
Rosetta finds oxygen on comet 67P in 'most surprising discovery to date' - Turukawa
http://www.theguardian.com/science/2015/oct/28/rosetta-finds-oxygen-on-comet-67p-in-most-surprising-discovery-to-date
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joshbaptiste
Very cool, planning and calculating a trajectory for a machine to land on a
moving comet 10 years in the future and retrieve data is truly an astonishing
feat.

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ctdonath
And despite its 100kg mass, weighs 1g when landed. That's like using rockets
to position a paperclip.

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deepnet
Philae's gas rocket was jammed, the wax seal had frozen or the sensor had
broken. The pilots wanted an extra day to get it working but they were told
the fanfare had begun and the various Presidents couldn't be disappointed so
they had to launch.

Therefore they had to throw the Philae 'paperclip' exactly right using only
Rosetta's thrusters to toss it toward the comet - no retrorocket to damp
landing, only math.

Calculations were further complicated by 67P's dual lobed masses with Lagrange
points inbetween the two lobes and an low escape velocity of 0.5 metres /
second - practically a 3-body problem. Dr Matt Taylor is an awesome pilot.

Add to this the unexpected surface density (hard ice-crete shell rather than
powdery floof) so the harpoon and leg screws would be worse than useless - it
was an incredible piece of spaceship trajectory design and luck.

Thankfully the anchoring harpoon failed to fire, it would likely have ejected
Philae from the comet.

The extreme reluctance of the OSIRIS team to share high resolution images of
the surface may have complicated the search for Philae ( for which they were
rightly but ineffectively chastised by the head of ESA ).

As the mission nears its close Rosetta will land on the comet and so post-
perihelion close views across the surface will become available.

The 6 CIVAS photos returned from the surface of 67P by Philae IMHO rank
alongside Armstrong's lunar footprint as humanity's greatest artworks.

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Gnewt
Were the power issues with Philae resolved? The last I heard, it was slowly
dying due to insufficient sun exposure, but some people said it might come
back to life when it got closer to the sun -- is this the case?

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ceejayoz
Just for a couple weeks in June/July.

[https://en.wikipedia.org/wiki/Philae_(spacecraft)#Reawakenin...](https://en.wikipedia.org/wiki/Philae_\(spacecraft\)#Reawakening)

