Space

Philae bounce on comet landing may cut mission short

Philae bounce on comet landing...
First surface image from Philae after comet landing (Image; ESA)
First surface image from Philae after comet landing (Image; ESA)
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Panorama of Philae landing site with lander superimposed (Image; ESA)
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Panorama of Philae landing site with lander superimposed (Image; ESA)
Panorama of Philae landing site (Image; ESA)
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Panorama of Philae landing site (Image; ESA)
First surface image from Philae after comet landing (Image; ESA)
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First surface image from Philae after comet landing (Image; ESA)
How Philae was supposed to anchor itself to the comet (Image; ESA)
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How Philae was supposed to anchor itself to the comet (Image; ESA)
Diagram of Philae (Image; ESA)
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Diagram of Philae (Image; ESA)
Artist's impression of Philae on the surface of 67/P
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Artist's impression of Philae on the surface of 67/P
Philae's first landing site and probable current position (Image; ESA)
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Philae's first landing site and probable current position (Image; ESA)
Close up of the first landing site as seen from Rosetta
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Close up of the first landing site as seen from Rosetta

During Wednesday’s historic landing on comet 67P/Churyumov-Gerasimenko, the European Space Agency (ESA) Philae lander suffered a setback that may cut its mission short. Due to equipment malfunctions, the unmanned, washing machine-sized lander failed to secure itself to the surface of the comet. In the 1/100,000 gravity, Philae bounced back into space twice, eventually landing in a hole about a kilometer (0.6 mi) from its designated landing area, where its batteries may not be able to charge properly.

The problems began during the powering up sequence before Philae separated from the Rosetta mothership on Wednesday morning. A fault was discovered in the cold-gas rocket system designed to keep the lander in contact with 67/P until its harpoons could fire and anchor it to the surface. However, mission control in Darmstadt, Germany, regarded the fault as minor enough to allow the landing to proceed.

At 15:34 GMT (lander time), Philae made contact with the comet after a seven-hour freefall descent. At first, the landing seemed a success except for some expected communication breaks, but later study of telemetry indicated that all did not go as planned.

Panorama of Philae landing site (Image; ESA)
Panorama of Philae landing site (Image; ESA)

As programmed, the screws on the feet of the lander’s legs tried to dig into the crust, but were unable to gain a purchase. Worse, for some still unknown reason, the harpoons failed to fire and Philae bounced back into space. It rose to an altitude of about a kilometer, then descended, bounced again at 17:25, rose to a much lower altitude, turned, then came to rest at 17:32 in a hole or crevice 6 ft (2 m) across and 6 ft deep.

ESA says that Philae is stable, but unanchored on the comet’s surface. It is lying on its side and has only two of its three legs in contact. Telemetry indicates that the lander was in shadow throughout the cometary night. However, its battery is charged, its instruments are functioning, and it is sending back the first close up images ever from a comet.

ESA scientists estimate that in its new position Philae is only receiving 1.5 hours of sunlight in 24 hours. If that is the case, the 60-hour charge in its batteries will run out no later than Saturday afternoon. The Philae team is currently studying its options.

Source: ESA

7 comments
MattII
Well, everything carries a risk.
James Smith
Despite the unexpected, this is still an astounding achievement. Even small things learned from this mission may lead to great things. Truly, we are living in the next great age of discovery.
Paul Anthony
"mission control in Darmstadt, Germany, regarded the fault as minor enough to allow the landing to proceed", surely this is not just impatience, but rather that they had no solution to the problem or no other choice.
CaptD
They landed on the Comet and everything else is an added bonus... SATUTE TO THE ENTIRE TEAM and to the ESA for leading the way!
Rehab
Often more is learned from set backs than easy success. Imagine where we will be in 10 years. It appears the big brains are starting to understand that robotics are what will make it possible for humans to live upon other worlds, not manned space travel. Look how long this mission took, impossible with humans on board. Let machines build are future worlds and we will go!
Gregg Eshelman
Next time maybe they'll design a lander that it doesn't matter which side is up. Make it so that it's wide and flat and will fall upright onto either flat side. Could even put some jets on it to flip it around so different instruments could be on either side. "Philae Bounce" If this was the 50's that would probably be the latest dance craze. ;-)
Derek Howe
So I was semi-successful. It kinda sounds like gentle crash landing. If a guy jumping a row of cars on a dirt bike and jumps over all the cars, but during the landing he bounces a few times and then lands on his side, and now doesn't have long to live........I don't think we would classify his attempt as a "Success".