After making history Wednesday by landing the first probe on the surface of a comet, European Space Agency scientists now face an agonizing wait to find out whether the Philae lander will continue sending data from 67P/Churyumov-Gerasimenko.
The culmination of an audacious 10-year mission, the Philae lander separated from its Rosetta mothership and successfully descended to the comet Wednesday. The touchdown, however, was fraught with problems, and the lander bounced twice before landing in the shadow of a cliff – a serious problem for the solar panels designed to provide long-term power to Philae after its primary and secondary batteries are exhausted.
In an early Friday press conference from the European Space Operations Center (ESOC) in Darmstadt, Germany, scientists explained that the lander may soon run out of battery power, making it unable to send any information from the comet’s surface.
“We’re not sure that the battery still has enough energy to transmit this data,” said Lander Project Manager Stephan Ulamec, explaining that ESA is scheduled to make contact with Philae at around 4 p.m. ET.
The agency should have a clearer idea of Philae’s status around midnight local time, which is 6 p.m. ET, according to Ulamec.
“It’s going to be really, really close, whether we make it,” added Valentina Lommatsch, a member of the lander control center team.
After initially touching down in the correct location, images taken by the probe suggest that it eventually settled just a few feet away from a cliff.
“We’re really unlucky – in a corner surrounded by rocks,” explained Lommatsch.
Scientists also remain unsure about the lander’s actual location.
“We’re still trying to locate it,” said Andrea Accomazzo, ESOC flight director. However, ESA is scanning an area between 0.6 and 1.2 square miles in an attempt to find the probe.
Designed to collect a host of data, one of Philae’s key tools is a drill, which will help scientists analyze the comet’s structure.
Scientists confirmed on Friday that the drill has extended around 10 inches from the lander’s base plate, although Lommatsch said that, at this stage, it’s difficult to tell whether it has penetrated the comet’s substrate.
“The drill has to make quite a distance,” she explained. “We will have to hope that it reaches the ground – it’s hard to say.”
“We started to drill, then we lost contact again,” said Ulamec. “Whether it will succeed in taking samples, we should know this evening.”
With the harpoons meant to anchor Philae to the ground failing to work properly, there had been concerns that the drill would push the lander back into space. Gravity on the comet is 1/100,000th that of Earth, meaning the lander weighs just 0.04 ounces there.
If the ESA can successfully make contact with the still-powered probe, scientists are looking at ways to move it out of the shadows. One option would be using the lander's flywheel, which keeps the probe stable in flight, but is deactivated on landing.
“An idea is to spin up the flywheel and get the lander out of the hole,” said Ulamec. “We were talking about this, and we’re still thinking about this.”
“We’re thinking about moving the landing gear up,” added Lommatsch. “And hoping that we can maybe ‘bounce’ our way out.”
Even if the probe’s batteries are exhausted and contact cannot be made late on Friday, scientists are hopeful that Philae could come ‘back to life’ when the comet’s orbit takes it closer to the sun.
Lommatsch noted that in August 2015 Philae may receive enough solar energy to power up its solar panels and send data from the comet’s surface. “Perhaps we will have something from the lander again,” she said. “Keep your fingers crossed.”
67P/Churyumov-Gerasimenko, which is known as a “short period” comet, takes 6.6 years to orbit the sun.
The comet, which is about 2.5 miles wide, travels at speeds up to 84,000 miles per hour.
Early on Thursday, the ESA released the first picture taken by the probe after determining that the craft had stabilized following its tension-filled landing. The agency subsequently released the first panoramic picture taken from the lander. The three feet of Philae's landing gear can be seen in some of the frames.
Philae and the Rosetta spacecraft plan to use 21 instruments to analyze the comet. Scientists hope the $1.62 billion mission will help them better understand comets and other celestial objects, as well as possibly answer questions about the origins of life on Earth.
Follow James Rogers on Twitter @jamesjrogers
The Associated Press contributed to this report.