Astronauts Prepare For Contingency Spacewalk



Astronauts Peggy Whitson and Jack Fischer are getting ready for a contingency spacewalk Tuesday morning. Whitson and Fischer are set to begin the spacewalk at 8 a.m. Tuesday for about two hours of maintenance work.

NASA Television coverage will begin at 6:30 a.m.

The spacewalkers are gathering their tools and checking their spacesuits today with assistance from Flight Engineer Thomas Pesquet. The trio are also reviewing the contingency spacewalk procedures.

The spacewalk's primary task is the removal and replacement of a data relay box, known as a Multiplexer-Demultiplexer (MDM), which failed Saturday morning. The MDM controls the functionality of station components such as the solar arrays, radiators, cooling loops and other systems.

Whitson will replace the failed MDM with a spare unit on the Starboard Zero truss. The truss is attached to the space-facing side of the U.S. Destiny lab module and is the centerpiece of the station's truss structure which houses the solar arrays, radiators and cooling loops. Fischer will install a pair of wireless communications antennas on the Destiny Lab, a task that was postponed during the May 12 spacewalk.

Tuesday's spacewalk will be the 201st in support of station assembly and maintenance. This will be Commander Whitson's 10th spacewalk likely moving her to third place all-time in cumulative spacewalking time. Flight Engineer Fischer will be embarking on his 2nd spacewalk.

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