How do you join NASA?

Answer 1

NASA is actually a pretty small government agency compared to others, but in general employees are just like any other Federal employee. Most have degrees in either Aerospace, Aeronautical Engineering, Mechanical/Electrical Engineering, Materials Engineering, Cryogenics, Thermal Engineering, or many other specialties that are germane to the Space Program itself. You apply to NASA just like any government job, but their hiring practices are pretty restricted, and you need a minimum 4-year technical or science degree. The Astronaut and Mission Specialist programs are different, as they seek candidates from specialized areas and with certain qualifications. For example, Astronauts are qualified military officers (usually recruited from the flight testing ranks), and Mission Specialists are Doctors in their respective fields.

NASA employees are still primarily administrators though - operation of NASA Centers and flight operations, as well as design, manufacturing, QA and testing of spacecraft are performed by private contractors, with other Federal employees responsible for local program oversight. As an example, though a DoD QA Engineer, I was assigned exclusively to NASA Manned Flight and Satellite programs for 9 years.

For more information on these jobs, you can go to the official US site at the related link.