Rosetta prepares to map then land on comet.

[BridgeTroll]

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

Philae 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?

[spuwho]

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.

[BridgeTroll]

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

[BridgeTroll]

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

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

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



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.



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.

[spuwho]

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.

[BridgeTroll]

The end is near... 

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

Rosetta'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.

[BridgeTroll]

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

[BridgeTroll]

Mission Complete!

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

AS 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.

WHY 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.

[KenFSU]

I love this:

http://imgur.com/a/o8klo