Comet Landing Bumpier Than Initially Thought

This historic landing of a spacecraft on a comet on Wednesday turned out to be not one but three landings as the craft hopped across the surface.

Because of the failure of a thruster that was to press it against the comet’s surface after touching down, the European Space Agency’s Philae lander, part of the $1.75 billion Rosetta mission, bounded up more than half a mile before falling to the surface of Comet 67P/Churyumov-Gerasimenko again nearly two hours later, more than half a mile away. That is a considerable distance across a comet that is only 2.5 miles wide.

Philae then bounced again, less high, and ended up with only two of its three legs on the surface, tipped against a boulder, a wall of rock or perhaps the side of a hole.

“We are almost vertical, one foot probably in the open air — open space. I’m sorry, there is no air around,” Jean-Pierre Bibring, the lead lander scientist, said at a news conference on Thursday.

Comet Lander Starts Drilling but Batteries a Worry

BERLIN — Good news: the spacecraft that landed on a comet has begun drilling below the surface to see what secrets the celestial body can reveal.

Bad news: Scientists at the European Space Agency that launched the historic mission still don't know exactly where the lander is on the comet and were anxiously hoping its batteries will keep running long enough to get the mining data and adjust the lander's position.

It was a race against time Friday for the Philae lander, which on Wednesday became the first spacecraft to touch down on a comet. Since then it has sent astonishing images from the icy, dusty comet named 67P/Churyumov-Gerasimenko and generated some data from onboard instruments such as one that measures temperatures. All this is taking place 311 million miles (500 million kilometers) from Earth on a comet traveling 41,000 mph (66,000 kph) through space.

Material beneath the surface of the comet has remained almost unchanged for 4.5 billion years — making those mining samples a cosmic time capsule that scientists are eager to study. Mission controllers said Philae was able to bore 25 centimeters (10 inches) into the comet's surface to start collecting the samples, but it's unclear whether it has enough power to be able to deliver any information on them.