BREVARD COUNTY, Fla. – The final two seats the “first all-civilian mission” to space have been filled.

Chris Sembroski, a Lockheed Martin employee and former Space Camp counselor, and Dr. Sian Proctor, a geoscientist and communication specialist, have been selected as crew members for the Inspiration4 mission. They join Shift4 Payments CEO Jared Isaacman and cancer survivor Hayley Arceneaux.

The full crew appeared together Tuesday at historic Launch Complex 39A at Kennedy Space Center.

The mission is designed to benefit St. Jude Children’s Research Hospital in Memphis, Tennessee. Issaaman, who will serve as the commander, is funding the mission.

“Inspiration4’s goal is to inspire humanity to support St. Jude here on earth while also seeing new possibilities for human spaceflight,”Isaacman said in a statement. “Each of these outstanding crew members embodies the best of humanity, and I am humbled to lead them on this historic and purposeful mission and the adventure of a lifetime.”

Sembroski, 41, contributed to a special fundraising campaign for St. Jude that offered a seat to a lucky donor. The campaign received nearly 72,000 entries. Sembroski will serve as the mission specialist and help manage payload and science experiments.

Proctor, 51, who will serve as the mission pilot, was selected from a pool of about 200 entrepreneurs who applied.

Arceneaux, who was announced as a crew member last month, works as a physician assistant at St. Jude. She will serve as mission’s medical officer.

For the Inspiration4 mission, the crew will spend three days in orbit around the Earth aboard a SpaceX Dragon capsule. The launch is targeted for no earlier than September 15 from Kennedy Space Center.