European Space Agency's Philae probe has woken up and made contact with controllers, seven months after it went into hibernation on the comet 67P/Churyumov-Gerasimenko.
The probe lost contact with its mothercraft Rosetta in November 2014, 60 hours after becoming the first spacecraft to land on a comet.
The craft's battery had failed to charge after it bounced twice off 67P/Churyumov-Gerasimenko.
A harpoon system had failed to activate correctly leaving the craft on its side beside a cliff about 1km from the original target.
Last month Andrea Accomazzo, flight director of the ESA's Rosetta Mission, told Al Jazeera he had almost given up hope the craft would wake up.
"I don't put too many hopes in having Philae reactivated," Accomazzo said. "I consider it not impossible but extremely unlikely."
There had been hopes as the comet neared the Sun that Philae's solar panels would recharge its batteries. Now it appears the craft has done just that, communicating for 85 seconds with controllers.
Many of the craft's 10 instruments were able to run their tests and transmit the results before its battery ran out.
It now looks likely that these tests may be able to be resumed, with indications that the craft may have been awake for some time before resuming contact.
"We have also received historical data - until now, however, the lander had not been able to contact us," the Philae Project team said in an email.
"Now, the scientists are waiting for the next contact. In Philae's mass memory, there are still more than 8,000 data packets, which will give the team information on what happened to Philae in the past few days."
The next two months are critical for the $1.8bn scientific mission because during this time the comet will reach its closest point to the sun and is likely to be the most active.
Last month the team controlling the Rosetta spacecraft, which has been orbiting the comet since last year, took drastic action and moved it into an orbit 125km above the comet after dust clouds caused a complete reset of its navigation instruments.
The mission had been expecting a gradual increase in the amount of dust and gas coming from 67P/Churyumov-Gerasimenko as it warmed up on its journey towards the sun at a speed of 18km per second.
The scientific instruments on board Rosetta have been measuring and photographing 67P/Churyumov-Gerasimenko from this new orbit.
The mission aims to unlock knowledge about the origins of the solar system and even life on Earth, which some believe may have started with comets "seeding" the planet with life-giving carbon molecules and water.
Source: Al Jazeera