Both the Defense Department and the National Aeronautics and Space Administration foresee a number of uses for such heavy-lift rockets.

Those selected will be among the first to pioneer a new generation of commercial launch vehicles and travel aboard a new heavy-lift rocket to distant destinations in deep space.

And the agency has also proposed developing a new heavy-lift rocket, at a cost of $10 billion to $12 billion, to support the space station and future projects.

In what would be called the Apollo Program, the primary mission of MSFC was developing the heavy-lift rockets - the Saturn family.

The shuttles would be largely replaced by a fleet of heavy-lift rockets, for robotic operations and later for human flight.

The Saturn 5 was scuttled, and no new heavy-lift rocket developed.

A core vehicle could be used alone to launch light payloads or a heavy-lift rocket could be built of several booster units containing dozens of engines.

The Magnum is a large heavy-lift rocket designed by NASA's Marshall Space Flight Center during the mid-1990s.

The United States, the Soviet Union and China got their start in heavy-lift rockets by developing intercontinental ballistic missiles.

NASA unveils the design for a new heavy-lift rocket to take humans to Mars and the asteroids.