Named after the patterns that stars form in the night sky, Constellation Systems is responsible for developing the Crew Exploration Vehicle (CEV) and related exploration architecture systems. Like the Apollo Command Module, the CEV represents one building block in a future exploration architecture that can send astronauts to the Moon and form the basis for exploration missions to other destinations. The Vision for Space Exploration sets a goal of developing a new CEV by 2014 that is capable of carrying astronauts beyond low Earth orbit and a goal of landing astronauts on the Moon no later than 2020.

Constellation Systems is the combination of large and small systems that will provide humans the capabilities necessary to travel and explore the solar system. Constellation Systems will be made up of Earth-to-orbit, in-space and surface transportation systems, surface and space-based infrastructures, power generation, communications systems, maintenance and science instrumentation, and robotic investigators and assistants.

In parallel with development of the CEV, robotic explorers will serve as trailblazers to reduce the risks and costs of future human operations at the Moon. With robots, we will build mission operations experience that can provide insight into the preparations required for extended human presence to Mars and other destinations in the Solar System.

The capabilities that comprise Constellation Systems will evolve over time, based on exploration goals, budgetary priorities, and analyses of cost, benefits, and risks. This evolution will take place in stages or "spirals" that will allow NASA greater flexibility in meeting its exploration objectives. Development will be supported by many organizations within and outside of NASA. This includes NASA Centers, industry, universities, other government agencies, and international participants. Our capabilities will be fed by the technologies developed within the Enterprise’Äôs Technology Research and Development Programs.

Crew Exploration Vehicle
In the simplest terms, the Crew Exploration Vehicle (CEV) is a vehicle to transport human crews beyond low-Earth orbit and back again. The CEV must be designed to serve multiple functions and operate in a variety of environments. For example, the CEV or versions of the CEV could operate for extended-duration in Earth orbit, in close proximity to or on the surface of the Moon and Mars.

Development of the CEV will take place in stages or spirals and will require many supporting systems. Supporting systems will include launch vehicles, in-space transportation, navigation and communication, life support, extravehicular activity, and mission operations support. The first, "boilerplate" flight tests of the Crew Exploration Vehicle are scheduled for 2008. They will be followed by more capable, uncrewed, flight tests in 2011, leading to the operational, crewed capability in 2014. The Office of Exploration Systems Mission Directorate employs a Requirements Division that works in concert with its Development Division on this iterative process of development, test, and requirements refinement.