This month, Russian and European engineers confirmed the success of their “open-heart surgery” on the computer lifeline of the International Space Station.

Teams from both the Russian space agency Roscosmos and the European Space Agency (ESA) developed a method in which an astronaut or cosmonaut aboard the space lab could upgrade the computers that keep the ISS on track and in the right position, known collectively as the Data Management System. It’s a task that ESA representatives described in a statement as “the equivalent of open-heart surgery on Earth!”

Engineers on the ground rigorously planned and tested the process before it would be performed in space to ensure that the repair work could be done on-site without posing any risk to the spacecraft or its inhabitants, according to ESA.

Read more: space