[amsat-bb] ANDE Deploy Anomoly
bruninga at usna.edu
Sat Dec 23 06:29:17 PST 2006
> I don't understand how it could have been allowed to stay
> hung in the can.
Oh, sorry. I assume that everyone had seen the video, but of course they probably havent. The can was also deployed. So the Shuttle was free to go.
> I cannot even begin to imagine a NASA manager signing off
> on anything remaining in the can "half cocked".
Yes, very true. What we meant was that the cans and their satellites were all deployed and all separated. But ANDE just didnt make it out of its can. It was presumably just floating there inside it.... probably the O-ring, which was the only thing holding the satellite got a little sticky and reduced the separation velocity to near 0. But all of this was well away from the shuttle.
> There is something missing from this story.
Yes. It all becomes clear when you look at the video on the web page, and then also look at the link showing the CAPE/ICU deployment system.
To find the web page, GOOGLE for ANDE OPS, and take the first one. Below the picture of the deploy, click on the movie.
To see the design of the CAPE/ICU system, see this link:
> Isn't it more likely that it was actually released
> on time and just came alive later when charging was
> sufficient? Do we know for a fact that it was not
> released? If so, what was the later release mechanism?
ANDE runs on 112 "D" cell Lithium primary cells, so she was ready to go as soon as the lid came off. She was "released" also as soon as the lid came off, so best theory is that the o-ring just got sticky and it took some thermal cycling to overcome the stiction. They have been mated under hundreds of lbs pressure since June.
To the media and most viewers, it looked like a nominal deploy. But we should have seen 5 pieces (three shell pieces and two satellites), but only 4 were visible.
And FCAL came out very slowly, and ANDE had an additional thingy, a small detent on one side, to cause it to spin slightly as it came out. This detent couild also have absrobed almost all of the initial velocity leaving it just floating inside. Eventualy gravity gradient and drag on the shell would hopefully let ANDE drift out.
I'm sure there will be a study.
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