"He is going to face budgetary constraints, technical issues, the remaining shuttle launches and pending retirement of the space shuttle," said Sen. Bill Nelson, D-Fla.
NASA faces $3 billion in possible budget cuts, reports CBS News correspondent Kimberly Dozier. The White House is reviewing NASA's entire manned space program, and may substitute something cheaper for the Bush-era rocket system currently planned to replace the shuttle.
The 62-year-old Bolden has faced tough fights before. If he's confirmed, he will be the first-ever African- American administrator.
"Charlie grew up in segregated South Carolina, couldn't even get an appointment to the Naval Academy and they had to work it out with a Congressman from a different state," Nelson said.
When he got to Annapolis, Bolden was promptly elected freshman class president.
"He knows how to motivate people," said CBS space consultant Bill Harwood. "Most folks think he will protect manned space flight in this country and try to move it forward."
In the meantime, NASA is eking out eight more missions with its three-decades-old shuttle craft.
This week, the Atlantis crew made its last repair visit to the Hubble Space telescope - Bolden commanded the shuttle mission which carried the Hubble into orbit in 1990.
NASA's next launch system, a combination of manned and unmanned rockets, was designed with one mission in mind: carrying astronauts and payloads to the space station, or the moon. It can't carry out drive-by repair missions, like the shuttle.
That's prompted criticism even within NASA.
"It just makes me want to cry to think that this is the end of it," said NASA scientist David Leckrone.
And there's a five year gap between the shuttle's last mission, and the new system.
"U.S. astronauts are having to hitch rides on Russian Soyuz rockets, and if they are any delays, of course that gap could get even bigger," Harwood said.
Inside NASA, most believe Bolden would not have taken this job, unless the White House was committed to keeping Americans in space. The president's stated goal is reaching the moon by 2020.