NASA Astronauts Step Outside Space Station for 1st of 3 Holiday Spacewalks

Astronauts Mike Hopkins and Rick Mastracchio ventured outside of the International Space Station to begin repairs on the station's vital cooling system on Dec. 21.
Astronauts Mike Hopkins and Rick Mastracchio ventured outside of the International Space Station to begin repairs on the station's vital cooling system on Dec. 21. (Image credit: NASA TV)

Two NASA astronauts have begun the first of three quickly planned spacewalks to fix a problem with the International Space Station's vital cooling system.

NASA astronauts Mike Hopkins and Rick Mastracchio ventured outside of the space station's Quest airlock today (Dec. 21) to begin the repairs. The spacewalk officially began at 7:01 a.m. EST (1200 GMT) when the two astronauts took their spacesuits to internal power. NASA TV will broadcast the entire 6.5-hour EVA (extra-vehicular activity or spacewalk), and you can watch the spacewalk live on

"It's a beautiful day," one of the astronauts said as he stepped outside of the orbiting outpost.

Mastracchio and Hopkins are leaving the confines of the station to remove and replace a failed pump module that helps keep equipment inside and outside of the space laboratory cool. The six space station residents are not in any immediate danger, but in order to get the station up to its fully functional status, the two astronauts will need to perform the spacewalks scheduled for today, Dec. 23 and, if necessary, Christmas Day (Dec. 25), NASA officials said. [Photos: Astronauts Spacewalk Outside to Fix Vital Cooling System]

For this first spacewalk, Hopkins and Mastracchio will focus on preparing the failed pump module for removal and getting the replacement module — stored outside of the station — ready for installation. Mastracchio will be connected to the space station's robotic arm during much of the spacewalk, and he is wearing the suit with red stripes. Hopkins' spacesuit has no stripes.

"We refer to it as a contingency spacewalk, and the skills really are fundamental," NASA astronaut Doug Wheelock said of the spacewalks during a NASA TV event Thursday. "We practice all of these skills, just rehearse them over and over again in the pool. The crew has done these particular skills. The skills are the same, but space always has surprises for us, especially when we go outside."

Veteran spacewalker Mastracchio has performed six EVAs totaling 38 hours and 30 minutes of spacewalk time. Today's spacewalk is Hopkins' first EVA. Japanese astronaut Kiochi Wakata will assist them from inside the station, driving the robotic arm.

Three Russian cosmonauts also live and work aboard the space station with Mastracchio, Hopkins and Wakata. Oleg Kotov, Sergey Ryazanskiy and Mikhail Tyurin round out the orbiting outpost's Expedition 38 crew.

Spaceflight firm Orbital Sciences was scheduled to launch an unmanned Cygnus spacecraft on a resupply mission to the space station on Dec. 19, however, that launch was pushed to no earlier than Jan. 7 to accommodate the urgent spacewalks.

Editor's Note: This story is an updated version of a previous spacewalk story - NASA Astronauts Perform 1st of 3 Holiday Spacewalks Saturday: Watch Live

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Miriam Kramer
Staff Writer

Miriam Kramer joined as a Staff Writer in December 2012. Since then, she has floated in weightlessness on a zero-gravity flight, felt the pull of 4-Gs in a trainer aircraft and watched rockets soar into space from Florida and Virginia. She also served as's lead space entertainment reporter, and enjoys all aspects of space news, astronomy and commercial spaceflight.  Miriam has also presented space stories during live interviews with Fox News and other TV and radio outlets. She originally hails from Knoxville, Tennessee where she and her family would take trips to dark spots on the outskirts of town to watch meteor showers every year. She loves to travel and one day hopes to see the northern lights in person. Miriam is currently a space reporter with Axios, writing the Axios Space newsletter. You can follow Miriam on Twitter.