Watch NASA astronauts collect microbial samples during spacewalk on ISS today (live video)

Editor’s Note: NASA has postponed today’s spacewalk with NASA astronauts Tracy C. Dyson and Matt Dominick due to a ‘spacesuit comfort’ issue.

Two NASA astronauts will blast off from the International Space Station today (June 13), and you can watch it live online for free.

NASA astronauts Tracy Caldwell Dyson and Matthew Dominick will perform the spacewalk, or extravehicular activity (EVA). The action is scheduled to start on 08:00 EDT (1200 GMT) and lasts about 6.5 hours.

You can watch the International Space Station (ISS) in action on this page and the Space.com homepage, courtesy of NASA, or directly through the space agency. Coverage will begin at 6:30 am EDT (1030 GMT). (You can read more about spacewalks and how they work on our EVA reference page.)

During their spacewalk, the pair will receive a faulty piece of communications equipment, known as a radio frequency array. Dyson will also sweep the exterior of the space station to collect samples for a study of microorganisms in extreme microgravity environments.

“There’s a group of scientists who are very interested in, for example, going to Mars and figuring out what we might carry with us on the surface of Mars — accidentally discovering something on the surface of Mars that actually came from us, something like that,” said Dina Contella, NASA’s deputy program manager for the International Space Station, on Tuesday (June 11) during a spacewalk press conference.

On Monday (June 10), NASA astronaut Mike Barratt assisted Dominic with a spacesuit fit check, according to a NASA blog update. That same day, Barratt, Dominick and Dyson were joined by NASA astronaut Jeanette Epps to review EVA procedures for the station’s Canadarm2, which will assist Dyson and Dominick with their duties on Thursday.

Thursday’s EVA is the first of three future spacewalks geared toward ongoing science and maintenance of the orbital laboratory. The other two are expected to take place this summer as well.

Having a spacewalk docked for Thursday affected the schedule of the first astronaut mission of Boeing’s Starliner capsule, called the Crew Flight Test (CFT).

CFT launched with NASA astronauts Butch Wilmore and Suni Williams on June 5. The pair rendezvoused and docked with the ISS a day later, and were scheduled to stay aboard for about a week. But Wilmore and Williams recently had their mission extended by a few days and are now expected to return to Earth no earlier than June 18.

NASA announced the delay on Sunday (June 9), citing the need for extra time for the station’s current astronauts to prepare for Thursday’s EVA. The extra days in orbit will also allow Wilmore, Williams and the ground crews to perform additional checks of the Starliner before the shakedown flight parachutes return to Earth.