Kellie Gerardi (born February 16, 1989) is an American popular science communicator, social media influencer, and commercial astronaut who is known for a sub-orbital spaceflight with Virgin Galactic as a payload specialist in 2023.

[7][8] As of 2024[update], she worked as a lead on the company's mission operations team, which provides customers like the United States Space Force with logistical and analytical support with the use of its data analysis software Gotham.

[10][2] In a 2015 contribution to HuffPost, she said reduced costs associated with spaceflight would extend the economy into space with lunar and low-earth orbit business opportunities.

[11] After meeting Richard Garriott at The Explorers Club, where she worked the coat check,[2][7] in 2014, Gerardi decided to join as a member.

[13][15][16] In an interview with Popular Science, she said they tested the ability to grow hops in a simulated Martian regolith using Earthen soil as a control.

[19] Gerardi completed a program called "Project PoSSUM", which stands for polar suborbital science in the upper mesosphere,[8] which includes study on topics such as bioastronautics and training in high altitude flights to experience weightlessness.

[4][8][3] In June 2024, Virgin Galactic announced Gerardi as a crew member on a second research spaceflight scheduled for as early as 2026 aboard the Company’s Delta Class spaceship.

[30][23] She began her social media career as a teenager on YouTube filming popular Christmas content of her family, when the site was new.

[38] Gerardi lives in Jupiter, Florida with her husband and their daughter Delta V, who was named for delta-v, the quantitative measure of a change in velocity.