Former NASA administrator Michael Griffin has left his post as the official lead man for the U.S. space agency, but remains skeptical of his replacement appointed by President Barack Obama, Charles Bolden.

Even though Griffin believes Bolden is qualified for the job, he's concerned regarding Bolden's decision to study and review the NASA manned spaceflight program.

"This review is not, in my judgment, necessary from a technical point of view," Griffin recently said during an interview.  "But it does seem to be necessary if we are going to quiet some of the criticism of what NASA is doing, and if we are going to get the new administration on board."

There was previous concern over a growing rift between NASA and President Obama when he was still out on the campaign trail.  Both Griffin and President Obama said the report posted in the Orlando Sentinel was "wrong" and overblown, with Griffin understanding he'd be replaced when Obama won the election.

Bolden already is facing a turbulent time as NASA administrator, and that likely won't get any easier in the near future.  The U.S. space agency faces budget issues, an aging shuttle fleet, an unfinished ISS, and a several year reliance on Russia to get supplies and astronauts to space.

Space experts are extremely curious to see how Bolden handles these issues, as Americans and politicians are watching his actions closely.

A 10-member group led by former Lockheed Martin CEO Norm Augstine will meet next week in the first of several public meetings to discuss NASA's future.  One such topic is the manned space program, which could eventually see the "scope, budget and timetable" of the mission altered.

Final results must be turned over to the White House in August.

Griffin will spend his time in retirement by serving as professor at the University of Alabama in Huntsville and will make speaking appearances across the country.