To impose certain requirements on the expenditure of funds by the National Aeronautics and Space Administration for the Constellation program.

Protecting Human Space Flight Act of 2010 - Requires amounts appropriated for FY2010 (or for prior fiscal years that remain available) to the National Aeronautics and Space Administration (NASA) for the Constellation Program to be spent only to carry out such program, including through contracts and necessary support activities. Prohibits the termination or descoping of contracts for the Constellation Program. Requires NASA to spend at least 90% of all such funds by September 30, 2010.