First-ever landing on comet2014.11.17
LANDING with a bounce after travelling four billion miles, a European spacecraft made history on Wednesday by reaching the icy, dusty surface of a speeding comet – a first designed to answer big questions about the universe.
The landing by the washing machine-sized craft after a decade-long journey required immense precision. However, it sits on a high cliff face, which is blocking its solar panels.
First indications were that the spacecraft touched down almost perfectly, save for an unplanned bounce, said Stephan Ulamec, head of the lander operation. But pictures beamed back showed it resting on its side in the shadow of a cliff.
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.
The landing team at mission control in Darmstadt (達姆施塔特 ), Germany 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 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 4.03pm GMT (12.03am local time), the agency received a signal that the lander had touched down.
While it may take a while to determine the exact state of the 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 US counterpart, Nasa.