Asteroid Capture

When most people imagine asteroid missions, they picture a spacecraft landing on a rocky surface to collect samples before returning home. But some engineers are exploring a far more ambitious idea: what if, instead of visiting an asteroid, we brought the asteroid to us?

This concept, known as asteroid capture, has been studied by NASA for over a decade. Early proposals envisioned a robotic spacecraft intercepting a small near-Earth asteroid, enclosing it in a giant inflatable bag, and slowly towing it into a stable orbit around the Moon. Once there, astronauts could visit it repeatedly, studying its composition, testing mining technologies, and practicing operations that would later be needed for missions deeper into the Solar System. More recent research has shifted toward redirecting smaller boulders from larger asteroids rather than moving an entire asteroid, making the engineering challenge considerably more realistic.

Capturing an asteroid is less about brute force than patience. Spacecraft would rely on highly efficient ion engines that produce only a gentle thrust—roughly the weight of a sheet of paper resting on your hand—but can operate continuously for years. Engineers must precisely calculate trajectories, account for the asteroid’s irregular rotation, and ensure that even tiny navigation errors do not accumulate over millions of kilometers. Every maneuver would be planned years in advance, with success depending more on orbital mechanics than raw power.

At first glance, towing an asteroid across space sounds like science fiction. Yet the motivation is surprisingly practical. Asteroids contain water that can be converted into rocket fuel, metals essential for future space infrastructure, and clues to the formation of the Solar System itself. Rather than treating them as distant objects to visit once, engineers are beginning to view them as resources that can be repositioned and used. Humanity’s first space quarry may not be built on an asteroid—it may start by bringing one into our own cosmic backyard.