Why bother with an expensive, potentially dangerous manned mission to an asteroid when you can just tow it to lunar orbit and study it there? That’s the thinking behind a recent proposal by NASA’s Keck Institute for Space Studies (KISS). Researchers there have come up with a plan to launch a spacecraft to a small 7-meter (23-foot) near-Earth asteroid, capture it, de-spin it and then tow the garage-sized rock into lunar orbit, where it could be studied and mined for raw materials at a convenient distance from home. The Keck team points out that 842 lbs. of rocks were returned from the moon during the entire Apollo program, while this mission would bring an approximately 1.1 million-pound kilogram asteroid within Earth’s reach by the year 2026. Total price tag: about 2.6 billion.
The craft would be launched from an Atlas rocket and travel to its target using a solar electric propulsion system similar to the one that propelled NASA’s Dawn spacecraft to the asteroid Vesta and will soon carry it to Ceres. Upon arrival, the probe will first study and characterize the asteroid. Prior to capture, the craft would match the asteroid’s rotation, then, using inflatable arms, extend a large bag around the object. Cinching cables would close the bag. Once secured inside, the probe would fire its thrusters to de-spin both it and the asteroid, and then return to the vicinity of the moon and park itself in lunar orbit.
Expect the entire mission to take a decade to complete. Escaping the Earth’s gravity using ion propulsion requires between 1.6 to 2.2 years, then 2 years to reach the asteroid and 2-6 years to return depending upon the asteroid’s mass. If we were to start working out the details now, including building the spacecraft, we might just get our asteroid home by the projected 2026 time frame.
Assuming that humans will be tooling around in lunar orbit by the 2020s, having a nearby asteroid opens up the possibility for mining. If we choose the right object, not only might there be precious metals available, but more importantly, water. Water can be used for shielding astronauts from dangerous solar radiation and cosmic rays on future missions to other planets. You can also chemically break down water into hydrogen and oxygen to make fuel for your spaceship.
It’s an intriguing idea that on the surface sounds almost as crazy as the sky-crane and tethers used to land the Curiosity rover on Mars last August. But hey, that was a carefully-engineered plan that worked flawlessly, and this may too. Read the full proposal HERE.