SpaceX

In 2015, while at the University of Colorado Boulder, Gillis began an internship at SpaceX, working on human-in-the-loop testing of the Dragon spacecraft before moving full-time to the astronaut training program.^[6]

She is a lead space operations engineer at SpaceX, responsible for overseeing the astronaut training program for the company's Crew Dragon vehicles. She prepared NASA astronauts for the first Demo-2 and Crew-1 missions and more recently directly trained Inspiration4 astronauts, the first all-civilian crew to go into orbit. Gillis is an experienced Mission Control Operator, who has supported real-time operations for Dragon's cargo resupply missions to and from the International Space Station as a Navigation Officer and as Crew Operations and Resources Engineer (CORE) for crew Dragon missions, the SpaceX equivalent of the NASA CAPCOM role.^[7]

Polaris Dawn

In September 2024 Gillis flew on Polaris Dawn, a private spaceflight operated by SpaceX on behalf of Shift4 CEO Jared Isaacman.^[8][9] She performed a stand-up extravehicular activity (SEVA) with Jared Isaacman, becoming the youngest person to do so. Gillis, along with Anna Menon, set the record for the farthest women from Earth^[10] (in 2026, Artemis II mission specialist Christina Koch travelled through lunar deep space). Later during the mission, Gillis, a classically trained violinist, played the solo violin part of "Rey's Theme" by John Williams from the 2015 film Star Wars: The Force Awakens to raise money for St. Jude Children's Research Hospital and El Sistema.^[11]

NASA

As of 2026, she serves at NASA as a Senior Advisor to the Administrator.^[12]