posted 05-11-2017 06:52 PM               

Astronauts to conduct 200th station spacewalk

Expedition 51 crew mates Peggy Whitson and Jack Fischer of NASA will perform a landmark 200th spacewalk at the International Space Station on Friday (May 12).

Whitson and Fischer will venture outside station at 7 a.m. CDT (1200 GMT) to replace a large avionics box that supplies electricity and data connections to experiments and replacement hardware stored outside the laboratory.

The ExPRESS Carrier Avionics, or ExPCA is located on the starboard 3 truss of the station on one of the depots housing critical spare parts. It will be replaced with a unit delivered to the station in April on board Orbital ATK's "S.S. John Glenn" Cygnus cargo spacecraft.

In addition, Whitson and Fischer will install a connector that will route data to the Alpha Magnetic Spectrometer (AMS) and help the crew determine the most efficient way to service the cosmic ray detector.

During the planned six and a half hour spacewalk, the astronauts also will install a protective shield on Pressurized Mating Adapter-3, which was moved from the Tranquility to the Harmony node in March. This adapter will host a new international docking adapter for the arrival of commercial crew spacecraft.

Whitson and Fischer also will rig a new high-definition camera and pair of wireless antennas to the exterior of the outpost.

Whitson, who already holds the U.S. record for most spacewalks by a female astronaut, will make this ninth excursion as extravehicular crew member 1 (EV-1), wearing a suit with red stripes. Fischer, EV-2, will wear a suit with no stripes on his first-ever spacewalk.

The first spacewalk in support of the assembly and maintenance of the International Space Station was conducted on Dec. 7, 1998, by NASA astronauts Jerry Ross and Jim Newman during space shuttle Endeavour's STS-88 mission.

posted 05-12-2017 07:45 AM               

Spacewalk delayed, shortened due to water leak

Today's spacewalk is starting later than planned and will be shortened after the loss of a service and cooling umbilical (SCU) to a water leak during preparations inside the Quest airlock.

Spacewalkers Peggy Whitson and Jack Fischer traded off use of the remaining SCU while the other relied on spacesuit battery power. The water leak was detected from the SCU leading to Fischer's spacesuit.

With the two spacesuits' battery reserves depleted, the EVA has been abbreviated to four hours, with Whitson and Fischer only tasked with replacing the ExPRESS Carrier Avionics box.

posted 05-12-2017 12:35 PM               

NASA astronauts complete milestone 200th spacewalk at space station

Two NASA astronauts working outside of the International Space Station performed a shortened but still successful spacewalk on Friday (May 12), marking the 200th extravehicular activity in the nearly 20 year history of the orbiting outpost.

Expedition 51 crewmates Peggy Whitson and Jack Fischer completed the extravehicular activity (EVA) which replaced an avionics box that routes power to experiments, added a data path to a cosmic ray detector and installed a shield on a docking port.

"It is amazing to do the 200th EVA aboard the International Space Station," said Whitson after re-entering the airlock.