Send a robot into space. Grab an asteroid. Bring it back to Earth orbit.
This may sound like a crazy plan, but it was discussed quite seriously last week by a group of scientists and engineers at the California Institute of Technology. The four-day workshop was dedicated to investigating the feasibility and requirements of capturing a near-Earth asteroid, bringing it closer to our planet and using it as a base for future manned spaceflight missions.
This is not something the scientists are imagining could be done some day off in the future. This is possible with the technology we have today and could be accomplished within a decade.
A robotic probe could anchor to an asteroid made mostly of nickel-iron with simple magnets or grab a rocky asteroid with a harpoon or specialized claws (see video below) and then push the asteroid using solar-electric propulsion. For asteroids too big for a robot to handle, a large spacecraft could fly near the object to act as a gravity tractor that deflects the asteroid’s trajectory, sending it toward Earth.
“Once you get over the initial reaction — ‘You want to do what?!’ — it actually starts to seem like a reasonable idea,” said engineer John Brophy from NASA’s Jet Propulsion Laboratory, who helped organize the workshop.
In fact, many of these ideas have been on the drawing board for years as part of NASA’s planetary defense program against large space-based objects that might threaten Earth. And there’s no shortage of potential targets. NASA estimates there are 19,500 asteroids at least 330 feet wide — large enough to detect with telescopes — within 28 million miles of Earth.