Polaris Dawn spacewalk: Watch live as SpaceX’s commercial astronauts attempt mission’s historic EVA

Their week-long mission, called Polaris Dawn, is fully private with no NASA involvement — but it’s no billionaire joyride. This spacewalk is a critical test of technical abilities that SpaceX will need to achieve Elon Musk’s ultimate goal of building a city on Mars.

It’s also a risky feat for all four Polaris Dawn crew members: Jared Isaacman, the mission’s billionaire benefactor and commander; Anna Menon and Sarah Gillis, two SpaceX engineers; and Scott Poteet, a retired Air Force pilot who previously led strategy at Isaacman’s company Shift4.

Even though only two are performing the spacewalk, the entire crew is drifting in the vacuum of space, wearing new spacesuits that haven’t been tested in-orbit yet. The stakes are high.

“I know that they take safety very seriously,” Leroy Chiao, a retired NASA astronaut who has spent more than 36 hours on spacewalks and consulted for SpaceX on its Safety Advisory Panel for 12 years, told Business Insider in an email.

He added that SpaceX knows any mishap would “seriously impact” commercial human spaceflight, “if not kill it.”

The Polaris program is livestreaming the spacewalk on X.

“I’ll be watching with great interest,” Chiao said.

The Polaris Dawn spacewalk plan

The spacewalk procedure began 48 hours before opening the Crew Dragon’s hatch, with a “pre-breathe.”

The two-day process slowly decreased the pressure in the spaceship’s cabin to eventually put the crew on 100% oxygen. That helped purge nitrogen from their blood and prevent a dangerous condition called “the bends.”

This procedure is similar to one that astronauts on the International Space Station use before their spacewalks, although their pre-breathes only last a few hours because they do it in the confines of a small, contained airlock. Crew Dragon has no airlock, so the crew had to balance the pressure in the entire cabin with the pressure in the spacesuits to give everyone’s body an opportunity to adjust. Hence, a longer, 48-hour pre-breathe.

After the pre-breathe, the Polaris crew donned their spacesuits — the first SpaceX has ever designed for spacewalks. Each spacesuit is connected to the spacecraft through an umbilical cord that is providing what the astronauts need to survive like power and air.

The crew then opened their spaceship’s hatch. Since there is no airlock, this exposed the entire cabin of the vehicle and its crew to the vacuum of space.

“You are taking on a lot of risk at that point,” Isaacman said in a briefing on August 19.

“You’re throwing away all the safety of your vehicle,” he added.

Then, Isaacman and Gillis left the spacecraft to perform tests on their spacesuits, but they always maintained contact with one of the many handrails added to the ship’s exterior for this mission. The other two — Menon and Poteet — stayed inside to provide support.

Isaccman was the first to depart the aircraft. He performed a series of mobility tests while looking down at the Earth below.

“We have a lot of work to do back home, but from here it’s sure looks like a perfect world,” Isaccman said during the livestream.

After Isaccmen returned to the spacecraft, Gillis departed and performed the same mobility tests. Shortly after, she returned to the spacecraft safely and closed the hatch.

The risks and stakes are high

The Polaris Dawn spacewalk plan — no airlock, vehicle fully open to space — is not totally unprecedented. NASA’s Gemini and Apollo programs did the same thing.

Abhi Tripathi, a former Dragon mission director at SpaceX, who now directs mission operations at UC Berkeley’s Space Sciences Laboratory, told BI that the spaceship was designed “from the beginning” to withstand unplanned depressurization events.

Tripathi added that he doesn’t see “any special risks” with the spacewalk. In fact, he admitted to feeling a bit of “FOMO and jealousy” seeing his former colleagues, Menon and Gillis, go to space.

What’s more, SpaceX has spent two and a half years upgrading the Crew Dragon, testing it, and running simulations with the four crew members to prepare for this spacewalk.

Chiao also expressed confidence that the company has “thoroughly reviewed” its flight plans.

But trying anything new in space is risky. And there’s a lot that’s new in this plan: a 48-hour pre-breathe protocol, the spacesuits, the fact that a Crew Dragon spacewalk has never happened before, and the fact that all the crew members will be new to spacewalking.

Isaacman previously flew to space in 2021 on another Crew Dragon flight he commissioned. Poteet was the mission director for that flight, called Inspiration4. Menon and Gillis have provided ground support for multiple SpaceX missions. None of them have ever been in the actual vacuum of space before, though.

“They will be testing a new suit with people who have never done this before,” Chiao said.

He added that depressurizing the entire cabin also adds risk for the two people remaining inside. They’ll be wearing spacesuits, too, but it will still be a more precarious situation than sitting inside a sealed, pressurized, environmentally controlled spacecraft.

As with any space mission or spacewalk, there is also a risk that any of the millions of bits of space debris orbiting Earth could impact the spacecraft and endanger its crew.

Tripathi previously worked in flight reliability at SpaceX, a division which is now led by Bill Gerstenmaier, who previously spent four decades overseeing various human spaceflight programs at NASA.

“I feel very comfortable that there’s maybe no better team in the world from a safety perspective than the folks that are trying to make sure every I is dotted and T’s are crossed at SpaceX,” Tripathi said.