Short Sharp Science - Light test for laser-guided bullet

Paul Marks, senior technology correspondent
 
(Image: Sandia National Laboratories)

A laser-seeking, self-steering bullet flies through the air, rendered visible by a glowing LED ensconced in its tip. No, it's not that the US military suddenly wants its enemies to see its bullets coming. Instead, its developers needed to test the weapon's in-flight steering electronics, to prove they can cope with the shock of being fired. The fact the LED stayed brightly lit means that the in-bullet circuits did indeed remain unbroken.

Invented by engineers at the US government's Sandia National Laboratories, the self-guided bullet homes in on a laser spot trained on a target from up to 1.4 kilometres away from its firing point. If the target is a moving truck, say, and it moves after the bullet is fired, the laser illumination as seen by a laser sensor in the bullet's nose instructs the bullet to finely twist tiny rudder-like fins on its rear end to keep it on target. The LED test proved that the sensor can remain powered after firing.

In a patent filing, Sandia says: "Computer simulations showed an unguided bullet under real-world conditions could miss a target more than 1,000 metres away by nine metres, but a guided bullet would get within 0.2 metres." You can read more about the specialised bullets here and watch them being fired here.

The challenge the Sandia team faces is making the tech-stuffed bullet cheap enough for everyday use. When stun gun maker Taser International launched a stun cartridge that can be fired from a shotgun, the resulting round, containing a shock battery and control electronics, cost a cool $150 a piece. "If they are going to fire that at a rioting crowd they may as well throw iPods at them," one arms control expert told New Scientist at the time.

http://www.newscientist.com