Dean Acosta, NASA Deputy Assistant Administrator and Press Secretary, moderates a press conference with NASA Administrator Michael Griffin Scott Horowitz, NASA Associate Administrator for Exploration Systems and Jeff Hanley, Constellation Program Manager, outlining specific center responsibilities associated with the Constellation Program for robotic and human Moon and Mars exploration, Monday, June 5, 2006, at NASA Headquarters in Washington. Photo Credit (NASA/Bill Ingalls)

Dean Acosta, NASA Deputy Assistant Administrator and Press Secretary, left, moderates a NASA Update with NASA Administrator Michael Griffin, Scott J. Horowitz, NASA Associate Administrator for Exploration Systems and Jeff Hanley, Constellation Program Manager, right, on Wednesday, June 5, 2006, at NASA Headquarters in Washington. Photo Credit: (NASA/Bill Ingalls)

Dean Acosta, NASA Deputy Assistant Administrator and Press Secretary, left, moderates a NASA Update with NASA Administrator Michael Griffin, second from left, Scott J. Horowitz, NASA Associate Administrator for Exploration Systems and Jeff Hanley, Constellation Program Manager, right, on Wednesday, June 5, 2006, at NASA Headquarters in Washington. Photo Credit: (NASA/Bill Ingalls)

Dean Acosta, NASA Deputy Assistant Administrator and Press Secretary, left, moderates a NASA Update with NASA Administrator Michael Griffin, second from left, Scott J. Horowitz, NASA Associate Administrator for Exploration Systems and Jeff Hanley, Constellation Program Manager, right, on Wednesday, June 5, 2006, at NASA Headquarters in Washington. Photo Credit: (NASA/Bill Ingalls)

NASA Administrator Michael Griffin, second from left, and Associate Administrator for Space Operations William Gerstenmaier, right, look on as Space Shuttle Program Manager Wayne Hale speaks from NASA's Marshall Space Flight Center during a media briefing about the space shuttle program and processing for the STS-121 mission, Friday, April 28, 2006, at NASA Headquarters in Washington. Moderator Dean Acosta looks on af far left. Photo Credit (NASA/Bill Ingalls)

NASA Administrator Michael Griffin, seated left, Scott Horowitz, NASA Associate Administrator for Exploration Systems and Jeff Hanley, Constellation Program Manager, right, are seen during a press conference outlining specific center responsibilities associated with the Constellation Program for robotic and human moon and Mars exploration, Monday, June 5, 2006, at NASA Headquarters in Washington. Dean Acosta, NASA Deputy Assistant Administrator and Press Secretary, far left, moderates the program. Photo Credit (NASA/Bill Ingalls)

KENNEDY SPACE CENTER, FLA. - A press conference after the landing of the orbiter Discovery and mission STS-121 crew features NASA and Kennedy Space Center senior management. From left, NASA Public Affairs Dean Acosta moderated questions posed to NASA Administrator Mike Griffin, Associate Administrator for Space Operations Bill Gerstenmaier and Shuttle Launch Director Mike Leinbach. Discovery traveled 5.3 million miles, landing on orbit 202. Mission elapsed time was 12 days, 18 hours, 37 minutes and 54 seconds. The landing is the 62nd at Kennedy Space Center and the 32nd for Discovery. Photo credit: NASA/George Shelton

NASA Administrator Michael Griffin is seen through a television camera at a NASA Update announcing to NASA employees and members of the media the responsibilities of the NASA centers associated with the Constellation Program for robotic and human Moon and Mars exploration on Wednesday, June 5, 2006, at NASA Headquarters in Washington. Griffin was joined by Scott J. Horowitz, NASA Associate Administrator for Exploration Systems and Jeff Hanley, Constellation Program Manager, right. Dean Acosta, NASA Deputy Assistant Administrator and Press Secretary, far left, moderates the program. Photo Credit: (NASA/Bill Ingalls)

NASA Administrator Michael Griffin, seated center, outlines the President's budget for fiscal year 2007 during a news conference, Monday, Feb. 6, 2006, at NASA Headquarters in Washington. The administrator was joined by the heads of NASA's four mission directorates to explain how the proposed $16.8 billion dollar budget supports the Vision for Space Exploration. The budget represents a 3.2% increase above the Fiscal Year 2006 appropriated budget. Photo Credit: (NASA/Bill Ingalls)

KENNEDY SPACE CENTER, FLA. - Leaders from space agencies around the world participate in a news briefing following the International Space Station Heads of Agency meeting held at Kennedy Space Center. From left are NASA Press Secretary Dean Acosta; NASA Administrator Michael Griffin; Canadian Space Agency Vice-President Space Science, Technology and Programs Virendra Jha; European Space Agency Director-General Jean-Jacques Dordain; Japan Aerospace Exploration Agency President Keiji Tachikawa; Japanese interpreter Masako Kaharia; Russian Federal Space Agency Head Anatolii Perminov; and Russian interpreter Elena Maroko. The purpose of the meeting was to review International Space Station cooperation and endorse a revision to the station configuration and assembly sequence. At the meeting, the partners reaffirmed their agencies' commitment to meet their mutual obligations, to implement six person crew operations in 2009 and an adequate number of shuttle flights to complete the assembly of the space station by the end of the decade. Photo credit: NASA/George Shelton