Jeff Thornburg is the CEO of Portal Space Systems. He started his career in the U.S. Air Force and earned his master's in aeronautical engineering from the Air Force Institute of Technology. While stationed at the Air Force Research Laboratory, Thornburg contributed to groundbreaking programs, including performing the world's first hydrogen full-flow staged combustion cycle engine demonstration.

Thornburg has held key roles in most of the private sector's most prominent commercial space companies, including VP of propulsion engineering at SpaceX, director of mechanical engineering and manufacturing for Amazon's project Kuiper, vice president of propulsion engineering at Stratolaunch, senior vice president of engineering at Agility Robotics, and chief of engineering at Commonwealth Fusion Systems.  

As SpaceX's second-ever head of propulsion engineering, he architected and developed the Raptor Engine for the Starship and Starship Booster programs. He also oversaw the successful launches of six Falcon 9s and streamlined certification processes with government agencies like NASA and the U.S. Air Force.

Throughout his career, Thornburg has been recognized with awards from NASA and the Air Force, including a NASA Space Flight Awareness award, the NASA Made It Happen award, the NASA Stennis Space Center Propulsion Test Director's Leadership Award, and an Air Force Research Laboratory Technical Program Manager of the Year.