Visiting (and eventually mining) asteroids is viewed by space development advocates as an imperative stepping stone to making our way out into the solar system. One group of President Obama's advisors, the Augustine Commission, counseled that a manned asteroid mission might bring the highest payoff per dollar spent in terms of science and essential skills for space exploration. A study was also commissioned to check the feasibility of bringing a small asteroid—on the order of 10,000kg—back to the International Space Station. It reported no showstoppers.

Cal Tech's Keck Institute for Space Studies (KISS) commissioned a larger study beginning in September 2011 and issued its report earlier this month. In it, a who's who of people from at least 17 organizations suggest that we bring a much larger asteroid near the Earth and visit it there. After all, in the decade it would take to develop the skills and equipment we'll need to visit the asteroid belt, we could identify a target and make the tiny course corrections in its orbit necessary to have it arrive at our doorstep seven to ten years later.

Figuratively speaking, a small mountain really could come to Mohammed. The much smaller spacecraft necessary to bring it could be launched on a conventional Atlas, Delta, or Falcon rocket.

In this case we're really talking about bringing home a molehill: only 500 metric tons and roughly 7 meters across. The KISS study points out that the Apollo mission brought back 382kg of samples in 6 missions, and the OSIRIS-REx mission would bring back 60 grams of surface material by 2023. By nudging an asteroid with some creative orbital mechanics, KISS suggested that 500 tons or larger would be well within the realm of possibility. Several targets could be identified every year.

The problem requires three technological developments, the first of which we've mastered—we now have the ability to identify candidate asteroids. The second is solar electric propulsion, a technology which has now been used on several small spacecraft. Scaling up, NASA recently received the results of four study contracts it awarded late last year for the construction of SEP-driven orbital tugboats. The last development involves NASA's plan to have a human presence in the area of space to which asteroids could safely be delivered by 2025: geosynchronous orbits and the Lagrange points between the Earth, the Moon, and the Sun. A small spacecraft could deliver between 28 and 70 times its own mass back into easier-to-access space. The KISS paper recommends placing this first asteroid in lunar orbit or at a lunar Lagrange point, for safety.

A robotic asteroid retrieval mission would contribute toward an invaluable advance in human spaceflight, a leap forward in several areas in which humankind must make progress in order to advance into the solar system. The necessary elements all exist. By the best metric in spaceflight available to measure feasibility today, the mission is only a one-billionaire problem. And as it happens, a few billionaires may be interested.

According to MIT's Technology Review, a new firm backed by several deep-pocketed investors will announce itself Tuesday at the Museum of Flight in Seattle. The firm calls itself Planetary Resources, and the people involved include Charles Simonyi of Microsoft, Sergey Brin and Larry Page of Google, James Cameron, Ross Perot Jr., and Peter Diamandis, founder of the X-Prize Foundation. With this much money involved, the eyeballs of space geeks everywhere are now expectantly coming to bear on Seattle.