BERLIN — The spacecraft that landed on a comet performed two tricky maneuvers Friday, by drilling into the rocky surface and rotating itself to catch more sunlight.

Both operations carried considerable risks, because they could have toppled the probe or pushed it out into the void. But without them, the Philae lander, which scored a historic first by touching down on a comet Wednesday, risked skipping a key scientific experiment and running out of battery power.

Scientists at the European Space Agency said the maneuvers appeared to have worked.

“My rotation was successful (35 degrees). Looks like a whole new comet from this angle,” read a message posted on the lander’s official Twitter account.

Earlier, the scientists tweeted: “First comet drilling is a fact!”

Since landing on comet 67P/Churyumov-Gerasimenko some 311 million miles away, the lander has performed a series of tests and sent reams of data, including photos, back to Earth.

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But with just two or three days of power in its primary battery, the lander has to rely on solar panels to generate electricity after that.

Scientists were concerned to find Thursday that Philae had unexpectedly bounced twice before coming to rest untethered to the surface, and that photos indicated it was next to a cliff that largely blocked sunlight from reaching two of its three solar panels.

With time running out, scientists decided to risk moving the lander and doing one of the most important experiments for which it was sent into space.

Material beneath the surface of the comet has remained almost unchanged for 4.5 billion years, making the mining samples a cosmic time capsule that scientists are eager to study.

Mission controllers said Philae bored 10 inches into the comet to start collecting the samples, but it’s unclear whether it has enough power to deliver any information on them.

It was also unclear whether the rotation had succeeded in getting the lander’s solar panels out of the shadow. Scientists are expected to know more when Philae re-establishes contact early Saturday.

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Meanwhile, the Rosetta – Philae’s mother ship, which is streaking through space in tandem with the comet – will use its 11 instruments to analyze the comet over the coming months.

Scientists hope the $1.6 billion project that was launched a decade ago will help them answer questions about the origins of the universe and life on Earth.

Communication with the lander is slow, with signals taking more than 28 minutes to travel between Earth and Rosetta.

No matter how long Philae keeps talking to them, scientists say they already have gathered huge amounts of data and are calling the expedition a roaring success.

“Let’s stop looking at things that we could have done if everything had worked properly,” said flight director Andrea Accomazzo. “Let us look at things that we have done, what we have achieved and what we have on the ground. This is unique and will be unique forever.”


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