For all the various elements asteroids may provide – from platinum to iron and silicon – perhaps the most immediately valuable resource they carry is water ice, which can be used to make rocket fuel.
Therein lies the early money, according to officials with DSI and with Planetary Resources.
One early market, DSI officials say, could well be communications satellites. These run out of fuel long before their hardware fails. Although in principle these satellites could be refueled, sending that fuel from Earth is prohibitively expensive. So, before their tanks run dry, they must be sent to graveyard orbits where they won't collide with other satellites and become space junk. Fuel manufactured in space from water ice liberated from asteroids, however, could extend the operating life of a satellite.
Each month of additional service is worth another $5 million to $8 million to a communications-satellite operator, notes David Gump, DSI's chief executive officer.
The ability to make and pump fuel in space also could cut the cost of a mission to Mars, he adds.
The near-term objectives DSI has set for its missions in 2015 and 2016 appear more aggressive than those Planetary Resources set for itself.
Where DSI plans to launch sample return missions beginning in 2016, Planetary Resources is focusing on two types of small but powerful space telescopes for use near Earth. One type would orbit continuously, alternating its gaze from space and the hunt for undiscovered asteroids and other cosmic objects to Earth for various remote-sensing tasks. Similar telescopes with added propulsion could be used to intercept asteroids that are discovered shortly before a close encounter with Earth. A third, more-capable class, would be sent to take the measure of distant asteroids.