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Project Apollo - NASSP 6.4.3 released!
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| | |-+  Apollo 8 vAGC Flight Plan
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Author Topic: Apollo 8 vAGC Flight Plan  (Read 3443 times)
Phaser
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« on: April 27, 2010, 09:53:01 PM »

I'm using the Jan 4 2010 Mods and CVS snapshot.

Is the Maneuver - 2nd Mid Course correction supposed to be a RCS firing only? I noticed there were no SPS checlist activites (after my TIG came and went  Bangs Head 2).  Then reading again carefully it sunk in that "TIG - 0 sec   MFD2   Use translational thrust until the PeA in MFD2 is close to 121.9k" suggests RCS only.

But what really suprised me was the total dV computed byt the AGC was 401 fps.  And my 4 or 5 thruster pulses to get my PeA to 121.9k didn't come any where near that much of a dV.
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Gunner_CAF
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« Reply #1 on: May 02, 2010, 01:54:46 AM »

I'm using the Jan 4 2010 Mods and CVS snapshot.

Is the Maneuver - 2nd Mid Course correction supposed to be a RCS firing only? I noticed there were no SPS checlist activites (after my TIG came and went  Bangs Head 2).  Then reading again carefully it sunk in that "TIG - 0 sec   MFD2   Use translational thrust until the PeA in MFD2 is close to 121.9k" suggests RCS only.

But what really suprised me was the total dV computed byt the AGC was 401 fps.  And my 4 or 5 thruster pulses to get my PeA to 121.9k didn't come any where near that much of a dV.

I just did the 2nd Mid Course correction tonight.  It helps to save, I sometimes need one or two run troughs to figure out what I need to do.  I only needed a dV of 8 fps.  My PeA ended up being 70.5K, I hope I don't hit anything Happy  Looks like the dV computed by the AGC isn't very accurate.

Gunner
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NLS le pingouin
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« Reply #2 on: May 03, 2010, 02:56:46 PM »

Isn't this flightplan out of date? I thougt the Apollo 7 and 8 flightplans was...

Wich scenario do you use for this mission? I don't have any for this one.
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Apathy Man
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« Reply #3 on: May 03, 2010, 06:06:10 PM »

I'm about halfway finished updating the Apollo 8 flightplan. I can confirm the TVC works good. However, I hit a snag where shortly after LOI the AGC locks up with the dreaded COMP ACTY. I'll add more to it once I find out a workaround. Still finding my way around a few things.
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"Whoopee!" Pete Conrad's first word upon stepping on the moon.
Gunner_CAF
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« Reply #4 on: May 03, 2010, 10:53:44 PM »

So far the Apollo 8 flightplan isn't bad.  I found a few things that should be fixed in the IMFD procedure at the mid-course correction.

One problem I did have was when I terminated the PTC Maneuver and started the 2nd mid-course correction.  When I performed the P52 alignment, the PROG light on the DSKY came on and it was followed by a gimbal lock.  I discovered that the PROG warning was telling me if I proceeded from this orientation, it would go into gimbal lock.  I pitched about 180 degrees first, then it was OK.

I have never seen the IMU change this much when I performed this alignment before.  It may be due to the State Vector update using the moon as a reference.  This must change the REFSMAT and the IMU aligns to this new position.  This may be a problem for others and might be a good note in the checklist.  I put a note in my checklist Happy

Gunner
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Phaser
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« Reply #5 on: May 09, 2010, 10:34:32 AM »

I'm about halfway finished updating the Apollo 8 flightplan. I can confirm the TVC works good. However, I hit a snag where shortly after LOI the AGC locks up with the dreaded COMP ACTY. I'll add more to it once I find out a workaround. Still finding my way around a few things.

I think my earlier problem where the FPS calc'ed by the CMC was so high was because I entered a Pet an hour earlier than the plan.  I did complete this mission although my landing lat/long was so far off it was laughable.  I did have the above happen after LOI.  I finally did a CMC restart and that actually fixed the problem.

I am now re-running the mission (and am happy to report I didn't have the 1st MCC issue), but am still getting AGC lockups post-LOI.  This time I have tried a CMC restart twice to no avail. I'm not sure what I can do to narrow the fault tree.  I do have a good post-LOI position saved so I am trying a few different things.
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Phaser
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« Reply #6 on: May 09, 2010, 10:37:16 AM »

Isn't this flightplan out of date? I thougt the Apollo 7 and 8 flightplans was...

Wich scenario do you use for this mission? I don't have any for this one.

....\Scenarios\Project Apollo - NASSP\Broken Scenarios\Virtual AGC\Apollo 8 - Launch.scn
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eddievhfan1984
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« Reply #7 on: May 16, 2010, 06:04:25 PM »

I also have some concerns about the scenario...

When I ran it, the launch did not initiate at the end of the CMC's clock; I had to manually initiate the lift-off. Then while doing my IMFD burn calculations, I got a solution which put my burn vector pointing towards
earth. I wasted 50 seconds of burn time just to put myself 80km inside the atmosphere.  Bangs Head 2  What?  Zip Lip

Can anyone provide assistance?
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Gunner_CAF
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« Reply #8 on: May 22, 2010, 12:03:19 AM »

I did my LOI and Orbit Circularization burn.  I made it into lunar orbit with no problems.  My PeA is off a bit more than I like, but I didn't hit the moon Happy  In the flight plan I found a few lines missing for the Circularization Burn in the IMFD setup instructions, but I just copied them from the instruction above.  Charge my batteries and a little nap, and it will be time to head for home.

Gunner
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