They are talking about Helium 3. It was first observed at UC Berkeley in 1939. It was an Australian physicist, Mark Oliphant, that theorized its existence in 1934. Used in the fusion reactors of the near future, 25 tons of HE3 would be enough to power the US for one year. One million tons of HE3 could generate 20 thousand terrawatt-years of thermal energy; ten times the energy available from mining all the remaining fossil fuels on Earth. Fusion reactions involving HE3 produce little radioactivity and no radioactive waste. There are problems with HE3 generated electrical power. One problem is that commercial scale HE3 fusion reactors have not yet been shown to be practical, much less demonstrated. This is partially because there is very little HE3 on Earth. The US possesses only about 29kg of HE3, and we can produce only about 15kg per year. An estimate of the value of HE3 is $3 billion per ton. Surveys of the Moon have indicated that there are about 1.1 million tons of HE3 available in the top few meters of the lunar surface. That $330 trillion worth of HE3. http://www.asi.org/adb/02/09/he3-intro.html Hence, an economic interest in returning to the Moon. America has announced plans to return to the Moon alone and set up permanent bases before 2024. Russia claims the reason is to dominate the supply of HE3.