William H. Gerstenmaier (born September 1954) is an aerospace engineer and policymaker, who served as Associate Administrator for Human Exploration and Operations between 2005 and July 10, 2019 at NASA’s headquarters in Washington and a special advisor to NASA's deputy administrator during July - December, 2019. Prior to being Associate Administrator, Gerstenmaier served as the International Space Station Office Program Manager, at Johnson Space Center, a position he began in June 2002. In February of 2020 Gerstenmaier joined SpaceX as Senior Principle Flight reliability Engineer Consultant, supporting Dragon Commercial Crew flights to ISS, Falcon 9 launches, Starlink, and Starship activities.
In 1977 after graduating from college, Gerstenmaier began his career at the Lewis Research Center (now Glen Research Center) in Cleveland Ohio. He began as an aeronautics research and test engineer working on subsonic and supersonic inlets and nozzles and running tests on Space Shuttle models in the 10-foot x 10-foot supersonic wind tunnel. In1980, Gerstenmaier moved to the Johnson Space Center in Houston Texas. Where he served as a Space Shuttle propulsion system flight controller. He was on console for the first Space Shuttle flight in 1981. In the mid-1980s, he was involved in the earliest phases of the International Space Station design at the Johnson Space Center. In 1984, he was a semi-finalist in the selection for NASA Astronaut Group 10. In 1988, he served as head of the Orbital Maneuvering Vehicle Operations Office. Following that, he became Director of Space Shuttle and Space Station Freedom Assembly Operations office. This office built all of the basic assembly plans that were later used to assemble the International Space Station. After spending two years at Purdue University pursuing a PhD in Aeronautics and astrodynamics, he returned to the Johnson Space and worked in the Flight design and Dynamics Division.
Gerstenmaier also served as Shuttle/Mir Program operations manager. In this role, he was the primary interface to the Russian Space Agency for operational issues, negotiating all protocols used in support of operations during the Shuttle/Mir missions. In addition, he supported NASA 2 operations in Russia, from January through September 1996 including responsibility for daily activities, as well as the health and safety of the NASA crew member on space station Mir. He scheduled science activities, public affairs activities, monitored Mir systems, and communicated with the NASA astronaut on Mir.
In 2002, Gerstenmaier became manager of the ISS Program. He was responsible for the day-to-day management, development, integration, and operation of the space station. This included the design, manufacturing, testing, and delivery of complex space flight hardware and software, and for its integration with the elements from international partners into a fully functional and operating space station.
Named associate administrator for the Space Operations Directorate in 2005, Gerstenmaier directed the safe completion of the last 21 Space Shuttle missions that witnessed assembly completion of the International Space Station. In this position, Gerstenmaier provided strategic direction for all aspects of NASA's human exploration of space and cross-agency space support functions of space communications and space launch vehicles. He provided programmatic direction for the operation and utilization of the International Space Station and its crew; development of the Gateway, Space Launch System and Orion spacecraft; and was providing strategic guidance and direction for the commercial crew and cargo programs.
Gerstenmaier is married to the former Marsha Ann Johnson. They have two children and four grandchildren.