The first physician to be selected for astronaut training. He later was the director of Space and Life Sciences at Johnson Space Center.
He served in the U.S. Navy and was a naval flight surgeon.
He went on one Skylab mission and served as CAPCOM (Capsule Communicator) for Apollo 13.
He married and had three children.
He studied medicine at Northwestern University, where actor Zach Braff went to school.