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Author Topic: Project Apollo 7 Beta to the Moon...  (Read 70150 times)
Christophe
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« Reply #15 on: June 17, 2007, 04:45:31 AM »

Just one word/suggestion about fuel management while orbiting the moon.
Astronauts in the reality defined some specific quantities left that were required at each phase of the mission. That was Q1, Q2, Q3... and so on.
What you can do, for example right after LOI is to compute as soon as possible a solution for TEI. That will give you a required delta V (or fuel quantity) you record and keep for later. Add the necessary quantity for MCC 5,6,7 (you can for example consider that it woyuld be the same than for the previous MCC's) and add a little supplementary fuel for unexpected thing, let say something like 2 or 3 percent.
All this defines a minimum quantity that you can call Q1 for example, and that you MUST keep in the tanks.
After that by substracting this Q1 from the quantity you have currently, that gives you an available quantity (Q2 for example) and delta V's for the moon maneuvers, like LOI2, circularization, plane adjustments, and so on...
Don't forget that the TEI solution may be rather different from an orbit to another, so a good solution to avoid bad surprises is to recompute an eventual TEI solution each time you changed your orbit and redo the Q computation to update your available fuel.
That's the way the pilots do in flight as well as the astronauts.
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Tschachim
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« Reply #16 on: June 17, 2007, 09:54:45 AM »

... and some historic fuel/oxidizer numbers from Apollo 11:
After LOI 1: 38.8% fuel / 39.0% oxidizer
After LOI 2: 36.2% fuel / 36.4% oxidizer
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Coussini
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« Reply #17 on: June 17, 2007, 01:26:51 PM »

Hello Tschachim and everybody. Actualy, i'll try to fix my french documentation according to new stuff of NASSP 7.0.

I'll try to do the same mission of Tschachim (Apollo 14). It's loking good. I'll try also to do the TLI using the DSKY and IMFD 4.6.

I'll give you my result.

P.S: I did an airport for orbiter... so now... i have a time to continue with NASSP. Thanks
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slaintemaith
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« Reply #18 on: June 17, 2007, 04:21:57 PM »

Hrm...  I'm not getting happy results with rendezvous.    Is there a particular orbit the CM is supposed to be in?  I'm getting to within 1.20km, and then everything goes to hell.  The ascent stage starts firing RCS in contradictory directions, and ultimately puts me in an uncontrollable spin--until I run out of RCS fuel.  I'm not using extreme time accel.  10x up to just before the 2:00 mark...which is when it seems to want to make attitude changes for burns.

Since I crashed on the one I started from launch (which had the CM in a nice, tight, circular, stable orbit) I started using the Pre-saved Apollo 14 mission with the LM on the ground.  In this instance, the CM is at 88.32k x 101.2k.  I do the startup procedure (since the LM's landed, but all the systems are off (go figure!) and then ascent procedures as described above. 

Any Thoughts?
« Last Edit: June 17, 2007, 04:57:31 PM by slaintemaith » Logged
Tschachim
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« Reply #19 on: June 18, 2007, 05:52:16 AM »

Do you mean the "Project Apollo - NASSP\Quickstart Missions\Apollo 14\Apollo 14 - LM after touchdown" scenario? The 2nd RCS tank in the LM was empty, I fixed that, if you do a CVS Update it should work again. But I'm not sure if the CSM is working properly in this scenario...

Cheers
Tschachim
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slaintemaith
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« Reply #20 on: June 18, 2007, 09:24:37 AM »

Yup--that's the scenario I used.
*Laughs*  Empty!  Did you check the oil too?  =)
Thanks for the quick-fix.  I'll have a go at it now.  But -should- the CSM be in a particular orbit around the moon?  I'm not sure how much leeway the LM's ascent autopilot has with regards to Apd, PeD, and Inc.  (Although Inc doesn't seem to be a problem)

As an aside, you might want to power up the LM in descent configuration in that scenario as well. 
« Last Edit: June 18, 2007, 09:30:04 AM by slaintemaith » Logged
Tschachim
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« Reply #21 on: June 18, 2007, 09:54:23 AM »

But -should- the CSM be in a particular orbit around the moon? 

I suppose yes. An 100 x 100 km orbit over the landing site is fine, the 100 x 80 km orbit is this scenario is fine, too. But I don't know the limits, only LazyD knows (the author of the autopilot). I suppose the offplane limit is quite small because of fuel and the ApA/PeA limits are rather big, but I never tried a let say 20 x 200 km orbit, sorry.

As an aside, you might want to power up the LM in descent configuration in that scenario as well. 

Yes, we'll fix that scenario sooner or later...

Cheers
Tschachim
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slaintemaith
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« Reply #22 on: June 18, 2007, 10:57:49 AM »

Reporting success.  Seems fuel in the second tank -is- important.  =)   Now I gotta brace myself for TEI.
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slaintemaith
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« Reply #23 on: June 21, 2007, 10:08:07 AM »

Confirmed!  Apart from some pesky cryo pressure problems at high accel, I've also made this flight from start to finish without modifying/restarting/editing the sim.

Good stuff!  Thanks for the guide, Tschu, (I think you're all we have until the checklists and wiki are done!) and thanks for everyone slaving away on this project.  It's the very best Orbiter has to offer.

(Although I wonder if you can stea---err...ask for AMSO's 3D models...Hrm...)

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Tschachim
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« Reply #24 on: June 22, 2007, 09:17:01 AM »

(Although I wonder if you can stea---err...ask for AMSO's 3D models...Hrm...)

I did that already (asking, not stealing, of course), but no answer from Alain yet. We'll see, there are various possibilities how to support the AMSO meshes, perhaps we'll end up with that you need to install AMSO and can configure the use of the AMSO meshes in the config options on the Orbiter's Extras tab (like hi res/low res currently).

Cheers
Tschachim
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Coussini
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« Reply #25 on: June 25, 2007, 05:36:26 PM »

There's some cowboy at 25 seconds at the MISSION TIMER. Press ABORT... and check the show of the astronauts. That's important for the astronauts to have a complete suit, with oxygen for that  Cool



That very cool, but it's probably not you want.... hi hi hi.
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dseagrav
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« Reply #26 on: June 25, 2007, 08:44:53 PM »

I fixed that bug in my last commit.
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Coussini
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« Reply #27 on: June 25, 2007, 09:32:21 PM »

Thanks. I'll waiting for the next beta module.
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michaelrad55
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« Reply #28 on: July 03, 2007, 04:28:32 PM »

I'm trying to set up the burn for the TEI.  Using IMFD 4.6, I have the two MFD's in shared mode.  My base approach MFD looks exactly like you have it, but in my orbit-eject MFD it's saying no data available from baseapproach.  Am I missing a step here?
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Tschachim
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« Reply #29 on: July 10, 2007, 09:22:49 AM »

Hm, I'm not sure, perhaps you need to retry with a different sharing configuration, for example MFD 0 shares MFD 1 instead of MFD 1 shares MFD 0. And I assume you mean the base approach mode of IMFD, not Base Approach MFD?

Cheers
Tschachim
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