--- Nate, WY0X, wrote:
I'm no expert, just some casual layman's notes below, but did you watch the replays on NASA TV, John? Some of what you saw could probably be described from the video from the External Tank (ET) centerline camera video. (Which is absolutely phenomenal by the way... if you haven't seen it and you're reading this, find an outlet for the Flight Day 1 video and watch the launch videos. The lame press here in the States doesn't ever play the good stuff.)
I've seen some external tank videos from previous missions, but didn't get a chance to see any for STS-116.
Just after MECO, there's a bunch of thruster, and (I think) OMS engine firing to pull away (+Z) from the dropped ET. Plus I would assume the main engine bells are probably still quite hot, possibly producing visible light? That last part is just a guess.
I did see some smaller flashes some time after the main engines extinguished (as I was walking back to my car, to be exact), so my guess is that they were due to OMS firings. I saw some "after glow" for a while as well.
--- Joe Leikhim, K4SAT wrote:
I would expect the main engines might continue run on for a while because of the fuel remaining in the lines and turbo pumps being under tremendous pressure and expansion. Also I think the engine bells are cooled by cryo fuel so some may remain inside as well and some flow desirable to cool down.
Could be.
Perhaps someone more familiar with the engines can describe the shutdown process. It is probably more complex than closing one set of valves so that unburned fuel doesn't burn/explode when the tank separates.
Sounds like a good question to pose to an astronaut the next time they show up on 2-meters. :-)
73, de John, KD2BD
Visit John on the Web at:
http://kd2bd.ham.org/ . . . .
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