NASSP: "Go Inertial" for Dummies? And missing state vector uplink.

[Wedge313]

Hello. I'm working the Apollo 11 mission, currently in lunar orbit, and have two (unrelated) questions:

First, what exactly do I do when the checklist says "Go Inertial"? At about 82+30 I was trying to set up for P22. I used V49 to maneuver to the assigned attitude. And then I'm supposed to "Go Inertial". What should I do switch-wise? Anything? (I understand the difference between Orb Rate and Inertial, but after maneuvering to an assigned attitude I'm not clear what "Go Inertial" means. If I'm no longer in Orb Rate, aren't I already doing it?). Also, after entering the landmark coordinates I get a 00407 alarm, and have to switch the CMC mode to Free and pitch up quite a bit before the auto optics can locate the landmark. Then I'm able to begin the pitch down/tracking//marking. Am I "Going Inertial" at this point?

And, at 83+30 I get the TEI-11 PAD, but was unable to uplink the state vector. Switches are all in the correct position, but when I send "Ready For Uplink" I get no Uplink Activity. I've used the Debug/Decrease State to try to repeat the process, but still no uplink. What can I check here?

Thanks!

 

[indy91]

Yeah go inertial just means that you are supposed to null the attitude rates. No specific IMU attitude or orb rate attitude relative to the Moon, just stay in the attitude you are.

407 alarm is normal in P22 if it's too early for the optics to track the target. You can ignore the alarm, although you should probably reset the program alarm when the target is finally in view or the auto optics might not work.

Does the MCC go as far as showing the "CSM state vector" message after you send the "ready for uplink?". And then just nothing happens? If that's the case the problem might be rather on the CSM side than the MCC side. On panel 3 try UP TLM CMD to RESET. Not sure that does much, but maybe that works. If not I can take a look at the scenario to see what happens there.

 

[Wedge313]

Thanks for the info. I went over my notes and noticed the "missing" uplink issue happened to me once before in the flight (around 25 hrs in). That time I used RTCC to generate a SV, don't know if that would affect any subsequent SV coming from MCC?

But being impatient, I pressed on with the flight without the new SV. I'm now at the 94 hour point. If I use the debug/decrease state feature, will that generate a good (current) SV? Or should I try using RTCC again?

I tend to think the problem lies with me or my laptop, and not the scenario itself. But I'll try going back to 83+30, resetting the UP TLM CMD a see what happens.

Thank you!

 

[rcflyinghokie]

RTCC uplinks shouldnt cause any issues with the MCC, I think a scn file might help debugging the MCC side though.