Rosetta space mission - Philae probe due to land on comet on 12th Nov 2014

[2hats]

To provide an idea of how dark the comet nucleus is see this ESA model of it (left hand side) which has to be heavily overexposed to see any details (right hand side):

 

[bi0boy]

Wasn't the solar-panel-not-getting-enough-sun problem reasonably foreseeable with a small irregular object like a comet?

Is there a reason they didn't put some plutonium on board to power things like they did with the Voyager probes, which are still happily communicating?

 

[2hats]

Is there a reason they didn't put some plutonium on board to power things like they did with the Voyager probes, which are still happily communicating?

ESA hasn't developed RTG technology, largely for political reasons.

 

[2hats]

Wasn't the solar-panel-not-getting-enough-sun problem reasonably foreseeable with a small irregular object like a comet?

Also - it was hence the two batteries on board which were (are) sufficient to complete the primary lander science programme.

 

[brogdale]

On "PM" Eddie Mair just asked an ESA bod what it's like having a probe where the sun don't shine.

 

[gentlegreen]

On "PM" Eddie Mair just asked an ESA bod what it's like having a probe where the sun don't shine.

The Home Service isn't what it used to be.
Bring back Ken Sykora.!

 

[SpookyFrank]

Currently they are radio range finding from orbiter to lander to locate it. Not sure yet if the drilling overnight has moved the lander. If they manage to get one further communication window with it this evening, and there is sufficient power left, they will try slewing the craft using the landing gear to orientate it into a more favourable charging position. Data from the lander should start flowing again around 0920UTC when the orbiter maneuvers for communications.

Someone has cooked up a nice little graphic of all the solar system bodies that have been landed upon:

Did we technically land on Earth or have we just been here all along?

 

[2hats]

Did we technically land on Earth or have we just been here all along?

I've definitely landed. Repeatedly.

 

[2hats]

Suggestion that the lander 'impacted' part of the wall of 'rock' it now finds itself largely surrounded by and that brought it to rest where it currently is:

The albedo of those patches certainly appears to differ from the rest of the material around the lander. Perhaps smoothed by soft impact.

In other news - one failed instrument - APXS (Alpha Proton X-ray Spectrometer designed to analyse cometary dust). It worked but data indicate it measured the spectrum of its own copper-titanium cover implying that failed to open.

Contact might be re-established around 2130UTC.

 

[StoneRoad]

That is quite a dent !
So that is about 80% of the experiments have worked - at least to some extent ?

 

[Crispy]

That is quite a dent !
So that is about 80% of the experiments have worked - at least to some extent ?

Looks that way. But not everything's had a chance to send its data back to Rosetta yet. They estimated 100Wh of power left in the battery at the last communication, and budgeted 80Wh for the science. The remaining 20Wh are for transmitting the data and (maybe? I don't know if this is actually being done?) giving something a wiggle to see if the lander can be moved to a nicer position.

EDIT: I can't remember where I got those 80 and 100 numbers from. Might be making it up. We'l know for sure this evening.

 

[2hats]

So that is about 80% of the experiments have worked - at least to some extent ?

100% of the instruments work. One appears to have collected no useful data. The view from the project leads is they have something like 80-90% of the science data that they originally planned to collect.

 

[2hats]

(maybe? I don't know if this is actually being done?) giving something a wiggle to see if the lander can be moved to a nicer position.

Yes. I think that has been added to the sequence as the final act.

 

[StoneRoad]

100% of the instruments work. One appears to have collected no useful data. The view from the project leads is they have something like 80-90% of the science data that they originally planned to collect.

That is better than I expected - very good news, hope that the last useful command will be to "hibernate" until the batteries are recharged - which could take a while, given the current orientation to the sun.

 

[alsoknownas]

That is better than I expected - very good news, hope that the last useful command will be to "hibernate" until the batteries are recharged - which could take a while, given the current orientation to the sun.

Don't think they can hibernate and sit and wait cos it all gets obliterated when it gets closer to the sun further down the line. You can tell I'm very technical, eh?

 

[StoneRoad]

I would hope that there will be an opportunity long enough between enough light to do battery recharging and getting too hot for some more science .................

 

[2hats]

When the power is almost exhausted I think it will just drop in to a hibernation mode and wait until it has sufficient to power up. Whether it succumbs to thermal excesses or the part of the nucleus it is sitting on sublimates/falls apart prior to that is anyone's guess. Even so, it could yet end up somewhere else on the surface or near to the surface, in sunlight, charge and then attempt to phone home. So provided Rosetta listens out periodically...

 

[farmerbarleymow]

Fingers crossed. I actually went to sleep last night feeling some kind of strange empathy with the little lander stuck on a remote chunk of rock millions of miles away.

Isn't it just! I'm always mentally willing the little bugger on.

 

[2hats]

The first touchdown site has been spotted in the imagery and agrees with flight dynamics' estimated trajectory (to within 10m):

 

[2hats]

Lander signal momentarily acquired.

e2a: stable signal back I think.

2e2a: yes, stable, data flowing, happy faces in the operations centre.

 

[2hats]

Data downloaded. Now uploading a sequence to instruct Philae to re-orient itself.

 

[Crispy]

BAD TIME: 0

 

[2hats]

The drill (SD2) went all the way down and all the way back (so presumably retrieved a sample for on board analysis):

 

[TheHoodedClaw]

Data downloaded. Now uploading a sequence to instruct Philae to re-orient itself.

This is a "Hail Mary" pass, I guess.

 

[chemn]

The drill (SD2) went all the way down and all the way back (so presumably retrieved a sample for on board analysis)

How long until we know I wonder? Wouldn't presuming be optimistic? Or are they fairly sure that the surface below is within reach of the drill?

 

[2hats]

35 degree rotation successful?

e2a: seems so. Battery levels reported as good.

 

[2hats]

Uh oh. Bus voltage reported as falling off rapidly. Lights might go out shortly...

e2a: charge on secondary battery is slowly climbing:


but voltages are dropping (closing towards the hibernation trigger):

 

[TheHoodedClaw]

 

[2hats]

Momentary loss of radio link...

 

[Crispy]

Agonising!