A smart bullet is a bullet that is able to do something other than simply follow its given trajectory, such as turning, changing speed or sending data. Such a projectile may be fired from a precision-guided firearm capable of programming its behavior. It is a miniaturized type of precision-guided munition. Types of smart bullets In 2008 the EXACTO program began under DARPA to develop a "fire and forget" smart sniper rifle system including a guided smart bullet and improved scope. The exact technologies of this smart bullet have yet to be released. EXACTO was test fired in 2014 and 2015 and results showing the bullet alter course to correct its path to its target were released. In 2012 Sandia National Laboratories announced a self-guided bullet prototype that could track a target illuminated with a laser designator. The bullet is capable of updating its position 30 times a second and hitting targets over a mile away. In mid-2016, Russia revealed it was developing a similar "smart bullet" weapon designed to hit targets at a distance of up to . Guided bullet The guided bullet was conceptualized by Dr. Rolin F. Barrett, Jr. and patented in August 1998. As first designed, the bullet would have three fiber-optic based eyes (at minimum, for three-dimensionality), evenly distributed about its circumference. To activate its guided nature, a laser is pointed at a target. As the bullet approaches its final destination, it adjusts its flight path in real time to allow an equivalent amount of light from the laser to enter each eye. The bullet would not travel in multiple directions as though it were an autonomous vehicle, but instead, would make small adjustments to its flight path to hit the target precisely where the laser was placed. Moreover, the laser would not have to originate from the source of the bullet, allowing the projectile to be fired at a target beyond visual range. To allow the bullet to modify its flight path, the body was designed as a metal and polymer combination. The polymer would act as a deformable surface that would deflect the air-stream and steer the bullet in real time. The guidance system is powered by a miniature lithium-polymer battery that is connected to the navigational circuits. Barrett went to great lengths to model the airflow of the bullet, studying butterflies with speed bumps to evaluate the effects of protruding surfaces. Due to