S78-35300 (31 Jan 1978) -- NASA Astronaut Dr. Ronald E. McNair (PH.D.) was assigned as a mission specialist and was a crewmember on two Space Shuttle Missions. He first flew on STS 41-B in 1984 where he performed numerous science experiments. On his second flight, STS 51-L, Dr. McNair died on January 28, 1986 when the Space Shuttle Challenger exploded after launch from the Kennedy Space Center, Florida. NASA Photograph