Researchers from Sandia National Laboratories are designing a self-guided bullet capable of homing in on targets up to a mile away. The Albuquerque-based security firm says the technology could prove useful for military and law enforcement officials, especially in sniper or hostage situations. Here, a brief guide to the innovation:

How does it work?
The bullet is designed to follow the point of a laser beam, adjusting its trajectory using a sophisticated array of tiny fins. The four-inch-long bullet has an optical sensor on its nose, which sends data to a series of electromagnetic actuators that steer the fins toward a target. "We can make corrections 30 times per second," researcher Red Jones tells BBC News. The bullet has proven successful in field tests and computer simulations, but there are still lingering "engineering issues."

What sort of issues?
Most bullets spin when they exit a gun's chamber to maximize speed and stability. But building a guidance system for a fast-spinning object proved too complicated. Instead, this "self-guided prototype minimizes spin, aiming to fly like a dart," says BBC News. While this helps improve the bullet's accuracy over long ranges, it slows the projectile down to 2,400 feet per second — "below standard military speeds."

So what's the solution?
The team is working on a "customized gunpowder" which could help the bullet "hit military speeds," says Daniel Terdiman at CBS News. The catch is making the bullet's electronics impervious to the initial explosive reaction in the gun's chamber.

How accurate is it?
From a distance of a mile, a standard bullet fired from a rifle pitches and yaws enough to miss a target by roughly 29 feet. But this "smart bullet" actually improves its accuracy with distance, and is capable of hitting a target a mile away within 8 inches, says Amir Iliaifar at Digital Trends. While this would obviously prove useful for long-distance snipers, the technology could also eventually find its way into "small caliber-arms as well," aiding the military, law enforcement agencies, and perhaps even recreational users like hunters.   

Sources: BBC News, CBS News, Digital Trends, Mashable