Cosmic first: European spacecraft lands on comet

DARMSTADT, Germany (AP) – The European Space Agency has achieved a historic first – landing a washing machine-sized spacecraft on a comet speeding through our solar system at 41,000 mph (66,000 kph).

Landing with a bounce after traveling 4 billion miles, the European spacecraft reached the icy, dusty surface of a speeding comet after a decade- long journey. It required immense precision, as even the slightest error could have resulted in stellar calamity.

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 with a chuckle.

Ulamec said thrusters that were meant to push the lander, called 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 were still 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.

Pioneer The landing team at mission control in Darmstadt had to sweat through a tense seven- hour wait that began when Philae dropped from the agency’s Rosetta space probe as both it and the comet hurtled through space at 41,000 mph (66,000 kph).

During the lander’s descent, scientists were powerless to do anything but watch, because its vast distance from Earth — more than 300 million miles — made it impossible to send instructions in real time.

Finally, at 16:03 GMT (11:03 a.m. EST), the agency received a signal that the lander had touched down.

While it may take a while to determine the exact state of the 220-pound (100-kilogram) lander, the fact that it was resting on the surface of the comet was already a huge success – the highlight of Rosetta’s decade-long mission to study comets and learn more about the origins of these celestial bodies.

The head of the European Space Agency underlined Europe’s pride in having achieved a unique first ahead of its U.S. counterpart, NASA.

``We are the first to have done that, and that will stay forever,’’ said the European agency’s director-general, Jean- Jacques Dordain.

NASA contributed three instruments to the mission and its Deep Space Network of giant radio antennas

Collect data

Scientists have likened the trillion or so comets in our solar system to time capsules that remain virtually unchanged since the earliest moments of the universe. They are most excited about the possibility that the mission might help confirm that comets brought the building blocks of life — organic matter and water — to Earth. They already know that comets contain amino acids, a key component of cells. Finding the right kind of amino acids and water would be an important hint that life on Earth did come from space.

Mark McCaughrean, a senior scientific adviser on the mission said Philae has ten instruments on board — including devices to measure light, electrical magnetism and heat — and flying up above the comet the Rosetta spacecraft has another 11 instruments. The Philae lander will provide plenty of images of a world no human has ever seen close up and will drill below the surface to extract a sample of the comet that will be analyzed onboard.

The lander’s batteries are expected to last just 64 hours enough for scientists to gather a huge wealth of data. In addition, the lander has a solar panel that should provide an hour’s worth of battery life per day for up to five months.

Challenge ahead

The comet is on a 6 ½-year elliptical orbit around the sun. This makes for great science, since Philae and Rosetta will be able to observe the comet becoming more active.

As 67P approaches the sun, the amount of matter it sheds will greatly increase, posing a potential risk to the lander and even to the Rosetta spacecraft flying in tandem with the comet. As the comet reaches perihelion, the closest point to the sun, the rising temperatures could also damage Philae. But the lander should remain stuck to the comet forever, even after its systems have shut down. Rosetta will continue to fly alongside the comet until the end of its useful lifetime in about two years. Scientists have suggested that a fitting end would be for it, too, to land on the comet and reunite with the lander once more.