Meadville Space Center
Welcome, Guest. Please login or register.
February 24, 2020, 09:35:47 PM

Login with username, password and session length
Search:     Advanced search
Welcome to the new Meadville Space Center forums!
25068 Posts in 2094 Topics by 2266 Members
Latest Member: twa517
* Home Help Search Login Register
+  Meadville Space Center
|-+  Project Apollo - NASSP
| |-+  Project Apollo - NASSP Development (Moderators: movieman, Tschachim, Swatch, lassombra)
| | |-+  Apollo 7: Calculating the CSI Burn (was "No P32 in A7 vAGC?")
« previous next »
Pages: [1] Print
Author Topic: Apollo 7: Calculating the CSI Burn (was "No P32 in A7 vAGC?")  (Read 5023 times)
almostfm
Full Member
***
Posts: 48


View Profile Email
« on: February 22, 2010, 04:49:39 PM »

While attempting to run the Apollo 7 rendezvous sequence, I got to the point where it was time to set up the CSI burn.  I tried to call up P32, but all that happened was the "OPP ERR" light came on.  Am I correct in guessing that P32 wasn't available in Colussus 249? I've attached a scenario in case it's just something I'm doing wrong.

  Scott

* Apollo 7 p32 problem.scn (157.1 KB - downloaded 204 times.)
Logged
dseagrav
Project Admin
Hero Member
*****
Posts: 1118


View Profile
« Reply #1 on: February 23, 2010, 12:47:52 PM »

There is no P32.
Logged
almostfm
Full Member
***
Posts: 48


View Profile Email
« Reply #2 on: February 24, 2010, 03:14:55 AM »

There is no P32.

  Well, I'll stop trying to run it, then  Wink

  thanks,
  Scott
Logged
Swatch
Moderator
Hero Member
****
Posts: 1003


jasonims
View Profile
« Reply #3 on: February 24, 2010, 03:46:06 AM »

Feel free to continue trying, just stop expecting...    Very Happy
Logged

My Project Apollo Work:
CM Visual
 -VC (~75% complete: texture work beginning again; mesh-78%; texture-70%)
Propulsion Particle Improvements (Focused on S1B right now, BETA 1.0 has been commited)
New Docking Method (~50% complete: research complete; coding partially completed, testing not underway)

Future Work:  (if it's here, it's deemed unnecessary to upcoming release)

Older Work:  (if it's here, it's fair game to whoever wants to improve)
EMS Implementation (committed: minor flaws, but groundwork is there, needs extensive testing)
EMS scrolls (committed: not refined, but usable)
SM Visual (committed: mesh-finished, texture-60%; possibly revisited in future)
J2 Texture (commited: room for improvement)
LRV (committed: mesh-finished, texture-90%; in future a ground up rebuild may be in order, but not on my plans)
Tschachim
Project Apollo - NASSP
Administrator
Hero Member
****
Posts: 3700


nassp.sf.net


View Profile WWW
« Reply #4 on: February 24, 2010, 07:03:41 AM »

Hm, bad news, that leaves the question how to calculate the CSI burn... Sigh
Perhaps we'll all need to learn GMAT: http://www.ibiblio.org/mscorbit/mscforum/index.php?topic=2276.0 ...  Wink
Logged

kneecaps
Project Team Member
Full Member
****
Posts: 217


36711000 kneecaps@shockpulse.co.uk
View Profile
« Reply #5 on: February 24, 2010, 06:06:54 PM »

STK version 8 was offered in 2D only mode after the 30 day eval. You don't NEED the 3d graphics to take advantage of the calculations, actually Astrogator is probably an additional module that's not free :S

Oh for the lack of mission support tools Sad.
Logged

"Okay. As soon as we find the Earth, we will do it."
- Frank Borman, Apollo 8

Current Work: ?? What next??

Future Work:
I know the AGC pretty well so anything need doing there?

On Hold/Completed:
SPS TVC in P40 issues.
P11 FDAI Error Needles (98%) complete. Comitted. Working A7 scenario.
P06 AGC Standby. Concluded. It's done by the AGC PSU.
Got us a complete AOH Volume II
meik84
Project Team Member
Sr. Member
****
Posts: 454



View Profile
« Reply #6 on: February 24, 2010, 07:21:58 PM »

Maybe they didn't need P32? The LM (or SIVB) was already in a nearly circular orbit, so you wouldn't need CSI and P32. I believe they used P38 and P39 for that -programs which were not available for the lunar missions. Just have a look at the GSOP for Colossus 249.
Logged
Tschachim
Project Apollo - NASSP
Administrator
Hero Member
****
Posts: 3700


nassp.sf.net


View Profile WWW
« Reply #7 on: February 25, 2010, 07:05:38 AM »

Maybe they didn't need P32? The LM (or SIVB) was already in a nearly circular orbit, so you wouldn't need CSI and P32

Looks like they did a CSI burn: http://www.ibiblio.org/mscorbit/mscforum/index.php?topic=1456.msg18941#msg18941
Quote
#4 028:00:56  CSI  7.76 sec SPS Put the CSM into a coelliptic orbit with the S-IVB.  We have this in the flightplan as the 2nd SPS Burn.

I believe they used P38 and P39 for that -programs which were not available for the lunar missions.

Ah, that's interesting, did you try P38 and P39? Does someone know what they did in reality?

Cheers
Tschachim
Logged

meik84
Project Team Member
Sr. Member
****
Posts: 454



View Profile
« Reply #8 on: February 25, 2010, 12:54:06 PM »

Quote
Does someone know what they did in reality?
The preliminary flight plan mentions P30 for the maneuvers prior to TPI. Looks like they really computed them on the ground and let the CMC do the time-critical part.
Logged
irnenginer
Project Team Member
Sr. Member
****
Posts: 271



View Profile
« Reply #9 on: February 25, 2010, 05:44:25 PM »

From the research I have done on that burn, it was uplinked from the ground and P30 used. I think there was something in the transcripts that confirmed it for me.

I have attempted to get at least get state vectors input from orbiter into GMAT, with the idea of using it to calculate this burn. But I could never get the SC to be in the right place with respect to the earth ground or in an orbit that looked right. Has anyone ever had success doing that?

Logged
almostfm
Full Member
***
Posts: 48


View Profile Email
« Reply #10 on: February 25, 2010, 07:39:00 PM »

From the research I have done on that burn, it was uplinked from the ground and P30 used. I think there was something in the transcripts that confirmed it for me.

I have attempted to get at least get state vectors input from orbiter into GMAT, with the idea of using it to calculate this burn. But I could never get the SC to be in the right place with respect to the earth ground or in an orbit that looked right. Has anyone ever had success doing that?

irnenginer,

  Are you ending up in a polar orbit when you input the SV?  I found by playing around that if I transposed the Y and Z terms in the SV (both position and velocity), and used the EarthMJ2000Eq coordinate system, I'd get the correct shape orbit.  I still haven't cracked the problem of getting the SC in the right place over the earth...
Logged
irnenginer
Project Team Member
Sr. Member
****
Posts: 271



View Profile
« Reply #11 on: February 25, 2010, 08:20:20 PM »

I did do the transpose thing, which does at least get you an orbit, but like you I could not get it to in right spot over the earth.
Logged
Pages: [1] Print 
« previous next »
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.10 | SMF © 2006-2009, Simple Machines LLC Valid XHTML 1.0! Valid CSS!