Helium-3 (He-3) is a light, non-radioactive isotope of helium with two protons and one neutron.
It's the Future of the Earth. It's rare on the Earth, but the billions of years of solar wind made the Moon perfect for Harvesting Helium 3.
Helium 3 is known of Mass Effect 1-2 (Video Games) and Moon (movie).
Dude1: Any clue what the Spaceships are going to use as fuel?
Dude2: Helium-3 for sure.