Polaris Dawn has landed.
The historic SpaceX astronaut mission, which included the first-ever private spacewalk, returned to Earth today (Sept. 15), landing safely in the Gulf of Mexico off the coast of Florida at 3:36 a.m. EDT (07:36 GMT).
"Polaris Dawn, our mission is complete. Thank you for all the great help in completing this mission," said mission commander Jared Isaacman after the crew landed in the ocean.
The re-entry was witnessed by astronauts aboard the International Space Station. "We actually had a pretty good view of the Polaris Dawn coming in. We were all kind of huddled up in the dome watching it," NASA astronaut Mike Barratt said, according to CBS' William Harwood. "That was pretty spectacular for us."
A historic private flight
Polaris Dawn was funded, organized and directed by billionaire tech entrepreneur Jared Isaacman, who did the same for SpaceX's Inspiration4 mission in September 2021, the first-ever fully private crewed flight to Earth orbit.
The wait for its second flight would not be that long: Polaris Dawn was originally scheduled for launch in 2022, but was repeatedly delayed due to the novelty and complexity of the mission.
Much of that complexity revolved around the spacewalk. For example, SpaceX had to develop and test its own extravehicular activity (EVA) suit, and modify Polaris Dawn's Crew Dragon capsule, called Resilience, for the occasion. Such modifications included installing a new hatch structure called Skywalker, which includes a ladder, handholds and footholds.
Polaris Dawn finally lifted off Tuesday (Sept. 10), sending Isaacman and three crewmates into orbit on a Falcon 9 rocket. Those companions were Scott "Kidd" Poteet, a former U.S. Air Force lieutenant colonel who served as a pilot, and mission specialists Sarah Gillis and Anna Menon, both engineers at SpaceX.
It didn't take long for the mission to make history. On Polaris Dawn's first day in space, Resilience reached a maximum altitude of 870 miles (1,400.7 kilometers) - higher than any manned spacecraft had ever gone in orbit.
It was also farther from our planet than any astronaut had traveled since the Apollo program ended in 1972. The Apollo astronauts were all men, so Gillis and Menon are now the most traveled women in history; no one else has strayed farther from their home planet.
Resilience then lowered its orbit to about 454 miles (730 km) to prepare for the EVA. There were other preparations as well; for example, the four crew members conducted a two-day "pre-breathing" campaign in orbit, purging their blood of nitrogen so they wouldn't get decompression sickness during the spacewalk. (Decompression sickness, also known as "the bends," is most common among divers. It occurs when nitrogen previously dissolved in the blood bubbles out due to a rapid drop in pressure.)
All four astronauts had to prepare themselves in this way, because all four of them would end up in space. Resilience has no airlock, so if the hatch were to open, the entire capsule would feel the effects.
The big moment came early Thursday morning (Sept. 12), when Isaacman poked his head out the open hatch and climbed into Skywalker to get an unobstructed view of the Earth below him.
"SpaceX, we still have a lot of work to do at home, but from here the world looks perfect," he said as he was exposed to the void.
Isaacman remained outside for nearly eight minutes, according to astrophysicist and satellite tracker Jonathan McDowell. He was followed out of the hatch by Gillis, whose EVA lasted seven minutes and 15 seconds. Neither was free floating in space; both remained in contact with Resilience, conducting what's known as a "stand-up EVA." Menon and Poteet remained in the capsule.
According to the Polaris Dawn team, the spacewalk officially began at 6:12 a.m. EDT (10:12 a.m. GMT), when the crew members pressurized their suits, and ended at 7:58 a.m. EDT (11:58 a.m. GMT), when Resilience was fully pressurized again. (According to McDowell, Resilience's hatch remained open for 26 minutes and 40 seconds.)
One of the main goals of the operation was to test SpaceX EVA suits, which the company hopes to use on many more missions in orbit and beyond.
"It's not lost on us that it may be 10 iterations and a lot of evolutions of the suit, but that one day someone will come up with a version of [it] "It could walk on Mars," Isaacman said during a pre-launch press conference on Aug. 26. "And it feels like, again, a great honor to have the opportunity to test it out on this flight."
Scientific experiments, engineering tests and more
While the spacewalk was the highlight, the Polaris Dawn crew also performed a variety of other tasks during their five days in space.
For example, the mission conducted 36 scientific experiments for 31 different institutions. Much of the orbital work will benefit NASA's Human Research Program, which seeks to learn more about how spaceflight affects the body and mind, and how to mitigate such effects.
"The information we gather with Polaris Dawn will provide critical insights to help NASA plan deeper space explorations to the Moon and Mars," said Jancy McPhee, NASA's deputy chief scientist for human exploration, in a statement ahead of the launch.
Polaris Dawn also tested the laser communications capabilities of SpaceX's Starlink broadband megaconstellation, using the satellites to transmit photos of home and other packets of data.
The astronauts also did some cultural and financial outreach. For example, Menon led an orbital reading of the children's book she co-wrote, "Kisses From Space" (Penguin Random House, 2024). According to SpaceX, proceeds from sales of the book will go to St. Jude Children's Hospital in Memphis. (Inspiration4 also supported St. Jude; that mission ultimately raised more than $250 million for the hospital.)
And Gillis played a song from "Star Wars" on the violin aboard Resilience. Her performance was synchronized with orchestras around the world for a music video put together by the Polaris Dawn team.
More Polaris missions are coming
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Polaris Dawn was the first of three planned missions in the Polaris program, which is funded and organized by Isaacman. Polaris "seeks to demonstrate key operational capabilities that will serve as building blocks to advance human exploration of the Moon, Mars, and beyond," according to its website.
We don't know much about the next two flights. But the program has announced that Flight 3 will be the first crewed mission of SpaceX's massive Starship Mars rocket.
Starship - the largest and most powerful launch vehicle ever built - has completed four test flights to date, most recently in June. SpaceX is still awaiting regulatory approval for a fifth flight, which isn't expected until late November.
