We no doubt live in exciting times. Before the end of this decade, we are likely to witness how commercial companies become the main providers of rides to space (or more specifically, to low Earth orbit). Some people will be able to buy a ticket for the ride of a lifetime, either on a suborbital flight (that is, a short, rocket-powered excursion just above the atmosphere, followed by a gliding return to the spaceport), or perhaps a longer stay on an orbiting space station.
On a slightly longer time-frame, perhaps 15 to 20 years, we may see yet another example of entrepreneur ingenuity and human technological prowess: the direct manipulation of a celestial body by a robotic spacecraft. A study conducted under the auspice of the Keck Institute for Space Studies (KISS) concludes that it will be possible to capture an asteroid with a diameter of 7 meters, and a mass of 500 tons, using technology that is already available or that will be available within this decade. The basic idea is for a spacecraft to deploy a 15-meter-diameter capture bag to store the asteroid, turn around and head for the moon, and “park” the asteroid on a lunar orbit. The total duration of such a mission would be approximately 10 years, at a price tag of $2.6 billion.
One may ask, why go through all the trouble of designing and launching a spacecraft to grab a rock (not even a very big one), to make it go around the moon? The KISS report provides several reasons: 1) it would be a precursor mission to the more ambitious one of sending astronauts to a near-Earth asteroid by 2025, as NASA intends to do. The value of a scout mission as the one studied resides in providing safety margins and mission planning for a future human expedition to an asteroid. In other words, it could serve as a “practice run”; 2) it would enable greater understanding of the capabilities that are necessary to deal with the potential threat of an asteroid that gets too close to Earth. An asteroid capture mission could teach us how to deflect an incoming object, by learning how to perform robotic proximity operations; 3) it would generate great interest in the public, as changing the orbit of a natural space object would undoubtedly provoke huge enthusiasm and inspiration to many people, not to mention the educational value of such an endeavor and its capacity to attract young minds towards careers in science and technology; and 4) an “asteroid return” mission such as this one would pave the way towards exploitation of natural resources in space, specifically minerals and water. That is, it would jump-start space mining.
The space news outlets over the last few weeks have incessantly divulged the announcement made by Planetary Resources, a new commercial venture with high-profile investors and advisors, such as film maker James Cameron and veteran NASA astronaut Thomas Jones, that it intends to develop technology to mine asteroids. But the company will initially look for water, instead of minerals. The components of water, hydrogen and oxygen, can be used as propellant for space rockets. As explained in an entry in the blog The Space Review, Planetary Resources hopes that extracting water from asteroids will allow them to set up propellant “depots” at strategic points near Earth, like “gas stations” for spaceships. Additionally, of course, that water can be used for the consumption of space crews.
The economic advantages of this scheme are evident: according to Planetary Resources, it costs $100,000 to launch one kilogram of propellant from Earth to a Lagrange point [a Lagrange point is a location in space near two massive objects, like the Earth and the moon, where a third object (like a spaceship) remains stationary with respect to them because it feels no net force]. But if a spacecraft is able to “refuel” in space, launch costs are reduced dramatically.
It may very well be, then, that we are witnessing a major revolution in human transportation. Space may become accessible to more people in the coming years and decades, and asteroids will provide an important foundation for human space travel. Not only can asteroids tell us how our solar system (Earth included) formed; they can also give us the resources to expand and thrive as a civilization.