Pictures of a Comet From 9 Meters Away 46
An anonymous reader writes: Back in November, the European Space Agency triumphantly put a lander on the surface of a comet and then tragically lost contact with it when it failed to anchor and couldn't harvest enough energy to stay operational. In June, the lander awoke and for a short time was able to send more data back. Now the ESA has published a bunch of pictures and scientific papers about the data gleaned from Philae's short windows of activity, including images of its descent to the surface. Phil Plait summarizes and analyzes the release. The most impressive image is from a mere 9 meters over the surface of comet 67P/Churyumov-Gerasimenko. An animated gif shows the lander's descent near the surface through a handful of pictures. Two shots of the same area from the Rosetta probe show where Philae bounced off the surface, ejecting an estimated 180kg of material in the process. It's a fascinating, close-up look at a very distant and unusual world.
Puzzling (Score:1)
It is puzzling why the lander moved so radically after landing. You would have thought that the landing control systems would have nulled out velocity before committing to touch down. If it was not possible to null the velocity the attempt should have been aborted and tried again. The landing of NEAR on Eros is particularly instructive of this conservative approach.
Re:Puzzling (Score:5, Funny)
Try landing on Gilly in Kerbal Space Program... any sneeze, in the near-zero gravity of a small asteroid/comet, will send you tumbling endlessly.
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Landing was even hard in the old Lunar Lander arcade game from back in the day. heh *feeds it more quarters for fuel*
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Moon Patrol was deceptively difficult, also...or at least the difficulty exponentially went bananas after 2-3 levels of easy boredom right smack dab into being almost impossible in addition to being boring.
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Ah... I liked Moon Patrol. Just start it on Q or whatever the higher level start was. That avoided the overly easy (boring) bits at least some.
Re:Puzzling (Score:5, Informative)
The relative velocities are quite low, because there is very little gravity. So their plan was not to make a jet system that reduces the landing velocity (you may be thinking of the moon landing), but instead to use a cold-gas jet to press the lander onto the surface [slate.com]. That system, unfortunately did not fire. Secondly (and perhaps related?), the trigger that should launch harpoons to anchor the lander did not execute. That is why it did not land, but bounce off again.
Re:Puzzling (Score:5, Informative)
"You would have thought the cold gas thrusters would have been checked out before a landing attempt was made."
What made you think they didn't check those?
http://spaceflightnow.com/2014/11/12/comet-landing-is-a-go-despite-thruster-problem/
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Not so much a malfunction as a poor configuration in the face of unexpected circumstances. The comet was apparently *much* softer than planned for, so the pressure sensors didn't pass the threshold to activate.
They were expecting rock, when in fact, they landed in a big pile of dust. Depending on the design of the harpoons, even if they had been triggered in that situation, they might not have had much to hold on to.
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You would have thought the cold gas thrusters would have been checked out before a landing attempt was made.
Oh, well, there we are then. Obviously they just had to have them "checked out" and everything would have worked fine.
Perhaps, though, you'd care to expand that two-word phrase a little, and explain to all of us exactly how you would have ensured that this sensitive piece of scientific equipment could survive a journey of ten years through space to land on a tiny ball of spinning rock and have everything go exactly to plan with absolutely no possibility of failure.
Landing on a comet ain't like dusting crops
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Such a self-test would be very useful, because just like your medical device, they'd just launch one of the other landers they had at hand and send the broken one in for repair.
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Exactly.
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You know what? Pray tell what medical stuff you work on so that I'll never let it anywhere near my body. You're an idiot.
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You would think the engineers would have had such a test for so crucial piece of equipment as the landing restraint system.
Of course they did. Stop being so obtuse.
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ESA had years in transit to check out the spacecraft.
Yeah, and if the thrusters check out to be broken, then what? Do you volunteer to sponsor a repair mission?
You're nuts. Truly, certifiably, nuts.
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I blame the metric system.
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It is puzzling why the lander moved so radically after landing.
Puzzling to you, perhaps, but then you didn't consider the possibility that you're ill-informed.
The landing system failed; had it worked, obviously, the lander would have, well, landed properly.
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The lander has no propulsion. Except for "hold-down" cold gas thrusters that could pin it down temporarily, but failed to fire, and harpoons, that didn't work either, there was nothing on it that could do much to alter its trajectory or retain it on the surface.
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It's a Rock (Score:2)
Where's Jebus' face? (Score:1)
Amazing (Score:4, Insightful)
Speaking as someone who was a little kid during the Apollo era these images are amazing. I feel so fortunate to be alive in the era of solar system and interstellar exploration. Pioneer, Mariner, Viking... it's like seeing what it would look like to walk on other worlds. Visualizing just how far away the Pioneer and Voyager probes are is mind-bending. And to see new views of Pluto... it's just so awesome. :)
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How do we develop competency in space without, you know, going into space?
Also, the money was spent on other taxpayers. The equipment is made by people who got paid using materials that were made by people who got paid. It's not like we threw cash into space - we gave cash to people in return for a fancy piece of equipment. The money, meanwhile, was spent on groceries and heating bills, and iPhones, trash bins, and shovels, and kayaks, and a bunch of other things.
Fantastic pictures (Score:2)
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someone needs to color this shit for me.