Dittemore, 51, who has been with NASA for 26 years, became the agency's public face during the nationally televised briefings that followed Columbia's spectacular disintegration on re-entry just minutes before its scheduled landing in Florida.

He said in a statement issued by NASA that his decision to leave was "a very difficult one, but it is a decision that I began struggling with long before the tragedy of the Columbia accident.

"The timing of my departure is based on what I believe will allow for the smoothest management transition possible, as the pace of work to return the shuttle to flight begins to ramp up."

Dittemore said he was leaving to join the private sector, but would remain until the Columbia Accident Investigation Board (CAIB) finishes its investigation into the causes of the February 1 disaster "and a complete return to flight path has been established."

Michael Kostelnik, Deputy Associate Administrator for the Space Shuttle and International Space Station Programs, lauded Dittemore for being "an integral part of the space shuttle program...for more than a quarter-century.

"I'm pleased Ron has decided to stay until our return to flight efforts are well established and I wish him the best as he begins a new chapter in his life."

The CAIB has already issued a series of recommendations to improve shuttle program safety that have been put into practice by NASA.

SPACE.WIRE