
End is nigh for Rosetta: Spacecraft will meet its end by crashing into a comet - Tomte
http://arstechnica.com/science/2016/06/after-brexit-comes-rosexitt-european-scientists-to-end-spacecrafts-life/
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gpvos
The press release itself is more informative:
[http://www.esa.int/Our_Activities/Space_Science/Rosetta/Rose...](http://www.esa.int/Our_Activities/Space_Science/Rosetta/Rosetta_finale_set_for_30_September)

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abpavel
"Commands uploaded in the days before will automatically ensure that the
transmitter as well as all attitude and orbit control units and instruments
are switched off upon impact, to fulfill spacecraft disposal requirements."

Is there a scientific reason for doing this? Keeping the instruments on seems
to be a far more logical option, just in case it survives 50cm/s descend.

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michaelt
According to
[http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/2007002...](http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20070021588.pdf)

    
    
      In 1995 NASA released the first detailed set of orbital
      debris mitigation guidelines [...] One of NASA’s policy
      objectives is to control the amount of orbital debris
      generated by accidental explosions. [...] The NASA safety
      standard goes on to identify typical systems that should
      be passivated, [...] electrical power systems, [...] the 
      discharge of all batteries and their disconnection from
      charging circuits
    

TLDR: Standards written for satellites being left in orbit want to avoid
explosions. This means dumping all fuel and compressed gas - and draining and
disconnecting any batteries.

Doesn't seem all that relevant in the disposal in question, of course; I can't
imagine the standard will make much difference to the amount of debris if the
craft is crashing into a comet anyway.

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Artlav
Huh, i heard them say "controlled descent". That is, they would try to land
the probe on the surface, rather than slam-crash it intentionally.

With the kind of gravity comets have, crashing might be trickier than landing.

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valarauca1
Crashing and Landing are the same operation. It's subjective from the _lander
's_ point of view which occurred. Gravity's role in either is identical :p

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grondilu
Crashing and landing are about as similar as dying and sleeping.

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tokai
So very alike except in intensity and duration?

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SerLava
As far as the individual parts are concerned, it is not at all alike.

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Yuioup
What would be badass is if they try to knock Philae out of its perch so that
it can be in a better solar position.

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Luc
Hmmm... The orbiter is about 10^3 kg, the comet about 10^13 kg, so 10 billion
times heavier. We're gonna need to build up some speed somehow!

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quarterto
Philae is the lander, not the comet.

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Luc
I was thinking cosmic billiards... in retrospect I probably shouldn't have
posted :)

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npongratz
Maybe we'll see a follow-up frame on xkcd's play-by-play:

[https://xkcd.com/1446/](https://xkcd.com/1446/)

This appears to have the full list of frames:

[http://www.explainxkcd.com/wiki/index.php/1446:_Landing/All_...](http://www.explainxkcd.com/wiki/index.php/1446:_Landing/All_pictures)

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strictnein
A flipbook of the second link would be great.

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MalcolmDiggs
Badass; that's how I wanna go.

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J_Darnley
Seconded. A one-way trip to another heavenly body sounds great.

