Rosetta mission: Robot heads towards comet surface

[jwl]

Rosetta mission: Robot heads towards comet surface
By Jonathan Amos
Science correspondent, BBC News, Darmstadt

At 08:35 GMT, the Rosetta satellite released its Philae lander towards Comet 67P/Churyumov-Gerasimenko, a large mass of ice and dust some 510 million km from Earth.

The mission will shine a light on some mysteries surrounding these icy relics from the formation of our Solar System.

Success would be a first for space exploration - no mission has previously made a soft landing on a comet.

The descent should take seven hours, with a signal confirming touchdown received at Earth at around 16:00 GMT.

"It's all down to Isaac Newton and the laws of physics now. Philae is on its way down to the surface," said Prof Mark McCaughrean, senior science adviser at the European Space Agency (Esa).

"If Isaac's friendly to us, we'll have a great landing later today."

Part of the difficulty is the very low gravity on the 4km-wide ice mountain.

Philae needs to be wary of simply bouncing back into space.

As a consequence, on contact it will deploy foot screws and harpoons to try to fasten its position.

It will then take a picture of its surroundings - a strange landscape containing deep pits and tall ice spires.

This is, though, an event with a highly uncertain outcome.

Early on Wednesday (GMT), the third "go/no-go" decision was delayed. The thruster system used to push the robot into the surface of the comet at the moment of touchdown could not be primed.

"We will just have to rely now on the harpoons, the screws in the feet, or the softness of the surface. It doesn't make it any easier, that's for sure," said lander chief Stephan Ulamec, from the German Space Agency.

The terrain that has been chosen for the landing on the rubber-duck-shaped object is far from flat.

Philae could bash into cliffs, topple down a steep slope, or even disappear into a fissure.

Esa's Rosetta mission manager Fred Jansen said that despite these challenges, he was very hopeful of a positive outcome.

"We've analysed the comet, we've analysed the terrain, and we're confident that the risks we have are still in the area of the 75% success ratio that we always felt," he told reporters here at Esa's mission control in Darmstadt, Germany.

And Prof Ian Wright, a leading British scientist working on the lander, said he was determined to be upbeat: "We realise this is a risky venture. In a sense that is part of the excitement of the whole thing. Exploration is like that: you go into the unknown, you're unsure of what you're going to face," he told BBC News.

The prize that awaits a successful landing is immense - the opportunity to sample directly a cosmic wonder.

Comets almost certainly hold vital clues about the original materials that went into building the Solar System more than 4.5 billion years ago.

One theory holds that they may have been responsible for delivering water to the planets.

line
Analysis by Science editor David Shukman

The handshakes are warm but the smiles are brittle here at the European Space Agency's mission control in Darmstadt. As the clock ticks down to the unprecedented attempt at landing on a comet, there's real nervousness in the air.

From the days of the earliest astronauts displaying the Right Stuff, space exploration has always required an ability to remain calm in the face of extraordinary pressure. But managing an audacious operation more than 300 million miles away, with so much uncertainty about the gravitational pull and a potentially treacherous surface, clearly demands more steel than normal.

A sudden influx of reporters and camera teams, and the arrival of VIPs, has added to the sense of drama. It reminds me of Europe's last great venture to touch down on an alien body: the Huygens mission that descended to the surface of Saturn's moon Titan in 2005. That was a triumph, and astounding images were sent back.

Now, with fingers crossed, there's an open admission that the mission's fate is far too hard to call. No-one will say it, but failure is an option, and success almost too exciting to contemplate.

line
Klim Churyumov
The comet's co-discoverer Klim Churyumov is in Darmstadt to follow the landing
Another idea is that they could even have "seeded" the Earth with the chemistry needed to help kick-start biology.

Philae's onboard instrumentation will test some of this thinking at 67P - if it can get down safely, and keep working long enough to run its experiments.

line
Key timings for landing effort (GMT)

• Rosetta delivery manoeuvre - shortly after 06:00

• Latest Go/No-go decision - before 07:35

• Philae separates from Rosetta - 08:35

• Confirmation signal at Earth of separation - 09:03

• Rosetta's post-delivery manoeuvre - 09:15

• Radio connection established - after 10:30

• First data from descending Philae - after 12:00

• Landing of Philae on 67P - after 15:30

• Confirmation signal at Earth - around 16:00

Esa's detailed landing timeline

line
The vast distance between the comet and Earth - 510 million km - means radio commands take almost half-an-hour to reach the spacecraft.

Nonetheless, the flight team had to put Rosetta on a very precise path, to make sure Philae has the best opportunity of arriving squarely in the chosen landing zone.

After being let go, the 100kg robot has no means of adjusting its descent; Philae will go where the comet's gravity pulls it.

Controllers in Darmstadt will want to hear not only that Philae landed in one piece but that it is securely fastened to the comet.

The nature and strength of the surface materials are unknown, however.

Philae could alight upon terrain whose constitution is anything between rock hard and puff-powder soft.

If it can, the robot will endeavour to lock itself in place with screws in its feet and harpoons that fire from its underside.

Esa has cautioned that success may require a large slice of luck in addition to the skill of all the teams involved.

Not only is landing on a comet an untried technique, but Wednesday's effort is also having to rely on some relatively old technologies.

Rosetta was despatched from Earth to catch 67P in 2004. That means it and Philae were designed and built in the 1990s.

And given the conservatism of space engineering, a number of its onboard systems will therefore undoubtedly be 1980s vintage.

But even if the landing attempt fails, the pictures and measurements of 67P acquired by the Rosetta mothership in recent weeks will be enough to re-write the textbooks.

"The real scientific value of this mission is spread all over Rosetta and its instruments, and the lander is just a part of that," explained Esa flight director Andrea Accomazzo.

"The lander is obviously spectacular; it's the thing the public recognise. But already, even before the landing, the scientific return of Rosetta is orders or magnitude above what we knew about comets previously."

http://www.bbc.co.uk/news/science-environment-30012854

[Crown]

Touchdown confirmed, they're not 100% sure if it is tethered yet (harpoons apparently didn't fire or failed), but the sensor on the landing gear show that it was a soft landing and that Philae has 'sunk in' about 4cm.

[Guardsman Bass]

Glad to hear they touched down. I hope it stays down, without the harpoons.

[Irbis]

Some interesting photos/videos: [link]

[GrandMasterTerwynn]

Current updates suggest that it landed three times (the first takeoff attaining an altitude of up to 1 km,) and is possibly sitting on its side now. They're wary of manually commanding the harpoons to fire out of fear that they'll just send the rover lander back into space again. They're also wary of using two of the lander's instruments, because they would require moving the lander.

BBC News story.
Also, Planetary Society senior editor Emily Lakdawalla's Twitter feed is full of up-to-date information on the Philae landing.

[jwl]

Glad to hear they touched down. I hope it stays down, without the harpoons.

It didn't.
https://twitter.com/Philae_ROMAP/status ... 0787896320

However, it appears it may have settled now.

[EnterpriseSovereign]

It would be terrible if after all that effort that it failed- this was what I was worried about when I heard it was on final approach. Whereabouts in the Solar System is the comet loacted anyway?

[LaCroix]

Glad to hear they touched down. I hope it stays down, without the harpoons.

It didn't.
https://twitter.com/Philae_ROMAP/status ... 0787896320

However, it appears it may have settled now.

It was just bouncing in joy...

[Crown]

It would be terrible if after all that effort that it failed- this was what I was worried about when I heard it was on final approach. Whereabouts in the Solar System is the comet loacted anyway?

It orbits between Jupiter and just inside Mar's orbit.

[Irbis]

Whereabouts in the Solar System is the comet loacted anyway?

Exact map is second picture in my link...

[dragon]

Lander has lost power, shutting down to suspended state

Scientific Method / Science & Exploration
Rosetta’s Philae lander has lost power
The spacecraft managed to send back scientific data before it shut down.

by Tiffany Kelly - Nov 15 2014, 3:32pm CST

Share
Tweet

102
Good job on those photos, Philae.
ESA/Rosetta/Philae/CIVA

Rosetta’s lander Philae, which made a historic touchdown on comet 67P/Churyumov-Gerasimenko earlier this week, has run out of battery power, the European Space Agency (ESA) said on Saturday.

In a blog post, ESA said that the lander is now in “idle mode” and it is unlikely that communication will be reestablished in the near future. Contact with the spacecraft was lost at 6:36pm ET on Nov. 14.

Philae was expected to deplete its battery power this weekend, but the event happened a little earlier than planned. The spacecraft had a bouncy landing on the comet on Nov. 12, which placed it in a spot that offered less sunlight to charge its solar panels.

Scientists were in a frenzy to deploy the lander’s instruments before the power went out. According to ESA, Philae transmitted all the data it collected back to Earth before it went to sleep.

"This machine performed magnificently under tough conditions, and we can be fully proud of the incredible scientific success Philae has delivered,” Stephan Ulamec, landing manager for the German Aerospace Agency (DLR), said in a statement.

Before the power went out, the lander sent back some incredible photos—the first ones ever taken on the surface of a comet. Scientists hope that the data sent from the lander can offer some insight on the composition of comets and possibly on the formation of our solar system.

The lander could wake up again if enough sunlight reaches its solar panels.

The Rosetta mission includes a lander and an orbiter. The orbiter will continue to fly over the comet and listen for possible signals coming from the lander.

link

[Lagmonster]

Discussion of sexism in STEM moved to its own SLAM thread.

[Jub]

I sucks that the lander ended up in an area where it can't get enough sun to stay functional. Still that data that they did get is likely to be amazing anyway, and their is still hope that in the weeks and months to come that the can locate the lander or the lander may get enough sun to come back online and do more science.

[Borgholio]

I sucks that the lander ended up in an area where it can't get enough sun to stay functional. Still that data that they did get is likely to be amazing anyway, and their is still hope that in the weeks and months to come that the can locate the lander or the lander may get enough sun to come back online and do more science.

Or when it gets closer, a jet from the comet pushes it back into space. That would be fun to witness.

[Raw Shark]

I sucks that the lander ended up in an area where it can't get enough sun to stay functional. Still that data that they did get is likely to be amazing anyway, and their is still hope that in the weeks and months to come that the can locate the lander or the lander may get enough sun to come back online and do more science.

It seems likely that the lander will get some kind of sun at least once in a while as it careens around with the comet on an elliptical orbit, unless it falls into a hole or something. We'll probably get random bursts of data from around the solar system every few years for a comically long time if nothing destroys it.

[jwl]

Researchers at the European Space Agency are anxiously awaiting their Christmas presents: new pictures of the Philae lander snapped by the orbiting Rosetta spacecraft just a few days ago. They should reveal whether the probe can wake up next year and continue studying comet 67P/Churyumov-Gerasimenko up close.

The exact location of Philae has been a mystery since it came to a rough landing on the comet in November. It came to rest in the shadow of a cliff, keeping its solar panels out of full sunlight and leaving ESA uncertain as to whether the probe would be able to wake up once its initial power supplies ran out.

The team are planning a review to figure out what went wrong. But the latest analysis of data gathered by Philae during its brief waking time on the comet suggest it is receiving just enough sunlight to survive the cold and is very likely to switch on again next year.

The team has created a rough 3D model of Philae's surroundings based on photographs captured after landing that suggests it is nestled between two rocky outcrops. The model suggests that the lander is currently receiving four and a half hours of sunlight a day, providing enough power to keep crucial components warm and run its boot-up sequence, but not enough to actually do science, said lead Philae scientist Jean-Pierre Bibring at the American Geophysical Union meeting in San Francisco, California earlier today.

Here comes the sun

High-resolution images of the landing spot will refine this 3D model and allow the team to predict how much more sunlight will reach Philae as comet 67P gets nearer to the sun. Rosetta pointed its camera in the right area a couple of weeks ago, but at a time when Philae was in shadow. New images taken over the weekend, when the landing area was lit up, are in the queue to be downloaded from Rosetta and should reach Earth in the next few days. "It's a bit like waiting for Christmas presents," said Rosetta scientist Matt Taylor.

"The question of how much power we'll get is really a function of where we are now," said Bibring, who is confident that Philae will be revived, perhaps as early as January, though later in the year is more likely. "My suspicion is that we'll be in a good shape."

If Philae does wake up, its awkward landing could actually be a boon for science. Analysis of the images already received have revealed a number of accessible icy surfaces – more than the probe would have been able to see from a flat landing spot.

"We have a large diversity of materials ahead of us, much larger than we hoped," said Bibring.

"It's a better spot than we could have wished, in terms of science," agreed Taylor.

Nearly all of Philae's instruments should get a second chance at studying the comet, if the probe reactivates. Only the MUPUS penetrator, a rod designed to hammer into the surface and measure the temperature, can't be reused. Bibring hopes to try drilling into the comet's surface, as readings from the previous drilling remain inconclusive. "We can essentially redo all that we had planned to do," he said.

http://www.newscientist.com/article/dn2 ... KhCKyusW8U

Posted 17th December, so the images should be in by now.

[Captain Seafort]

It's woken up again

[Eternal_Freedom]

Awesome!

[SpottedKitty]

There was a bit about this on BBC News just a little while ago. Fascinating — I wonder how much more we'll be able to see now that there's a bit more sunlight in the area of the lander.

[Raw Shark]

Nailed it.

[Eternal_Freedom]

Bizarrely, we had a talk on this very subject at Thursday's Astronomy Society meeting. The guy said "well hopefully it might possibly wake up in the next month or so."

[Borgholio]

Heard about this on the radio. Last info they had was that the lander has enough power for normal operations but they're waiting a bit just to make sure everything is still working. Wouldn't it be need to get close-up pics of the comet out-gassing as it approaches the sun?

[Lagmonster]

I only a month or two ago got my Certificate of Acknowledgement for helping choose the landing site. The contest victory went to one guy, but they sent a special certificate out to everyone who chose the same thing (albeit a little more slowly).

[Jaepheth]

Lots of buzz about how some of the comet's characteristics may be explained by alien microbes:

Link to theguardian.com

Philae comet could be home to alien life, say scientists

Astronomers say features of comet landed on by spacecraft in November, such as black crust and icy lakes, suggest living micro-organisms beneath surface

The comet landed on by the spacecraft Philae could well be home to an abundance of alien microbial life, according to leading astronomers.

Features of the comet, named 67P/Churyumov-Gerasimenko, such as its organic-rich black crust, are most likely explained by the presence of living organisms beneath an icy surface, the scientists have said.

Rosetta, the European spacecraft orbiting the comet, is also said to have picked up strange clusters of organic material that resemble viral particles.

The European Space Agency pulled off a sensational feat of engineering and captured the imagination of space-travel enthusiasts across the world when Philae landed on the comet in November. Since then, the lander has undergone a period of hibernation from which it awoke in June, having recharged its solar panels.

Neither Rosetta nor Philae are equipped to search for direct evidence of life after a proposal to include this in the mission was allegedly laughed out of court. Maverick astronomer and astrobiologist Prof Chandra Wickramasinghe, who was involved in the mission planning 15 years ago, believes people should be more open to the possibility of alien life.

Wickramasinghe said: “Five hundred years ago it was a struggle to have people accept that the Earth was not the centre of the universe. After that revolution our thinking has remained Earth-centred in relation to life and biology. It’s deeply ingrained in our scientific culture and it will take a lot of evidence to kick it over.”

Prof Wickramasinghe’s views are regarded as several steps outside the scientific mainstream. He has previously suggested that the SARS virus arrived to Earth from space and that airborne spores that caused rainfall in Kerala to turn a reddish hue had an extraterrestrial origin.

He and colleague Dr Max Wallis, from the University of Cardiff, believe 67P and other comets like it could provide homes for living microbes similar to the “extremophiles” that inhabit the most inhospitable regions of the Earth.

Comets may have helped to sow the seeds of life on Earth and possibly other planets such as Mars, they argue.

The scientists have carried out computer simulations that suggest microbes could inhabit watery regions of the comet. Organisms containing anti-freeze salts could be active at temperatures as low as -40C, their research shows.

The comet has a black hydrocarbon crust overlaying ice, smooth icy “seas” and flat-bottomed craters containing lakes of re-frozen water overlain with organic debris.
Wickramasinghe said data coming from the comet seems to point to “micro-organisms being involved in the formation of the icy structures, the preponderance of aromatic hydrocarbons, and the very dark surface”.

“These are not easily explained in terms of prebiotic chemistry. The dark material is being constantly replenished as it is boiled off by heat from the sun. Something must be doing that at a fairly prolific rate.”

The astronomers present their case for life on 67P at the Royal Astronomical Society’s National Astronomy Meeting in Llandudno, Wales.

[Borgholio]

It would be very interesting if the first ET life would be found on a comet, as opposed to another planet or a moon.