Rosetta Mission Touchdown Site Confirmed, ESA Green-Lights Comet Landing Attempt

Chuck Bednar for – Your Universe Online
The ESA announced on Wednesday that, following a comprehensive readiness review, the Rosetta mission’s Philae probe had been given the green light to attempt a landing on comet 67P/Churyumov–Gerasimenko next month.
Philae will now attempt to become the first spacecraft ever to attempt a soft landing on a comet when it looks to touch down at the primary landing site on November 12, the agency said. That landing site, identified by the ESA as Site J, is located on the smaller of 67P/C-G’s two lobes – or, as Amina Khan of the Los Angeles Times put it, the “head” of the so-called “rubber duck” comet.
“Now that we know where we are definitely aiming for, we are an important step closer to carrying out this exciting – but high-risk – operation,” Fred Jansen, ESA’s Rosetta mission manager, said in a statement. “However, there are still a number of key milestones to complete before we can give the final Go for landing.”
The final review took place on October 14, more than two months since Rosetta moved within 100 kilometers on the icy comet. Currently, the spacecraft is just 10 kilometers away from the center of 67P/C-G’s four kilometer body, giving ESA scientists a closer look at both the primary and backup landing sites and allowing them to complete a full hazard assessment less than one month before Philae’s historic attempted landing.
“In the run-up to Philae’s release, there are to be a number of other checkpoints during which mission officials will decide whether to continue forward,” Khan said “If all goes well, Rosetta will back up from the comet to about 14 miles out before letting Philae go. Then, as Philae descends to the surface of 67P/Churyumov-Gerasimenko over seven hours, it will take snapshot after snapshot of the comet and sample the dust, gas and plasma nearby.”
BBC News science correspondent Jonathan Amos explained that Rosetta will eject Philae shortly after 08:30 GMT from a distance of approximately 20 kilometers above the comet’s surface. The lander’s descent is expected to last approximately seven hours, and roughly 30 minutes later, ESA scientists will know whether or not the mission was a success.
Once Philae touches down, it will use harpoons and ice screws in order to secure itself and make sure it doesn’t get thrown off of the low-gravity comet. Afterwards, it will begin recharging its solar-powered batteries, and it will eventually start using a suite of 10 instruments to analyze 67P/C-G.
While the lander will likely stop working next March, as the comet nears the sun, Rosetta is expected to follow it throughout its closest approach around the Milky Way’s central star in August 2015 and then back towards the outer reaches of the solar system. The goal of the mission is to study how comets evolve and, ideally, to learn more about how the Solar System formed, how water came to be, and possibly even how life on Earth began.

Image Above: Using the CIVA camera on Rosetta’s Philae lander, the spacecraft have snapped a ‘selfie’ at comet 67P/Churyumov–Gerasimenko from a distance of about 16 km from the surface of the comet. The image was taken on 7 October and captures the side of the Rosetta spacecraft and one of Rosetta’s 14 m-long solar wings, with the comet in the background. Credit: ESA/Rosetta/Philae/CIVA [ Full Size Image ]
Also on Wednesday, Philae was able to capture images of 67P/C-G, including what Philip Sherwell of The Telegraph dubbed “the ultimate ‘space selfie’” – a photo of the comet that shows “a jet blasting off the surface, a stream of gas produced when sunlight hits and warms the ice on the ‘neck’ of the rubber duck-shaped celestial object. It also captures the side of the Rosetta ‘mothership’ carrying the Philae… and its solar powering panel in the foreground.”
“The newly-released image, taken as the Rosetta hovers near the comet some 300 million miles from Earth, is actually a composite of two shots taken in quick succession but with different exposure times,” he added. “The next image sent from the Philae will be a ‘goodbye’ shot as it parts from the Rosetta and heads down towards the 2.5 mile wide comet.”
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