Question Skylab 2 Mission

[jwh07]

I,m working the Skylab and following YouTube video I’m guess is from indy91 on the mission.

1st there’s a display that I can’t find or is it not available?

2nd in the video at 15 seconds before burns there’s thrusters that come on and it looks like the CM is in translation mode , how is that set up for what I think is pre thrusting?

3rd when I use the RTCC for Skylab intersep I,m also getting a PAD from CAPCOM for NC1 sometime after I’ve already uplinked the maneuver from RTCC and started P31 then P40 is this normal?

Thanks for any info.

 

[indy91]

1st there’s a display that I can’t find or is it not available?

The relative motion graph is just something I added with video editing, so that a viewer of the video can keep track of where the CSM currently is. It's just based on a MATLAB script I made.

2nd in the video at 15 seconds before burns there’s thrusters that come on and it looks like the CM is in translation mode , how is that set up for what I think is pre thrusting?

It's an ullage burn with the RCS, to settle the propellant before SPS ignition. It was manually done for all SPS burns where about half the propellant had already been burned, so on a mission like Skylab 2 (but also Apollo 7) that already launched with a lot less than 100% propellant it was done on every burn. In the LM the LGC does the ullage automatically, but with the CSM it is manual. There isn't anything simulated in NASSP for propellants that aren't settled, so not doing it has no bad effects. But procedurally it is the realistic thing to do.

3rd when I use the RTCC for Skylab intersep I,m also getting a PAD from CAPCOM for NC1 sometime after I’ve already uplinked the maneuver from RTCC and started P31 then P40 is this normal?

Skylab 2 has support by the MCC feature (with the CAPCOM menu), so if you just wanted to fly the rendezvous with Skylab as normal then you don't have to use the RTCC MFD at all. If you just want to mess around and not receive anything from the MCC I would suggest disabling the mission tracking. In the CAPCOM menu that is pressing 9 (for the debug menu) and then 2 (Toggle MT).

 

[jwh07]

Thanks Indy91 you are the man with all the answers.

Copy on 1 and 3

As for #2 for the ullage is there a checklist for setting that up or procedure?

Also can you tell me which Apollo checklist that this mission uses because I can’t find one that says Skylab 2. ?

I’m working my way through this mission and the learning curve is unreal

I got to NC1 burn time and had problems but I’m getting there.

Thanks again for your time

 

[jwh07]

Disregard my ullage question about procedure I understand now that is manually done with RCS translation, guessing aft thrusting for DV change.

Also guessing it’s using Apollo 7 checklist.

Thanks again

 

[jwh07]

Sorry Indy one more question

In video you input GET in P31 then number of rev’s the TPI time.

Where did you get that time TPI?

If I’m just running the mission with MCC.

Thanks again

 

[indy91]

There is a special MCC update that shows only NC1 and TPI time of ignition, maybe you missed it. It comes at T+30 minutes.

 

[jwh07]

Copy that
Thanks again