D. Jason Cothern

Donald Jason Cothern (born November 12, 1970) is a United States Space Force major general who serves as the Missile Defense Agency Deputy Director and Program Executive for Ground-based Midcourse Defense. He previously served as the deputy commander of the Space Systems Command. He transferred to the Space Force from the United States Air Force in May 2021.

Prior to his current assignment, he was the assistant program director for development at the F-35 Lighting II Joint Program Office, where he was responsible for F-35 fighter fifth generation modernization activities.

Cothern was commissioned in 1993 as an ROTC graduate of the University of Central Florida. He served as the director of the Department of Defense’s Space Test Program and the Air Force's Hosted Payloads Office. As STP director, he also led the Rocket Systems Launch Program, where he was mission director for the DoD's first SpaceX Falcon 9 launch that flew NASA and National Oceanic and Atmospheric Administration's Deep Space Climate Observatory (DSCOVR) satellite in February 2015.

In July 2023, Cothern was nominated for promotion to major general.