Space Station Astronauts Taking Spacewalk Today: Watch It Live

NASA astronaut Scott Kelly is seen during his first spacewalk outside the International Space Station on Oct. 28, 2015. Kelly and crewmate Tim Kopra will make a 3-hour spacewalk today (Dec. 21) to fix a stuck railcar on the station.
NASA astronaut Scott Kelly is seen during his first spacewalk outside the International Space Station on Oct. 28, 2015. Kelly and crewmate Tim Kopra will make a 3-hour spacewalk today (Dec. 21) to fix a stuck railcar on the station. (Image credit: NASA)

Two American astronauts will take a short, but unplanned, spacewalk today (Dec. 21) to fix a stuck railcar on the International Space Station in time for the arrival of a new cargo ship later this week.

NASA astronauts Scott Kelly and Tim Kopra expect to spend more than three hours to latch down the outpost's Mobile Transporter, a railcar that moves the station's robotic arm along the length of its backbone-like main truss. You can watch the spacewalk repair live here beginning at 7:30 a.m. EST (1230 GMT), courtesy of NASA TV.

The Mobile Transporter must be latched securely in place ahead of the planned arrival of Russia's unmanned Progress 62 cargo ship on Wednesday (Dec. 23), NASA officials have said. The railcar jammed up last week, stopping just 4 inches (10 centimeters) away from its intended storage point near the center of the station's main truss.

NASA engineers suspect a stuck brake handle is what stalled the Mobile Transporter, but need Kelly and Kopra to manually free the railcar and secure it in place.

Today's space station repair will mark the third career spacewalk for Kelly and the second for Kopra, who only just arrived at the International Space Station last week aboard a Russian Soyuz spacecraft. Kelly and Kopra form one-third of the station's six-man crew. British astronaut Tim Peake and Russian cosmonauts Mikhail Kornienko, Sergey Volkov and Yuri Malenchenko round out the crew.

Kelly and Kornienko are flying a one-year mission to the space station and due to return to Earth in March with Volkov, who is on a six-month trip. Kopra, Peake and Malenchenko launched to the space station on Dec. 15 to begin their own half-year in orbit.

Email Tariq Malik at tmalik@space.com or follow him @tariqjmalik and Google+. Follow us @Spacedotcom, Facebook and Google+. Original article on Space.com.

Join our Space Forums to keep talking space on the latest missions, night sky and more! And if you have a news tip, correction or comment, let us know at: community@space.com.

Tariq Malik
Editor-in-Chief

Tariq is the Editor-in-Chief of Space.com and joined the team in 2001, first as an intern and staff writer, and later as an editor. He covers human spaceflight, exploration and space science, as well as skywatching and entertainment. He became Space.com's Managing Editor in 2009 and Editor-in-Chief in 2019. Before joining Space.com, Tariq was a staff reporter for The Los Angeles Times covering education and city beats in La Habra, Fullerton and Huntington Beach. In October 2022, Tariq received the Harry Kolcum Award for excellence in space reporting from the National Space Club Florida Committee. He is also an Eagle Scout (yes, he has the Space Exploration merit badge) and went to Space Camp four times as a kid and a fifth time as an adult. He has journalism degrees from the University of Southern California and New York University. You can find Tariq at Space.com and as the co-host to the This Week In Space podcast with space historian Rod Pyle on the TWiT network. To see his latest project, you can follow Tariq on Twitter @tariqjmalik.