In a remarkably calm reaction for what sounds like the plot of an epic space movie, NASA has announced it plans to send two astronauts on an emergency spacewalk on Tuesday, May 23, to fix a problem after a computer failure on the ISS over the weekend.

The data relay box was one of two onboard that control the functioning of major systems across the International Space Station (ISS), including radiators, solar arrays, cooling systems, and other equipment.

On Saturday morning, the system was reported to have failed, and after careful consideration and thorough testing of a backup unit by veteran astronaut Peggy Whitson, NASA gave the green light for an emergency spacewalk to replace the broken one.

NASA was keen to stress nobody was in any danger at any point, explaining in a statement that the ISS’ other multiplexer-demultiplexer (MDM) data relay box was running perfectly and the failure has had little impact on station activities.

Station commander Whitson and fellow NASA astronaut and flight engineer Jack Fischer will conduct the spacewalk, which is expected to last around two hours, on Tuesday at 8am EDT (1pm BST). In addition to replacing the failed box, Fischer will also install a pair of wireless communications antennas on the Destiny Lab, which had originally been planned for the last spacewalk on May 12.

As usual, NASA will begin live streaming the event on NASA Television at 6.30am EDT (11.30am BST).

The MDM that failed was installed with upgraded software on a spacewalk on March 30 by Whitson and flight engineer Shane Kimbrough, who has since returned to Earth. The cause of the failure is not yet known, but it is thought to be an internal failure of the box itself.

NASA’s last emergency spacewalk was back in December 2015, when two US astronauts had to leave the ISS and go outside to release the brakes on a robot’s arm, according to Reuters.  

This will be Fischer’s second spacewalk and Whitson’s 10th – in April, Whitson set the record for longest time spent in space by a US astronaut. It will also be the 201st spacewalk in support of maintaining the ISS, so don’t expect any Passengers or The Martian style endings. For these seasoned pros, it’s just another walk in the park.