They are making progress in producing more energy than when they started more than 25 years ago , but there 's still much work to be done . Helium-3 is in scarce supply on Earth , much more abundant on the moon . Comment: University of Wisconsin team has built a small reactor to show 3He might work as fuel . Former Apollo astronaut thinks U.S. needs new space policy , agency and moon return is vital .
Helium-3 is in scarce supply on Earth , much more abundant on the moon . Comment: University of Wisconsin team has built a small reactor to show 3He might work as fuel . Former Apollo astronaut thinks U.S. needs new space policy , agency and moon return is vital .