ISS spacewalk to study microorganisms on exterior of orbiting lab

NASA spacewalker and Expedition 64 Flight Engineer Victor Glover works to ready the International Space Station's port-side truss structure on January 27, 2021, for future solar array upgrades. On Thursday, NASA astronauts Tracy Dyson and Matt Dominick from Expedition 71 will take part in "U.S. Spacewalk 90" to scrape microorganisms from the exterior of ISS to study the origins of life. File Photo by NASA/UPI

June 11 (UPI) -- NASA astronauts will venture into space Thursday to scrape microorganisms from the outside of the International Space Station and study the origins of life.

Their live-streamed spacewalk also will include some repairs.

NASA plans to steam "U.S. Spacewalk 90," which is estimated to start at 8 a.m. EDT on Thursday and last about six and a half hours, on NASA+, NASA Television, the NASA app, YouTube, as well as on the space agency's website.

"We're putting space on demand and at your fingertips with NASA's new streaming platform," Marc Elkins, NASA Headquarters' Office of Communications associate administrator, said earlier this year.

"Transforming our digital presence will help us better tell the stories of how NASA explores the unknown in air and space, inspires through discovery and innovates for the benefit of humanity."

NASA astronaut Tracy Dyson will take part in her fourth spacewalk Thursday outside of the International Space Station with NASA astronaut Matt Dominick. The pair will scrape microorganisms from the exterior of the orbiting laboratory to study survivability in space. File Photo by Pavel Mikheyev/EPA-EFE/POOL
NASA astronaut Tracy Dyson will take part in her fourth spacewalk Thursday outside of the International Space Station with NASA astronaut Matt Dominick. The pair will scrape microorganisms from the exterior of the orbiting laboratory to study survivability in space. File Photo by Pavel Mikheyev/EPA-EFE/POOL

Astronauts Tracy Dyson and Matt Dominick will exit the ISS Quest airlock early Thursday to collect samples of microorganisms on the outside of the orbiting laboratory and to remove a faulty electronics box.

Viewers will be able to identify Dyson, who will be wearing a spacesuit with red stripes, and Dominick, who will wear an unmarked suit. This will be Dyson's fourth spacewalk and Dominick's first.

"We are excited to go outside the space station in a few weeks," Dominick wrote last month in a post on X.

"We are preparing now by setting up our tools, working on our spacesuits, and studying procedures and contingencies."

"Super awesome to go do that. We've been inside the space station for the past couple of months running research or fixing the inside of the space station. But now we get to go outside," Dominick said in a video last month, as he prepared his spacesuit for Thursday's journey.

Dominick and Dyson have been at ISS with five other Expedition 71 crew members since April 5, and are set to return to Earth in September. Last week, they welcomed Boeing's Starliner crew Barry "Butch" Wilmore and Sunita Williams to the space station, as they work to test and certify Starliner over the next seven days.

For Thursday's spacewalk, which is the first of three planned over the next several weeks, Dyson and Dominick will collect samples for future analysis to understand how microorganisms can survive and reproduce on the exterior of ISS, where solar radiation can vary between 248 and -148 degrees Fahrenheit. The astronauts will study the extremophiles, which scientists say can survive space's harsh environments for long periods of time.

Dyson and Dominick also will remove a faulty electronics box, called a radio frequency group, from a communications antenna on the starboard truss of the space station during Thursday's walk.

Two more spacewalks are scheduled for later this month and in July. Spacewalk 91, which will replace an external high-definition camera on ISS, is scheduled for Monday, June 24. Spacewalk 92, which will replace a rate gyro assembly to provide data on orientation of the space station, is scheduled for Tuesday, July 2.