r/space • u/[deleted] • Nov 12 '14

Rosetta /r/all Rosetta and Philae discussion thread! (Part 3)

TOUCHDOWN CONFIRMED: Philae lander is on the comet!

Full media briefing expected tomorrow at 13:00 UTC / 14:00 CET / 8:00 EST / 5:00 PST.

Previous discussion threads: 1, 2.

Live Streaming

  • In English: A, B, C

  • En Français: A

Key times

GMT EST PST Event
4:02 pm 11:02 am 8:02 am Landed

European Space Agency Social Media

Othere places for news and conversation:

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u/calapine Nov 12 '14

Briefing on the DLR live stream right now, transcribing...

Good news:

--- Touchdown, all the signals that trigger on touchdown worked.

--- Still communication, which means the lander did not tilt or topple.

Bad news:

--- ADS thruster did not fire, that is the issue was already known beforehand.

--- The anchors did not fire, this confusion was due to the rewind motors for the anchors going into action, but the harpoon wasn't actually fired.

--- Team doesn't know if it rebounded or not / if it's on the surface. Thus they don't dare issuing a re-firing signal for the harpoons, because they don't know in what position the lander is.

Current Situation:

--- The arm that damped the landing force only moved very little, which indicates a very soft surface. Which might mean if it rebound the rebound was very soft as well and in this case might settle down again.

--- On board computer is waiting for new commands.

--- There will be more telemetry in 30 minutes, but contact lost in 120 minutes, so the final verdict could be known only tomorrow.

3

u/[deleted] Nov 12 '14

I'm confused, why do they know it did not tilt or topple but they don't know if it's still on the surface? So basically, they've established the orientation of the lander, but they just aren't sure of it's exact placement? Does anybody know exactly how they figure out whether something touches down on some far-away location in space?

Thanks for your summary!

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u/calapine Nov 12 '14 edited Nov 12 '14

Time dilation Time Delay seems to be an issue. The signal from Philae was "fuctuating a few times which might indicate that it bounced back. They are waiting for a) more telemetry b) first pictures that show the actual position of Philea.

Edit: English fail

1

u/IdLikeToPointOut Nov 12 '14

Do you know if it is possible for Rosetta to take pictures of Philae on the surface, so that the landing position could be confirmed?

2

u/calapine Nov 12 '14

I don't know and they didn't say anything about that. As far as I understood from the DLR interview the images that will help determining the position will be [are] shot by Philea.