SpaceX launches Polaris Dawn, where astronauts will venture farther than any humans in more than 50 years

A SpaceX Falcon 9 lifted off in the early hours of Tuesday morning carrying a crew that will attempt the first commercial spacewalk and travel higher than any crewed mission in 50 years.

The Polaris Dawn mission lifted off from NASA’s Kennedy Space Center at 5:23 a.m. EST after several delays due to inclement weather. Near the end of the first day of the mission, the SpaceX Crew Dragon capsule’s orbit will reach a high point of 1,400 kilometers (870 miles). This will be the highest altitude humans have traveled since the Apollo 17 mission to the moon in 1972, and three times higher than the International Space Station.

The four-person crew will be blasting through the high-energy Van Allen belt, where radiation is far higher than at lower altitudes. During that phase of the mission, they’ll be conducting research to better understand the effects of radiation on the human body.

“We stand to learn quite a bit from [that environment] in terms of human health science and research,” mission leader Jared Isaacman said in a news conference last month. “If we get to Mars someday, we’d love to be able to come back and be healthy enough to tell people about it, so I think that it’s worthwhile to get some exposure in that environment.”

The crew includes billionaire entrepreneur Isaacman, who founded Shift4 Payments; mission pilot Scott “Kidd” Poteet, a retired U.S. Air Force Lieutenant Colonel; and two SpaceX employees, mission specialist Sarah Gillis, an engineer and astronaut trainer, and mission specialist Anna Menon, a medical director who also runs SpaceX’s mission control during its flights.

On day three of the five-day mission, the crew will lower the Dragon’s altitude to around 700 kilometers (435 miles). At that point, they’ll attempt the first spacewalk not involving government astronauts. All four will don spacesuits and open the hatch of the spacecraft, though only two crew members, Isaacman and Gillis, will exit the Dragon. They’ll take turns venturing into the vacuum of space for around 15 to 20 minutes while tethered to the capsule by umbilical cords.

The crew will be donning new extravehicular activity suits designed by SpaceX, and these suits will be put to the test for the first time. SpaceX also introduced a series of modifications to Dragon, like handholds around the hatch, as mobility aids for the spacewalk. These handholds will be crucial because Isaacman and Gillis aren’t planning on doing any free-floating, but will hold onto the Dragon at all points through the walk. The entire operation, from venting the Dragon to depressurization, will take about two hours.

The suits are especially exciting given SpaceX’s long-term ambitions to establish a human colony on Mars, as hundreds or thousands of people could wear similar suits in the future.

This mission is a partnership between Isaacman and SpaceX. Neither party has ever disclosed the cost of the flight, nor how much Isaacman is paying to fly, but it offers a welcome opportunity for SpaceX to test its technology in orbit. Besides the suits, the crew will also test communications between the Dragon and SpaceX’s Starlink constellation, which would enable in-capsule Wi-Fi, a critical piece of tech that could enable reliable crew communications on future missions to the moon or Mars.

This will be the first of three missions in Isaacman's Polaris program. The third is intended to be the first crewed launch of SpaceX’s Starship. He first traveled to space three years ago on the Inspiration4 private astronaut mission that also launched with SpaceX.

Shortly after lift-off, Isaacman expressed his thanks to the company: “We wouldn't be on this journey without all 14,000 of you back at SpaceX,” he said.

After five days in orbit, the crew will return to Earth and splash down off either coast of Florida.