Meadville Space Center
Welcome, Guest. Please login or register.
November 24, 2020, 02:06:50 AM

Login with username, password and session length
Search:     Advanced search
Project Apollo - NASSP 6.4.3 released!
http://nassp.sf.net
25068 Posts in 2094 Topics by 2267 Members
Latest Member: Apollo Next
* Home Help Search Login Register
+  Meadville Space Center
|-+  Project Apollo - NASSP
| |-+  Project Apollo - NASSP News & Discussion
| | |-+  Support & Bugs (Moderators: movieman, Tschachim, Swatch, lassombra)
| | | |-+  P52 Question ...
« previous next »
Pages: [1] Print
Author Topic: P52 Question ...  (Read 1352 times)
bertog
Full Member
***
Posts: 30

g.bertolino@garellicomputers.com
View Profile
« on: March 21, 2007, 04:39:06 AM »

Hi all,

Last night I've try using the EOCA scenario provide by Christophe some P52 using the preferred option and the Ops3 REFSMMAT.

Everything is working well, but when the CMC drive optics to find the select star I found it orizzontally match the cross in the SCT but vertically placed at the top of the SCT.

I've centered with the SCT and mark the star using SXT.

The result of the two star mark is a poor +01598  Embarassed

This mean the the IMU is out of his alignment or that I've made something wrong in the mark procedure ?

How to realing the IMU in the best way ?
Logged

<< Hey, there it is ! There it is !! Son of a gun, right down the middle of the road !! >> - Pete Conrad
Christophe
Project Team Member
Hero Member
****
Posts: 1072


View Profile Email
« Reply #1 on: March 21, 2007, 05:29:39 AM »

Hmmm probably something wrong in the mark procedure. The sequence is a bit confused while running P52. By the past it happened to me to do some mistake with the star ID code. After the mark I remember you're asked to confirm the latest star used and not to enter the next one. I did that mistake very often at the beginning and of course the result was wrong.
May be you did something like this?
Logged
bertog
Full Member
***
Posts: 30

g.bertolino@garellicomputers.com
View Profile
« Reply #2 on: March 21, 2007, 05:39:37 AM »

Could you confirm that this sequence is right ?

After marking the star

F50 25
00016

PRO

F01 71
[Same Star Code as the previous F01 70]
PRO

F01 70
[Second Star Code]
PRO

And it begin the second mark sequence ...

It's Ok ?



Logged

<< Hey, there it is ! There it is !! Son of a gun, right down the middle of the road !! >> - Pete Conrad
Tschachim
Project Apollo - NASSP
Administrator
Hero Member
****
Posts: 3700


nassp.sf.net


View Profile WWW
« Reply #3 on: March 21, 2007, 12:07:49 PM »

Look here: http://nassp.sf.net/wiki/IMU_Realign_checklist_%28Virtual_AGC%29

... and someone just added a strange comment about Confused "PROing the options" Confused to this article, which seems to be wrong, at least I don't understand it. I reverted the edit, but if the guy is around here I would be interested in what was meant by the comment and to resolve the issue...

Cheers
Tschachim

Logged

Tschachim
Project Apollo - NASSP
Administrator
Hero Member
****
Posts: 3700


nassp.sf.net


View Profile WWW
« Reply #4 on: March 21, 2007, 07:14:13 PM »

Last night I've try using the EOCA scenario provide by Christophe some P52 using the preferred option and the Ops3 REFSMMAT.

I did that, too. The first automatic navigation star was 32, the attached screenshot shows the expected position. The IMU is quite misaligned, about 1-2 in each axis. Christophe, I really suggest to take a look at the latest beta and Apollo 7, which has really the better pad load (especially the ephemerides) and to do a P52 as soon as you reached orbit.

I'm still working towards my first EOCA burn soon, the excel is really great!  Happy

Cheers
Tschachim


* EOCA_P52.jpg (24.86 KB, 541x544 - viewed 113 times.)
Logged

Christophe
Project Team Member
Hero Member
****
Posts: 1072


View Profile Email
« Reply #5 on: March 22, 2007, 05:37:34 AM »

Thanks Tschachim.
In fact I worked tonight on the init page (which will renamed as <Config & Init>) of the EOCA to allow the user to put in the state vector and MJD of his own favorite scenario.
That would definitely solve the test scn trouble.
Hope I can post a new beta before tomorrow afternoon cause I' m on duty ( Sad) this weekend from friday to monday.
Logged
bertog
Full Member
***
Posts: 30

g.bertolino@garellicomputers.com
View Profile
« Reply #6 on: March 23, 2007, 04:55:20 AM »

The last question ...

How is possible to recover this bad IMU ? Is needed to update the REFSMMAT it self or via the P52 is possible to realign the IMU ?
Logged

<< Hey, there it is ! There it is !! Son of a gun, right down the middle of the road !! >> - Pete Conrad
Tschachim
Project Apollo - NASSP
Administrator
Hero Member
****
Posts: 3700


nassp.sf.net


View Profile WWW
« Reply #7 on: March 23, 2007, 05:07:38 AM »

You can realign the IMU by using P52, option 3.

Cheers
Tschachim
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!