With the opening of the hatch on their SpaceX Dragon capsule, the four-person crew of the Polaris Dawn mission became exposed to the vacuum of space.
Then, hundreds of miles above the Earth, tech billionaire and mission commander Jared Isaacman took a giant leap for private space exploration.
"Back at home we all have a lot of work to do, but from here, Earth sure looks like the perfect world," he said, as he emerged from the capsule.
With that, Isaacman conducted the first spacewalk by a commercial company. Aside from launches and re-entries, spacewalks are considered the most dangerous part of a space mission.
RELATED STORY | Polaris space mission will provide the first private space walk
"This is a major step forward in terms of space travel for humans," said Ilan Kelman, a professor at University College London. "It also brings with it incredible risks because a lot of the technology is new. A lot of it has not been fully tested in outer space."
During the spacewalk, the crew conducted tests to see how their experimental spacesuits operated in the harsh environment of outer space.
What makes this mission even more unusual, though, are the people involved in it.
The four-person crew is not made up of professional career astronauts. Instead, it consists of two SpaceX engineers, a former Air Force pilot and Isaacman, the commander of the mission.
Isaacman and SpaceX engineer Sarah Gillis conducted the spacewalk. Each spent about 10 minutes outside the capsule, tethered to it via a ladder-like structure and a 12-foot line.
"It's people with a very different background and very different training from what has happened before in terms of professional astronauts," Kelman said. "So, it's always this balance between risk and reward."
The Polaris Dawn crew will be in orbit for a couple more days after the spacewalk. Their total mission is scheduled for five days. Then, there will come another risky part to this mission: reentry into Earth's atmosphere.
RELATED STORY | Tech billionaire pulls off first private spacewalk high above Earth
