Space-X's Inspiration Four flight has filled all four seats after announcing its last two crew mates on Tuesday.
The historic, all civillian three-day space trip is being paid for and commanded by billionaire Jared Issacman.
The trip this fall will raise $200 million for St. Jude in Memphis.
Joining him is an Arizona-based science educator and a Seattle data engineer.
A previously selected passenger on the trip is St. Jude employee and child cancer survivor Hayley Arceneaux.
Arceneaux received care from St. Jude as a child where she now works as a physician's assistant.