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For 1st time, spacecraft lands on comet | TribLIVE.com
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For 1st time, spacecraft lands on comet

Throughout human history, comets have been distant, mysterious heavenly bodies. The hunks of rock and ice streak through the sky, streaming bright tails of gas as the sun warms them.

On Wednesday, humankind finally made contact with one. The European Space Agency’s Rosetta spacecraft defied all odds and dropped its payload, a washing-machine size probe named Philae, on a cold, speeding target more than 300 million miles from Earth.

Indications were that the spacecraft touched down almost perfectly, save for an unplanned bounce, said Stephan Ulamec, head of the lander operation.

“Today we didn’t just land once. We maybe even landed twice,” he said.

Ulamec said thrusters that were meant to push Philae onto the surface, and harpoons that would have anchored it to the comet failed to deploy properly. Initial data from the spacecraft indicated that it lifted off again, turned and then came to rest.

Scientists are trying to fully understand what happened and whether those failures would affect the lander’s ability to remain on the comet, called 67P/Churyumov-Gerasimenko. But so far, most of the instruments were working fine and sending back data as hoped, Ulamec said.

“Tomorrow morning, we should know a lot more,” he said.

The landing team at mission control in Darmstadt, Germany, had to sweat through a tense seven-hour wait that began when Philae dropped from the agency’s Rosetta as both it and the comet hurtled through space at 41,000 mph.

During the lander’s descent, scientists were powerless to do anything but watch, because its vast distance from Earth made it impossible to send instructions in real time.

Finally, at 11:03 a.m. EST, the agency received a signal that the lander had touched down.

“This is a big step for human civilization,” said the head of the space agency, Jean-Jacques Dordain, as a crowd of scientists, guests and VIPs cheered and applauded in relief.

While it may take a while to determine the exact state of the 220-pound lander, the fact that it was resting on the surface of the comet was a huge success — the highlight of Rosetta’s decade-long mission to study comets.

Europe took pride in its achievement.

“We are the first to have done that, and that will stay forever,” Dordain said.

NASA contributed three instruments to the mission and its Deep Space Network of giant radio antennas has been key to communicating with Rosetta.

Eight-time spacewalking astronaut John Grunsfeld, now associate administrator for science at NASA, called the landing “a breakthrough moment in the exploration of our solar system and a milestone for international cooperation.”

“The data collected by Rosetta will provide the scientific community, and the world, with a treasure-trove of data,” he said in a statement.

Swaddled inside the comet are the secrets of the early solar system, the elements present when the sun was new and the planets were forming. To study a comet up close would be a cosmological dream, a time capsule.

“By studying one in enormous detail, we can hope to unlock the puzzle of all of the others,” said Mark McCaughrean, a senior scientific adviser to the mission.

The insight gleaned will give researchers the opportunity to test the theory that comets brought organic matter and water to Earth billions of years ago, giving them a key role in the evolution of life on our planet, said Klim Churyumov, one of the two astronomers to discover the comet in 1969.

Rosetta and Philae will accompany the 2½-mile wide comet as it races past the sun. Between them, they will use 21 instruments to take 3-D images, analyze the comet’s chemical composition and electrical properties, and even probe its internal structure.


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