SpaceX is making history by launching the first ever all-civilian mission to orbit, and you can watch it happen live. The aerospace corporation is opening a five-hour launch window for the mission called Inspiration4 today, September 15th, at 8:02PM Eastern time. Inspiration4 was paid for a billionaire who was relatively unknown before this: Shift4 Payments CEO Jared Isaacman. He’s bringing three more people with him, and none of them are trained astronauts or have been to space before.

Isaacman, who’s an experienced pilot, will be the mission’s commander, while Hayley Arceneaux will be its medical officer. Arceneaux is a physician assistant at St. Jude Children’s Research Hospital who had cancer herself as a child. According to The Atlantic, one of the goals for this mission is to raise $200 million for the hospital, and Isaacman wanted to bring one of its employees. 

Geoscience professor and former NASA astronaut program finalist Sian Proctor will serve as the mission pilot. Finally, data engineer and Iraq War veteran Chris Sembroski will serve as mission specialist. Proctor won an online competition organized by Isaacman, while Sembroski got his slot from a friend who won a raffle for a seat on the mission.

The team trained together for six months and completed a full rehearsal of launch day activities on September 13th. They’ll spend three days orbiting our planet aboard SpaceX’s Crew Dragon capsule that will blast off on top of a Falcon 9 rocket. While they’re hurtling across space, the team will conduct scientific research meant to provide more data on the effects of long-duration spaceflights on the human body. 

SpaceX has started streaming the event on its website and its YouTube page. Netflix will also stream the launch on YouTube.