Today, NASA astronauts Peggy Whitson and Jack Fischer will perform the 200th spacewalk outside the International Space Station (ISS). These include replacing a large avionics box that supplies electricity and data connections for various onboard science experiments, and installing a fabric shield created to protect against micrometeorites on one of the spacecraft's pressurized mating adapters.
The spacewalk had been scheduled to begin at 8 a.m. EDT (1200 GMT), the US space agency said. The adaptor will enable companies like SpaceX and Boeing to visit the station, making it an important port for the future of space exploration. An equipment water leak has shortened the spacewalk.
Watch the spacewalk live from NASA's website here.
Mission Control stressed throughout the morning that Fischer's suit was fine and that the leak was confined to the umbilical hose.
The very first spacewalk at the ISS took place on December 7, 1998.
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The spacewalk started at 3:45 p.m. EDT on the third orbit when White opened the hatch and used the hand-held manuevering oxygen-jet gun to push himself out of the capsule.
The 1 spacewalk in support of construction, maintenance or fix of the space station happened in 1998, when the NASA still used space shuttles and the space station itself was like a tiny, New York City apartment compared to the expansive space mansion that it is today.
The EVA started over the Pacific Ocean near Hawaii and lasted 23 minutes, ending over the Gulf of Mexico.
Today's spacewalk builds on a historic career for Peggy Whitson.
The highest-priority tasks for the spacewalk, which had been slated to last 6 1/2 hours, are to replace a 200-pound electronics box that routes commands and data to experiments, and to install equipment to troubleshoot a cooling system problem with the station's $2 billion dark matter detector.
The station orbits the Earth at a height of about 250 miles (400 kilometers), circling the planet every 90 minutes at a speed of about 17,500 miles (28,000 kilometers) per hour.