Mission managers at the European Space Operations Centre in Darmstadt, Germany, made contact with Philae at around 0930 GMT this morning, downloading data from experiments conducted overnight and uploading new commands, including starting the lander's drill.
"It started to drill but then we lost contact again," said Philae manager Stephan Ulamec during a press conference this afternoon. This was expected, as the data link goes down as the mother ship Rosetta moves behind the comet. The link should be working again by 2100 GMT this evening, but it will take two more hours to actually download the data.
Philae may not be able to make contact at all. The team estimates that the lander needs 80 watt-hours of energy in its battery to complete its operations and upload the results. Simulations suggest Philae has around 100 watt-hours left – a tight margin. The team tried to switch the spacecraft to a low-power mode, but the command did not upload before they lost contact. "If we do not receive an update it is probably because the battery is flat," said Ulamec – or an asteroid fell on Philae, he joked.