Question BMAG light

[ryan]

Hey,
Is the BMAG light on the Command Module C&W a thing that's going to be added? On the pre-launch checklist there is a step that you check that the light has gone out on the BMAG warm-up.
Sorry if this is a question that has already been asked.
Thanks, Ryan.

 

[meik84]

If you can provide a rough thermodynamic model of the BMAGs, i.e. how long it took from BMAG PWR -WARM UP to BMAG light out...
I've dug around the docs for the BMAGs and found everything, but not how long warm up took. I do have data for the IMU (when I remember right, they 'cooked' that poor thing intentionally during one of the unmanned test flights), but for the BMAGs...nothing.

 

[jackswigert1970]

On the pre-launch checklist there is a step that you check that the light has gone out on the BMAG warm-up.
Thanks, Ryan.

I don't think the BMAG light matters. I've done multiple launches and the BMAG light never came on and all the launches worked well the rest of the time.

 

[ryan]

I'd imagine it took about a hour or so. The backup crew put it on warm up in the middle of his checklist and the prime crew turn it on around the middle too. Although I'm only going off rough memory on that.
You would of thought alot of documentation would exsist on them being that they are a pretty crucial device.


And Jack Swigert, that's not the point though.

 

[jackswigert1970]

Ok I didn't know what you were trying to say sorry.

 

[indy91]

I think the main point is that the NASSP panel doesn't even have the BMAG lights, neither on or off. That is due to the CSM panels being based on a slightly outdated Systems Handbook, which had a few configuration differences from the one that was actually flown on all Block II missions. Another difference would be the optics switch, which actually was two separate switches (one for optics zero/off, one for optics mode CMC/manual). For the BMAG light there currently is a static temperature defined in the BMAG class and the CWS already has the right logic for setting the light on caused by temperature. The only thing missing is the lights on the CWS bitmap. So the main step to implement this is adding the lights to the bitmap.

 

[meik84]

To check that the light is out before switching to operate is sound operational behaviour, but it does not mean that the light has gone out right then. Especially during prelaunch things were left "sitting as they are", just because they weren't needed at that point.
Just for reference: the IMU took less then 15 min from about 20° C (IMU STBY PWR cbs out) to operational conditions. I'd figure the BMAGs lay in that region, too, but I have no proof for that.

 

[ryan]

I think the main point is that the NASSP panel doesn't even have the BMAG lights, neither on or off. That is due to the CSM panels being based on a slightly outdated Systems Handbook, which had a few configuration differences from the one that was actually flown on all Block II missions. Another difference would be the optics switch, which actually was two separate switches (one for optics zero/off, one for optics mode CMC/manual). For the BMAG light there currently is a static temperature defined in the BMAG class and the CWS already has the right logic for setting the light on caused by temperature. The only thing missing is the lights on the CWS bitmap. So the main step to implement this is adding the lights to the bitmap.

That's exactly what I was trying to say but I'm not as eloquent with my words than I think I am :lol: