Scott Kelly Takes First Spacewalk Ever After almost 400 Days in Space

This was the 189th spacewalk devoted to station assembly and maintenance since construction began in 1998, the fifth so far this year and the first for Kelly and Lindgren.

Two NASA astronauts stepped out on a spacewalk on Wednesday for upgrades and maintenance at the orbiting global Space Station, the U.S. space agency said.

Expedition 45 commander Scott Kelly and flight engineer Kjell Lindgren returned to the space station’s airlock where repressurization began about 3:19 p.m ET, marking the official end of the spacewalk, NASA said in a live broadcast of the event.

Kelly is on the verge of breaking the 215-day record for the longest mission in space.

Before Wednesday’s spacewalk, Kelly’s identical twin, Mark, a retired astronaut, urged his brother to be careful but still have fun. In addition to the routine lube work, they routed cable for a future docking port, removed insulation from an electronic switching unit, and covered an antimatter and dark matter detector. Lindgren is routing the power cables.

“You guys did a great job”, radioed Tracy Caldwell Dyson, an astronaut working with the crew from the flight control center in Houston. The future missions are slated to carry up to four new crew members to the station in the near future in order to allow more research to be performed in orbit and to return American launch capabilities for its astronauts. In 2013, an astronaut performing a spacewalk nearly drowned when his helmet flooded with water.

Mr Kelly and Mr Lindgren picked up work from NASA’s last spacewalks almost eight months ago. Russian Mikhail Kornienko is also part of the one-year experiment, although it will fall shy of the 14-month world record held by a fellow cosmonaut. “The countdown clock is ticking”, he said last week in a tweet.

President Barack Obama already has relayed congratulations. He spent 437 days aboard the Russian space station Mir in 1994 and 1995.