Michael Landon Gernhardt (born May 4, 1956) is a retired NASA astronaut, manager of the Environmental Physiology Laboratory, and principal investigator of the Prebreathe Reduction Program (PRP) at the Lyndon B. Johnson Space Center.

Gernhardt was selected as an astronaut in March 1992 and flew on four space shuttle missions: STS-69 (1995), STS-83 (1997), STS-94 (1997), and STS-104 (2001). Over his career, he spent more than 43 days in space and completed four spacewalks totaling 23 hours and 16 minutes. He then participated in the development and field implementation of a variety of new decompression tables. From 1984 to 1988, Gernhardt worked as Manager, and then Vice President of Special Projects, for Oceaneering International. During this time, he led the development of a telerobotic system for subsea platform cleaning and inspection, as well as a variety of new diver and robot tools. In 1988, he founded Oceaneering Space Systems, a company formed to transfer subsea technology and operational experience to the ISS program.

  • Member of the astronaut support team at Kennedy Space Center, Florida, responsible for Shuttle prelaunch vehicle checkout, crew ingress/egress
  • Spacecraft communicator (CAPCOM) at Mission Control Center, Houston, during various Shuttle missions
  • Lead an international research team in developing a new exercise prebreathe protocol that improved the safety and efficiency of space walks from the ISS.

Gernhardt presently serves as a member of the astronaut office EVA branch, as Principal Investigator of the Prebreathe Reduction Program, and as Manager of JSC's Environmental Physiology Laboratory. In April 2005, he was the commander of the NEEMO 8 mission.

Gernhardt drove the lunar rover prototype at President Barack Obama's inaugural parade on January 20, 2009.

On September 19, 2011, NASA announced that Gernhardt would participate in the NEEMO 15 mission in October 2011 from the DeepWorker submersible. The DeepWorker is a small submarine used as an underwater stand-in for the Space Exploration Vehicle, which might someday be used to explore the surface of an asteroid.

In June 2012, Gernhardt piloted the DeepWorker as part of the NEEMO 16 mission, for which he was principal investigator.

Spaceflight experience

STS-69 (Endeavour) took place from September 7–18, 1995.