Elon Musk’s SpaceX is planning to send its first “all-civilian” crew to space at the end of 2021 in a charity-focused mission commanded by tech entrepreneur Jared Isaacman.

The company said in a press release it’ll pick three people to ride alongside Isaacman to orbit aboard SpaceX’s Crew Dragon capsule.

Isaacman, a trained pilot and the chief executive of Shift4 Payments, said he donated $100 million to St. Jude Children’s Research Hospital and wants to help raise $200 million more by inviting people to donate at least $10 to St. Jude for a chance to get picked.

SpaceX announces first ‘all-civilian’ mission to space https://t.co/7cNg6C8kxq pic.twitter.com/ZIBlLZtHTK

— The Verge (@verge) February 1, 2021

Three people will be chosen “to represent the mission pillars of leadership, hope, generosity and prosperity,” according to a press release — though one person was already picked, Isaacman said during a press call on Monday.

The full crew “will be announced in the weeks ahead,” SpaceX said.

“This is an important milestone towards enabling access to space for everyone,” Musk told reporters on the call, adding that it’s part of SpaceX’s broader goal to “bring the cost down over time and make space accessible to all.”

The mission, named Inspiration4, will launch from SpaceX’s 39A launch site at NASA’s Kennedy Space Center in Florida atop the company’s Falcon 9 rocket. Prior to flight, crew members will get special training from SpaceX with “a specific focus on orbital mechanics, operating in microgravity, zero gravity, and other forms of stress testing.”

The four-person crew will spend up to five days in the acorn-shaped Crew Dragon capsule as it orbits Earth every 90 minutes “along a customized flight path,” SpaceX and the contest’s official rules said.

“The mission parameters are up to Jared,” Musk said. The mission could last anywhere from two to four days long, “but if you wanna stay up longer that’s fine too,” he added.

Musk and Isaacman offered scant details on the kind of training the crew members will go through, but it’ll be long enough for the participants — three strangers — to get to know each other before spending a few days confined to Crew Dragon’s tight cabin.

“We are all going to know each other incredibly well, long before we ever strapped into Dragon, I can promise you that,” Isaacman said.

Crew members must be “physically and psychologically fit for training,” under 6 feet and 6 inches tall and weigh less than 250 pounds, per the fundraiser’s official rules (a person who’s able to ride the Incredible Hulk roller coaster in Florida would be a perfect fit, Musk said).

If the mission gets delayed past 2022, crew members will each get an “alternate prize” of $150,000, the fine print added.

SpaceX has launched two crews to space already, but those were with trained NASA astronauts — including one astronaut from Japan’s space agency — on government-funded trips to the International Space Station.

The Inspiration4 mission marks SpaceX’s latest private astronaut mission to be announced: The company’s Ax-1 mission, also planned for the end of 2021, hosts a crew of four private astronauts paying $55 million each for an eight-day trip to the ISS.

And in 2018 Elon Musk announced Japanese billionaire Yusaku Maezawa will hitch a ride around the moon on SpaceX’s new rocket system Starship, which is in development.

SpaceX developed its Crew Dragon capsule with a more than $2 billion contract under NASA’s Commercial Crew Program, the agency’s initiative to spur private spacecraft development.

Kathy Lueders, who led the crew program and is currently NASA’s human spaceflight chief, tweeted after the Inspiration4 reveal on Monday she was “excited to see one of the original goals of @Commercial_Crew come to be with the expansion of new commercial activities beyond our own in low-Earth orbit.”

Isaacman told reporters the mission kicks off the biggest fundraiser ever for St. Jude, a children’s hospital with an already massive fundraising reach.

“If we’re going to continue making advances up there in space, then we have an obligation to do the same down here on Earth,” he said.