Rosetta comet chaser completes "big burn"

NeVeR

yipeeeee wrote: »

Amazing we can communicate with something 300 milllion miles away, just think about that.

Fascinating.

Ya think they are on the meteor network......




I'll get my coat !

Alun

Latest media briefing due to start at 13:00 on rosetta.esa.int !

BarryD

"We haven’t entirely located it. It’s not very close to the landing site we wanted but its not very far away. When we discussed the landing site we chose one, but we explored several sites. We are sort of on the other side of the B site. Probably."

Jean Pierre Bibring, Philae Lead Scientist

Hmm - you'd think the cameras on Rosetta itself might be able to identify it?? Presumably otherwise they can do some form of trilateration using the radio signals to plot it's position?? Presumably they know the location of Rosetta fairly accurately.

Javan

BarryD wrote: »

"We haven’t entirely located it. It’s not very close to the landing site we wanted but its not very far away. When we discussed the landing site we chose one, but we explored several sites. We are sort of on the other side of the B site. Probably."

Jean Pierre Bibring, Philae Lead Scientist

Hmm - you'd think the cameras on Rosetta itself might be able to identify it?? Presumably otherwise they can do some form of trilateration using the radio signals to plot it's position?? Presumably they know the location of Rosetta fairly accurately.

The Rosetta camera is not able to resolve something as small as the lander from the orbital height.
The images taken from 10km have a resolution of about 83cm per pixel. At that resolution the lander would be about a single pixel.
The current orbit is higher than 10 km, so the lander would be smaller than a single pixel.


.. of course I could be wrong! that Osiris scientist seemed confident of actually imaging the lander from the orbiter.

Nolars

https://twitter.com/Philae2014/status/532892983755309056/photo/1

shedweller

Nolars wrote: »

https://twitter.com/Philae2014/status/532892983755309056/photo/1

Taken 40m from the surface. Was that on the way down or up, i wonder??

josip

shedweller wrote: »

Taken 40m from the surface. Was that on the way down or up, i wonder??

I would guess on the way down given that the surface doesn't look disturbed.
Pity it didn't stick there, looks like a nice spot.

josip

So the Philae positives

• The camera works
• It has comms to Rosetta
• The batteries are working

The negatives

• Of the 3 different mechanisms for securing it to the comet none of them worked/were effective
• Its orientation on the comet is unknown, it could be on its side since only 2 legs are in contact with the surface of the comet
• It could have as little as 30 hours of battery life left
• Its not getting enough light to recharge its batteries

These are the instruments on board.

APXS The Alpha Particle X-ray Spectrometer detects alpha particles and X-rays, which provide information on the elemental composition of the comet's surface. The instrument is an improved version of the APXS of the Mars Pathfinder.
COSAC The COmetary SAmpling and Composition instrument is a combined gas chromatograph and time-of-flight mass spectrometer to perform analysis of soil samples and determine the content of volatile components.
Ptolemy An instrument measuring stable isotope ratios of key volatiles on the comet's nucleus.
ÇIVA The Comet Nucleus Infrared and Visible Analyzer is a group of six identical micro-cameras that take panoramic pictures of the surface. Each camera has a 1024×1024 pixel CCD detector. A spectrometer studies the composition, texture and albedo (reflectivity) of samples collected from the surface.
ROLIS The Rosetta Lander Imaging System is a CCD camera that will obtain high-resolution images during descent and stereo panoramic images of areas sampled by other instruments. The CCD detector consists of 1024×1024 pixels.
CONSERT The COmet Nucleus Sounding Experiment by Radiowave Transmission experiment will use electromagnetic wave propagation to determine the comet's internal structure. A radar on Rosetta will transmit a signal through the nucleus to be received by a detector on Philae.
MUPUS The MUlti-PUrpose Sensors for Surface and Sub-Surface Science instrument will measure the density, thermal and mechanical properties of the comet's surface.
ROMAP The Rosetta Lander Magnetometer and Plasma Monitor is a magnetometer and plasma sensor to study the nucleus' magnetic field and its interactions with the solar wind.
SESAME The Surface Electric Sounding and Acoustic Monitoring Experiments will use three instruments to measure properties of the comet's outer layers. The Cometary Acoustic Sounding Surface Experiment (CASSE) measures the way in which sound travels through the surface. The Permittivity Probe (PP) investigates its electrical characteristics, and the Dust Impact Monitor (DIM) measures dust falling back to the surface
SD2 The Drill, Sample, and Distribution subsystem obtains soil samples from the comet at depths of 0 to 230 millimetres (0.0 to 9.1 in) and distributes them to the Ptolemy, COSAC, and ÇIVA subsystems for analyses.

If we exclude any instrument that would be inoperable if the lander is on its side that just leaves ROLIS, CONSERT, MUPUS and ROMAP as instruments that could still work from my very basic analysis of the lander design.

2 components of the lander have worked (ROLIS and Radio Comms) and 2 have not worked (Thruster and Harpoon firing) so from that I'm extrapolating, very tenuously, a 50% failure rate of instrumentation. Which after 10 years of cosmic rays wouldn't be bad.

So 2 of the 4 instruments would be expected to work.
And one of those is the already working ROLIS, so that just leaves one other of CONSERT, MUPUS and ROMAP.

Too pesimistic?
Or too optimistic?

Javan

josip wrote: »

So the Philae positives

• The camera works
• It has comms to Rosetta
• The batteries are working

The negatives

• Of the 3 different mechanisms for securing it to the comet none of them worked/were effective
• Its orientation on the comet is unknown, it could be on its side since only 2 legs are in contact with the surface of the comet
• It could have as little as 30 hours of battery life left
• Its not getting enough light to recharge its batteries

These are the instruments on board.



If we exclude any instrument that would be inoperable if the lander is on its side that just leaves ROLIS, CONSERT, MUPUS and ROMAP as instruments that could still work from my very basic analysis of the lander design.

2 components of the lander have worked (ROLIS and Radio Comms) and 2 have not worked (Thruster and Harpoon firing) so from that I'm extrapolating, very tenuously, a 50% failure rate of instrumentation. Which after 10 years of cosmic rays wouldn't be bad.

So 2 of the 4 instruments would be expected to work.
And one of those is the already working ROLIS, so that just leaves one other of CONSERT, MUPUS and ROMAP.

Too pesimistic?
Or too optimistic?

We know that ÇIVA, ROLIS and CONSERT are working, and I think I heard that ROMAP was working also.

The experiments that are most in doubt are those that require mechanical action. With no anchor they are understandably reluctant to start changing the balance by moving stuff about.

shedweller

If it is indeed on its side then they may just do all the science they can with what they have. There may be a chance of drilling at the end but it depends on the orientation of Philae and whats under it. It may be whats causing it to be tilted over so it may then be drillable! Last resort stuff of course.
If theres empty space under the lander then as a last resort after all experiments are done i think they should fire the harpoon if at all possible to see if they can right the lander. As i said, it's all very last resort stuff but i would certainly do it when all else is done.
Another thing, whats the story with the flywheel(s)? If there's more than one could they use them to right Philae? I'm thinking they are fixed inside so it may not be possible. But if they can tilt and move like in hubble et al then theres a chance they could right Philae that way.
Given the potential loss of solar panels and definite loss of solar gain based on where it landed, their options for any of the above are severely limited.
Exciting times though!:)

Stargate

shedweller wrote: »

If it is indeed on its side then they may just do all the science they can with what they have. There may be a chance of drilling at the end but it depends on the orientation of Philae and whats under it. It may be whats causing it to be tilted over so it may then be drillable! Last resort stuff of course.
If theres empty space under the lander then as a last resort after all experiments are done i think they should fire the harpoon if at all possible to see if they can right the lander. As i said, it's all very last resort stuff but i would certainly do it when all else is done.
Another thing, whats the story with the flywheel(s)? If there's more than one could they use them to right Philae? I'm thinking they are fixed inside so it may not be possible. But if they can tilt and move like in hubble et al then theres a chance they could right Philae that way.
Given the potential loss of solar panels and definite loss of solar gain based on where it landed, their options for any of the above are severely limited.
Exciting times though!:)

I would hope Philae can do a " Spirit and Opportunity " and surprise us all .

Come on baby we are with you ! :P

mickmackey1

shedweller wrote: »

If theres empty space under the lander then as a last resort after all experiments are done i think they should fire the harpoon if at all possible to see if they can right the lander. As i said, it's all very last resort stuff but i would certainly do it when all else is done.

They actually said there's a possibility the batteries might be re-energised when the comet's position relative to the sun changes in a few months. So they can't even be sure they're in a last resort scenario

Alun

mickmackey1 wrote: »

They actually said there's a possibility the batteries might be re-energised when the comet's position relative to the sun changes in a few months. So they can't even be sure they're in a last resort scenario

Yes, apparently when the batteries are empty it automatically goes into a deep sleep again, and when/if sufficient solar power is available, it's first used to warm up the internals of the lander and the batteries and when warmed up then starts charging. Once there's sufficient power it then springs into life again automatically.

shedweller

So its not all bad then. Yay!

brevity

I really hope it's going to be okay!

brevity

https://twitter.com/Philae_MUPUS/status/532983269261053952

expectationlost

why is it deploying the thing if its not pointing to the ground?

brevity

expectationlost wrote: »

why is it deployin the thing if its not pointing to the ground?

Maybe it's coming out of the side? Not sure really. Trying to find out more on twitter

Edit:

https://twitter.com/Philae_MUPUS/status/533004149005512704

brevity

https://twitter.com/Philae_MUPUS/status/533011127551393793

brevity

Whoever is manning the twitter account doesn't suffer fools

Keeping an eye on tweets from the @Philae_MUPUS instrument, which will try to move the lander by hammering into the comet #CometLanding

.@rcourt No that is wrong! We will deploy our thermal sensors to take the measurements MUPUS was designed to do.

brevity

https://twitter.com/Philae_MUPUS/status/533021560593219584

There's doins a transpiring

shedweller

Nailbiting! Just back from seeing Interstellar and boy am i wishing i was a spaaacemaaaan!!!

brevity

https://twitter.com/Philae_MUPUS/status/533024295443005442

Seems as though it's started some light hammering similar to this.

Rosetta Lander Philae - Mupus & Sesame First Scie…: http://youtu.be/7Hj5SG-99HE

https://twitter.com/Philae_MUPUS/status/533024553992466433

brevity

https://twitter.com/Philae_MUPUS/status/533040327058534400

shedweller

Awesome. Just awesome. Keep it up lads!

stoneill

Fox: "Why did America waste money landing on a comet?"
Scientist: "This is a European mission."
Fox: "Why didn't America get there first?"

jumbobreakfast

Philae is larger than I thought:
http://www.universetoday.com/114154/how-do-you-land-on-a-comet-very-carefully/

Mickeroo

stoneill wrote: »

Fox: "Why did America waste money landing on a comet?"
Scientist: "This is a European mission."
Fox: "Why didn't America get there first?"

Please tell me that exchange really happened

Harold Finchs Machine

Whats the fascination with twitter?

brevity

Harold Finchs Machine wrote: »

Whats the fascination with twitter?

It's a twitter account manned by a team at ESA. They give information and updates about the various instruments on Philae Lander.