NASA safety chief Bryan O'Connor, who also is a veteran shuttle pilot and mission commander, is leaving the space agency at the end of August.
O'Connor said in a statement that the successful completion of NASA's 135th and final shuttle mission prompted his decision to depart NASA on Aug. 31.
"Even though good practice suggests shorter tours for senior leaders, I did not want to pass the safety baton until after the STS-135 crew left Atlantis on the runway," O'Connor said.
"This transition is a great time to let someone new take on this wonderful role you've permitted me to serve in."
O'Connor was a chief safety advocate in the NASA Astronaut Office in the days following the 1986 Challenger accident and oversaw the selection and development of a crew escape system that astronauts could use to bail out of a crippled shuttle during controlled gliding flight. The presidential commission that investigated the Challenger accident recommended NASA develop such a system.
O'Connor served as shuttle program manager in the early to mid-1990s and stepped down from the position when NASA instituted the same type of shuttle management structure that was cited as a contributing cause of the Challenger accident. He returned to NASA in June 2002.
Check out more about O'Connor's distinguished career HERE