The Constellation Program work assignments for the National Aeronautics and Space Administration's field centers are to be announced Tuesday by the space agency's Exploration Systems Mission Directorate in Washington.

After the official announcement, NASA said each of its centers will detail their specific work assignment. Each NASA center is already in the process of designing and developing the Ares rockets and Orion spacecraft that will take astronauts and cargo to the International Space Station and then on missions to the moon.

The new work assignments will build on the progress the Constellation Program is making with its transportation system, NASA said, and will advance work related to the lunar lander, surface systems and extravehicular activities by astronauts.