NASA astronauts Tracy C. Dyson and Matthew Dominick are currently getting ready to exit the International Space Station (ISS). No, they are not coming back to Earth, they will be taking the airlock to perform an extravehicular activity (EVA), better known as a spacewalk, around the station, which is being streamed live today. Part of it will be maintenance of the station, but there is also some exciting science too, including scooping up some microbes to study.

Dyson and Dominick will be removing a radio frequency group hardware from a pallet that is on the outside of the Destiny Laboratory Module. They will be helped in this job by the Canadarm2 – the robotic arm of the station – piloted by NASA Flight Engineers Mike Barratt and Jeanette Epps, who practiced the manouver on the computer already. 

The spacewalk is due to last around 6.5 hours, and following the scheduled maintenance, the astronauts will be swabbing the surfaces of the Destiny module and also the Quest module as part of a research project called ISS External Microorganisms. 

There are life support system vents on those modules and both bacteria and fungi might have found our way out of the ISS. The question is can they survive there? The samples will be brought down to Earth for detailed analysis. Bacteria on the ISS has already been seen to have mutated into something very different from its earthly counterparts so scientists are curious about their ability to adapt to the harsh environment of space.

This is the first of three EVAs scheduled for this summer. Although relatively common, spacewalks are dangerous, with one in five having serious incidents and close calls. Luckily the "emergency" on the ISS yesterday, accidentally broadcast across all its live channels, was actually a medical training simulation, even if it did cause a brief panic.

The broadcast begins 6:30 a.m. ET (12pm UTC) and it can be followed in the video above, or on NASA+, NASA Television, the NASA app, YouTube, and the agency’s website.