Polaris Dawn: The world's first commercial spacewalk was the 20th EVA in history

Two private astronauts conducting the first commercial spacewalk didn't float out of their spacecraft, but stood up.

Polaris Dawn crewmates Jared Isaacman and Sarah Gillis took turns exiting the top hatch of SpaceX’s Dragon spacecraft, “Resilience,” on Thursday (Sept. 12). It was the first time non-government astronauts left the protective confines of their vehicle to enter the vacuum of space. It was also the 20th stand-up extravehicular activity (SEVA) in history.

“I think we all have a lot of work to do at home, but from here Earth looks like a perfect world,” Isaacman said as he stepped through the Dragon's hatch and saw the planet illuminated before entering the nighttime atmosphere.

Isaacman, the billionaire businessman who funded this five-day flight and two other Polaris missions that followed, was the first to poke his helmeted head out of the spot where the docking ring would normally be if Dragon were to connect with the International Space Station. Instead, SpaceX outfitted the capsule with the “Skywalker,” a set of rails and foot supports that was specifically designed to keep astronauts tethered and connected by umbilical cord in contact with the vehicle.

With Dragon's nose pointed toward Earth and its front flap deployed to act as a shield against any flying micrometeoroid debris, Isaacman and Gillis each took about 10 minutes to put SpaceX's EVA suit through its paces.

“It includes all kinds of technology, including a head-up display and a helmet camera. [and] “A whole new architecture for joint mobility,” Polaris Dawn crewmate Anna Menon said of SpaceX’s new EVA suits during a pre-fight press conference. “There’s thermal insulation throughout the suit, including a copper indium tin oxide visor that provides thermal and solar protection. And then throughout the suit, there’s all kinds of redundancy, both in the oxygen supply to the suit and in all the valves and all the seals throughout the suit.”

On Resilience, Scott “Kidd” Poteet and Menon also wore EVA spacesuits, as the lack of an airlock on Dragon meant that the entire cabin had to be depressurized for their crewmates' spacewalk. Agency first used the same approach for its Gemini spacecraft in the mid-1960s, which is also when a distinction was first defined between performing a full-speed EVA, a SEVA, or an IVA (intravehicular activity).

Poteet and Menon, as IVA crew members, helped Isaacman and Gillis manage the 8-foot (2.4 m) of umbilical cables that supplied oxygen and power to the two spacewalkers' suits, extending from their garments into the Dragon.

Because Isaacman and Gillis never completely left the Dragon's vestibule (they kept at least part of their bodies inside at all times), the two added to the tally of standing EVAs conducted since 1966, when Agency astronaut Michael Collins stood in his seat and took photos outside the pilot-side hatch of the Gemini 10 capsule.

“We're not just going to float around,” Isaacman said of his own SEVA ahead of the launch of the Polaris Dawn mission. “We want to learn from history and always maintain at least one point of contact.”

In the 58 years since Collins conducted her first spacewalk, other astronauts, Russian cosmonauts and Chinese taikonauts have emerged from spacecraft hatches.

In 1969, David Scott stood up from the command module hatch while his Apollo 9 crewmate Rusty Schweickart performed a full spacewalk outside the lunar module in an Earth-orbiting test. Two years later, Scott performed a spacewalk out of the top hatch of the Apollo 15 lunar module to survey his surroundings before performing three spacewalks on the lunar surface.

Apollo astronauts Jim Irwin, Charlie Duke, and Harrison Schmitt also performed standing EVAs to photograph their crewmates while recovering science and film results during a trio of deep space EVAs between the Moon and Earth.

In 1977, Georgy Grechko and Yuri Romanenko became the first cosmonauts to perform standing EVAs. As they hovered halfway out of the Salyut 6 space station’s airlock, Grechko inspected a docking adapter for damage as the two tested what were then the new Orlan spacesuits.

The last standing EVA before Polaris Dawn was in 2008, during the first spacewalk by a Chinese taikonaut. Liu Boming spent most of the 22-minute EVA inside the orbital module of the Shenzhou 7 spacecraft, but at one point stood up to hand Zhai Zhigang a Chinese national flag to wave outside.

The Polaris Dawn spacewalk was the 477th EVA (of any type) in history. The spacewalk began at 6:12 a.m. EDT (1012 GMT) when the crew switched to oxygen supplies in their suits and lasted one hour and 46 minutes.