Asmart bullet is abullet that is able to do something other than simply follow its given trajectory, such as turning, changing speed or sending data.[1] Such a projectile may be fired from aprecision-guided firearm capable of programming its behavior. It is a miniaturized type ofprecision-guided munition.
In 2008 theEXACTO program began underDARPA to develop a "fire-and-forget" smartsniper 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.[2]
In 2012Sandia National Laboratories announced a self-guided bullet prototype that could track a target illuminated with alaser designator. The bullet is capable of updating its position 30 times a second and hitting targets over a mile away.[3]
In mid-2016, Russia revealed it was developing a similar "smart bullet" weapon designed to hit targets at a distance of up to 10 kilometres (6.2 mi).[4][5]
The guided bullet was conceptualized by Dr. Rolin F. Barrett, Jr. and patented in August 1998.[6]
As first designed, the bullet would have threefiber-optic based eyes (at minimum, for three-dimensionality), evenly distributed about itscircumference. To activate its guided nature, alaser 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 anautonomous 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 theprojectile to be fired at a targetbeyond visual range.[7]
To allow the bullet to modify its flight path, the body was designed as a metal andpolymer combination. The polymer would act as a deformable surface that would deflect the air-stream and steer the bullet in real time. Theguidance system is powered by a miniaturelithium-polymer battery that is connected to the navigational circuits.[7]
Barrett went to great lengths to model the airflow of the bullet, studyingbutterflies with speed bumps to evaluate the effects of protruding surfaces. Due to a lack ofballistic programs at the time, custom simulations were written inMathcad to solve for numerous flight variables. In addition to modeling the flight, theinterior ballistics were modeled by continuously alteringpolynomial curves until they were in agreement with publicly available data. Due to a lack of availableterminal ballistics data that would have been representative of the guided bullet, the data was compared to that oflarge game hunting bullets.[8]
One kind of smart bullet is a projectile that is capable of changing its course during flight. One use of this would be to enable soldiers to stay behind protective cover and shoot around corners. One implementation uses aspoiler and microgyro to control the bullet.[9]
Honeywell Aerospace has producedinertial measurement units based onMEMS and microelectronics technologies that it claims can survive the shock of being fired out of a gun.[10]
Another type of smart bullet is one that can transmit data about the location that has been hit. A prototype has been created by researchers at theUniversity of Florida inGainesville, Florida,USA with funding fromLockheed Martin.[11] The bullet (projectile) has the capability to send data up to a distance of 70 meters.