Watch NASA astronauts collect microbe samples during ISS spacewalk today (livestream video)

NASA astronauts Tracy Caldwell Dyson and Matthew Dominick will perform the spacewalk, or extravehicular activity (EVA). The action is scheduled to start at 8 a.m. EDT (1200 GMT) and last about 6.5 hours.

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

During their spacewalk, the duo will retrieve a faulty piece of communications equipment, known as the radio frequency group. Dyson will also swab the exterior of the space station to gather samples for a study of microorganisms in extreme microgravity environments.

“There is a group of scientists that’s very interested in this, for example, for going to Mars and understanding what we might carry with us to the Martian surface — accidentally discovering something on the Martian surface that actually came from us, that kind of thing,” Dina Contella, NASAs deputy program manager for the International Space Station, said Tuesday (June 11) during a spacewalk-previewing press briefing.

On Monday (June 10), fellow NASA astronaut Mike Barratt assisted Dominick with a spacesuit fit check, according to a NASA blog update. The 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 tasks on Thursday.

Thursday’s EVA is the first of three upcoming 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 on the docket for Thursday affected the schedule for the first-ever astronaut mission of Boeing’s Starliner capsule, called Crew Flight Test (CFT).

CFT launched with NASA astronauts Butch Wilmore and Suni Williams on June 5. The duo 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 several 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 additional days in orbit will also allow Wilmore, Williams and ground teams to perform additional checks of Starliner before the shakedown flight parachutes back down to Earth.