Right now, three different organizations are developing long-term strategies for gathering resources from space. Obviously NASA is one of them, but also Deep Space Industries, and Planetary Resources.
Their primary target? The primary target, would be: Asteroid mining.
The new industry known as asteroid mining is important because asteroids host ice and rock, of course, which means they also have minerals, metals, and silicate materials as well as carbonaceous from the deepest regions of space. Mining asteroids could provide us with more materials to use on Earth but, more importantly, mining asteroids could yield extremely beneficial as we look to the future and start exploring our neighboring planets. Mars, for example, is first on that list.
But one reason why asteroid mining is important has to do with water. Asteroids are generally made out of ice, which means they are generally made out of water. Water, of course, is an extremely important resource in space, but it is especially important since spacecraft are often powered by solar panels, which could then, actually, break the water down into hydrogen and oxygen for fuel. By virtue of this process, then, endless space travel would easily become more commonplace.
Apparently, though, there is another very good reason for mining asteroids. While some movies and other science fiction stories may have suggested that an asteroid could hurl its way to earth and destroy life as we know it, it has never really been approached as a possibility. However, with asteroid mining at our fingertips we would also know the chemical and physical compositions of these frozen space rocks, which might make it easier to destroy them in the future, should one or more get a little too close to our planet.