London: Rosetta, which was launched about ten year ago on a long quest to chase and land on a comet, will be roused by an onboard "alarm clock" at 10:00 GMT on Monday.
Europe`s Rosetta probe has spent the past two-and-a-half-years in hibernation trying to conserve power.
After waking up, Rosetta is going to warm its systems before sending a signal to Earth.
Rosetta is due to meet Comet 67P/Churyumov-Gerasimenko in August.
And after spending a couple of months studying and mapping the 4km-wide ball of ice and dust, it`s going to drop a small robot on to the comet`s surface to gather samples and panoramic images.
Controllers at the European Space Agency `s (ESA) operations centre in Darmstadt, Germany, have no idea precisely when Monday`s all-important message will arrive, but they anticipate receiving it between 17:30 and 18:30 GMT.