Editor’s note: Follow along with CNN’s live updates as the SpaceX Polaris Dawn crew attempts the first commercial spacewalk.
A four-person crew of civilians on board SpaceX’s Polaris Dawn mission are preparing to unlock the hatch of their capsule and make history as the first group of non-government astronauts to conduct a spacewalk.
SpaceX is hosting a live webcast of the event — also known as an extravehicular activity (EVA) — which kicked off a little after 6:00 a.m. ET.
The entire SpaceX Crew Dragon vehicle propelling and protecting the crew will be depressurized and exposed to the vacuum of space — a dangerous and historic milestone in the Polaris Dawn crew’s five-day journey through Earth’s orbit. The mission has already set records, traveling farther into space than any human since NASA’s Apollo program concluded more than 50 years ago.
The crewmates — which includes Shift4 Payments CEO Jared Isaacman, Polaris Dawn’s financer; his close friend and former US Air Force pilot Scott “Kidd” Poteet; and SpaceX engineers Anna Menon and Sarah Gillis — have been preparing for this spacewalk since they took flight at 5:23 a.m. ET Tuesday.
The team has been slowly undergoing what is called a “pre-breathe” process, a step intended to purge their blood of nitrogen to prevent the gas from bubbling — a potentially lethal condition — as they experience the vacuum of space.
What to expect
Though the crew previously reached a peak altitude of more than 1,400 kilometers (870 miles), the spacewalk is expected to occur while their vehicle is traveling between 190 and 700 kilometers above Earth (118 to 435 miles).
All told, the Crew Dragon capsule is expected to spend about two hours exposed to space after the crew opens a hatch located at the top of vehicle.
But only Gillis and Isaacman will actually exit the spacecraft, for a combined total of roughly 20 minutes. They’ll walk up a mobility aid — essentially a ladder that SpaceX has dubbed “skywalker” — to venture into the endless void.
“There’s a lot of time built in for venting (or depressurizing the spacecraft) and repressurizing,” Isaacman told CNN about the two-hour spacewalk window. “And probably the biggest fear that (we’ve tried to) protect for is a failure to repressurize the vehicle — because then all you have is your oxygen reserves to get back home in about two hours if needed.
“So I don’t expect we’ll have too much sight-seeing time,” Isaacman added.
Brand-new suits
While Isaacman and Gillis are outside the capsule, however, they will focus on demonstrating how their brand-new EVA suits work in space.
EVA suits essentially function as spacecraft unto themselves — just shaped and formatted to fit the human body. Unlike the iconic puffy white spacesuits that government astronauts use while exiting the International Space Station for a spacewalk, the SpaceX EVA suits do not include a Primary Life Support System, or PLSS, according to Garrett Reisman, a former NASA astronaut who serves as a SpaceX consultant.
A PLSS is essentially a backpack that allows ISS astronauts to float more freely through space to carry out complex tasks, such as repairing and replacing hardware outside the space station. Instead, the Polaris Dawn crew will receive their life support from long hoses attached to their spacecraft.
Still, SpaceX’s EVA suits are an impressive feat of engineering. The company designed and developed the spacesuits in just two and a half years — specifically for this mission.
The goal was to develop spacesuits that could one day be produced on a large scale, rather than expensive and bespoke objects currently used by space agencies.
When discussing the vision for the EVA suits in an interview with CNN, Isaacman referenced the bigger picture goal: to one day have entire settlements of people living in space.
Isaacman said he discussed that vision with SpaceX CEO Elon Musk, and they agreed: “We need space suits. And, you know, they shouldn’t cost hundreds of millions of dollars. We need tens of thousands of them someday.”
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