Jared Isaacman, the 41-year-old founder and CEO of Shift4Payments, led the recently concluded SpaceX Polaris Dawn mission, where a team of four ventured farther into the cosmos than any humans in half a century
Jared Isaacman, the 41-year-old founder and CEO of Shift4Payments, led the recently concluded SpaceX Polaris Dawn mission, where a team of four ventured farther into the cosmos than any humans in half a century AFP

The commander of the daring space voyage that included the first-ever spacewalk by private astronauts described opening the hatch into the void as an "emotional experience" that left him in awe, yet deeply aware of the dangers.

Jared Isaacman, the 41-year-old founder and CEO of Shift4Payments, led the recently concluded SpaceX Polaris Dawn mission, where a team of four ventured farther into the cosmos than any humans in half a century.

On the mission's third day in orbit, Isaacman and crewmate Sarah Gillis, a SpaceX engineer, conducted the first extravehicular activity (EVA) by non-government astronauts -- marking a giant leap forward for the commercial space industry.

"What an emotional experience, a sensory overload," Isaacman said during a Space on social media site X on Tuesday.

"There's the physical exertion, there's the pressure changes, the temperature changes -- it gets a little cold -- and then, of course, the overwhelming visual sensation, when you see Earth with no kind of barrier between you other than the visor that's in front of you."

Since Soviet cosmonaut Alexei Leonov performed the first spacewalk in 1965, national space agencies have executed hundreds of EVAs.

Isaacman and Gillis gripped onto a hatch structure called "Skywalker" for the few minutes they each spent partly outside their Dragon spacecraft, while government astronauts have carried out far more daring feats, including floating away on a tether, or flying jetpacks untethered.

But Isaacman stressed the importance of his commercial endeavor was the benefit it brought to accelerating the evolution of SpaceX's next-generation spacesuit, as Elon Musk's company sets its sights on the colonization of Mars.

He added that while he was overwhelmed by the planet's beauty, the experience was far from peaceful.

"This is a hard, very threatening environment," he said, likening his experience to that of early maritime explorers sailing to the ends of the Earth.

Crewmate Gillis, who followed Isaacman outside, didn't have the same stunning views of Earth.

Still, the classically trained violinist was thrilled as she recapped the experience of playing a rousing rendition of "Rey's Theme" by Star Wars composer John Williams.

Bringing a violin into space came with its own set of challenges. Gillis had to use a smaller bow, and the instrument underwent rigorous testing to ensure it could withstand exposure to the vacuum during the spacewalk, as the Dragon spacecraft lacks an airlock.

"It was so interesting to be able to play an instrument in space," she said. "There were so many instances where you're just trying to keep it still enough that you can actually play successfuly."

The violin will be auctioned off, along with copies of a children's book authored by astronaut Anna Menon and read from space, to raise funds for St. Jude's Hospital.