Helium-3 factfile

Helium-3 was discovered in lunar samples brought back from the Apollo missions in the late 1960s and 1970s.
Some scientists estimate that there are more than 100 million tonnes of helium-3 on the moon - more than enough to power the planet for hundreds of years. Theoretically, space engineers would super-heat the Moon's surface, process the helium-3 gas that lies at a depth of about nine feet and return it to earth to process it in fusion reactors.
But despite Russian claims, the American energy department is not currently funding any helium-3 fusion research - an indication that Washington still needs to be convinced the project is worthwhile.
Russia and China take it much more seriously if only because many believe that the country that controls the production of helium-3 will also enjoy superpower status as the world's dominant energy supplier.