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To: BenLurkin

If the thrusters aren’t working, what would cause a “bounce”? I thought it was a given that if the harpoons didn’t work and the craft didn’t stick the landing, the only way to stay on the surface was those thrusters, given the weakness of the gravitational field.


3 posted on 11/12/2014 2:38:49 PM PST by jjsheridan5 (Remember Mississippi -- leave the GOP plantation)
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To: jjsheridan5

From what I’ve heard about that craft, it has no thrusters. No way of steering. It gets moved into position by its “mother ship” then dropped onto the surface. Nothing holding it on right now except for sheer luck.


7 posted on 11/12/2014 2:45:43 PM PST by christx30 (Freedom above all.)
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To: jjsheridan5; christx30
I read that it has threaded feet as a separate means of anchoring. Not as much holding power as the harpoon system, but more sticking force than provided by just good luck.

Critical to mission success is the lander's ability to hold onto the rock, dust and ice at landing. As there was a real risk of the lander bouncing off the comet, harpoons, landing leg ice screws and thrusters needed to work in concert to ensure Philae stayed in place. Apart from the harpoon system failing, another component of the landing system did not operate -- the cold gas thrusters. These thrusters were designed to push the lander into the cometary surface on landing.
Rosetta's Lander Grabs Onto Comet and Lands : Discovery News
15 posted on 11/12/2014 2:57:23 PM PST by Cboldt
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To: jjsheridan5

I read the downforce thrust jet was bad ordered... if that is the case what force will oppose the firing of these “harpoons” downward? Does someone need to explain Newton’s first law here to these scientists?


36 posted on 11/12/2014 6:48:59 PM PST by Rodamala
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