The United States plans to set up a colony on the south pole of the moon around 2020 as a base for further manned exploration of the solar system, NASA announced on Monday.
The project, which would send a man back to the lunar surface for the first time since 1972, is designed as a long-term joint effort of 14 of the world's space agencies, the National Aeronautics and Space Administration said.
NASA plans to set up a solar-powered base on the moon's south pole that, after construction is completed, could serve as a forward base for manned missions to Mars.
US President George W Bush declared in 2004 a vision of sending a manned exploratory mission to the red planet.
The US space agency said in a statement that it had focused its Global Exploration Strategy, first outlined in April, on two issues: "why we are returning to the moon and what we plan to do when we get there."
NASA said it pulled together detailed answers to those questions by polling more than 1,000 experts, from 13 other space agencies, including those of China, India, Russia and Ukraine, and from public and private organisations and businesses, including commercial space exploration operations.
"This strategy will enable interested nations to leverage their capabilities and financial and technical contributions, making optimum use of globally available knowledge and resources to help energise a coordinated effort that will propel us into this new age of discovery and exploration," said NASA Deputy Administrator Shana Dale.
The project will begin, NASA said, with four person crews visiting the moon on a series of week-long visits to build up a living quarters with its own power units and lunar exploration vehicles.
The first mission will be launched by 2020, in the current plan. Before human missions are started, unmanned robotic missions will be undertaken to lay the groundwork, handling landing site reconnaissance, natural resource assessments, and technology risk checks.
After the permanent facilities are established, the program will be 180-day visits to the moon, during which trips to Mars can be planned.
NASA, Russia and the European Space Agency are currently constructing the International Space Station in orbit around the Earth which could itself be a springboard and operations base for the moon program.
On Thursday, the NASA shuttle Discovery will launch on the newest construction mission to the ISS, one of 14 planned between now and 2010 to complete the building of the ISS before the aging shuttle fleet is retired.
"NASA's goal is to enable a sustainable space exploration effort in which participating organisations can achieve individual goals with mutually beneficial results."
NASA's lunar program plans under the Global Exploration Strategy are being laid out in a Space Exploration Conference on December 4-6 in Houston, Texas.