The Philae lander on the distant comet 67P has sent another stream of data back to Earth before losing power.
The little probe delivered everything expected from it, just as its failing battery dropped it into standby mode.
Philae is pressed up against a cliff. Deep shadows mean it cannot now get enough light on to its solar panels to recharge its systems.
The European Space Agency (Esa) fears this contact may have been the robot’s last – certainly for a while.
A tweet from the official Philae lander account said: “I’ll tell you more about my new home, comet 67P soon… zzzzz.”
Philae descended to the comet’s surface on Wednesday – the first time in history that a space mission has made a soft landing on a comet.
The next opportunity to talk to Philae was set to begin at around 10:00 GMT (11:00 CET), when the orbiting Rosetta satellite – which delivered it to the 4km-wide “ice mountain” – comes over the horizon.
But with only 1.5 hours of sunshine falling on the robot during the comet’s 12-hour day, it seems doubtful the battery will have recovered enough performance to complete the radio link.
Engineers did manage to maximise the possibility of it happening, though, by sending a command to reorientate the lander.
This involved raising Philae by 4cm and rotating its main housing by 35%. This will ensure the largest solar panel catches the most light.