Thursday, July 19, 2018

PHILAE versus 67P don't forget the AM

Most analysis on why Philae "bounced" on the surface of 67P focus on the various failures of the legs, jet, screws and hooks which, if even one worked well, should have stuck the landing. My hypothesis that I am placing here, is that the landing was indeed stuck, but that the failure to consider the effect of de-spinning the fly-wheel inside Philae when considering the conservation of Angular Momentum (AM) was completely the reason it *jumped and spun*.
Philae would have managed to, with well designed legs and a stable rotation, screw at least one of the legs and be stationary enough, and signal such back to ROSETTA that the landing stuck. One of the first things that Philae then does, is to de-spin the fly wheel. However, with its long legs giving such leverage, the de-spin could have almost been designed to send it flying again.

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