SpaceX announced Monday it’s aiming to launch this year the first all-civilian mission into Earth’s orbit, led by a tech billionaire who plans to raffle off one of the spots aboard the craft. An all-civilian mission is a huge stepping stone for the private spaceflight industry, but it also presents enormous challenges. Musk said SpaceX’s top priority will be to maximize the safety of the crew.

Entrepreneur Jared Isaacman is to be joined by three other novice astronauts for a multi-day journey into space, including one lucky winner of a drawing. SpaceX, the company started by Elon Musk, said Isaacman is “donating the three seats alongside him… to individuals from the general public who will be announced in the weeks ahead.”

Launch of the Dragon spacecraft is being targeted for “no earlier than the fourth quarter of this year”, the firm said. The Inspiration4 mission will travel into orbit aboard SpaceX’s Dragon spacecraft from Launch Complex 39A at NASA’s Kennedy Space Center in Cape Canaveral, Florida. SpaceX has been launching rockets from Launch Complex 39A since 2017, and the historic pad was previously used for both space shuttle flights and Saturn V launches during NASA’s Apollo moon program

Meanwhile, one seat will go to a worker from St. Jude Children’s Research Hospital, which treats childhood cancers and pediatric diseases, and the second is to be drawn from those who enter the raffle and are encouraged to donate to the hospital.

A third will be picked by a panel of judges from entrepreneurs who use an ecommerce tool from Isaacman’s company, Shift4 Payments. All three crewmembers “will receive commercial astronaut training by SpaceX on the Falcon 9 launch vehicle and Dragon spacecraft,” as well as orbital mechanics and stress testing, including operating in micro- or zero gravity, the statement said.

SpaceX says that during the multi-day mission, the astronauts will orbit Earth every 90 minutes. After the mission, the spacecraft will reenter the atmosphere for a water landing off the Florida coast.