Nasa has successfully managed to reboot the computer on its Mars Odyssey spacecraft.
There were a few tense moments as the reboot of the computer was carried out, with fears that years of space radiation had damaged it.
Nasa's scientists had also been concerned that a damaged power component would mean the spacecraft's backups would not come back online.
However, Phillip Varghese, the mission's Project Manager, told the press that the operation was a total success.
"For nearly two years, we have not known for certain whether the backup systems would be usable, so this successful reboot has allowed us to ascertain their health and availability for future use," said Varghese.
Mars Odyssey has been in orbit around Earth's nearest neighbour since 2001, beaming back information on the red planet that has fascinated humankind for thousands of years.
That mission will start again in a matter of days.