As mankind learns more and more about the infinite void surrounding our planet, concern grows that we might eventually be wiped out by a rogue chunk of rock. There are literally billions of sizable asteroids floating around in space and it’s really only a matter of luck that we haven’t already been crushed to death from above. In response to this existential horror, scientists have long been contemplating different ways to deflect or destroy an earthbound cosmic missile, and while most solutions involve destroying the asteroid outright, that brings with it a whole new set of problems.

Say you spot an incoming asteroid and launch a nuke to blow the thing to pieces. Basic physics will tell you that the resulting shrapnel will still come flying toward Earth, and that “solution” has actually turned a single problem into millions of equally catastrophic problems. Essentially, it’s the difference between being shot by a rifle and being shot by a shotgun — either way the target ends up dead.

Thus, most scientists are now working on ways to deflect an asteroid, rather than destroy it. The simplest ideas involve landing an engine on the asteroid that could propel it away from our planet, but that would be intensely expensive and far from fool-proof. What if the engine fails?

Alison Gibbings and Massimiliano Vasile however, have a different idea. The duo, aerospace engineers at the UK’s University of Strathclyde, recently proposed a plan that would see a 500 kilogram swarm of tiny spacecraft launched toward an asteroid. Though small, these relatively simple, solar-powered spacecraft could, en masse, provide enough thrust to deflect a 250 meter rock away from Earth. Plus, with so many separate spacecraft working toward a single goal, the possibility of failure is exponentially lessened, and the asteroid, instead of breaking into dangerous fragments, would be harmlessly nudged away from its apocalyptic destination.

There is one caveat to this plan however. According to the scientists’ calculations, we would have to discover and prepare for the asteroid years ahead of time. Launching the swarm is relatively simple, but their capacity to steer an asteroid off course is very gradual, and requires a sizable time investment.

Still, it’s a solid plan. We’ve just got to keep our fingers crossed that the scientific community will keep us informed about any and all giant rocks hurtling in our direction. Bruce Willis won’t be around to protect us forever.