In April 1966, Carr was one of the
nineteen new astronauts selected by NASA. Upon his selection being announced, he was assigned to the test directors section of
Marine Air Control Squadron 3, which tested and evaluated the
Marine Tactical Data System. He was involved in the development and testing of the
Lunar Roving Vehicle. He was in the likely crew rotation position to fly as lunar module pilot for
Apollo 19 and walk on the Moon before this mission was canceled in 1970.
Skylab 4 by balancing Skylab 4 crewmate
William Pogue on his finger Carr was commander of
Skylab 4 (third and final crewed visit to the
Skylab Orbital Workshop) launched November 16, 1973, with splashdown on February 8, 1974. He was the first rookie astronaut to command a mission since
Neil Armstrong on
Gemini 8 (later followed by
Joe Engle on
STS-2 in 1981 and
Raja Chari on
SpaceX Crew-3 in 2021) and was accompanied on the record-setting flight by science pilot
Edward Gibson and pilot
William Pogue. The crew successfully completed 56 experiments, 26 science demonstrations, 15 subsystem-detailed objectives, and 13 student investigations during their 1,214 orbits of the
Earth. They carried out observations of the Earth using hand-held cameras and the camera and
sensor array from Skylab's Earth Resources Experiment Package. They also recorded 338 hours of observations of the Sun using Skylab's
Apollo Telescope Mount. Between February 1974 and March 1978, Carr and his Skylab 4 teammates held the world record for individual time in space: 2,017 hours 15 minutes 32 seconds, and Carr logged 15 hours and 51 minute in three
EVAs outside the Orbital Workshop. In mid-1977, Carr was named head of the design support group within the Astronaut Office responsible for providing crew support to such activities as space transportation system design, simulations, testing, and safety assessment, and for development of man/machine interface requirements. and from NASA in June 1977. == Later life ==