Directly from Wikipedia:
Constellation (abbreviated CxP) is a human spaceflight program within NASA, the space agency of the United States. The stated goals of the program are gaining significant experience in operating away from Earth's environment, developing technologies needed for opening the space frontier and conducting fundamental science.1 Constellation was developed through the Exploration Systems Architecture Study, which determined how NASA would pursue the goals laid out in the Vision for Space Exploration and the NASA Authorization Act of 2005.

As part of the Constellation program, NASA plans to develop spacecraft and booster vehicles to replace the Space Shuttle and send astronauts back to the Moon and possibly to Mars as well. Currently, NASA is in the process of designing two boosters, the Ares I and Ares V. Ares I will have the sole function of launching mission crews into orbit. Ares V will be designed to launch other hardware for use on missions and will have a heavier lift capacity than the Ares I booster. In addition to these two boosters, NASA is designing a set of other spacecraft for use during Constellation. These will include the Orion crew capsule, the Earth Departure Stage and the Altair lunar lander.2

Please follow the source link for much more info.
Source(s):
http://en.wikipedia.org/wiki/Constellation_program

Permalink | Report