezvous calculations [17:50:49] rendezvous about 44h after launch [17:50:59] and the Soyuz apparently couldn't go very high up [17:51:05] and Apollo chased it from below [17:51:34] oh yeah, that will be fun [17:51:50] 90x100 orbit after a phasing correction maneuver [17:52:06] but decayed to 90x90 16 hours later [17:52:18] I don't think that will be very accurate targeting without drag taken into account :D [17:52:58] "eddievhfan1984 commented 43 minutes ago" [17:53:13] oh! [17:53:27] oh man! haven't seen that name in a long time [17:57:57] and the funniest rendezvous technique to me is still the contingency re-rendezvous with the S-IVB to get the docking module [17:58:12] if they couldn't safe the S-IVB at first and the CSM has to move away from it [17:58:24] all of this at low altitude [17:58:37] oh jeez [17:58:49] and because of differential drag the CSM has to, on purpose, stay in the draggiest attitude or else the relative onboard navigation doesn't work [17:59:03] that's crazy! haha [18:00:08] "The lack [18:00:21] of an atmospheric drag model in the CSM computer [18:00:31] further complicated relative navigation. The S-IVB [18:00:38] attitude was designed to minimize atmospheric drag and [18:00:45] provide attitude stability, while the CSM attitude was [18:00:56] defined to maximize atmospheric drag while permitting [18:01:05] sextant tracking of the S-IVB. The attitudes of both [18:01:16] vehicles minimized differential drag effects on relative [18:01:23] motion." [18:01:30] I'm kind of surprised they didn't add a drag model to Skylark [18:01:42] yeah, it can't be that much slower [18:01:53] The onboard rendezvous calculations don't use coasting integration though [18:02:05] maybe that's why you still had to use this maximum drag attitude [18:02:58] wouldn't have helped to have drag in the coasting integration if that has no effect on burn calculations [18:04:34] not sure all of this profile would be onboard targeted though [18:04:48] but you still need it for onboard navigation and the final part I guess [18:05:02] otherwise you need a new state vector every orbit [18:05:29] ah nice we have the procedures for the "booster rendezvous" [18:06:19] ah [18:06:34] "STDN tracking not as accurate as CMC SXT tracking" [18:06:48] "STDN SOR1 and SOR2 maneuver solutions will be computed using CMC state vectors" [18:06:59] aside from that though, the burns are P30 [18:07:10] ground calculated [18:07:24] just with CMC state vectors [18:07:34] although there is a backup onboard calculation apparently [18:10:53] ah I had an idea for the S-IVB drag [18:11:04] I can make the SLA panels variable drag elements in Orbiter [18:11:21] and if I make it 4 individual elements then the 4th, not fully deployed, panel will make the S-IVB spin [18:11:30] for Apollo 7 [18:17:50] oh that's fun! [18:19:18] S-IVB will be more predictable if it's spinning [18:19:34] then it evens out over time [18:19:46] the drag [18:19:58] otherwise in NASSP it usually ends up in a random attitude [18:20:06] power running out before APS propellant runs out [18:23:09] I never really considered that spinning would make it more predictable, but that makes sense [18:25:08] I've seen it very slowly drift out of the normal orb rate attitude it was in before the power is shut off [18:25:29] which I don't like, could be in any attitude then [18:25:37] hours later [18:26:48] in reality they would track the S-IVB all the time and adjust a drag multiplier in the RTCC [18:26:57] but do I really want to teach our MCC to do that :D [18:27:28] sounds like a pain :D [18:27:54] we have procedures for this [18:28:09] and the RTACF had a dedicated processor for it [18:28:20] basically comparing two state vectors taken at different times [18:28:33] and calculating which drag multiplier gets the two vector on the same trajectory [18:36:02] indy91, I think our rockets actually are perfectly upright on the launch pad [18:36:22] they can be slightly rotated [18:36:32] roll is really the only thing that can happen [18:36:46] yaw and pitch are good as the area is flat [18:36:55] https://github.com/orbiternassp/NASSP/commit/eae73f7ce73bc3f9ce0bbdfdfe1c4e95b0a56c49 [18:38:27] with that I think the LV is locked into a perfectly upright position until liftoff [18:38:49] hmm [18:39:10] when did I implement this "theodolite" function... [18:39:47] I definitely had implemented that because you could get a roll [18:40:03] especially if you did an Apollo 7 and did a SM RCS hotfire [18:41:04] seems like that was before your update [18:41:16] time flies [18:41:26] I could have sworn it wasn't that long ago :D [18:41:40] I guess it's no problem then even to do the SM RCS hotfire [18:41:50] have to check that some time haha [18:42:03] right now I am pretty sure the rocket will not budge even if you somehow got the F1 engines to ignite early [18:42:10] I like it [18:44:21] I even tried to use a version of that for the LM [18:44:38] but of course the LM would then always be upright, even on sloped surfaces [18:44:52] which is not ideal for the LM [18:46:28] I guess it can only be in old scenarios then that our Saturn is slightly rotated wrong [18:46:45] so that perfect initial alignment function is not strictly required anymore for the Saturn [18:47:13] hmm but wouldn't even old scenarios "snap" to the correct position? [18:47:50] ah true [18:48:07] this is in ML code [18:48:21] wait did I add that for the SIB? [18:48:33] do we have the same for the other launch complex? [18:48:43] I thought I did [18:48:55] you did [18:49:07] I see it [18:49:18] must be a long time then when I last checked the initial alignment and it wasn't perfect [18:49:29] LC34 [18:49:41] which missions used LC37? [18:49:51] Apollo 5 [18:50:02] I don't think it has it yet [18:50:16] does it need it? [18:50:31] not really, the same "theodolite" function is called [18:50:46] maybe there is a slight LM IMU misalignment [18:51:00] there is anyway due to the wrong Earth shape [18:51:33] right [19:04:29] I guess next I am flying another Apollo 7 rendezvous [19:04:43] back to the basics haha [19:20:24] to test drag? [19:21:15] mostly if the S-IVB will tumble [19:21:34] I have already flown both Apollo 7 and 9 with full drag a while back [19:22:21] to see if the MCC can handle it [19:22:33] right [19:27:20] found an error in my logic. The SLA panel will fix itself near the same time as our LVDC looses power. [19:27:36] So there never even is a time when it can cause a tumble :D [19:30:27] so I might have to send it tumbling in another way [19:33:01] although maybe just having these additional drag elements might cause a disturbance... [20:04:07] why does the panel fix itself? [20:14:53] who knows [20:15:12] it wasn't fully deployed when the CSM left the S-IVB [20:15:27] at 3:15h GET [20:15:41] but it was fully deployed when they arrived at it 24 hours later during the rendezvous [20:15:56] so somewhere in between it must have finally fully deployed [20:16:17] we just simulate that by the panel moving somewhere in the middle there [20:16:39] // The +X (+Y in Apollo axes) moved to about 25° only at first, [20:16:56] // during the rendezvous in orbit 19 (about MET 30h) the panel was found [20:17:10] // hinged completely, so we do that at MET 15h (see Mission Report 11.7) [20:17:25] maybe tumbling at a high rate did it :D [20:17:40] oh! so that actually happened. I thought you meant it was some weird bug haha [20:17:56] it was, just in hardware haha [20:18:11] lol gotcha [20:18:28] it will just be the weird geometry with the panels in general that sends it tumbling, nothing dampening the movement [20:24:26] indy91, just testing one of my ATDP generated missions with a launch+TLI with the venting [20:24:47] at TB5+10451.649995 [20:25:06] SV Accuracy: 764.909056 -6.145226 286.640633 [20:25:20] I want to say thats not bad [20:25:32] did you give it an IU state vector update at all? [20:26:55] in any case that is very good yes haha [20:27:50] none [20:28:24] it would be the default/Apollo 17 LVDC venting model [20:28:44] I thought that wasn't as good haha [20:29:06] the error actually seems smaller then before the update [20:29:21] almost suspiciously good... [20:29:37] it's probably the heavier rocket [20:29:53] I guess because the LVDC expected the venting but there was none [20:30:08] nah the venting calculations did exist before but were disabled [20:30:26] my MATLAB simulations showed that the Apollo 17 model wasn't as good as I had also seen in NASSP [20:30:43] but it's probably the simulations being off [20:30:55] LVDC has an acceleration model for the venting [20:31:08] so if the rocket is heavier, which it is on Apollo 17 [20:31:21] then LVDC and actual behavior will agree better [20:31:32] that's probably how this comes [20:31:44] the Apollo 17 LVDC venting model plus a stack that weighs as much as the Apollo 11 vehicle is what I had basically simulated [20:32:01] that should give like 10km error at this TB5 time [20:33:14] I had seen similar accuracy as you when I actually launched Apollo 17 a while back [20:34:04] actually if I adjust the stack weight in my simulations, I wonder what I get then [20:38:27] definitely a smaller error with more weight [20:38:45] but still like 9km at your time [20:39:02] maybe it's the 90 NM orbit somehow [20:40:32] doesn't make a difference [20:41:03] or maybe the no-venting errors we previous had and the venting error just cancel each other out :D [21:00:03] hmm [21:00:18] is it normal to have a visual vent during TLI? [21:01:45] https://www.dropbox.com/scl/fi/5b1gzhrf2e9l8lvlbbrlw/Screenshot-2023-12-20-16.01.06.png?rlkey=gj13gorialokbhu84ijboytzj&dl=0 [21:03:11] congrats [21:03:24] first bug found [21:03:39] during a burn the tank pressures are cheated [21:03:51] so it shouldn't really do any venting [21:04:05] could also be the vent valves stuck open [21:04:19] would be an issue with the flight sequence program [21:05:18] before TLI ignition there can be a vent a few times per minute [21:05:31] but during, definitely not [21:05:49] your scenario is using the J mission flight sequence? [21:06:50] should be yes [21:07:09] what are the pressures during the burn? [21:07:25] LH2 [21:07:37] this is the LH2 non-propulsive vent [21:07:49] give me a sec I will have to go back and check [21:08:02] I should probably check in a scenario from before TB6 [21:08:16] if it's a problem with the S-IVB propulsion code or just some flight sequence program problem [21:11:02] oh no [21:11:11] I might already know what it is [21:11:28] very silly bug [21:11:43] not a big problem [21:11:56] https://www.dropbox.com/scl/fi/nfaqk3dd9ycy69jrkt5dh/Apollo-19-Before-TB6.scn?rlkey=0i3lyk0b8epw2gco950ay87ut&dl=0 [21:12:13] when I say the pressures are cheated during a burn [21:12:27] it then bypasses a bunch of code simulating the behavior [21:12:44] it also bypasses, and never updates, the venting level used for the particle effect [21:12:55] like I said, in TB5 before TLI you get non-propulsive vents occasionally [21:13:10] maybe you had such a vent when it started firing up the engine [21:13:24] then it would show the particle effect for the vent until the engine stops again [21:13:36] in TB6* [21:15:46] solution would be to just set the particle effect levels to 0 during the burn [21:16:25] I'll try to confirm if this is what happened to you [21:16:48] do you still want me to check what the pressures were during the burn? [21:17:23] nope, it's probably not that. [21:17:45] I'll just check if you had an ongoing, short NPV vent during engine ignition [21:20:25] ok [21:20:56] I also just notice that there was venting post-TLI and it stopped abruptly when the stack maneuvered to separation attitude [21:21:07] funny how that happens :D [21:21:21] almost like a vent would get in the way for TD&E so they stop it haha [21:21:36] it's schedule to stop exactly then [21:21:43] scheduled* [21:21:55] ah [21:22:13] all non-propulsive vents [21:22:27] there is a propulsive one in the cutoff attitude [21:22:39] at least I can now light a cigarette [21:23:10] or maybe thats not how that works :D [21:25:20] I think the H2 is the cigarette in that comparison :D [21:25:39] for which you can use a lighter [21:25:54] ok, so, I did not get a vent during the burn [21:26:06] but the pressure was extremely close to needing a NPV again [21:26:16] and I used time accel [21:26:39] so I still think what happened to you is a particle effect state that didn't get updated [21:27:07] it is unlucky timing for it to happen [21:27:24] we get such a vent maybe once per minute, I think even less [21:27:44] and it only lasts a few seconds [21:28:04] you could try to replicate it on your end with a debug string, just to get final confirmation [21:28:19] but I am fairly sure I know what happened anyway [21:29:32] the vent didn't start DURING the burn, right? [21:29:48] it was probably already there at ignition? [21:30:00] hmm [21:30:13] I think it started after ignition [21:30:25] or maybe a bit before but only a few seconds [21:30:38] because I remember during TB6 looking at the SIVB and seeing no vent [21:31:05] yeah, it would have started seconds before ignition [21:31:19] it only lasts a few seconds [21:31:34] and the J-2 burning bypasses the update of the particle effect state [21:31:56] so it can only have become stuck on during such a short vent [21:32:08] ah so that is a normal vent but should only last a few seconds? [21:32:33] it's a little bit of an issue that we only get in NASSP, but it's not totally unrealistic [21:32:47] basically, our LH2 is constantly heating up [21:33:00] a bit of it is boiled [21:33:12] goes into gas [21:33:25] during TB5, the CVS is one and the gas is reliefed [21:33:39] so the pressure in the gas is kept down that way [21:33:51] during TB6 you first get a re-pressurization [21:34:04] and then no normal venting is done [21:34:16] but for us it still heats up [21:34:28] and the pressure rises [21:34:41] and above a certain level it reliefs some of it [21:34:56] ah [21:35:10] which did not actually happen because the repress cooled things down [21:35:23] so can all these new vents be manually operated by PAMFD commands? [21:35:36] yep [21:35:48] you can watch this pressure behavior on the tank pressure [21:36:01] I guess you can in theory restart the SIVB with the right command sequence [21:36:14] yeah [21:36:27] but that's a bunch of commands :D [21:36:40] say if I want to eyeball my way to Venus [21:36:54] starting in TB6 you get a H2 pressure increase to 31 PSI [21:37:10] then the repress is stopped [21:37:25] but this (unrealistic) heating up continues and it slowly goes to 34 PSI [21:37:40] that's where it does a short vent back to 31 PSI [21:37:52] you during TB6 this happens once every 1-2 minutes [21:38:04] and during* [21:38:11] what I saw just in your scenario was a pressure of right at 34 PSI [21:38:24] but not quite enough to trigger the vent [21:38:38] must have been slightly different for you [21:38:51] probably because I used 10x [21:39:07] I want it confirmed, I'll do it once without time accel [21:39:21] and watching the pressure [21:39:36] and then I will just reset the particle effect level to 0 during a burn [21:39:49] that's the bugfix [21:40:53] of course you already find such a bug today :D [21:45:08] its those TLI-2's, they really give it a workout :D [21:45:47] is it even TLI-2? [21:46:12] 3:40h for TB6 [21:46:35] or Atlantic window [21:46:57] TLI-2 pacific [21:47:07] ah makes sense [21:47:17] TLI-1 had a TB6 of 2:12 [21:47:26] very early [21:47:35] LOX pressure goes up a bit too slow for my taste on these TLI-2s [21:47:45] on repressurization [21:52:44] AlexB_88, bug confirmed, I got it this time [21:52:59] good [21:53:15] engine ignition while it was reliving the pressure [21:53:27] relieving* [21:53:40] I'll also reset the LOX vent effects, even though they should definitely not be on [21:54:46] I will have a PR for that with some Apollo 7 scenario fixes [21:55:03] another bug from my branch I just discovered [21:55:15] in some old scenarios the separated S-IVB has nearly full propellant again [22:03:53] PR is up [22:04:58] I'm sure these won't be the last fixes from this update haha [22:06:31] thanks [22:06:42] nope haha [22:07:07] well, it already works pretty good in my opinion, great work! [22:08:32] PR approved [22:09:03] thanks! I am fairly happy with how it turned out. And then some day we might simulate the tank behavior in a more realistic way. [22:09:19] then this vent stuck open bug couldn't even have happened [22:09:58] good night! [22:14:47] AlexB_88, if you want to go to Venus, you should do it before we merge my thermal systems overhaul [22:15:11] haha [22:16:02] systems sdk doesn't take distance from the sun into account, it just has a fixed solar flux. [22:16:18] I have fixed that [22:16:51] Ill quickly convince Nik to make his trajectory tool able to calculate Trans Venus Injection, before we merge your PR :D [22:18:37] so I guess with your update, things would get very cold, very fast [22:19:13] ugh [22:19:29] or very hot, very fast? [22:20:58] I tested it in Venus Orbit and I recall seeing quad temps shoot up to 250ish [22:21:47] I don't think you'd have too much trouble on the way there, and a flyby would probably be fine [22:22:35] In reality, I'd imagine that some shading from the SIVb would be used for thermal control [22:23:11] which we could easily add to the thermal engine [22:24:08] just one more condition to check for "InSunlight" [22:33:14] I've got half a mind to try scenerio-editoring my way to a Venus flyby to test that now. [22:33:31] One way or another NASSP is eventually going to Venus [22:41:36] nice [14:57:11] good morning [14:58:08] hey [14:58:29] ouch my failure branch has a nice few merge conflicts due to the S-IVB venting update [15:02:59] thats what I get for implementing S-IVB engine failures [15:05:53] for some reason every time I rebase my systems branch, I get a merge conflict with one particular scenerio: "Apollo 11 05 before SIVb seperation" [15:06:14] ha, what did we do with that one [15:06:23] maybe we manually edited some system thing [15:06:36] 109 other scenerios auto-merge, but that one always picks a random line, that is identical to the others [15:07:13] oh not even consistent [15:08:15] well, not enteierly random, for the battery update it didn't like the battery temps changing [15:09:06] I guess that makes sense [15:12:22] and for your vent update, it had an issue with the SIVb vent state [15:15:00] just git being git [15:22:38] probably [16:03:04] hey [16:18:32] morning! [16:33:27] hey guys [16:33:44] AlexB_88, I'm looking at the failure branch. I think I want to at least do something more with switch failures [16:33:48] probably save/load them [16:40:50] ah yes that should be good [16:45:28] and the clear button in the PAMFD clears them all [16:51:36] right [16:53:14] ATDP question [16:53:22] whats the difference between [16:54:08] the Free Return checkbox on the Mission Planning tab and the LV Targeting tab? [16:54:56] well I think the one on the Mission Planning tab forces a TLC time that is free return [16:55:05] but not sure about the other one [16:55:40] usually it should be set to the same thing on both pages [16:56:14] it does work differently internally [16:56:24] the QRTP free return targeting is very reliable [16:56:29] on the mission planning page it is not [16:56:35] still buggy [16:56:51] but you can e.g. manually adjust the TLC time on the mission planning page [16:56:57] to get 0 ft/s PC+2 [16:57:04] and then select free return for LV targeting [16:57:05] that works fine [16:57:25] ah [16:59:43] So if I understand right, no matter what TLC time you have on the mission planning page, even if it gives a high DV PC+2, if you check the Free Return on the LV targeting tab, the TLI will put you in Free Return? [17:00:21] it will try [17:00:29] maybe it doesn't work if it's too far off [17:00:45] maybe thats one way of already building a hybrid mission [17:00:57] but if you check the free return, then the LV targeting will not try to use the TLC time [17:01:09] in all cases it targets 60 NM pericynthion [17:01:21] so you don't gain anything from doing it that way [17:01:24] right [17:01:46] even wastes fuel [17:01:53] as you get a non-zero MCC-2 [17:02:03] and not really any gain in LOI DV from it [17:02:12] yeah [17:03:26] high guess a true hybrid mission starts you out on a high PC free return, which the tool can't do yet I guess [17:09:04] yeah [17:09:16] well also, the MCC-2 on a hybrid mission often did a plane change [17:09:25] different latitude of pericynthion [17:09:31] cheaper plane change than during LOI [17:09:51] but that also can't be done yet, also not by tricking the tool with different free return settings [17:11:03] right [17:11:46] I mean in the end they did those hybrid trajectories just because they didnt have full faith yet I guess lol [17:12:04] ideally it would be straight non-free from TLI [17:12:23] I guess thats the most fuel-efficient [17:36:05] Not to get too far ahead of ourselves, but do we know enough about that Belcomm 3-inpulse trajectory to impliment a mission design around it? [17:37:14] *Bellcomm [17:37:53]