
Rosetta ends its mission - pcrh
http://www.bbc.co.uk/news/live/science-environment-37499184
======
wbhart
They apparently got photos down to 5m (or maybe only 51m) above the comet.
Here are images on the way down.

[https://www.cieletespace.fr/actualites/dernieres-images-
de-r...](https://www.cieletespace.fr/actualites/dernieres-images-de-rosetta-
avant-son-contact-avec-la-comete)

[https://twitter.com/C_et_E_Photos/status/781809777370423296](https://twitter.com/C_et_E_Photos/status/781809777370423296)

[https://twitter.com/ESA_Rosetta/status/781808178048696321](https://twitter.com/ESA_Rosetta/status/781808178048696321)

[https://twitter.com/elakdawalla/status/781809255443673088](https://twitter.com/elakdawalla/status/781809255443673088)

[https://twitter.com/C_et_E_Photos/status/781819361241817088](https://twitter.com/C_et_E_Photos/status/781819361241817088)

[https://twitter.com/ESA_Rosetta/status/781825922647355392](https://twitter.com/ESA_Rosetta/status/781825922647355392)

[https://twitter.com/elakdawalla/status/781834822583017472](https://twitter.com/elakdawalla/status/781834822583017472)

~~~
eric_h
just wanted to add that I highly recommend following @elakdawalla on twitter -
she tweets lots of great things about the various space missions that are in
progress.

~~~
idlewords
She is an absolute treasure. Her longer-form blog posts are also fantastic
reading [http://www.planetary.org/blogs/emily-
lakdawalla/](http://www.planetary.org/blogs/emily-lakdawalla/)

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mino
I found this FAQ very informative:

[http://www.esa.int/Our_Activities/Space_Science/Rosetta/Rose...](http://www.esa.int/Our_Activities/Space_Science/Rosetta/Rosetta_s_grand_finale_frequently_asked_questions)

Also, the per-instrument bitrate breakdown for the last minutes:

[http://blogs.esa.int/rosetta/2016/09/28/science-til-the-
very...](http://blogs.esa.int/rosetta/2016/09/28/science-til-the-very-end/)

Goodbye Rosetta!

------
3chelon
Can anyone explain why they would (a) crash, rather than attempt to land the
probe on the comet's surface, and (b) turn the power off at the moment of
touchdown?

Everything I've read (admittedly, not much) says they will get more data from
crashing it, but that makes no sense to me. Surely landing it as intact as
possible and leaving it running means it could send data whilst it has any
remaining power, and maybe again in the future whenever it gets enough
sunlight? Even if it was just a semi-intact archaeological curiosity for
future generations, surely that would be better than wilfully destroying it?

~~~
JulianMorrison
They "crashed" it at a walking pace, at worst it's a bit twisted, definitely
still an archeological curiosity. Why do that? Probably to try to get close-
approach data that the detachable probe failed to. Why crash? I don't know if
the vehicle even has the capability to retro-thrust itself to a stop but
trying would be a fiddly maneuver and would likely mess up the science
(puffing up an opaque cloud of dust, blasting the landing site). So approach-
and-keep-going makes sense. But then the vehicle will lithobrake with
predictable smashy consequences. So it's toast one way or the other; turning
it off is probably just tidiness.

All the above is guesses but seems to make sense to me.

~~~
datenwolf
> …lithobrake…

Thanks for adding this to my vocabulary.

~~~
ColinDabritz
Seconded, "performed a lithobraking maneuver" is now on my list next to "rapid
unscheduled disassembly".

------
xgbi
I'll know rosetta has "landed" when the XKCD has been updated:
[https://xkcd.com/1446/](https://xkcd.com/1446/)

~~~
mnw21cam
And indeed, it has: [http://xkcd.com/1740/](http://xkcd.com/1740/)

~~~
TuringTest
And Earth is saved!

------
anilgulecha
Our little trouble seem so tiny, when you see something like
[https://pbs.twimg.com/media/Ctk7stYWEAA10jf.jpg:large](https://pbs.twimg.com/media/Ctk7stYWEAA10jf.jpg:large)
and ponder on one of our vessel landing on there.

(Don't astronauts feel a very strong version of this when they look back at
the blue globe from space?)

~~~
asimuvPR
I felt something similar while using a VR headset with space simulator. It
really changed me.

~~~
sixdimensional
I would like to experience this. Could you elaborate - what space simulator
was it and which VR headset? Thank you!

~~~
asimuvPR
It was at a conference. The software was part of a suite of an edtech library.
I don't remember the company. The headset was a Vive.

------
Stratoscope
I love Paul Coxon's tweet of the Rosetta mission told in emoji:

[https://twitter.com/paulcoxon/status/781785896513314816](https://twitter.com/paulcoxon/status/781785896513314816)

------
ljf
I've only been following this news very lightly - but it is fascinating. This
gave me more detail on the 'why' it was being crashed:
[http://www.telegraph.co.uk/news/0/rosetta-mission-what-is-
it...](http://www.telegraph.co.uk/news/0/rosetta-mission-what-is-it-and-when-
will-it-crash-into-a-comet/)

------
thewavelength
I wonder why they uploaded a special software which disallows any
communication prior to the impact [1]. Why don't they just let Rosetta impact
and have a look if it still works? Why is it necessary to shut it down to
disallow command instructions from earth?

[1]
[http://www.esa.int/Our_Activities/Space_Science/Rosetta/Rose...](http://www.esa.int/Our_Activities/Space_Science/Rosetta/Rosetta_s_grand_finale_frequently_asked_questions)

~~~
pducks32
The antenna is incredibly strong (or would be if it got some sunlight) so it's
important to not interfere with communications in deep space that we may want
in the future and even sensors on earth. These scientists—I imagine—fell in
love a long time ago from staring at the deep beauty of space; it'd be quite a
shame if we drowned it out with our petty no-longer-useful noises.

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sandworm101
Wait a second. With every other probe or rover story the experts talk about
how there is no "shutdown" command, that there is no need and that having one
only creates a risk of inadvertent use.

Is this just PR to cover the fact that this probe will be sitting alone in the
dark but still 'alive' should it get enough power? See
[https://xkcd.com/695/](https://xkcd.com/695/)

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flinty
feel strangely emotional about the end of the mission :(

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jankeromnes
GMT is deprecated, please use UTC instead: "GMT is no longer precisely defined
by the scientific community" \-
[https://en.wikipedia.org/wiki/Coordinated_Universal_Time](https://en.wikipedia.org/wiki/Coordinated_Universal_Time)

~~~
willvarfar
Trying to tell the Brits not to use GMT is like trying to tell the HN audience
that there are exactly 1000 bytes in a kilobyte ;)

~~~
_asummers
Or getting Americans on the metric system.

~~~
Toenex
You start by making gun calibres metric. Then they either start using the
metric system or stop using guns. Win either way.

~~~
mirkules
No then we just end up with two standards, like a 9mm caliber which is the
same as the .380 ACP and others (diameter wise)

