Future of U.S human space flight

A commission is reviewing the future of U.S. human spaceflight and will present up to a half-dozen options to President Obama late next month, ranging from a conservative, methodical space program to an aggressive blueprint for a mission to Mars.

NASA is having budget constraints and is planning to retire the space shuttle next year and continuing the station program until at least 2015. Lunar flights will not start until after 2020.

The White House established the Review of U.S. Human Space Flight Plans Committee in May to help chart the nation's future in space. It will complete its report by the end of August.

After space shuttle Endeavour returned Friday from its current mission, there are only seven more flights planned for the spaceplane.