Computing Apollo 7 phasing maneuver

[indy91]

Does this post automatically gets added to the post above?

I guess I can already explain what the script does.

1. Calculate the orbital period of the CSM/S-IVB, which are still docked at the time of calculation.

2. Calculate the number of orbits that the S-IVB will do in the time intervall (26:25:00-3:20:20 in this case)

3. Propagate the orbit to the maneuver time

4. Very basic assumption of the distance in time with the current velocity: t_diff=distance/v_SIVB

5. necessary period to reach the distance in the required time

6. iterative process of calculating the dv necessary to attain the period

 

[meik84]

Seems to work.:thumbup:
Too bad that your autopilot cannot control our CSM. Would've been a cool thing to track the SIVB and at least try out the TPI program of Colossus 249. Oh well, I'm getting greedy again...
BTW: I've seen that you wrote a script with Apollo's rendezvous targeting routines. Did you really implement the routines as stated in the GSOP? I'm just interested, as orbiter and the CMC/LGC use different coordinate systems and you'd have to convert between both...

 

[indy91]

I'm just interested, as orbiter and the CMC/LGC use different coordinate systems and you'd have to convert between both...

You just discovered my worst nightmare...

Yeah, I tried to make a futuristic autopilot for Greg Burch's LSTS vehicles, but while researching ended up using a lot of the LGC routines. And by using I mean understanding and implementing them with some simplifications and adjustments. With the coordinate systems it gets even better: I have a great book about Orbital mechanics and that uses yet another system. :facepalm:

I guess I know a lot about the whole LM ascent and rendezvous now. That's why I instantly thought I could help, even though I misunderstood your problem at first

I know this is quite off-topic, but what's the problem the TPI program?

 

[meik84]

I know this is quite off-topic, but what's the problem the TPI program?

Nothing. It just would have been quite interesting if your script would work with 'our' CSM, so that you can really play with the CMC. We still don't know if this whole tracking and rendezvous targeting stuff works, due to the fact that we weren't able to establish realistic distances between the CSM and the SIVB.

You just discovered my worst nightmare...

Hihi. I came along something similar when implementing the LVDC. My girlfriend looked at me with a very strange gaze when I held my left hand on the globus with thumb, index and middle finger extended, while trying to find out which axis is what and how you've got to rotate orbiters system to match LVDC's. "Sweetie, I'm also sitting on the launch pad. Now come to bed." Holy cow, I love this women...:blush:

 

[indy91]

Hmm, I don't really know what is the best way to show you this, I just upload a refined and annotated version of the lua script and hope you can understand everything in it. If not I'll explain it in a different way.

I hope I could help you and I am always happy to help again! :tiphat:

 

[meik84]

Don't worry. I'll take a look at it and come back with those unsolvable questions. Promise!
Anyway, thanks for your help. At least you've demonstarted that the problem is solvable -and that's 75% of the work.:thumbup: