PM: You've suggested an asteroid could be brought closer to the Earth to make it easier to mine. Is that really feasible?
EA: It is. One of the ways that we could do that is simply to turn the water on an asteroid into rocket fuel and burn it in a thruster that nudges its trajectory. Split water into hydrogen and oxygen, and you get the same fuels that launch space shuttles. Some asteroids are 20 percent water, and that amount would let you move the thing anywhere in the solar system.
Another way is to set up a catapult on the asteroid itself and use the thermal energy of the sun to wind up the catapult. Then you throw stuff off in the opposite direction you want the asteroid to go. Conservation of momentum will eventually move the thing forward—like standing on a skateboard and shooting a gun.
CL: This is not only our view. A Keck Institute "return an asteroid study," involving people at JPL, NASA Johnson Space Center and Caltech, showed that the technology exists to place small asteroids a few meters wide in orbit around the moon for further study.
PM: Can you think of any other uses for asteroid repositioning?
EA: There is one incredible concept: We could place the asteroid in an orbit between the Earth and Mars to allow astronauts who want to get there to hop on and off it like a bus. Think about that. You could make a spacecraft out of the asteroid.
PM: Apart from your commitment to turn a profit for your investors, might there be spin-offs for the rest of us?
EA: Hopefully, we'll be finding hundreds of new asteroids that would not otherwise have been discovered—including asteroids that are Earth-threatening. We do need to develop the ability to move asteroids: Every few hundred years an asteroid strikes that is capable of creating great loss of life and billions of dollars’ worth of damage. If the 1908 Tunguska meteor had struck London or New York, it would have killed millions of people. It is one of the few natural risks we know will happen—the question is when. And we have to be ready for that. So while some might regard moving asteroids as risky, it really is something we need for our planet's future safety.
PM: What will be your first priority: seeking precious metals or rocket fuel on the asteroids?
EA: One of our first goals is to deploy networks of orbital rocket propellant depots, effectively setting up gas stations throughout the inner solar system to open up highways for spaceflight.
PM: So you are planning filling stations for people like Elon Musk, the SpaceX billionaire planning a crewed mission to Mars?
EA: Elon and I share a common goal, in fact we share many common goals. But nothing would enable Mars settlement faster than a drastic reduction in the cost of getting to and from the planet, which would be directly helped by having fuel depots throughout the inner solar system.
This article originally appeared in New Scientist.