WASHINGTON The top Democrat and Republican on the Senate Commerce, Science and Transportation Committee called May 27 for NASA’s inspector general to investigate the sudden removal of the head of NASA’s marked-for-cancellation Constellation program.

Constellation Program Manager Jeff Hanley notified his senior staff of his removal May 26 in a short e-mail, a copy of which was obtained by Space News.

“I’ve been advised by [headquarters] that my services as [Constellation program manager] are no longer required, effective immediately,” Hanley wrote in a May 26 e-mail sent to the Constellation program’s senior staff. “Dale Thomas will be Acting PM until something more formal is issued from [NASA Exploration Systems Mission Directorate].”

NASA Administrator Charles Bolden, who was testifying before the House Science and Technology Committee when Hanley’s e-mail went out, was asked by Rep. Gabrielle Giffords (D-Ariz.) during the hearing whether it was true the program manager had been removed from his post.

“That is probably correct,” Bolden replied. “It is not an action that I took. It was an action taken by the Exploration Mission Directorate head Doug Cooke and the Johnson Space Center Director Mike Coats. I have been in consultation with them about that. My understanding is that they were to get together with him this morning.”

NASA spokeswoman Lynette Madison told Space News that Hanley has been reassigned a new position at Johnson Space Center (JSC) — associate director for strategic capabilities — where he will be responsible for retaining “as many of JSC’s human space flight core competencies as possible during the Constellation transition and [space shuttle] phase out.”

In a May 27 letter, Sens. John D. Rockefeller (D-W.Va.) and Kay Bailey Hutchison (R-Texas) asked NASA Inspector General Paul Martin to “conduct an investigation into the circumstances of Mr. Hanley’s reassignment, and whether his removal as program manager was related to Mr. Hanley’s well-publicized efforts to preserve the Constellation Program, consistent with Congressional enactments.”

NASA has spent about $10 billion on Constellation, a 5-year-old effort to replace the retiring space shuttle with new rockets and spacecraft optimized for lunar missions. NASA proposed canceling Constellation in its 2011 budget request, though the agency is currently refining a plan to continue development of the Orion Crew Exploration Vehicle — a key component of Constellation — for use as an emergency lifeboat at the international space station.

Bolden told the House Science and Technology Committee during the May 26 hearing that NASA would spend about $4.5 billion on the restructured Orion program.