There are billions of tons of water ice on the poles of the Moon. Shackleton Energy plans to extract lunar water ice, turn it into rocket fuel and create fuel stations in Earth's orbit. Just like on Earth you won't get far on a single tank of gas, what we can do in space today is straight-jacketed by how much fuel we can bring along from the Earth's surface.
The fuel stations aim to change how we do business in space and jump-start a multi-trillion dollar industry. Shackleton Energy claims its lunar ice program will cost less than one-tenth of the Apollo program, generates revenue within 4 years and breaks even within 12 years. They claim they can make moon mining happen with $10 billion.