Pres. Obama to outline 'new course' for NASA at Thursday event

However, the White House's proposed overhaul of NASA's funding structure has so far piqued many members of Congress, some of whom charge it would leave the agency without a clearly defined mission or means to get there.

Among early the early critics are Sens. Kay Bailey Hutchison (R-Tx.) and David Vitter (R-La.), who have questioned the logic behind the administration's emphasis on research and have promised to fight the end of the shuttle program.

Still others fear the effective end of NASA's shuttle program will result in thousands of lost jobs, at Kennedy Space Center or elsewhere. Bolden himself confirmed as much in an interview with reporters last week, noting he felt the elimination of agency positions was a "very serious and real concern."

"But this is what we call progress, unfortunately," Bolden said. "If you look at every area of technology in this country, as you advance there are fewer and fewer manual-type jobs. That's what happens when you advance technology."

"We're doing everything within our power ... to help everybody understand we're expanding the amount of programs we have so that we can try to put people to work who are interested in being a part of the space program," he continued. "Are we going to be able to employ everybody that used to work in shuttle? No, we're not. But that was never a vision."

Still, the president's NASA budget will require congressional approval -- a period during which lawmakers will have the opportunity to amend, if not totally reverse, the administration's proposed changes.