Metro Jacksonville

http://www.newscientist.com/article/dn25995-cometmapping-rosetta-spacecraft-prepares-for-duty.html

Comet-mapping Rosetta spacecraft prepares for duty

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QuoteIf all goes to plan, this week we should be getting our first close-up look at a brand new world. On Wednesday 6 August, the European Space Agency's Rosetta spacecraft will rendezvous with the comet it has been chasing for the past 10 years. Mapping and landing on comet 67P/Churyumov-Gerasimenko will be a challenge unlike anything space explorers have faced before.

"When you go to Mars nowadays, you know everything," says Rosetta flight director Andrea Accomazzo. Not so for Rosetta's target. "We don't know the mass, we don't know the gravity field, we don't know how to fly around this object."

Previous spacecraft have flown by comets at high speed. Rosetta, on receiving ESA's commands, sent today, will slow to just 1 metre per second relative to its destination.

Because the comet's gravity is so weak, Rosetta will initially manoeuvre around it in a series of controlled triangles. These will start at a distance of 100 kilometres and move closer in over the next few weeks as ESA learns more about the comet's structure. Eventually it will enter a proper orbit determined only by gravity, getting as close as 10 kilometres.

Mapping the duck

Pictures released last month have already revealed the comet is made of two pieces fused together in a shape likened to a rubber duck. That means its gravitational pull tugs in strange and unpredictable directions, so creating a detailed 3D model of the comet is a top navigational priority. "We are acquiring hourly images so we can see the body, reconstruct its shape and characterise features of its surface," says Accomazzo.

Missions to asteroids, like NASA's NEAR Shoemaker, have orbited similarly lumpy rocks, but a comet offers new challenges. Gases frozen beneath Churyumov-Gerasimenko's surface could escape explosively as the comet nears the sun and warms up. As they spurt out they will push against Rosetta's solar panels, possibly as strongly as the comet's gravity, but in the opposite direction.

Rosetta is in for a bumpy ride, and there will be no time for ESA researchers to catch their breath. Philae, a smaller probe that has ridden along with Rosetta, must touch down on Churyumov-Gerasimenko's surface by 11 November: any delays will make landing much trickier as the comet becomes increasingly active on its approach to the sun.

Little time
"We have to do this at warp speed. We have very little time between the discovery of a new world and landing," says Holger Sierks, lead researcher on Rosetta's main camera OSIRIS, which will map the comet's surface.

Cartographers know the difficulties involved in wrapping a flat map around a globe, but they can at least lay down lines of latitude and longitude with ease when mapping our planet. "It is more difficult to mosaic a highly irregular body like our rubber ducky," says Sierks. "The whole coordinate system on this body is tricky."

ESA will announce a shortlist of landing sites in September. Data from all of Rosetta's scientific instruments and measurements of how the comet affects the probe's trajectory will influence the eventual choice.

Dark and dusty

According to measurements released last week, the comet's average surface temperature is -70 °C, around 20-30 °C warmer than predicted. That makes it likely that the surface is dark and dusty rather than coated in clean ice. Understanding how the surface temperature changes as the comet nears the sun will be a factor in where to land, as certain sites may become unstable.

One spot that might already be off limits is the "neck" of the duck. Despite being of great scientific interest, it may prove too difficult to touch down on, as gravity may not be acting at a right angle to the surface. "It would be like landing on a slope," says Accomazzo.

For now, we can look forward to the first high-resolution images of Churyumov-Gerasimenko, which should be around 100 times better than those already released and will take an hour for the probe to transmit early on Wednesday morning. "It's the end of a 10-year trip in the solar system and the start of the exploration of a new world," says Accomazzo.

http://www.youtube.com/v/mtumfWiXW9U

The comet, as photographed by the European Space Agency's Rosetta spacecraft, is 2.5 miles wide.
(http://static01.nyt.com/images/2014/08/07/science/space/07comet-cnd/07comet-cnd-master675.jpg)

QuoteEuropean Spacecraft Pulls Alongside Comet
By KENNETH CHANGAUG. 6, 2014

After 10 years and a journey of four billion miles, the European Space Agency's Rosetta spacecraft arrived at its destination on Wednesday for the first extended, close examination of a comet.

A six-minute thruster firing at 5 a.m. Eastern time, the last in a series of 10 over the past few months, slowed Rosetta to the pace of a person walking, about two miles per hour relative to the speed of its target, Comet 67P/Churyumov-Gerasimenko.

"It is like driving a car or a bus on a motorway for 10 years," said Andrea Accomazzo, the flight director, at a post-rendezvous news conference. "Now we've entered downtown. We're downtown and we have to start orienting ourselves. We don't know the town yet, so we have to discover it first."

Over the coming months, Rosetta and its comet, called C-G for short, will plunge together toward the sun.

In November, a small 220-pound lander is to leave the spacecraft, set down on the comet and harpoon itself to the surface, the first time a spacecraft has gently landed on a comet.

At this point, the comet and its shadowing spacecraft are more than 330 million miles from the sun (more than three times as far out as Earth), traveling at 35,000 miles per hour. With the final firing of the thruster, Rosetta was a mere 60 miles from the comet's surface.

"This morning, we hit a milestone, an important milestone of this mission," said Laurence O'Rourke, a member of its science team.

"But this mission isn't just about arriving at a comet," he went on. "It's about studying the comet. It's about placing a lander on a comet, but again the mission does not end there. The science continues. We're trying to follow this comet all around its orbit."

Rosetta is still not close enough to be captured by the comet's gravity, but instead will be flying a triangular path in front of the comet as it maps the surface. It will eventually move within 6.2 miles of the surface and enter orbit around the comet.

Comets, made of ice, dust and rock, are frozen leftovers from the formation of the solar system. Rosetta is named after the Rosetta Stone, the engraved block that was crucial in deciphering Egyptian hieroglyphics, and scientists hope the spacecraft's observations will offer important clues to how the solar system came together 4.5 billion years ago. (Rosetta's lander, Philae, is named for an island in the Nile River.)

Photographs have revealed a surprisingly irregular shape for the two-and-a-half-mile-wide comet, possibly an amalgamation of two icy bodies or a result of uneven weathering during previous trips to the inner solar system. From a distance, the blurry blob looked something like a rubber duck; as the details came into focus, it began to bear a closer resemblance to a knob of ginger flying through space.

At the news conference, Holger Sierks, the principal investigator for Rosetta's high-resolution camera, revealed the latest images, pointing to cliffs, deep shadows and also flat areas with boulders sitting on the surface. "We'll learn in the coming months what this is telling us," he said.

The spacecraft had earlier measured the flow of water vapor streaming off the comet at a rate of about two cups a second, which would fill an Olympic-size swimming pool in about 100 days. As the comet accelerates toward the sun, its surface will warm, and the trickle will grow to a torrent a hundred or a thousand times that size, contributing to the long tail that is characteristic of comets.

Measurements in July put the average surface temperature at minus 94 degrees Fahrenheit, or minus 70 Celsius. That was warm enough to indicate that the surface was not exclusively ice and that some parts were dusty and darker, absorbing more heat from the sun.

An unsolved mystery of Earth is where the water in the oceans came from; some suggest it came from comets. The water in comets from the distant Oort Cloud, far beyond Pluto, does not match the water on Earth, but the water in nearer comets may.

C-G is one of the nearer comets: Its orbit extends not far beyond Jupiter. Scientists should now be able to get a better idea of its composition by measuring temperatures at its surface and a few inches below, and in the gases streaming off the comet, along with the weight of water molecules streaming off it.

Much of the work in the next three months is to find a safe place for Philae to land. Once released from Rosetta, the lander will be pulled down by the comet's gravity and will strike its surface at a couple of miles per hour, like someone walking into a wall. "It's hurting but it doesn't kill you," said Stephan Ulamec, head of the consortium that built the lander.

The harpoons and a thruster will help keep it from bouncing off, although Dr. Ulamec said recent photographs suggested a dusty surface more like cigarette ash or newly fallen snow than hard ice. "But actually we do not know it yet," he said. "We will only find out when we land there."

Designed to operate through 2015, Rosetta and Philae will make observations as the comet makes its nearest approach to the sun a little more than a year from now, at 115 million miles, still outside the orbit of Earth. The comet will remain too dim to be seen by the naked eye.

Other missions to comets have made brief flybys, beginning with the International Sun-Earth Explorer-3 in September 1985. NASA's Deep Impact slammed into a comet in 2005, and another mission, Stardust, has collected particles of dust and returned them to Earth for study.

(ISEE-3 is back in the news, because the spacecraft, still largely working, will zip past Earth again on Sunday.)

The $1.7 billion Rosetta mission will provide a much longer, much closer look at one comet. Instead of taking a brief snapshot, the spacecraft will observe C-G going from a quiescent ball of ice and rock to an active comet spewing out dust and gas and then make before-and-after comparisons.

Launched in March 2004, Rosetta — a boxy structure roughly nine by seven feet, powered by two 47-foot-long solar panels — followed a circuitous route through the solar system, using flybys of the Earth and Mars to fling itself into the same orbital path as Comet C-G. In January, it emerged from a hibernation of two and a half years and began its final approach.

http://www.nytimes.com/2014/08/07/science/space/spacecraft-pulls-alongside-comet.html

Great update BT!!  I had forgotten all about this mission.  Very exciting to watch!

(http://news.bbcimg.co.uk/media/images/77159000/jpg/_77159328_landing.jpg)

QuoteEurope's Rosetta mission, which aims to put a robot on Comet 67P/Churyumov-Gerasimenko, has identified five potential locations for the touchdown.

The choice of sites was driven largely by operational considerations - they are places engineers believe a lander can get down with the least risk.

No-one has attempted to land on a 10-billion-tonne comet before.

The Rosetta probe will despatch its Philae contact robot to 67P's icy surface on 11 November.

The European Space Agency says it will be a one-shot opportunity.

Rosetta and the comet are currently about 400 million km from Earth, making real-time radio control impossible.

Instead, the process will have to be fully automated with commands uploaded several days in advance.

The five sites on the "longlist" were selected at the end of a special meeting convened in Toulouse, France, this past weekend.

Esa project managers were joined by attendees from the space agencies of France (Cnes) and Germany (DLR), which play key roles in the Philae effort.

Instrument principal investigators on the washing machine-sized robot were also there to argue their preferences, as were the engineers, who could explain the technical possibilities.

If one considers the comet to look like a rubber duck, then three of the chosen potentials (B, I and J) are on the head. Two are on the body (A and C). The dramatic neck region has been ruled out.

The letter designation stems from an even longer list of 10 that was used to kick-off the whole selection process. The letter ordering carries no weight.

A landing site needs to be relatively flat and free from boulders and fissures.
One key requirement has been the need to find places on the comet that experience something of a day/night cycle.

This will give not only a better appreciation of the changing behaviour of 67P under all conditions, but will provide the lander with some important protection - from too much sun, which could lead to overheating, or too little light, which would make it difficult to charge the batteries.

The engineers have also emphasised the need to find locations where Rosetta can deliver Philae at the right altitude and velocity, and maintain a communications link throughout the descent, which is likely to take several hours.
The longlist will be reduced to a leading candidate and perhaps a couple of back-ups in mid-September.

A final go/no-go decision on a target landing site is expected by mid-October.

By then, Rosetta's cameras and other instruments will have returned detailed data on the number one choice.

Comet 67P has very little gravitational attraction - several hundred thousand times weaker than what Philae would experience at the Earth's surface.

For this reason, it will touch down at no more than a walking pace - about 1m/s.

It will use harpoons and ice screws to try to hang on to the comet and avoid bouncing back into space.
(http://news.bbcimg.co.uk/media/images/77093000/jpg/_77093269_77093268.jpg)

http://www.bbc.com/news/science-environment-28923010

http://www.newscientist.com/article/dn26177-no-easy-parking-spot-for-firstever-comet-landing.html#.VBBsM9rD-1s

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QuoteNo easy parking spot for first-ever comet landing
16:25 09 September 2014 by Stuart Clark

Landing on a comet will be even harder than we thought. The strange shape of comet 67P/Churyumov-Gerasimenko does not present as many safe landing sites for the European Space Agency's Rosetta spacecraft as mission planners had hoped.

"Its shape is exciting scientifically but it [creates] a lot of challenges," says project scientist Matt Taylor at the European Space Research and Technology Centre in Noordwijk, the Netherlands. He calls the comet "the duck" because from some angles it resembles a rubber one.

The probe arrived at 67P on 6 August after a 10-year journeyMovie Camera. The plan is to release a probe called Philae to land on the comet's surface on 11 November. ESA announced five candidate touchdown sites on 25 August, but on 8 September at the European Planetary Sciences Congress in Cascais, Portugal, the team admitted that none of the sites looked very safe.

"All landing sites are worse than expected because of the shape of the body," said the lander's lead scientist, Hermann Böhnhardt of the Max Planck Institute for Solar System Research in Göttingen, Germany.

Worse means smaller. Philae is designed to land within an ellipse 1 kilometre in length. Of the five shortlisted sites, only site B (pictured below), at the "head" of the duck, meets that requirement. There are some larger, smoother sites on the base of the duck's "body" but they are too poorly lit to let the lander recharge its batteries during its four-month mission.

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New images from Rosetta's high-res camera reveal what appear to be layered cliffs across the comet. These are good for determining the comet's history, but could damage Philae if it hits them.

Once Philae leaves Rosetta, there will be no chance to alter its trajectory. It will take 5 to 8 hours to drift to the surface under the comet's weak gravity. Should it hit rough ground and tumble on to its side, some science may still be possible, but settling upside-down would almost certainly spell doom for the lander mission.

Meanwhile, Rosetta has captured its first grains ejected by the comet and shown that such emissions vary throughout its 12.4-hour day. 67P ejects most particles in the afternoon from the duck's "neck". Examining this site could help show if the comet began life as one body or two.

Can't wait for the landing! 

http://www.newscientist.com/article/dn26212-rosetta-landing-site-chosen-for-first-comet-mission.html#.VBbzDNrD-1s

QuoteRosetta: landing site chosen for first comet mission
13:04 15 September 2014 by  Jacob Aron

When it comes to comets, J marks the spot. The European Space Agency has announced the landing site for its Rosetta mission to comet 67P/Churyumov-Gerasimenko, following a meeting this weekend to whittle down a shortlist of five possibilities.

The J landing spot, on the "head" of the comet, was chosen for having the smoothest surface, but that doesn't mean Rosetta's lander probe, Philae, will touch down without incident. "There are flat areas but there is also rough terrain, there are some cliffs and some boulders," says Stephan Ulamec, who is in charge of Philae. "It is not an easy task."

ESA will hold a public competition to come up with a better name for the landing site.

Philae will be released in mid-November – the exact date will be confirmed later this month – and take seven hours to reach the comet's surface. Rosetta will have to constantly manoeuvreMovie Camera as it orbits 67P to keep in touch with Philae and let ESA monitor the landing process.

Easier landing

If ESA discovers that J is unsuitable between now and November, they have selected a backup site, C. Landing on this spot would give Philae a view of the comet's "neck", which is of high scientific interest, but J won out as the easier place to touch down. Switching to the backup could delay landing by four weeks, as ESA will have to redo its plans for the descent and scientific analysis. "We might be able to skip certain steps, but there is a potential delay," says Rosetta mission manager Fred Jansen.
 
When Philae lands, its first task will be snapping a 360-degree panorama of the surface, along with measurements of the gas pressure and dust distribution at the landing site. Later, it will drill beneath the surface and analyse pristine comet material. It is hoped that Philae will also see jets of gas and dust emerging from nearby pits as the comet heats up as it travels towards the sun.

The comet's duck-like shape makes the job of landing far more complex, says Jansen. Before arriving at 67P, ESA had expected a roughly spherical comet and predicted a 70 to 75 per cent chance of a successful landing. Now it hasn't dared to calculate the odds, as the show must go on regardless. "Lander delivery has to happen for the mission to continue," says Jansen.

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Quote7 Gadgets Rosetta Is Sending To the Surface of the Comet

Last week, the European Space Agency announced a final date—November 11—for when it will release its Rosetta lander, a tiny pod called Philae, down to the surface of the comet. Like a cosmic hobo carrying a stick and bindle, it will travel laden with only the essentials. Thanks to Universe Today, ESA, and NASA, we know what it's bringing.

The tools and instruments that will accompany Philae down to the surface of comet 67P/Churyumov–Gerasimenko are crucial. It's our first chance to truly analyze a comet, and these mechanisms will be responsible for it. Universe Today's Tim Reyes points out that Philae weighs only 220 pounds, so all of the instruments it's bringing are absolutely essential, and have been whittled down to be as light and tiny as possible.
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Photovoltaic Panels

Again, Philae is light—and it doesn't have a whole lot of battery power to work with. So it will bring with it a series of photovoltaic panels, 21 square feet in all, to power all of its busy days spent digging, listening, and analyzing the comet.

Sensors to Listen to the Comet

As part of a package that includes sensors to measure things like permittivity, Philae will also send acoustic waves across the comet using a transmitter! Then, with receivers embedded in its legs, it will measure how they bounce off and through the comet. According to Reyes, they'll also record audio of the "creaks" and "groans" on the surface.
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A Transmitter To Send Radio Through the Comet's Core

ESA's team is interested in what's inside the comet, so they'll use a simple method to get some basic measurements: Radio. While Rosetta orbits around the side of the comet opposite of the lander, it will put out radio waves which Philae will receive and return. Essentially, they're performing tomography—imaging the interior of the comet by sending waves through it and listening to how they distort and move.

A Hammering Arm to Bury Sensors In the Surface

Here's a fascinating one: A mechanical arm will "hammer" up to a foot into the comet's surface with an accelerometer and a thermometer at its tip—measuring not only the thermal makeup, but how deep the hammer can punch before it's stopped. Other sensors will measure the temperature of the comet as it gets closer to the blazing hot sun.
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A Drill

Rosetta and Philae are on a mission to analyze—or "taste," as the ESA says, the dust and ice on the comet. So Philae will use a drill to collect and then transport surface samples to a series of ovens where they'll be studied by the other devices on the lander. Since the little lander doesn't have much power to work with, the ESA says the drill consumes only a hundredth of the power your average drill does. Here's where it's located, shown on a replica of Philae:
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Cameras

A system called CIVA-P (which weighs less than 100 grams!) will shoot color and infrared images of the landing site, while another imaging system called ROLIS will shoot images of the process of landing, along with close-ups of the comet's surface.

A Spectrometer To Measure Chemical Makeup

This device can measure the chemical makeup of samples on comet 67P/Churyumov–Gerasimenko's surface—how much hydrogen or helium exists up (down?) there, for example—by exposing samples to radiation. That radiation creates energy by interacting with the samples, which the spectrometer can measure.
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http://gizmodo.com/7-gadgets-rosetta-is-sending-to-the-surface-of-the-come-1638271065

Rosetta Spacecraft's Comet Companion Is Spouting Jets (Photo)
By Mike Wall, Senior Writer   |   October 03, 2014 07:00am ET

(http://i.space.com/images/i/000/042/610/i02/rosetta-jets-comet-67p.jpg?1412291998)

QuoteA European spacecraft's comet companion is starting to wake up as it gets closer and closer to the sun.

The European Space Agency's Rosetta probe, which arrived in orbit around Comet 67P/Churyumov-Gerasimenko in August after a 10-year deep-space chase, has photographed jets of gas and dust erupting from the icy wanderer's surface.

"The main talking point of this image is the spectacular region of activity at the neck of 67P/C-G," European Space Agency (ESA) officials wrote in a description of the photo, a four-image montage taken on Sept. 26 when Rosetta was 16 miles (26 kilometers) from the comet.

"What we're seeing is the product of ices sublimating and gases escaping from inside the comet, carrying streams of dust out into space," they added. "As the comet gets progressively closer to the sun along its orbit, the surface will become warmer, and the level of activity will increase, producing a vast coma around the nucleus, along with a tail."

The $1.7 billion (1.3 billion euros) Rosetta mission launched in March 2004 and took a circuitous path through space, finally catching up to the 2.5-mile-wide (4 km) Comet 67P on Aug. 6 of this year. On that date, Rosetta became the first probe ever to orbit a comet.

The Rosetta team aims to make some more history soon. On Nov. 12, the probe will deploy a lander called Philae, which will spiral slowly down toward 67P and, if all goes according to plan, become the first robot to make a soft touchdown on a comet. Philae will snap photos and analyze samples of the comet.

Rosetta should continue studying 67P through at least December 2015, observing how the icy body changes as it approaches the sun. The mission's data should reveal a great deal about comet composition and, by extension, the early days of the solar system, mission team members say. (Comets are "time capsules" of material left over from the solar system's formation.)

http://www.space.com/27337-rosetta-spacecraft-comet-jets-photo.html

Seems there's a more than zero chance one of those jets would push Rosetta off the comet, or otherwise damage it.

A small lander named Philae will detach from Rosetta and land on the comet...

OK, knock Philae, the Rosetta lander, off the comet ...

http://www.popsci.com/article/technology/esa-confirms-rosettas-landing-site-rubber-ducky-comet?dom=PSC&loc=recent&lnk=5&con=esa-confirms-rosettas-landing-site-on-rubber-ducky-comet

Quote
ESA Confirms Rosetta's Landing Site On Rubber Ducky Comet

Now comes the hard part: actually landing.

By Loren Grush

Posted 10.15.2014 at 2:03 pm

After more than 10 years of traveling through space, the Rosetta spacecraft -- the first space vehicle to travel to a comet -- is finally taking a load off. Well, part of it is, anyway.

This morning, the European Space Agency confirmed the landing site for Rosetta's lander, Philae, on comet 67P/Churyumov-Gerasimenko. Out of five potential areas for touchdown, a region known as Site J was picked for the historic landing, which is currently scheduled for November 12. Site J is located on the smaller of the comet's "lobes" (or the "head" of the rubber ducky-shaped comet).

The landing will mark the first time a spacecraft has touched down on a comet. But the mission won't exactly be a cakewalk. There's still a lot more to be done before the landing can happen, and comet 67P's weird shape means there's a significant chance the 220-pound lander will more crash than land.

On November 11, the day before the expected touchdown, the flight dynamics team will have to make a series of "Go/No-Go" decisions in order to determine that Rosetta is where it needs to be to deliver Philae safely. Since Rosetta arrived at the comet on August 6, it has been moving closer to the comet body every day. Right now, it's about 10 kilometers away from 67P, which is only 4 kilometers wide itself. But on landing day, the spacecraft will need to be 22.5 kilometers away from the comet's center.

Two hours before Philae is released, Rosetta will perform a short maneuver to ensure the lander is on the right trajectory to land (and not crash).  As of now, Philae's separation is scheduled for 8:35 am GMT, or 3:35 in the morning for those on the East coast. The landing will occur about seven hours after that, but because of the travel signal time between Rosetta and Earth, we won't know if it made it down safely until 28 minutes later.

During its descent to 67P, Philae will take pictures and even perform a few experiments, testing the dust and plasma environment surrounding the comet. Once it makes it to its new home, Philae has about 64 hours of primary battery life to conduct its first sequence of science experiments.

After that, lengthier experiments kind of all depend on how much longer the batteries can last. Philae has solar panels for generating energy, but the team expects that dust will eventually settle on them, complicating the process. Man, if only 67P had an outlet...

Finally, in March 2015, the comet will have moved along its orbit, bringing it much closer to the sun. By that point, Philae will be so hot that it can't continue with its work, and the whole operation will come to an end. But though we will have lost a lander, hopefully we will have gained a significant understanding about the evolution of comets -- and the origins of our Solar System.

(http://www.popsci.com/sites/popsci.com/files/styles/image_full/public/Philae_s_primary_landing_site_from_30_km_node_full_image_2.jpg?itok=lmbDZcrW)

Only a few days away from landing!

http://www.youtube.com/v/4-Wbb9cDeGY

On the edge of my seat!

Me too    8)

Here we go...

http://www.esa.int/Our_Activities/Operations/Live_updates_Rosetta_mission_comet_landing

http://new.livestream.com/esa/cometlanding

This is supercool. I haven't been this excited about a solar system event since the Moon landing (a long time ago)...

It is supercool Irv!  They are having some issues to overcome... had some problems powering up and detaching and the thruster that is supposed to push the lander firmly down on the comet seems to be not working... they will have to rely on a soft landing and the harpoon system to stick the landing...  8)

Philae has detached and on her own...


(http://blogs.esa.int/rosetta/files/2014/11/CIVA_Farewell.jpg)

QuoteThe image was taken with the lander's CIVA-P imaging system and captures one of Rosetta's 14 metre-long solar arrays. It was stored onboard the lander until the radio link was established with Rosetta around two hours after separation, and then relayed to Earth.

The lander separated from the orbiter at 09:03 GMT/10:03 CET and is expected to touch down on Comet 67P/Churyumov–Gerasimenko seven hours later. Confirmation of a successful touchdown is expected in a one-hour window centred on 16:02 GMT / 17:02 CET.

Timeline...

Quote12/11 09:03:20 10:03:20 PHILAE SEPARATION (Forecast; 94-sec window)
Separation confirmation received on ground via ESA's NNO New Norcia station
12/11 09:04:12 10:04:12 Lander (ÇIVA) obtains first images of Orbiter (FAREWELL1)
12/11 09:06:17 10:06:17 Lander (ÇIVA) obtains seconds images of Orbiter (FAREWELL2)
12/11 09:12:17 10:12:17 Lander / Orbiter separation distance now ~100m
Earliest autodeployment of landing gear and ROMAP boom antenna
12/11 09:25:50 10:25:50 Lander starts rotation of 14 degrees to stable landing orientation
12/11 09:43:20 10:43:20 Rosetta performs post-delivery manoeuvre
Burn will be followed by loss of signal due to subsequent slew back to nominal pointing
Manoeuvre magnitude to be determined on 12/11
12/11 09:47:17 10:47:17 Lander completes all post-separation activities
12/11 10:53:20 11:53:20 Acquisition of signal (AOS) from Rosetta
Expected AOS; link with Rosetta now re-established
12/11 11:59:20 12:59:20 Start of stored data downlink from Rosetta & Philae
12/11 12:20:00 13:20:00 EOT DSN Canberra
12/11 13:15:00 14:15:00 BOT DSN Madrid
12/11 13:55:00 14:55:00 BOT ESA MLG
12/11 14:27:00 15:27:00 EOT NNO
12/11 14:58:57 15:58:57 Lander - switch-on Anchor & CivaRolis

12/11 15:01:57 16:01:57 Lander - start imaging landing site and switch on ADS (Active Descent System)
12/11 15:07:02 16:07:02 ROLIS begins imaging
12/11 15:17:15 16:17:15 On board Lander, systems conduct final pre-touch-down operations
12/11 15:22:20 16:22:20 Start of Lander touch-down window
12/11 16:02:20 17:02:20 EXPECTED LANDING and receipt of signal (Forecast; 40 min variability) 
12/11 - - Upon landing - start post-touch-down operations including:
* ADS thruster fires for ~15 sec to avoid rebound
* Harpoons (X2) fire to secure Lander to surface
* Flywheel off
12/11 16:07:12 17:07:12 ÇIVA-P panoramic imaging on
Lander obtains first images of surface and transmits same (forecast; depends on landing time)
12/11 16:07:14 17:07:14 Separation, Descent & Landing (SDL) science observations continue: Ptolemy & COSAC begin science gathering; data collected during descent and initial surface observations will be uploaded
12/11 16:39:39 17:39:39 Lander completes SDL operations; upload of science data
12/11 17:49:07 18:49:07 Lander begins First Science Sequence (FSS) Block 1; runs about 7 hours
12/11 19:00:00 20:00:00 EOT DSN Madrid
12/11 19:03:00 20:03:00 End of Lander/Orbiter first communication window
13/11 01:43:00 02:43:00 BOT ESA NNO
13/11 02:59:00 03:59:00 EOT ESA MLG

Keen for more details? Download the extended version of this timeline here.

Notes:

BOT Begin of track
EOT End of track
NNO ESA - ESTRACK 35m New Norcia tracking station, Australia
MLG ESA - ESTRACK 35m Malargüe tracking station, Argentina
LDR Philae Lander
ROS Rosetta Orbiter
LCC Lander Control Centre, DLR/Cologne
ESOC Rosetta Control Centre, ESA/Darmstadt
ROLIS Rosetta Lander Imaging System (ROLIS): CCD imager designed to return images of the landing site before and after Philae has landed
ADS Active Descent System (ADS) - this system emits cold gas thrust at touchdown to avoid rebound.
BOT Indicates when station is pointing & ready. Actual acquisition of signal may come only afterwards 
DSS 25 NASA - DSN 34m Goldstone tracking station, California, USA
DSS 45 NASA - DSN 34m Canberra tracking station, Australia
DSS 55 NASA - DSN 34m Madrid tracking station, Spain
DSS 54 NASA - DSN 34m Madrid tracking station, Spain
MVR Manoeuvre - a thruster burn to change direction and/or speed
MSS (Mechanical Support System) is the lander side of Philae which executes the mechanical separation from the orbiter.
ESS ESS (Electrical Support System) is the orbiter part of the lander. The ESS controls the orbiter communication interface with the lander. ESS itself operates as usual as power and data interface to the Orbiter.

Link to Lander science instruments via http://www.esa.int/Our_Activities/Space_Science/Rosetta/Lander_Instruments

Picture of lander Philae from Rosetta descending towards comet...

(https://pbs.twimg.com/media/B2P8u1eCUAAEZ67.jpg)

I think it should be landing in the next few minutes...

http://www.youtube.com/v/szKZ77MbF9Q

SUCCESS!!!!

They have landed and it is communicating... images in a few hours...  8)

(http://blogs.esa.int/rosetta/files/2014/11/CIVAROLIS_FLD_SC_20141112.png)

QuoteThe image shows was acquired during descent on 12 November 2014 at 14:38:41 UT, from a distance of approximately 3 km from the surface. The landing site is imaged with a resolution of about 3m per pixel.

The ROLIS instrument is a down-looking imager that acquires images during the descent and doubles as a multispectral close-up camera after the landing. The aim of the ROLIS experiment is to study the texture and microstructure of the comet's surface.

In the upper right corner a segment of the Philae landing gear is visible.

http://www.esa.int/Our_Activities/Space_Science/Rosetta/Touchdown!_Rosetta_s_Philae_probe_lands_on_comet

Quote

Touchdown! Rosetta's Philae probe lands on comet

12 November 2014
ESA's Rosetta mission has soft-landed its Philae probe on a comet, the first time in history that such an extraordinary feat has been achieved.

After a tense wait during the seven-hour descent to the surface of Comet 67P/Churyumov–Gerasimenko, the signal confirming the successful touchdown arrived on Earth at 16:03 GMT (17:03 CET).

The confirmation was relayed via the Rosetta orbiter to Earth and picked up simultaneously by ESA's ground station in Malargüe, Argentina and NASA's station in Madrid, Spain. The signal was immediately confirmed at ESA's Space Operations Centre, ESOC, in Darmstadt, and DLR's Lander Control Centre in Cologne, both in Germany.

The first data from the lander's instruments were transmitted to the Philae Science, Operations and Navigation Centre at France's CNES space agency in Toulouse.

"Our ambitious Rosetta mission has secured a place in the history books: not only is it the first to rendezvous with and orbit a comet, but it is now also the first to deliver a lander to a comet's surface," noted Jean-Jacques Dordain, ESA's Director General.

"With Rosetta we are opening a door to the origin of planet Earth and fostering a better understanding of our future. ESA and its Rosetta mission partners have achieved something extraordinary today."

"After more than 10 years travelling through space, we're now making the best ever scientific analysis of one of the oldest remnants of our Solar System," said Alvaro Giménez, ESA's Director of Science and Robotic Exploration.

"Decades of preparation have paved the way for today's success, ensuring that Rosetta continues to be a game-changer in cometary science and space exploration."

"We are extremely relieved to be safely on the surface of the comet, especially given the extra challenges that we faced with the health of the lander," said Stephan Ulamec, Philae Lander Manager at the DLR German Aerospace Center.

"In the next hours we'll learn exactly where and how we've landed, and we'll start getting as much science as we can from the surface of this fascinating world."

Rosetta was launched on 2 March 2004 and travelled 6.4 billion kilometres through the Solar System before arriving at the comet on 6 August 2014.

"Rosetta's journey has been a continuous operational challenge, requiring an innovative approach, precision and long experience," said Thomas Reiter, ESA Director of Human Spaceflight and Operations.

"This success is testimony to the outstanding teamwork and the unique knowhow in operating spacecraft acquired at the European Space Agency over the decades." 

The landing site, named Agilkia and located on the head of the bizarre double-lobed object, was chosen just six weeks after arrival based on images and data collected at distances of 30–100 km from the comet. Those first images soon revealed the comet as a world littered with boulders, towering cliffs and daunting precipices and pits, with jets of gas and dust streaming from the surface.

Following a period spent at 10 km to allow further close-up study of the chosen landing site, Rosetta moved onto a more distant trajectory to prepare for Philae's deployment.

Five critical go/no-go decisions were made last night and early this morning, confirming different stages of readiness ahead of separation, along with a final preseparation manoeuvre by the orbiter.

Deployment was confirmed at 09:03 GMT (10:03 CET) at a distance of 22.5km from the centre of the comet. During the seven-hour descent, which was made without propulsion or guidance, Philae took images and recorded information about the comet's environment.

"One of the greatest uncertainties associated with the delivery of the lander was the position of Rosetta at the time of deployment, which was influenced by the activity of the comet at that specific moment, and which in turn could also have affected the lander's descent trajectory," said Sylvain Lodiot, ESA Rosetta Spacecraft Operations Manager.

"Furthermore, we're performing these operations in an environment that we've only just started learning about, 510 million kilometres from Earth."

Touchdown was planned to take place at a speed of around 1 m/s, with the three-legged landing gear absorbing the impact to prevent rebound, and an ice screw in each foot driving into the surface.

But during the final health checks of the lander before separation, a problem was detected with the small thruster on top that was designed to counteract the recoil of the harpoons to push the lander down onto the surface. The conditions of landing – including whether or not the thruster performed – along with the exact location of Philae on the comet are being analysed.

The first images from the surface are being downlinked to Earth and should be available within a few hours of touchdown. 

Over the next 2.5 days, the lander will conduct its primary science mission, assuming that its main battery remains in good health. An extended science phase using the rechargeable secondary battery may be possible, assuming Sun illumination conditions allow and dust settling on the solar panels does not prevent it. This extended phase could last until March 2015, after which conditions inside the lander are expected to be too hot for it to continue operating.

Science highlights from the primary phase will include a full panoramic view of the landing site, including a section in 3D, high-resolution images of the surface immediately underneath the lander, on-the-spot analysis of the composition of the comet's surface materials, and a drill that will take samples from a depth of 23 cm and feed them to an onboard laboratory for analysis.

The lander will also measure the electrical and mechanical characteristics of the surface. In addition, low-frequency radio signals will be beamed between Philae and the orbiter through the nucleus to probe the internal structure.

The detailed surface measurements that Philae makes at its landing site will complement and calibrate the extensive remote observations made by the orbiter covering the whole comet.

"Rosetta is trying to answer the very big questions about the history of our Solar System. What were the conditions like at its infancy and how did it evolve? What role did comets play in this evolution? How do comets work?" said Matt Taylor, ESA Rosetta project scientist.

"Today's successful landing is undoubtedly the cherry on the icing of a 4 km-wide cake, but we're also looking further ahead and onto the next stage of this ground-breaking mission, as we continue to follow the comet around the Sun for 13 months, watching as its activity changes and its surface evolves."

While Philae begins its close-up study of the comet, Rosetta must manoeuvre from its post-separation path back into an orbit around the comet, eventually returning to a 20 km orbit on 6 December.

Next year, as the comet grows more active, Rosetta will need to step further back and fly unbound 'orbits', but dipping in briefly with daring flybys, some of which will bring it within just 8 km of the comet centre.

The comet will reach its closest distance to the Sun on 13 August 2015 at about 185 million km, roughly between the orbits of Earth and Mars. Rosetta will follow it throughout the remainder of 2015, as they head away from the Sun and activity begins to subside.

"It's been an extremely long and hard journey to reach today's once-in-a-lifetime event, but it was absolutely worthwhile. We look forward to the continued success of the great scientific endeavour that is the Rosetta mission as it promises to revolutionise our understanding of comets," said Fred Jansen, ESA Rosetta mission manager.

(http://news.bbcimg.co.uk/media/images/78948000/jpg/_78948269_78948268.jpg)
This photo from Philae shows the surface during the lander's approach


http://www.bbc.com/news/science-environment-30026398

QuoteEuropean robot probe has made the first, historic landing on a comet, but its status remains uncertain after harpoons failed to anchor it to the surface.

Officials said the craft may have lifted off the comet after touchdown before returning to the surface.

Mission scientist Stephan Ulamec said: "Maybe we didn't just land once, we landed twice."

He said it would take further analysis to understand what has happened to it.

A landing on Comet 67P/Churyumov-Gerasimenko was confirmed at about 1605 GMT.

There were cheers and hugs at the control room in Darmstadt, Germany, after the signal was confirmed.

It was designed to shine a light on some of the mysteries of these icy relics from the formation of the Solar System.

The landing caps a 6.4 billion-kilometre journey that was begun a decade ago.

The lander sank about 4cm into the surface, suggesting a relatively soft surface.

But shortly after, scientists confirmed that the harpoons, designed to fasten the spacecraft to the ball of ice, did not fire as intended.

In a media briefing, Dr Ulamec, the mission's landing chief, said: "What we know is we touched down, we landed at the comet at the time when you all saw us cheering and when it was announced.

"We had a very clear signal there, we received data from the landing - housekeeping and science data - that's the good news."

But then Dr Ulamec delivered the bad news. He said telemetry from the craft suggested it may have drifted off the surface after landing and started to turn. This subsequently came to an end, which Dr Ulamec interpreted as a possible "second landing" on Comet 67P.

This "bounce" was always a possibility, but had been made more likely by the failure of the harpoons to deploy.

The first pictures from the surface have already reached Earth and are being processed in preparation for release.

Scientists were initially elated following the confirmation of a landing.

Astronaut Chris Hadfield, famous for performing David Bowie's Space Oddity on the space station, said of the comet: "Now we're close enough to lick it, and see what it's really made of."

Prof Monica Grady of the Open University, who has worked on the project from its earliest days, was at mission control in Darmstadt and was jumping for joy when the news came through.

She told BBC News: "I can't believe it, it's fantastic, we've landed - we've waited so long for this."

But the news about the harpoons has cast a pall over the celebrations. Scientists will now take a decision on whether to re-fire them.

Scientists believe Philae was in a stable configuration when they last had contact with the probe. But they have now lost radio "visibility" and will only re-establish contact on Thursday.

Earlier, a thruster system designed to push the robot down into the surface of the comet failed.

Part of the difficulty is the very low gravity on the 4km-wide ice mountain.
The nature and strength of the materials on the surface are unknown.

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

Controllers in Darmstadt have already received pictures from the surface of the comet, but are getting intermittent drop-out in the lander's signal.

Analysis by Science editor David Shukman

Landing on the small strange world of a comet ranks as one of the greatest achievements in space exploration. Neil Armstrong and Buzz Aldrin would obviously take pride of place.

People might debate the relative prowess of robotic rovers driving on Mars or the Voyager spacecraft edging out of the solar system.

But touching down on a primordial lump of rock and ice that dates from the earliest days of the Solar System - and which is hurtling through space at 34,000 mph - is a genuine triumph by any standards.

Dreaming up the plan 25 years ago, enduring 10 years of journeying through space, handling the tension of edging close to the comet more than 300 million miles away - all these are remarkable in their own right.

Rosetta's orbits around the comet are generating unexpected insights. But landing will help achieve a dream of establishing invaluable ground truth about a body that previous generations could only gawp at in wonder or terror.

line
Paolo Ferri, head of operations at Esa, told BBC News: "We need to stabilise this situation over the next three hours."

Philae was deployed to take pictures of the comet's landscape and to analyse its chemical composition.

They are hoping its surface materials will hold fresh insights into the origins of our Solar System more than 4.5 billion years ago.

One theory holds that comets were responsible for delivering water to the planets. Another idea is that they could have "seeded" the Earth with the chemistry needed to help kick-start life.

http://www.dailymail.co.uk/sciencetech/article-2831125/Rosetta-mission-broken-thruster-computer-glitch-scupper-today-s-historic-landing-comet-67P.html

QuoteFive simple words marked the fulfilment of an extraordinary feat of space exploration yesterday when scientists announced: 'We are on the comet.'

To cheers and hugs, ecstatic experts delivered the news that a machine the size of a dishwasher had dropped onto an icy rock more than 300 million miles away.

However, they later revealed that the mission is already in jeopardy as it emerged the lander, which was supposed to use harpoons to tether itself to the comet's surface, had been unable to fire them and appeared to be moving around. 

(http://i.dailymail.co.uk/i/pix/2014/11/12/1415830508005_wps_57_PHILEA_LANDER_Rosetta_spa.jpg)

It was a worrying end to an extraordinary day.

At the European Space Agency's mission control, a faint radio signal came back from the Philae lander at 4pm – proof that it had finally reached the surface of the comet 67P/Churyumov-Gerasimenko after a decade-long chase through space.

Dr Stephan Ulamec, who ran the audacious landing programme, said early tests suggested the craft had bounced softly before turning and settling again.

He said: 'It touched down and was re-bouncing. So maybe today, we didn't just land, we landed twice.'

Last night the team were still not sure how securely Philae was fastened after landing thrusters and anchoring harpoons failed to fire.

It was not clear if its three ice screws had deployed either.

Dr Ulamec said: 'Did we just land in a soft-sand box and everything is fine? Or is there something else happening? We still do not fully understand what has happened.'

Scientists will not know the status of the project until further tests are completed this afternoon.

However, last night they were treating the landing itself as a success.

British scientist Dr Matt Taylor, who played a key role in the mission, said: 'To see this mountaineering effort, that we've descended a lander to the surface of a comet, I can't put words to it. It's beautiful.'

And the expert was so confident of success that he had even had an image of the space probe tattooed on his right leg.

Before the attempt yesterday, there was also a good luck message from a man who had once boasted of boldly going into space himself.

Star Trek actor William Shatner sent the team a video in which the 83-year-old said: 'Good luck Rosetta, Philae's gonna land.'

One scientist then described the seven hours of 'terror' they went through to drop the Philae lander 13.6 miles above the comet from its mothership, Rosetta.

Dr Matthew Genge, of Imperial College London, said during the wait: 'This is the most difficult landing in space history – like landing a balloon in a city centre on a windy day with your eyes closed.'

Much of the equipment aboard the lander was switched on for the first time after lying dormant during the ten-year journey.

Klim Churyumov, one of the Ukrainians who discovered the comet 45 years ago and named it, said from mission control in Darmstadt, Germany: 'We saw the first light from this comet in 1969, now we are landing on it. It is a fantastic, outstanding event, the first like it in human civilization.'

The probe is equipped with cameras, a suite of ten instruments, and a drill that can bore out samples to a depth of nine inches.

Ptolemy, a British-built laboratory the size of a shoebox, will be used to analyse the composition of samples from the 4.5billion-year-old comet.

Scientists hope the £1billion project will solve some of the greatest puzzles in science – including the origins of life on Earth.

Open University Professor Ian Wright, who helped create Ptolemy, said: 'The idea that comets may have brought the building blocks of life to Earth is one of the reasons why we want to study them.'

Professor Stanley Cowley, planetary scientist at the University of Leicester, added: 'It is an interesting relic from that otherwise inaccessible epoch.'

However, controllers have revealed that because harpoons supposed to tether it to the surface had not fired, the lander may have actually bounced, effectively landing twice - and leaving it attached only by screws on its legs.

'It's complicated to land on a comet, and complicated to understand what has happened during this landing,' said Dr Stefan Ulamec, Philae Lander Manager.

(http://i.dailymail.co.uk/i/pix/2014/11/12/1415815553460_wps_9_12N_ROSETTA_LANDING_ONLIN.jpg)

http://www.theguardian.com/science/across-the-universe/live/2014/nov/13/rosetta-mission-philae-lander-live-coverage-comet-esa

19m ago07:15
The hunt for Philae continues. It is not yet know exactly where Philae is located on the comet but the thinking is that the lander is not too far away from its original target point.

The lander bounced twice yesterday, finally coming to rest two hours after the original touchdown.

Contact was re-established with Philae this morning around 6:00 GMT, just two minutes after the window opened.

Fred Jansen, Rosetta mission manager, told me, "Yesterday there were people who said that if the lander jumped up and was hovering for an hour or two, the comet would rotate underneath it and then you could be anywhere. But to see the signal so close to the planned time means that we must be close to our original landing spot."

22m ago07:12
The good news from mission control is that scientific data is flowing in, even though the communications link between Philae and Rosetta remains intermittent.

"We have telemetry and massive data already. This is a success," says mission manager Fred Jansen.

28m ago07:05
We still don't know the exact location of Philae. Ingenious Esa engineers are planning to use the radar instrument CONSERT to triangulate its position. The instrument on Rosetta is designed to probe the comet's subsurface using radio waves, which are pinged back to the orbiter by a transponder in the Philae lander.

During the descent, CONSERT showed that the lander was just 50 metres adrift from the targeted landing spot. Esa had planned for the error in position being up to 500 metres.

Of course, that was before those two slow-motion bounces. Magnetic field data from Philae's ROMAT instrument revealed three "landings". The first was almost exactly on the expected arrival time of 15:33 GMT. But as we now know the anchoring harpoons did not fire and Philae rebounded.

In the weak gravity of the comet it took about two hours for the lander to return to the surface after that first bounce. It touched down for a second time at 17:26 GMT, then bounced again before finally coming to rest at 17:33.

37m ago06:57
We've been promised four more pictures from the press conference at 1pm GMT forming the first 360° panorama of the surface. Worryingly, an Esa official has let slip that there "may" not be a horizon visible in those either.

41m ago06:52
Philae may be wedged in a hole

If Philae is wedged in a hole, this could be a serious problem because its initial battery life is only 60 hours. Thereafter it must rely on solar power. "We are definitely not in the open," says mission manager Fred Jansen.

Discussions are taking place about whether to deploy the lander's drills and other moveable parts to nudge it into a better position.

41m ago06:52
The image released this morning comprises two CIVA images from the full panorama of six images that will be released at 1pm. These will show the other two legs of the lander, and provide a full panorama of the landing site. CIVA itself comprises six micro cameras dotted around Philae's body.

46m ago06:47
There will be a press conference in Darmstadt at 1pm GMT revealing what the scientists have gleaned from the data coming back from Philae. We'll livestream that and report the highlights here. The suspicion is that the lander is in a crater or facing a cliff.

A mosaic of two images taken by the lander's CIVA camera shows one of Philae's legs and the craggy surface. Esa had been expecting a view of the horizon ... "We're either looking into a ditch or we are against a wall," project scientist Matt Taylor has told our astronomy blogger Stuart Clark.

(http://i.guim.co.uk/static/w-620/h--/q-95/sys-images/Guardian/Pix/pictures/2014/11/13/1415873992941/f7166bdc-4410-460d-8ee5-4377ab480e25-620x372.jpeg)

QuoteFirst image from the surface of Comet 67P/Churyumov-Gerasimenko from the Rosetta million's lander Philae

http://www.bbc.com/news/science-environment-30034060

QuoteTouching down on a comet is mind-blowing in itself, but try picturing how the tiny Philae lander has then bounced around its new home.

From what we know, the lander rose hundreds of metres above the surface at one stage and remained in flight for nearly two hours. One might say it was airborne, except that the comet has no air.

In any event, it may have risen vertically or drifted sideways - we should hear later. Either way, while Philae was off the surface, the comet will have rotated beneath it. Each rotation takes about 12 hours which means the lander may effectively travelled across one-sixth of the comet's surface.

By the time it came down again, the original landing zone - chosen for its relative safety and ideal amount of sunshine - was left far behind. The lander is now in different, undetermined area that may prove far more hazardous.

The first picture is confusing, but suggests Philae is sitting at an angle. Everyone here is hungry for more news.

http://www.theguardian.com/science/across-the-universe/live/2014/nov/13/rosetta-mission-philae-lander-live-coverage-comet-esa

(http://i.guim.co.uk/static/w-620/h--/q-95/sys-images/Guardian/Pix/pictures/2014/11/13/1415893536443/065eb4a6-180b-4c25-85e6-ac2a623af1b6-540x540.jpeg)

QuotePhilae is thought to be resting somewhere in candidate landing site B, shown here. The exact location of the lander is unknown but it is probably toward the bottom right of the image. Originally this landing site was rejected by Esa on account of the large boulders and the poorer illumination than site J, which was chosen and became known as Agilkia.

QuoteDrilling for samples will be risky


Philae has been designed to achieve its main science objectives within its initial 60-hour battery life. When asked at the press conference what was the absolutely fundamental investigation to be performed, Jean-Pierre Bibring – lead scientist for the lander – said it was to analyse the organic molecules on the comet.

To do that, it must get samples into its PTOLEMY, COSAC and CIVA instruments. There are two ways to do this: by sniffing and drilling. Sniffing involves opening the instruments and allowing molecules from the comet's surface to drift in. The instruments are already acquiring samples like this and returning data.

Drilling is much riskier because it could topple the lander. Newton's third law of motion says that for every action there is an equal and opposite reaction. In the minuscule gravity of the comet, any movement by Philae's tools could cause the whole lander to shift or even take off again.

The drill turning one way will make Philae want to turn the other. Pushing down into the surface will push the lander in the opposite direction.

"We don't want to start drilling and end the mission," says Bibring. So they will try this only towards the end of the 60-hour nominal mission.

(http://news.bbcimg.co.uk/media/images/78971000/jpg/_78971511_philae_landing_zone_624.jpg)

http://blogs.esa.int/rosetta/2014/11/14/how-and-where-is-philae/

Quote→How (and where) is Philae?
   

The current status of Rosetta's lander Philae was discussed live during a Google Hangout this afternoon, together with scientists and engineers from the mission teams at ESA and partner agencies. The teams are very happy about the lander and the successful functioning of all instruments that were operated so far.

As reported by Stefan Ulamec, the lander manager from DLR, last night a sequence of commands to operate a number of instruments was uploaded to the lander. The resulting data were downlinked earlier today and the scientists are currently analysing them and trying to figure out what they mean.

One of the instruments that was activated during this sequence is MUPUS, the MUlti-PUrpose Sensors for Surface and Sub-Surface Science, which has hopefully penetrated and hammered into the surface of the comet to test its thermal and mechanical properties.

Another instrument that was deployed during this sequence is APXS, the Alpha Proton X-ray Spectrometer, to probe the elemental composition of the comet's surface.

They also conducted new measurements with CONSERT (COmet Nucleus Sounding Experiment by Radio-wave Transmission), an instrument that is operated both on the lander and the orbiter. The CONSERT data will be used to get a better estimate of the lander's position, which has not been extactly identified yet.

The search for Philae is on, using not only CONSERT data, but also imagery from Rosetta - both from the OSIRIS imaging system and the navigation camera (NavCam) - as well as the data collected locally by the lander.

Holger Sierks, Principal investigator of OSIRIS, mentioned that images taken after touchdown are still to be downlinked; as soon as the images become available to the team, they will try to locate not only the lander's current position but also its bouncing trajectory after the first touchdown. Meanwhile, they are continuing to image the surface of the comet with OSIRIS.

Another instrument that was operated on the lander is SD2, the sampling, drilling and distribution (SD2) subsystem, which was activated and started drilling. Philippe Gaudon, manager of Philae's Science, Operations and Navigation Centre (SONC) at CNES, Toulouse, explained that the mechanism was working well, as they saw the drill go 25 cm below its base plate.

Shortly after, however, the link with Philae was lost - as expected, since the lander had moved below the horizon from Rosetta - so the results of this first drilling session should be available in the evening.

If successful, the first sample collected by the drill is scheduled to be fed to COSAC, the COmetary SAmpling and Composition experiment that will analyse the cometary material looking for organic compounds and measuring the chirality of the molecules.

A crucial uncertainty at the moment is the duration of the primary battery, which may run out before the end of this final block of the first science sequence. As explained by Valentina Lommatsch from the Lander Control Center at DLR, simulations that were run last night indicate that the battery might still have around 100 Wh left, which may be just enough to complete the sequence and relay back the data if the temperature of the battery does not decrease. The outcome will be known for sure only late this evening.

As for the position of the lander, Valentina Lommatsch explained that all three of Philae's legs are on the ground, but the sunlight received at the solar panels is very low, which is likely due to the local topography of the site of final touchdown. As reported by Stefan Ulemec, one of the panels is receiving sunlight for about one hour and twenty minutes and two more panels for about twenty-thirty minutes every comet day (which lasts 12.4 hours). They also confirmed that the lander has not moved since the third touchdown, after which the first CIVA-P panorama was taken.

The orbiter is doing great by the way, as reported by Andrea Accomazzo, ESA Rosetta Flight Director at ESOC. The team had to manoeuvre Rosetta to keep visibility with the location on the comet where Philae is, and the signal received from the lander is very stable. Of course, everyone is looking forward to finding its exact location on the comet's surface and, most importantly, to hearing back from Philae tonight.

Matt Taylor, Rosetta project scientist at ESA, mentioned that both orbiter and lander have been performing outstanding measurements so far, at the very cutting edge of science. Everyone's looking forward to the first scientific results, which will be presented next month at the Planetary Sciences Section of the American Geophysical Union.

Looking forward to the scientific output of the mission are also the two guests who joined the Google Hangout from the United States, Jeff Grossman and Gordon Johnston from the OSIRIS-REx Program at NASA, who are eagerly learning from Rosetta in sight of their coming asteroid study and sample return mission, planned to launch in a couple of years.

But for the moment, all eyes are turned on Philae: both on the short term, waiting to get the signal back from the lander tonight, and on the longer term. Even if its current location does not offer optimal exposure to sunlight to fully recharge the secondary batteries, it is possible that, as the comet approaches to the Sun, the illumination will increase and Philae will once more wake up and talk to us.

http://www.newscientist.com/article/dn26571-philaes-hop-skip-and-jump-across-comet-67p.html

QuotePhilae's hop, skip and jump across comet 67P
15:02 17 November 2014 by Jacob Aron


(http://www.newscientist.com/data/images/ns/cms/dn26571/dn26571-1_1200.jpg)

The European Space Agency's comet-hopper Philae was caught in action as it travelled above the surface of comet 67P/Churyumov–Gerasimenko last week. ESA has just released this composite image showing Philae's journey as seen by the orbiting Rosetta spacecraft.

Philae first touched down at 1535 GMT on 12 November before bouncing away from 67P, perhaps as high as 1 kilometre. The first three inset images, from left to right, show Philae as it descended towards the surface. The fourth image, taken shortly after the bounce, show the impression in the surface left by Philae – one that wasn't there in a picture taken at 1518 GMT.

The picture on the far right shows Philae ominously flying over a shadowed region. The spacecraft came to rest again at 1725 GMT, bounced a second time, and reached its final resting point at 1732 GMT. ESA has still not established the location of this last landing, but it is working hard to compare images taken by Philae on the ground with images and triangulation data from Rosetta.

The lander is now in hibernation mode. Whether or not it wakes up again will depend on getting enough sunlight on its solar panels to recharge its batteries.

(http://www.newscientist.com/data/images/ns/cms/dn26571/dn26571-3_475.gif)

Another image, released yesterday, shows a low-resolution view of Philae's first bounce. You can see the dust cloud thrown up from the surface, along with the lander and its shadow – taking up just a few pixels.

http://www.newscientist.com/article/dn26612-rosettawatch-homing-in-on-philaes-resting-spot.html

Quote#Rosettawatch: homing in on Philae's resting spot
17:39 25 November 2014 by Jacob Aron

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It has been two weeks since the Philae spacecraft touched down on comet 67P/Churyumov-Gerasimenko, but the European Space Agency still doesn't know if it successfully drilled the comet's surface. They don't even know where it finally came to rest. Meanwhile, its orbiting companion Rosetta is continuing its mission.

Readings from CONSERT, a radar instrument that linked Philae with Rosetta before the lander ran out of power, have narrowed potential landing spots to a 350 metre by 30 metre strip on the comet's head. Scientists at the ESA are now searching images from Rosetta's cameras to see if they can spot Philae, but it is in a region of deep shadow and is only likely to show up when light bounces off its solar panels.

As for Philae's drill, it was one of the last instruments to be activated before the lander switched off. Mission managers know the drill operated as expected, but because the probe was sitting at angle they don't know whether it delivered a sample to the COSAC instrument. This was designed to study molecules from the comet by heating material in an oven and measuring the resulting gas.

Rosetta ramping up
COSAC's data is inconclusive. There may not have been a sample, or the sample may have been too dry, meaning only small amounts of gas were released. "I would have loved to see a clear signal from a clear sample," says COSAC lead Fred Goesmann. "My pessimistic view is we'll never know."




That could be the case even if the ESA can reconnect with Philae, were it to wake up as more sunlight hits its solar panels . The lander's drill has no direct way of confirming it has taken a sample, and there is no camera in the oven the sample was delivered to, even though other lower-temperature ovens on the probe have such cameras. Goesmann says scientists discussed other sensors to confirm a sample during mission planning, but they discarded the idea because of strict weight limits on the lander.

No more data is expected from Philae any time soon, but having delivered the lander, Rosetta is now ramping up its scientific mission. The ESA has placed the spacecraft back into a higher orbit, 30 kilometres above the comet, but it will dip to 20 kilometres on 3 December for 10 days to gather data on the increasing dust and gas spewing from 67P as it nears the sun. The plan is to stay as close to the comet as possible without putting Rosetta at risk from the comet's increasing activity.

My guess is the Philae will wake up again as the comet get closer to the sun. But because the grappling hooks didnt take as planned, it will get ejected back into space as the comet releases it gases. Since only the comets weak gravity is holding it in place, if that field changes as the comet loses mass, its possible it might "roll over" and become more functional.

Should be some interesting science in the interim.

Quote from: spuwho on November 26, 2014, 09:39:52 AM
My guess is the Philae will wake up again as the comet get closer to the sun. But because the grappling hooks didnt take as planned, it will get ejected back into space as the comet releases it gases. Since only the comets weak gravity is holding it in place, if that field changes as the comet loses mass, its possible it might "roll over" and become more functional.

Should be some interesting science in the interim.

I think that is what they are counting on. The orbiting Rosetta will gather tons of data as the comet slowly dissolves as it nears the sun...

http://www.newscientist.com/article/mg22429994.700-rosettawatch-comet-water-is-not-like-earths.html

Quote#RosettaWatch: Comet water is not like Earth's
10 December 2014 by Jacob Aron

IF EARTH got its water from space, it probably wasn't delivered by comet. That's according to the latest data from the European Space Agency's Rosetta spacecraft, which has been analysing the water content of comet 67P/Churyumov-Gerasimenko and found it doesn't match the water on Earth.

The question of where Earth got its water – whether from asteroids, comets or in some other way – is a subject of ongoing debate. So analysing comet 67P's water was one of Rosetta's main goals. The spacecraft's ROSINA instrument has been sniffing the vapour around the comet ever since reaching it in August.

Kathrin Altwegg of the University of Bern in Switzerland and her colleagues have now analysed 67P's water, by looking at the amount of deuterium, a heavy isotope of hydrogen, and comparing it with the amount of regular hydrogen (Science, DOI: 10.1126/science.1261952).

"As soon as we got water from the comet, the pattern changed immediately," says Altwegg. The comet's water has around three times as much deuterium as water on Earth, the researchers found. The ratio found on some other comets is much closer to that on Earth, suggesting a link between the icy space rocks and terrestrial water. The different composition of 67P's water suggests a more complex picture.

"We know there is material out there that has the signature of Earth's water in it, but is it the material that supplied it?" says Edwin Bergin of the University of Michigan, Ann Arbor, who previously found that comet Hartley 2 has similar water to that of Earth. Models of asteroid and comet motion within the solar system suggest asteroids were more likely to cross paths with Earth, but we don't yet know if they had the right mix of water to create the oceans. "We need many more measurements of this type to get an understanding of the diversity within the population," Bergin says

"In the end, Earth's oceans are probably a mix of many things," says Altwegg.

The data collected so far may not be the last word on 67P's water. It is possible that there are pockets of water with a different deuterium-to-hydrogen ratio that could be released as the comet nears the sun and heats up. The two halves of the duck-shaped 67P might even have different hydrogen signatures, which would suggest they were once distinct bodies that formed in different parts of the solar system before colliding. "That would be a very interesting result," says Altwegg.

ROSINA's job has been made harder by the loss of Philae, the probe that landed on 67P in November but was unable to survive due to a lack of solar power. That could make signals of heavier molecules, particularly the amino acids necessary for life, more ambiguous.

"The identification of molecules is certainly more difficult," says Altwegg, who had hoped to compare ROSINA's data with Philae's Ptolemy instrument, which was designed to measure molecules in a different way. "If you have two different instruments you can resolve it, and this we cannot do, so it's all on ROSINA more or less."

Rosetta gets a peek at Comet 67P's "underside"

3 hours ago by Jason Major, Universe Today

(http://cdn.phys.org/newman/gfx/news/2015/1-rosettagetsa.jpg)

QuoteA particularly dramatic view of comet 67P/C-G due to the angle of solar illumination, this is a mosaic made from four images acquired by Rosetta's NavCam on January 16, 2015, from a distance of 28.4 km (17.6 miles). The assembled image shows the larger "bottom" lobe of 67P, with a flat region called Imhotep along the left side and, on the lower right, the transition area stretching up to the comet's smaller "head" lobe. Outgassing jets can be seen as faint streaks at the upper right, and ejected dust grains show up as bright specks above its surface.

Read more at: http://phys.org/news/2015-01-rosetta-peek-comet-67p-underside.html#jCp

http://www.universetoday.com/118901/rosettas-comet-really-blows-up-in-latest-images/

(http://d1jqu7g1y74ds1.cloudfront.net/wp-content/uploads/2015/02/Comet67P_NavCamFeb3-580x305.jpg)

QuoteRosetta's Comet Really "Blows Up" in Latest Images

by Jason Major   on February 9, 2015

First off: no, comet 67P/Churyumov-Gerasimenko is not about to explode or disintegrate. But as it steadily gets nearer to the Sun the comet's jets are getting more and more active and they're putting on quite a show for the orbiting Rosetta spacecraft! Click the image for a jeterrific hi-res version.

The images above were captured by Rosetta's NavCam on Jan. 31 and Feb. 3 from a distance of about 28 km (17 miles). Each is a mosaic of four separate NavCam acquisitions and they have been adjusted and tinted in Photoshop by yours truly to further enhance the jets' visibility. (You can view the original image mosaics and source frames here and here.)

These dramatic views are just a hint at what's in store; 67P's activity will only be increasing in the coming weeks and months and, this weekend, Rosetta will be swooping down for an extreme close pass over its surface!

This Saturday, Feb. 14, Rosetta will be performing a very close pass of the comet's nucleus, soaring over the Imhotep region at an altitude of only 6 km (3.7 miles) at 12:41 UTC. This will allow the spacecraft to closely image the comet's surface, as well as investigate the behavior of its jets and how they interact with its developing coma.

"The upcoming close flyby will allow unique scientific observations, providing us with high-resolution measurements of the surface over a range of wavelengths and giving us the opportunity to sample – taste or sniff – the very innermost parts of the comet's atmosphere," said Rosetta project scientist Matt Taylor.

Read more about Rosetta's Valentine's Day close pass here and watch an animation of how it will be executed below.

https://www.youtube.com/v/dxF2wE24hCI

http://youtu.be/dxF2wE24hCI

(http://www.slate.com/content/dam/slate/blogs/bad_astronomy/2015/02/16/rosetta_feb14_closeup.jpg.CROP.original-original.jpg)

(http://www.slate.com/content/dam/slate/blogs/bad_astronomy/2015/02/16/rosetta_feb14_closeup_plains.jpg.CROP.original-original.jpg)

(http://www.slate.com/content/dam/slate/blogs/bad_astronomy/2015/02/16/rosetta_feb14_closeup_layers.jpg.CROP.original-original.jpg)

(http://www.esa.int/var/esa/storage/images/esa_multimedia/images/2015/02/14_february_close_flyby_10_15_gmt/15257461-1-eng-GB/14_February_close_flyby_10_15_GMT_node_full_image_2.jpg)

QuoteTitle 14 February close flyby, 10:15 GMT
Released 16/02/2015 3:00 pm
Copyright ESA/Rosetta/NavCam – CC BY-SA IGO 3.0
Description
Four-image montage of Comet 67P/Churyumov–Gerasimenko comprising images taken on 14 February 2015 during the first dedicated close flyby. This image set was taken at 10:32 GMT from a distance of 12.6 km from the comet centre, or about 10.6 km from the surface seen in the foreground. Using the surface distance, the image scale is 0.9 m/pixel and the montage measures about 1.8 km across.

Closest approach of about 6 km from the comet's surface took place at 12:41 GMT.

The individual images making up this mosaic can be accessed via the blog: CometWatch 14 February – flyby special

(http://www.esa.int/var/esa/storage/images/esa_multimedia/images/2015/02/14_february_close_flyby_19_42_gmt/15257529-1-eng-GB/14_February_close_flyby_19_42_GMT_node_full_image_2.jpg)

QuoteTitle 14 February close flyby, 19:42 GMT
Released 16/02/2015 3:00 pm
Copyright ESA/Rosetta/NavCam – CC BY-SA IGO 3.0
Description
Four-image montage of Comet 67P/Churyumov–Gerasimenko comprising images taken on 14 February 2015 during the first dedicated close flyby. This set was taken at 19:42 GMT from a distance of 31.6 km from the comet centre. The image scale is 2.7 m/pixel and the montage measures 5.5 km across.

Closest approach of about 6 km from the comet's surface took place at 12:41 GMT.

The individual images making up this mosaic can be accessed via the blog: CometWatch 14 February – flyby special

http://www.theverge.com/2015/3/11/8189569/philae-lander-waking-first-attempt

QuoteScientists prepare to wake Philae lander from its deep sleep in the shadows of comet 67P
By James Vincent  on March 11, 2015 07:36 am  @jjvincent

Starting tomorrow, scientists from the European Space Agency (ESA) will attempt to make contact with the stricken Philae lander for the first time in nearly four months.

The spacecraft successfully touched down on comet 67P/Churyumov-Gerasimenko in November last year, but an unexpectedly bouncy landing left it stranded in an area far colder and with far less sunlight than scientists had originally planned. The craft was able to carry out a number of experiments over the next three days, but eventually entered a low power state before it ran out of power. Now, as the comet draws closer to the Sun and receives more heat and light, scientists are hopeful it will awaken again in the coming weeks, to finish off the work it started.

"Philae currently receives about twice as much solar energy as it did in November last year," says the lander's project manager Stephan Ulamec. "It will probably still be too cold for the lander to wake up, but it is worth trying. The prospects will improve with each passing day."

For Philae to wake up completely, the interior of the craft must be at least -45ºC and its solar panels must be receiving a minimum of 5.5 watts of power. Once its core systems realize that these criteria have been met, the lander will attempt to charge its battery, switching on its receiver every 30 minutes to listen for instructions from the orbiting Rosetta. Scientists say it's possible that Philae has already woken up, but that the lander doesn't yet have enough power to communicate with Rosetta.

"At this time, we do not yet know that the lander is awake," says Koen Geurts of the Rosetta control center. "To send us an answer, Philae must also turn its transmitter – and that requires additional power."

Between the 11th and 20th of March, Rosetta will make a number of flybys during Philae's daytime — that is, when the side of the comet its on is exposed to sunlight. A day on 67P currently lasts 12.4 hours and scientists believe that Philae is only exposed to the Sun for 1.3 hours every day — not even half of what was planned for. If initial communication is made in the next few weeks, scientists can begin checking on Philae's condition. "We will then evaluate the data," says Geurts. "What is the state of the rechargeable battery? Is everything on the lander still functioning? What is the temperature? How much energy is it receiving?"

Even if this initial attempt at communication doesn't work, ESA scientists are hopeful that they will have more chances in the future as the comet gets closer to the Sun. "If we cannot establish contact with Philae before 20 March, we will make another attempt at the next opportunity," says Ulamec. "Once we can communicate with Philae again, the scientific work can begin."

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http://www.newscientist.com/article/dn27723-philae-awakes-what-next-for-probe-after-7-month-nap-on-comet.html

QuotePhilae awakes: What next for probe after 7 month nap on comet?
11:08 15 June 2015 by Jacob Aron

What a wake-up call. On Saturday night, the German Aerospace Center (DLR) in Cologne received 85 seconds of incredibly good news: a data chirp from the missing European Space Agency lander Philae. Despite seven months adrift and alone on comet 67P/Churyumov-Gerasimenko since its bumpy landing last year, Philae is back and ready for science.

"Philae is doing very well – it has an operating temperature of -35 °C and has 24 watts of power available," said lander manager Stephan Ulamec. "The lander is ready for operations." Here is what's next:

Listen closely
Philae has finally made contact, but only intermittently, so the first order of business is establishing a better link. The lander speaks to Earth via the orbiting Rosetta satellite, meaning communication is only possible during certain windows when the spacecraft is overheard.

Philae only transmitted for a minute and a half out of a possible 2-hour window, meaning the link isn't ideal, and the lander team heard nothing during a broadcast window on Sunday. Reorienting Rosetta should help, said ESA project scientist Matt Taylor.

Catch up
The mission team was able to download and analyse 300 data packets from Philae during its brief communication on Saturday, but they revealed that over 8000 more are sitting in the lander's memory awaiting transmission. That suggests Philae has been operational recently but unable to transmit, so downloading this data will give the team clues about what the lander has experienced in the past few days.

Get to work
The researchers and engineers behind Philae have had months to prepare for the lander's reawakening, and have been planning sequences of short commands that can be performed quickly without stressing its battery.

Once communications are properly established, the team will upload the commands in the hope of gathering more scientific data about comet 67P. First on the list are the temperature and magnetic field readings, with the possibility of more images from the surface to come later.

Go for broke
During its initial time awake on 67P, Philae failed to drill into the comet's surface and heat up samples in its oven, so researchers are keen to have another go. Both operations require a large amount of power, so it may not be possible. There is also a worry that using the drill could disturb the lander's precarious position against a cliff face, so it may be too risky.

Say goodbye – maybe
If Philae's touchdown had gone according to plan, it would probably be dead by now. The original landing site would have placed the probe in full sunlight, allowing it to continue operations for perhaps three months. But as comet 67P neared the sun and its surface warmed, Philae would have been placed at risk.

Now, all bets are off. 67P is growing even hotter and becoming more active, shooting off jets of gas as it reaches its closest approach to the sun on 13 August, so Philae could once more be under threat.

Or, its unexpectedly sheltered position could protect it, allowing the probe to ride out the worst of the sun and continue monitoring 67P on the other side of its orbit. With a mission this unpredictable, who can tell?

They extended the Rosetta mission yesterday. They are going to continue to follow the comet after it passes the sun and just before Rosetta gets out of range for its solar cells, they are going to land it physically on the comet where it will take a magic carpet ride for posterity.

It would be cool if on the comets return to the sun, the probe "wakes up" again but they say the panels will not survive the landing.

Yes... Rosetta is still orbiting the comet on its outbound journey through our solar system.  The mission will end in 3 months getting closer and closer until crashing... in September.

https://www.youtube.com/v/VxC0_icfwCM

Sooo... with three weeks to go before its planned suicide... Rosetta finds the lost Philae lander.   8)

http://motherboard.vice.com/read/philae-found-comet-chaser-rosetta-spots-lander-weeks-before-its-death

QuotePhilae Found! Comet Chaser Rosetta Spots Lander Weeks Before Its Death
WRITTEN BY BEN SULLIVAN
September 5, 2016 // 11:40 AM EST

(http://motherboard-images.vice.com/content-images/contentimage/37249/1473089909046124.jpg)

With less than one month to go before the end of the European Space Agency's mission to Comet 67P/Churyumov–Gerasimenko, the Rosetta orbiter's high-res camera has at last spotted the Philae lander jammed into a shadowy crack.

In the photo taken by Rosetta's OSIRIS camera, which came within 2.7 km of the comet's surface, the main body of Philae can clearly be seen—easily identifiable with two of its three legs proudly on display.

Matt Taylor, Rosetta mission project scientist, told Motherboard, "Philae was the cherry on the top of the Rosetta cake, which has become a REALLY massive science cake. Philae was there to provide the ground truth. Now we know exactly where that ground is..."

The image was downlinked on Sunday evening, and first seen by Cecilia Tubiana of the OSIRIS camera team.

"With only a month left of the Rosetta mission, we are so happy to have finally imaged Philae, and to see it in such amazing detail," Tubiana said in a statement.

The Philae lander was shot towards Comet 67P from the Rosetta orbiter in 2014, but stopped communicating after three days when the lander's battery died out. ESA scientists concluded that, after bouncing, Philae ended up in a ditch or underneath an icy overhang, sheltered from the sunlight that gave power to its solar panels. That hypothesis has proved to be correct, with the image from Rosetta now clearly showing how good Philae really was at hide and seek.

(http://motherboard-images.vice.com/content-images/contentimage/37249/1473089447773241.jpg)

The last ever sighting of Philae was when the lander first touched down on a region of Comet 67P known as Agilkia. Philae then bounced and flew for two hours until landing at its final resting place, named Abydos.

Philae last communicated with Earth in July 2015, with final attempts to contact the lander by ESA failing in January of this year. In July, ESA finally switched off Rosetta's Electrical Support System Processor Unit to conserve power as the comet raced more than 520 million kilometres away from the Sun.

"This remarkable discovery comes at the end of a long, painstaking search," said Patrick Martin, ESA's Rosetta Mission Manager. "We were beginning to think that Philae would remain lost forever. It is incredible we have captured this at the final hour."

Rosetta will complete its mission with a controlled descent (crash) into the surface of the comet at the end of this month, finally joining Philae to rest in peace on Comet 67P's long adventure through our Solar System.

Why crash Rosetta?

Just let it circle the comet until it makes its circle back to the Sun and let it revive, or let it try to revive.

The end is near...  :'(

https://cosmosmagazine.com/space/rosetta-s-grand-finale-probing-comet-67p-s-pits

QuoteRosetta's grand finale – probing Comet 67P's pits
The final part of the spacecraft's mission ends in its demise.

At the end of the month, the Rosetta spacecraft, which has been keeping Comet 67P/Churyumov-Gerasimenko company for the past two years, will crash into its companion near a region of pits that spray dusty jets and end the mission.

On 29 September, Rosetta will be ordered to start its collision manoeuvre, dropping onto a pitted area called Ma'at on the head of the rubber-ducky-shaped comet.

Its target point is beside a 130-metre-wide pit informally called Deir el-Medina (after an Egyptian town home to a pit filled with archaeological artefacts) taking the measurements all the while – until it crashes around 10.40 UTC on 30 September and we lose contact for good.

Why Ma-at? The pits' walls are studded with metre-sized lumps nicknamed goosebumps which planetary scientists think might be cometesimals – chunks of material that stuck together in the early days of the solar system.

Despite the simple-sounding final task – dropping on the comet – it's going to be tricky.

Operators will need to adjust the precise timing and duration of the final manoeuvre burns, the distance from the comet at that time, the non-uniform gravity of the comet and any effects on Roestta of material streaming from the comet.

A multitude of different trajectories has been calculated taking these variations into account, each resulting in a different touchdown point. But estimates predict that the spacecraft will crash within an ellipse, 700 metres by 500 metres, centred on the target point.

And while the spacecraft managed to find and snap a photo of the Philae probe last week, wedged in a crack on the comet's small lobe, the pair won't be reunited. The crash landing site, while on the small lobe, is on the other side.

(https://cosmos-magazine.imgix.net/file/spina/photo/7654/120916_rosetta_1.jpg?fit=clip&w=835)

https://www.youtube.com/v/K_7u71Lu3S4

Mission Complete!

http://www.popsci.com/rosetta-spacecraft-ends-mission-successfully

QuoteAS ROSETTA SPACECRAFT CRASH-LANDS SUCCESSFULLY, A BITTERSWEET CELEBRATION
MISSION ACCOMPLISHED
By Shannon Stirone

After traveling 4.9 billion miles, the first spacecraft to orbit a comet ended its mission today by softly "landing" onto Churyumov-Gerasimenko or 67/P. At 4:19 am Pacific time, the team here at Jet Propulsion Laboratory in California received confirmation that Rosetta had carried out its final command, to end its life by crashing into the surface of the comet.

"The whole process of landing was perfect," says Project Scientist Bonnie Buratti. "We weren't sure about the gravity field of the comet or the off-gassing, but it went flawlessly."

Spectacular new photos that Rosetta took during its final descent show the comet in a new perspective, only achievable by crashing the craft into the surface. Buratti and JPL Project Manager Art Chmielewski are connected via Skype from Germany to walk the team at JPL through the new close-up images, which show small boulders and pebbles up close. "We got to take these images with unprecedented resolution," says Chmielewski. "When the spacecraft went for its suicidal landing, we got confirmation that it's there, and upon touching the surface, it disconnected itself."

"These are the tiny little building blocks that made up the planet. We are answering the most fundamental questions of how we got here," says Buratti.

It's a bittersweet day. Many people here on the JPL Rosetta team have spent over a decade planning the mission and studying 67/P. The beginning and end of this mission mark a lifetime of planning, sequencing and scientific research for dozens of people around the world. The mission was first proposed back in the 1970s but wasn't accepted by the European Space Agency until 1993. Rosetta launched in 2004, and finally entered orbit around the comet in 2014. It's been conducting research for the last two years, providing scientists with a surplus of data.

It's a sad day when we lose a spacecraft that's delivered so much important science to researchers, but, here at JPL, there's cake.

QuoteWHY THE ROSETTA SPACECRAFT HAD TO DIE
SLOW-MO SUICIDE
By Sarah Fecht

Rest in peace, Rosetta. The comet-chasing European spacecraft descended to its death this morning in a controlled crash, after a two-year mission to explore a duck-shaped comet as it approached the sun.

Despite the Philae lander's botched landing in 2014, the Rosetta mission's orbiter went on to accomplish great things, and this morning it gave the mission the soft landing originally intended for Philae. The orbiter touched down at a nice and easy pace of about two miles per hour.
European Space Agency scientists knew they would have to pull the plug sometime. Rosetta's job was to monitor changes in Comet 67P/Churyumov-Gerasimenko as its orbit brought it closer to the sun, heating it up and causing gas and dust to poof off. Now the comet's path has brought it away from the sun and it's getting colder and darker. Rosetta's solar panels were no longer getting sufficient sunlight to keep the spacecraft warm and powered-up enough to function. Communications were also becoming more difficult.

Battered from comet dust and radiation, and running low on the fuel that would keep it in orbit, Rosetta's death dive provided a treasure trove of new data about the comet. The slow-motion plummet allowed Rosetta to sample gas and dust closer to the surface than ever before, and onboard cameras snapped pictures of the "goose bumps" lining the pits in the region of Rosetta's final resting place. These 3-foot-wide lumps are believed to be the remains of the gunk that clumped together to form the comet back in the early days of the solar system.

Rosetta crash-landed in a 430-foot-wide pit known as Deir el-Medina. It sent back its last photograph from a distance of about 167 feet.
Rosetta's signal was lost on impact.
To date, scientists have only sorted through about five percent of all the data from the ROSINA instrument, which measured the composition of the comet's surroundings. So although the mission is over, we'll still be learning about Rosetta's findings for months to come.

I love this:

http://imgur.com/a/o8klo