"The Global Exploration Roadmap, unveiled by the International Space
Exploration Coordination Group on Sept. 22, offers two 25-year human
pathways to Mars.

One follows the “Asteroid next” approach favored by U.S. President
Barack Obama, while the other features a “Moon next” gateway more
akin to the George W. Bush administration’s scrapped Constellation
program."

See:

http://www.aviationweek.com/aw/gener...&channel=space