For the military, some of most sought after game-changing weapons are the ones that enable fighters to nail enemies from afar. This is evident in the heavy investment in attack drones, long range cruise missiles and ambitious pet projects like the hypersonic railgun. But bringing ultra long range capabilities to basic firearms -- one of biggest potential breakthroughs -- has long been elusive.
That's because bullets, unlike jet-powered cruise missiles, rely on the spinning action generated when fired to sustain velocity. And unlike the projectiles being tested for the Navy's dreamy hypersonic railgun prototype, they don't have the luxury of a gigantic electricmagnetic circuit that can generate 4,000 mph blasts. What this means is that if it were to ever happen, researchers would essentially need to re-invent the bullet.
Now, a pair of researchers at Sandia National Laboratories believe they may have just done that. Red Jones and Brian Kast recently developed and successfully tested a dart-like, self-guided bullet for small-caliber, smooth-bore firearms that could hit laser-designated targets at distances of more than a mile (about 2,000 meters).
Their design for the four-inch-long bullet includes an optical sensor in the nose to detect a laser beam on a target. The sensor sends information to guidance and control electronics that use an algorithm in an eight-bit central processing unit to control electromagnetic actuators. These actuators steer tiny fins that guide the bullet to the target.
Whereas a spinning bullet can create accuracy problems when attempting to hit long distance targets, the fins enable the projectile to fly without spin. Instead it twists and turns as it navigates towards the target. It also doesn't require a device found in guided missiles called an inertial measuring unit, which would add substantially to its cost. The prototype bullet's pitch and yaw steering is done at a set rate based on its mass and size, which means corrections don't need to be as precise as larger guided missiles.
The new bullet design was put through computer simulations which showed that while an unguided bullet under real-world conditions might miss a target more than a half mile away (1,000 meters away) by 9.8 yards, a guided bullet would land within 8 inches. And in a field test of a prototype with a tiny light-emitting diode (LED) attached, the researchers demonstrated that the bullet's built-in technology was able to withstand being blasted from a gun and can reach speeds of 2,400 feet per second, or Mach 2.1, using commercially available gunpowder. They're confident it could reach standard military speeds using customized gunpowder.
In the meantime, they've filed a patent for the new bullet technology and are seeking a private company partner to complete testing and bring a guided bullet to the marketplace.