AMSO AMSO Lunar Liftoff problems

aa416295

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Hi there.

I'm trying to complete the ASMO Apollo 11 mission. I used the great AMSO for dummies document, and everything has gone well, right up until I liftoff from the lunar surface. For some reason, no matter how many times I try, it the LM (on auto pilot) fails to reach orbit. I've tried half a dozen times, and the altitude reached varies, but generally the engine fires until I reach an altitude of 7-10K (one time it went up to like 30k), then the engine shuts down, the LM pitches and rolls onto it's side, then with RCS thrusters firing constantly, it falls back to impact the lunar surface... I must be doing something wrong, but I don't know what it is... I've watched some videos on YouTube, but they are very old. I'm using Orbiter 2016, and the AMSO version 1.23. If anyone has any suggestions, I'd love to hear them.

regards
Troy
 

asbjos

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Hello, and welcome to the forum!
Just to be sure: have you selected the "Limited fuel" setting in Orbiter Launchpad -> Parameters -> Limited fuel?
If it's not selected, AMSO will probably be confused by your vessel not being lighter as it burns the fuel.
 

jarmonik

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I couldn't get Apollo 11 to work due to some terrain elevation issues. However, Apollo 12 did lift-off properly and made a rendezvous maneuvers too without any issues. So the auto-pilot took the ascent stage from the surface to 30 meters from CSM.

Also you can reach the AMSO developer through Dan's Forum
 

aa416295

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Thanks for the replys.

I do have limited fuel selected. I've tried to do the Apollo 17 quickstart on the surface, and I have the same problem with it. It climbs a bit, pitches over and starts accelerating, then just sort of gives up... I checked the autopilot before takeoff, and it says it's go for ascent, but it fails to reach orbit every time. All the other autopilots (DOI, PDI, etc) seem to work fine...
 

1987VCRProductions

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I just noticed this recently when running Apollo 16 with damage and failure sim on and I had to abort PDI early in the braking phase, the LM acts like it has no idea what to do and it just wallows around a bit before giving up. Even aborts close to the ground (tested with Apollo 11) give a similar result. I did get 17 to work normally because that was the first mission I tried when I first got the 2016 version of AMSO, the LM on ascent reaches orbit but the initial pitch-over after lift-off is unstable. I think it might have to do with the autopilot getting confused between the "sea level" altitude Orbiter gives you above a certain altitude and the actual altitude Orbiter gives you when you're close to the surface, since the program was written when all the bodies in Orbiter were smooth spheres. I could be dead wrong though so take that guess with a grain of salt.
 
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jgrillo2002

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I will tell you this. I have the same issue, the only workaround is to manually pitch down 90 degrees but just let the autopilot do the work. I think it has something to do with the elevation mapping.
 

1987VCRProductions

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I just tried lunar ascent with Apollo 16 and it ran normally but the cut-off was way early, I simply relit the engine and flew it the rest of the way into the nominal orbit manually. Should I compile a list of the lunar ascents that work and the ones that have issues?
 

Sbb1413

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Hi there.

I'm trying to complete the ASMO Apollo 11 mission. I used the great AMSO for dummies document, and everything has gone well, right up until I liftoff from the lunar surface. For some reason, no matter how many times I try, it the LM (on auto pilot) fails to reach orbit. I've tried half a dozen times, and the altitude reached varies, but generally the engine fires until I reach an altitude of 7-10K (one time it went up to like 30k), then the engine shuts down, the LM pitches and rolls onto it's side, then with RCS thrusters firing constantly, it falls back to impact the lunar surface... I must be doing something wrong, but I don't know what it is... I've watched some videos on YouTube, but they are very old. I'm using Orbiter 2016, and the AMSO version 1.23. If anyone has any suggestions, I'd love to hear them.

regards
Troy
Same case goes to me.
 
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