Emergency spacewalk outside ISS underway; NASA astronauts Peggy Whitson and Jack Fischer take the reigns – Watch LIVE

(Image for representational purposes only)

New Delhi: Spacewalks are events that science and space enthusiasts look forward to with the initiation of every consecutive expedition launch. This time, however, NASA astronauts were asked to conduct an unscheduled emergency spacewalk to replace a critical computer relay box – that failed on May 20.

NASA astronauts Peggy Whitson and Jack Fischer have begun the spacewalk outside the International Space Station (ISS).

The relay box, known as a multiplexer-demultiplexer (MDM), is one of two units that regulate the operation of radiators, solar arrays and cooling loops. They also route commands to other vital station systems.

The spacewalk is currently underway and the LIVE coverage can be viewed here!

While the cause of the MDM failure is not known, NASA says the crew on the station is in no danger, and the MDM failure – believed to be internal to the box itself – has had no impact on station activities. Because each MDM is capable of performing the critical station functions.

The failed relay box was installed in the space station truss March 30 during a spacewalk by Whitson and Expedition 50 commander Shane Kimbrough.

Whitson, who prepared a spare data relay box May 21 and tested components installed in the replacement, said that the spare MDM is ready to be brought outside to replace the failed unit.

During the spacewalk planned to last about 2.5 hours, Whitson will replace the MDM, while Fischer will install a pair of antennas on the US Destiny Laboratory module to enhance wireless communication capability for future spacewalks.

The spacewalk – the 10th for Whitson and the second for Fischer – will be the 201st in support of space station assembly and maintenance. It is also the sixth spacewalk conducted from the Quest airlock this year.

Whitson, who already is the leading female spacewalker in history, will be designated extravehicular crew member 1 (EV-1) wearing a suit with red stripes. Fischer will be designated as EV-2, wearing a suit with no stripes.

A similar MDM replacement spacewalk was conducted in April 2014 by Expedition 39 crewmembers Steve Swanson and Rick Mastracchio of NASA.