US astronauts repair ISS equipment during spacewalk

The repairment was done in a record breaking 2 hours and 46 minutes long spacewalk, whereas, the usual was supposed to be a 6.5 hours-long spacewalk

In what can be called a miraculous victory of humanity, two astronauts were able to repair equipment, which helps power the International Space Station. Astronaut Peggy Whitson along with Jack Fischer, who is the flight engineer, achieved the feat of replacing the equipment that broke down last Saturday leading to the spacewalk that was hailed by scientists as a "critical contingency spacewalk" and was deemed to be a "high priority."


The device, which is called MDM or multiplexer-demultiplexer, is a computer relay box weighing about 50 pounds, when on the surface of Earth. The size of the device is like a microwave oven. Although, the weight and size of the device might sound meagre, the functions it performs is critical to ISS, where it helps with operating the solar arrays, robotic equipments and helps generate electric power. It also helps with balancing and keeping a check at the operation of both the radiators and cooling loops.

Although there are two MDMs present in the orbiting outpost, which means that the failure of one would not be affecting the lives of the crew at the ISS or obstruct the functioning of the station, but experts were concerned about the failure and expected a replacement as soon as possible, which was achieved in the record breaking 2 hours and 46 minutes long spacewalk.

In the spacewalk to repair the malfunctioning MDM, Peggy Whitson along with Jack Fischer achieved the feat in less than the usual 6.5 hours of a spacewalk, where Whitson took the lead.


Peggy Whitson has recently made the record of being the first woman to spend 60 hours, 21 minutes on a spacewalk, which she achieved during the 10 spacewalks she went on and now she is at the third position among people, who have spent the most time in spacewalks.

Peggy Whitson, on this particular spacewalk, which was 201st in regards to the repairing and maintenance of the ISS, first took out the broken down MDM and then cleaned the area because of the presence of debris and then installed the new MDM. In Rob Navias' commentary, he noted: "We now have two healthy MDMs."

No reason for the failure of the MDM was stated, which was installed not long back, in March, by Whitson and Shane Kimbrough.


No reason for the failure of the MDM has been stated yet, which was installed not long back, in March, by Whitson and Shane Kimbrough.

Fischer, on the other hand, was on his second spacewalk and achieved the feat of facilitating wireless communication in future spacewalks with the installation of antennas on the US Destiny Laboratory module.

Peggy Whitson and Jack Fischer NASA
Related topics : Nasa