The team behind the comet probe Philae say they are "confident" it will wake up again at some point.
Lander manager Stephan Ulamec said he hoped to achieve contact again after the spacecraft's batteries died on Friday.
But that might not happen until next spring, when Philae and the comet it is riding on - 67P/Churyumov-Gerasimenko - get closer to the sun, warming up a secondary battery on board.
A few days of sunshine on the solar panels should be enough to charge the battery sufficiently to conduct science runs, Mr Ulamec said.
His team are still waiting to find out whether Philae managed to drill into the comet and extract a sample for analysis.
Material beneath the surface of the comet has remained almost unchanged for 4.5 billion years, so the samples would be a cosmic time capsule that scientists are eager to study.
One of the things they are most excited about is the possibility that the mission could confirm that comets brought the building blocks of life - including water - to Earth.
Thsee incredible images show the moment the probe dropped from its satellite and first landed on Comet 67P five days ago.
Scientists racing against time to keep the Philae comet lander operating are debating whether to try 'hopping' the probe to a new location.
After the first man-made craft landed on a moving comet we look at the pictures sent back from the daring descent to the historic landing.