The most significant part of their mission was carried out today by the crew members of SpaceX’s Polaris Dawn mission: they conducted the first-ever spacewalk by private astronauts.

The mission’s crew consists of 41-year-old billionaire Jared Isaacman, 50-year-old former Air Force commander Scott Poteet, and SpaceX employees Sarah Gillis, 30, and Anna Menon, 38.

Jared Isaacman and Sarah Gillis exited the “Crew Dragon Resilience” spacecraft at noon (Greek time) for the spacewalk, marking another milestone in the development of the commercial space industry.

Isaacman stepped out of the capsule just before 2:00 PM (Greek time) and, while looking at Earth, remarked, “Back home, we all have a lot of work to do, but from here, it looks like a perfect world.” His spacewalk lasted around 10 minutes before he returned to the capsule. Sarah Gillis followed around 2:10 and returned to the capsule after 10 minutes.

At 2:20, Gillis closed the capsule’s hatch, and the recompression process began.

Polaris Dawn is the first of three planned missions under billionaire Jared Isaacman’s Polaris Program. Just like NASA’s “Project Gemini” in the mid-1960s, which prepared for the Apollo program, this mission aims to gather experience and develop techniques and technologies for future commercial missions to the Moon, Mars, and beyond.

The Polaris Dawn mission marks the third flight of SpaceX’s “Crew Dragon Resilience,” which previously flew the Crew-1 and Inspiration4 missions—the latter being the first fully commercial space mission, also funded by Jared Isaacman.

After its successful launch on Tuesday, Polaris Dawn began its mission by flying higher than any other human spaceflight since Apollo 17’s return from the Moon in 1972. “Resilience” was initially placed at 1,200 km and completed several orbits before reaching the highest point of its trajectory at 1,400.7 km.

After completing the high-altitude segment of the mission, “Resilience” lowered its apogee to around 700 km to prepare for Thursday’s spacewalk. This will be the first time a spacewalk takes place during a commercial mission or by commercial astronauts. Both Isaacman and Sarah Gillis of SpaceX are expected to exit the capsule to test their space suits in the vacuum of space. The other two crew members, Scott Poteet and Anna Menon will remain inside Dragon but will still be exposed to the vacuum since Dragon doesn’t have an airlock, meaning the entire capsule will be depressurized during this phase of the mission.

This achievement further advances the development of technologies for future missions to the Moon, Mars, and beyond.