A sleeping space probe called Rosetta was successfully reactivated on Monday and phoned home to let engineers know it was safe!
Rosetta was launched in 2004 as part of a daring mission to land on a comet.
It was put into hibernation in 2011 to save power. It was so far away from the Sun that its solar panels could not have kept it running.
The probe woke up at 10am on Monday and sent a signal to confirm all its systems are working.
Rosetta is due to drop a lander on Comet 67P/Churyumov-Gerasimenko on 11 November.
Comets are believed to contain materials that have remained largely unchanged since the formation of the Solar System 4.6billion years ago.
Jean-Jacques Dordain from the European Space Agency said: "Rosetta is a unique mission... comets may be at the origin of who we are."