Rosetta's Comet Landing

[aaronvan]

Philae long-term stability in doubt.

Neither the harpoons nor the ice screws successfully deployed.

Still waiting for surface photos.

 

[Lord Blackadder]

Looks like the lander bounced up to three times, 1Km off the surface of the comet, before coming to rest, possibly on its side, possibly on the edge of a crater.

Lots of issues to deal with - the lander's orientation might not give the solar panels enough sunlight to keep the battery charged. Operating the drills on the legs might help re-orient the craft - or it might knock it into the crater and end the mission.

 

[Michaelgtrusa]

A comet. 510 million kilometers away. Looking so familiar, so unspectacular. This blows my mind. #CometLanding.

 

[decafjava]

A comet. 510 million kilometers away. Looking so familiar, so unspectacular. This blows my mind. #CometLanding.

I know, comets look more interesting with their tail. Astounding stuff indeed.

 

[aaronvan]

I know, comets look more interesting with their tail. Astounding stuff indeed.

Remember, this stuff is the primeval ingredients of the solar system!

 

[MacNut]

Fifty-six hours after landing on the surface of a comet, Philae sent one more round of data about its new home across 310 million miles of space. Then, its power went out.

"@Rosetta, I'm feeling a bit tired, did you get all my data? I might take a nap..." read a message on the @philae2014 Twitter feed.

The Rosetta mission's twitter response: "You've done a great job Philae, something no spacecraft has ever done before."

And then later: "S'ok Philae, I’ve got it from here for now. Rest well..."

All the experiments on board the lander had a chance to run and return information back to Earth. Philae's instruments scooped up material from the comet's surface, took its temperature, sent radio waves through its nucleus, and went hunting for hints of organic material. Cameras took the first panoramic images from the surface of a comet.

Friday morning, ESA officials expressed concern that the lander would not have enough battery power left to send back any more data from experiments it was conducting on its new, icy home.

When Philae landed on the comet on Wednesday, it had enough battery power for about 60 hours of work. Scientists initially hoped that it would continue to operate on solar power, but the lander seemed to have settled in a hole on the comet, where it was surrounded by rock-like structures that block the sun.

Stefan Ulamec, the lander manager from DLR, said the that one of the solar panels on the lander was getting about an hour and 20 minutes of sunlight a day. Two other panels got just 20 to 30 minutes a day, he said.

At a news conference Friday morning before the last signal was received, Ulamec said it was possible that scientists would not hear from the lander again.

"We are hoping to get contact again this evening, but it is not secured," he said. "Maybe the battery will be empty before it talks to us."

Happily, that turned out not to be the case. On Friday evening, ESA reported that all the science experiments had been deployed, and that the lander had been rotated 35 degrees in an attempt to get more sun on one of its larger solar panels.

There is a chance that as the comet flies closer to the sun, the increase in solar energy will allow ESA to communicate with Philae once again.

ESA officials say the odds of that happening are small, but with Philae, the little lander that could, anything is possible.

http://www.latimes.com/science/sciencenow/la-sci-sn-philae-lander-data-20141114-htmlstory.html

 

[localoid]

When comet-landing robots sleep, do they dream of electric sheep?

 

[Scepticalscribe]

An amazing story; a pity that the battery ran down before the benefits of the neatly executed manoeuvre could kick in to hall revive and restore the battery.

Still, absolutely incredible. A fantastic achievement.

 

[aaronvan]

When comet-landing robots sleep, do they dream of electric sheep?

That's a real "********" thing to say.

 

[Huntn]

http://www.latimes.com/science/sciencenow/la-sci-sn-philae-lander-data-20141114-htmlstory.html

Don't comets rotate even a little? And if they don't, I'd think on their journey, there would be sun exposure and opportunities for this lander to get sunlight and it's batteries charged, no?

I'd be concerned about the lander feet lock down not happening when it touched down.

 

[thewitt]

It is getting sunlight, just not much.

 

[MacNut]

Don't comets rotate even a little? And if they don't, I'd think on their journey, there would be sun exposure and opportunities for this lander to get sunlight and it's batteries charged, no?

I'd be concerned about the lander feet lock down not happening when it touched down.

The problem is that it landed in the shadows. So one panel is getting slightly more sun than the other. The hope is that when the comet passes closer to the sun that it may provide more power.

When Philae landed on the comet on Wednesday, it had enough battery power for about 60 hours of work. Scientists initially hoped that it would continue to operate on solar power, but the lander seemed to have settled in a hole on the comet, where it was surrounded by rock-like structures that block the sun.

 

[Huntn]

The problem is that it landed in the shadows. So one panel is getting slightly more sun than the other. The hope is that when the comet passes closer to the sun that it may provide more power.

This is an amazing achievement over 10 years. I assume after separation from it's launch rocket, this lander has a minimal/moderate ability to changed it's velocity and yet it can go out with the proper speed and trajectory to rendezvous with a a comet, I assume is traveling very fast through space.

Rosetta overview/timeline- launched Mar 2004.

 

[Scepticalscribe]

This is an amazing achievement over 10 years. I assume after separation from it's launch rocket, this lander has a minimal/moderate ability to changed it's velocity and yet it can go out with the proper speed and trajectory to rendezvous with a a comet, I assume is traveling very fast through space.

Rosetta overview/timeline- launched Mar 2004.

Agreed, it is an amazing and extraordinarily impressive achievement.

Moreover, it is also a salutary reminder that so much remains as yet unknown in the whole field of space exploration, and, for that matter, so much can go wrong on a mission, that, when it goes right, or mostly right, or somewhat right, it is still a cause for celebration, and worth reminding ourselves that this is knowledge that is always hard earned, no matter how easy it looks, or seems to be. Even now, little in the field of space exploration can be taken for granted.

 

[Gutwrench]

Agreed, it is an amazing and extraordinarily impressive achievement.

Moreover, it is also a salutary reminder that so much remains as yet unknown in the whole field of space exploration, and, for that matter, so much can go wrong on a mission, that, when it goes right, or mostly right, or somewhat right, it is still a cause for celebration, and worth reminding ourselves that this is knowledge that is always hard earned, no matter how easy it looks, or seems to be. Even now, little in the field of space exploration can be taken for granted.

Oh my gosh! With all well earned respect, but, wholly moly, you have propensity to overuse commas, in my, unofficial, but somewhat educated, education.

And maybe, if you are aware, and could be so generously kind, inform, this uninformed reader, of any recommended rule(s), known or otherwise, governing the use, excessive or otherwise, of parenthetical phrases in clear and concise English writing structure?

 

[Huntn]

Oh my gosh! With all well earned respect, but, wholly moly, you have propensity to overuse commas, in my, unofficial, but somewhat educated, education.

And maybe, if you are aware, and could be so generously kind, inform, this uninformed reader, of any recommended rule(s), known or otherwise, governing the use, excessive or otherwise, of parenthetical phrases in clear and concise English writing structure?

There may have been one or two extra commas by my reckoning, but not enough to lament the "propensity to overuse commas" comment. Maybe a less propensity for policing grammar would make a more enjoyable experience for all.

 

[Gutwrench]

You should have seen my prep and college grades when it came to grammar. If you had you'd know I don't police grammar much. I do, however, have a propensity, however lame, to bring a tad of sarcasm and levity to many contributions. Hence my generous, but obviously inadequate, sprinkling of winking emoticons.

Sorry that went over your head, but it is, however, understandable.

 

[juanm]

I don't mind the commas, but for what it's worth, the font she uses is adequate on paper but hard to read on screen. I recall reading a post where she explains she likes it more, though, so if she likes it that much I can live with it. I'm now using Comic Sans, a font universally abhorred, to drive my point home

Back to the comet, now. I wonder what -if any- compromises they do when they choose new but unproven technology to put on a mission so long they have to plan so far into the future.

 

[Scepticalscribe]

I don't mind the commas, but for what it's worth, the font she uses is adequate on paper but hard to read on screen. I recall reading a post where she explains she likes it more, though, so if she likes it that much I can live with it. I'm now using Comic Sans, a font universally abhorred, to drive my point home

Back to the comet, now. I wonder what -if any- compromises they do when they choose new but unproven technology to put on a mission so long.

But my question is do you like Comic Sans? Otherwise, what point are you trying to make?

Of course, I don't much care for Comic Sans - but I don't much care for most fonts which I see online - especially Arial, which I deeply detest.

Re the English language and the writing of English, I will freely admit that I love the language and enjoy using it.

Never mind. It takes all sorts, and all of that……

Nonetheless, if some of the members of the self-appointed grammar police are to take to the ether on a thread that was supposed to be discussing the almost, more-or-less, not entirely successful landing of a probe on a comet, then I would suggest that some of their attention might be better directed towards addressing the grammatical deficiencies and linguistic shortcomings of some of those who do not appear to be overly endowed with tools of basic literacy, you know, full stops, commas, capital letters, punctuation, paragraphs, stuff like that.

Re the comet, I think it is more a case of you fly and plan with the best technology that is available when the mission lifts off and then, hope for the best.

So far, oddly enough, that approach has paid handsome dividends, and there is little point regretting what had not been invented when the launch blasted off.

The Voyager missions, which launched in the 1980s - flying on what subsequently became clear was very, very basic technology - broadcast back a wealth of data on all of the 'gas giants'. Extraordinary.

 

[MacNut]

Oh my gosh! With all well earned respect, but, wholly moly, you have propensity to overuse commas, in my, unofficial, but somewhat educated, education.

And maybe, if you are aware, and could be so generously kind, inform, this uninformed reader, of any recommended rule(s), known or otherwise, governing the use, excessive or otherwise, of parenthetical phrases in clear and concise English writing structure?

I think he was channeling William Shattner.

----------

The Voyager missions, which launched in the 1980s - flying on what subsequently became clear was very, very basic technology - broadcast back a wealth of data on all of the 'gas giants'. Extraordinary. [/SIZE][/FONT]

Wasn't Voyager in the late 70's?

 

[lowendlinux]

You'll never use math in the real world

 

[Scepticalscribe]

I think he was channeling William Shattner.

----------

Wasn't Voyager in the late 70's?

You'll never use math in the real world

No, personally, I always preferred Mr Spock. And I have always found space travel to be absolutely awesome - those who fail to see the glory and wonder of it all must suffer from stunted imaginations, and that is what I assumed this thread was about.

I think the Voyagers were launched in the late 1970s (must double check that), and flew past Jupiter & Saturn in the very early 1980s - 1980, and 1981; the second one subsequently was able to fly past Uranus and Neptune in 1986 and 1989. My point is that I actually recall all this, and remember following it with utter fascination - I was at school when it all started and thought it was simply brilliant.

And, for those of us Across the Pond, it is still the study of mathematics, or maths.

 

[localoid]

Mankind's first-ever probe of a comet found traces of organic molecules and a surface much harder than imagined, scientists said Tuesday of initial sample data from robot lab Philae. The probe's COSAC gas analyser managed to "'sniff' the atmosphere and detect the first organic molecules" shortly after landing.

Read more at: Phys.org

 

[MacNut]

Philae settles in dust covered Ice

The first touchdown recorded by Philae occurred at 15:34 GMT (with the signal arriving on Earth at 16:03 GMT), but it later transpired that the harpoons and ice screws did not deploy as planned and the lander subsequently rebounded, experiencing two further touchdowns, at 17:25 and 17:32 GMT (spacecraft time), respectively.

Because part of the MUPUS package was contained in the harpoons, some temperature and accelerometer data could not be gathered. However, the MUPUS thermal mapper, located on the body of the lander, worked throughout the descent and during all three touchdowns.

At Philae’s final landing spot, the MUPUS probe recorded a temperature of –153°C close to the floor of the lander’s balcony before it was deployed. Then, after deployment, the sensors near the tip cooled by about 10°C over a period of roughly half an hour.

“We think this is either due to radiative transfer of heat to the cold nearby wall seen in the CIVA images or because the probe had been pushed into a cold dust pile,” says Jörg Knollenberg, instrument scientist for MUPUS at DLR.

The probe then started to hammer itself into the subsurface, but was unable to make more than a few millimetres of progress even at the highest power level of the hammer motor.

“If we compare the data with laboratory measurements, we think that the probe encountered a hard surface with strength comparable to that of solid ice,” says Tilman Spohn, principal investigator for MUPUS.

Looking at the results of the thermal mapper and the probe together, the team have made the preliminary assessment that the upper layers of the comet’s surface consist of dust of 10–20 cm thickness, overlaying mechanically strong ice or ice and dust mixtures.

At greater depths, the ice likely becomes more porous, as the overall low density of the nucleus – determined by instruments on the Rosetta orbiter – suggests.

Looking to the future, Tilman Spohn says, “MUPUS could be used again if we get enough power. Then we could perform direct observations of the layer that the probe is standing in and see how it evolves as we get closer to the Sun.”

http://blogs.esa.int/rosetta/2014/11/18/philae-settles-in-dust-covered-ice/

 

[ucfgrad93]

Hopefully we haven't heard the last from the probe. This has been amazing to follow.