Almost 20 years after humans first walked on the Moon, the US space agency is sending a spacecraft back - not to land astronauts, but to look for water.
The Lunar Prospector spacecraft, due to lift off on Tuesday from Cape Canaveral in Florida, will undertake an 18-month mission which if successful could lead to a land rush comparable with the Klondike's search for gold. Having water available would mean that a Moon base would become feasible, since breathable oxygen could easily be extracted from the water by electrolysis, powered by solar energy.
That in turn could revitalise the space race, at a time when crewed missions beyond Earth have begun to seem too expensive and pointless because of the difficulty of surviving in the harsh emptiness of space. With the Moon as a staging post, more ambitious missions to the planets, and especially Mars, could be contemplated.
One of the instruments on board the Prospector spacecraft has been specially designed to detect the presence of hydrogen on the Moon's surface. If there is water ice frozen deep in the craters at the Moon's poles, as scientists suspect there might be, it will be detected.
The impetus for the search came in 1994, when a US military satellite picked up unusual radar reflections from deep within craters at the lunar south pole that looked very like those from water ice. One aim of the pounds 40m mission is to discover whether these images were real or just mirages.
"If we can find sufficient water, it's going to be a land rush like the Oklahoma Sooners," said Bill Feldman, project leader for the Los Alamos Laboratory in the US, which provided the hydrogen-seeking instrument.
"Water is the key resource that will support life as well as travel from the Moon to the planets. Besides sustaining life for Moon colonies, hydrogen from the ice can be extracted for rocket fuel," Mr Feldman said. "I am sure that there are people who would colonise the Moon once sufficient water is available," he continued. "The Moon is one of the best environments you could possibly have for any number of scientific and commercial enterprises."
Other instruments will provide clues as to how and when the Moon formed and map the Moon's irregular magnetic field.Reuse content