The study included science and exploration objectives that were earlier developed by representatives of fourteen countries, as part of the "Global Exploration Strategy" (pdf file).

The Global Exploration Strategy begins, "Space exploration enriches and strengthens humanity’s future. Searching for answers to fundamental questions such as: ‘Where did we come from?’ ‘What is our place in the universe?’ and ‘What is our destiny?’ can bring nations together in a common cause, reveal new knowledge, inspire young people and stimulate technical and commercial innovation on Earth. The Global Exploration Strategy is key to delivering these benefits."

Specifically, NASA looked at the capabilities, with Project Constellation, of the Ares V heavy-life launch vehicle, which will carry the Earth Departure Stage and the Altair lunar lander into space, and the Altair lunar lander, which will set NASA astronauts onto the lunar surface.

The study was headed by the Constellation Program Office at the Johnson Space Center in Clear Lake City, just outside of Houston, Texas.

The CPO study concluded that all the technical parameters needed for Phase A—which is the first phase in preparing the vehicle requirements—has been met.

The head of the Constellation Program made comments on the announcement. Please read on.