…this time from Henry Spencer:
Such separation problems – even including collisions – have happened before. Large rocket motors often produce noticeable thrust for a surprisingly long time after they officially shut down, as remaining gases and fluids leak out, and this thrust can overwhelm the effect of small separation motors trying to separate the stages. (Just such a problem caused the failure of a Falcon I launch last year.) Or perhaps not all the Ares I-X separation motors actually fired.
Two such problems in one launch would be an odd coincidence, but there’s at least one way that both could have the same cause: suppose a wiring error sent the ignition signal for some of the separation motors to the tumble motors instead?
This may sound far-fetched, but there have been a number of cases of cross-wiring of multiple similar devices, especially in early tests of new systems. For example, on the second unmanned test of the Saturn V in 1968, a shutdown command directed at one second-stage engine shut down its neighbour as well, because they were partly cross-wired.
Well, even if true, it’s not reasonable to expect them to get the wiring perfect. They had to launch this thing on a pinch-penny budget of only half a billion dollars.
And the controversy of “did it or didn’t it recontact” continues in comments at NASA Watch.
You mean they don’t even know if it hit the upper stage?
Yeah the whole “this is just a poor ol’ test flight, don’t expect perfection” schtick is amusing. I expect a lot more perfection out of a $500M test launch than I do out of say a $10M Falcon 1 launch. But hey, this is NASA, the smartest guys in the room. We wouldn’t want to risk our future in space on those risky startups after all…
Yawn.
~Jon
Good one Jonathan. I think I’d rather ride a Falcon! One of the comments on NASA Watch claims that “lack of a debris field shows there was no contact”. Duh -I thought they were all going pretty much the same direction.
The SRB had an IMU, certainly carried the data down, and probably transmitted the data via telemetry as well. If the was a recontact, it will show on the accelerometer data. Someone should do an FOIA, that will make them ‘fess up.
If this were a SpaceX flight test, we’d be able to watch the video.