David Carl Hilmers (born January 28, 1950) is a former NASA astronaut who flew four Space Shuttle missions.

His recreational interests include playing the piano, gardening, electronics, spending time with his family, and all types of sports.

STS-51-J Atlantis, a classified Department of Defense mission, launched from Kennedy Space Center, Florida, on October 3, 1985.

STS-26 Discovery, the first mission to be flown after the Challenger accident, was launched from the Kennedy Space Center, Florida, on September 29, 1988.

During the four-day mission, the crew successfully deployed the Tracking and Data Relay Satellite (TDRS-C), which was subsequently carried to orbit by the Inertial Upper Stage (IUS) rocket.

After 72 orbits of the Earth, the STS-36 mission concluded with a lakebed landing at Edwards Air Force Base, California, on March 4, 1990, after traveling 1.87 million miles.

Fifty-five major experiments conducted in the International Microgravity Laboratory-1 module were provided by investigators from eleven countries, and represented a broad spectrum of scientific disciplines.

During 128 orbits of the Earth, the STS-42 crew accomplished the mission's primary objective of investigating the effects of microgravity on materials processing and life sciences.

Biological experiments on the effects of zero gravity on plants, tissues, bacteria, insects and human vestibular response were also conducted.

[1] Hilmers retired from NASA and the United States Marine Corps in October 1992, and went on to complete medical school and residency in the combined Internal Medicine/Pediatrics program at Baylor College of Medicine.

He spends much of his spare time providing humanitarian medical care locally in Houston and in developing nations, including disaster relief efforts in Iraq, Peru, Sri Lanka, the Philippines, Haiti, and in Liberia during the Ebola outbreak in 2014.