Philae comet lander phones home

Philae comet lander phones hom...
Artist's concept of Philae
Artist's concept of Philae
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Diagram of Philae
Diagram of Philae
Artist's concept of Philae
Artist's concept of Philae
Diagram of the Rosetta orbiter
Diagram of the Rosetta orbiter
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After seven months of hibernation and dwindling hopes, the European Space Agency (ESA) has announced that its unmanned Philae comet lander has reestablished contact with the Rosetta mothership and mission control. The European Space Operations Centre in Darmstadt received the first signals on Saturday at 22:28 CEST, indicating that the lander has warmed up and charged its batteries sufficiently to return to active duty.

"Philae is doing very well; it has an operating temperature of minus 35º C (minus 31º F) and has 24 Watts available," says German Aerospace Center (DLR) Philae Project Manager Dr. Stephan Ulamec. "The lander is ready for operations."

ESA says that the washing machine-sized lander has so far sent back 300 data packets outlining its present status during 85 seconds of contact with mission control using the unmanned Rosetta orbiter as a relay. Analysis by DLR indicates that Philae had already been active for some time before contact was reestablished and that another 8,000 packets of data are awaiting download when Rosetta and the lander move back into a favorable position for another transmission.

Diagram of Philae
Diagram of Philae

The Philae lander was the first manmade object to make a soft landing on a comet. On November 12, 2014, it made contact with the surface of Comet 67P/Churyumov-Gerasimenko, but due to a malfunction in its landing systems it was unable to anchor itself. As a result, it rebounded four times before finally coming to rest at an unconfirmed location that has been called Abydos.

Unfortunately, the spacecraft landed on its side next to a cliff wall, where not enough sunlight could reach its solar panels and provide power. After 54 hours, the batteries went dead and Philae went into hibernation 15 November 15, 2014 at 01:15 CET. After a failed attempt to reestablish contact in March, Rosetta has been keeping a watching brief in hopes of the landing waking up. Now that that has happened, the pioneering mission can continue to expand our knowledge of comets. Good news!

Source: ESA

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What an awesome little probe. Go Philae.
Pierre Collet
And thanks to the fact that it is in the shade, it should be able to monitor the comet's outgassing during perihelion (which would have been impossible if it had landed on the originally planned spot, as temperature there was expected to be too hot for Philae as early as last March!)
So it looks like the mishap of the uncontrolled landing is a wonderul bonus, after all!
ESA continue to say that Philae's landing system malfunctioned as the probe did not attach itself to what was expected to be an icy surface. The facts are that several comets have been "inspected" by various space probes and what they have found is far from what the long held consensus on comet composition is. All have been found to be rocky and very dry bodies with substances that could only have been formed in extremely high temperatures which is completely at odds with the icy snowball theories. Philae's landing spikes probably functioned as designed but if they hit rock and not the ice they were designed to perforate then of course the lander rebounded instead of attaching itself to the surface at the first touchdown. In any case it is indeed a fantastic feat but hopefully the comet scientists will begin to realise that what their probes are finding does not correlate with what they have always thought that comets were. They need to rethink their standpoints and accept that presently accepted theories of comet formation are wrong. To my mind, the website has a much more convincing theory of comet (and asteroid) formation and I'm willing to bet that in 5-7 years their explanations will become accepted especially as there will be more and more direct evidence that contradicts the icy snowball origins. Besides recently there was a "sungrazer" comet that passed within 100.000 km of the sun's surface and astronomers where extremely surprised to see it survived and fly back out in it's highly elliptical orbit. This could happen if the comet was made from hard rock but never if it was mostly composed of ice.... So Philae is also not going to see any "outgassing" of water vapor because there is no ice or reservoirs of water under the surface.
Soft landing like this
Dave Lawrence
Go Phil Go . . . . .
Daniel Harbin
On a lighter note the whole 7 months thing sounds like some scifi plot where the lander is abducted and then months later we hear from it again. So expect the lander to come back to earth and unleash an alien bent on world domination.
Why didn't they add one more landing leg at the top of Philae and use a triangular pyramid structure as the landing/attachment assembly? (So four feet in a pyramid shape) That way no matter which way it rolled it would have landed on it's "feet" (3 of them) and then the internal payload could have re-orientated itself to sample the surface. It would also have allowed for re-positioning the solar.