Fitting the electronics required to guide a projectile which is around 54 mm long and has a 12.7 mm maximum diameter is a real challenge. Not only must all the elements withstand the acceleration when the round is fired, but the internal components must also be tested individually with real weapon firings.
To our knowledge only the United States and Russia launched a programme aimed at providing their snipers with guided rounds. Known as EXACTO (for Extreme Accuracy Tasked Ordnance), one of the US projects launched by DARPA led to some demonstrations in 2015, however no products seem to have been developed out of that project. As for the Russian round, its development started when EXACTO was going to demo; little is known about the fate of the 12.7×108 mm guided round aimed at improving the performances of Russian long-range rifles.
The I-SMART (ISL Sniper Munition Actuated to Reach Target) 12.7 mm bullet, as the round is called at the Research Institute of Saint-Louis, is made of five different elements. Starting from the round tip we find the optics, used in the terminal guidance phase, followed by the navigation electronics, then comes the power supply, the actuation and finally communications.
An optical sensor in the tip ensures terminal guidance; but so far for testing, the trajectory correction has been calculated in a ground unit. Hence the round “talks” with the sniper ground station during the flight. This communication solution should be replaced in the future design by on-board calculation.
The aerodynamic actuators have already been tested at laboratory and wind tunnel level but have still to be tested in a real firing. ISL aims at allowing a considerable 50 metres lateral correction capacity at 2,000 metres range. Considering the flight time of around three seconds, this would not just increase hit probability but would also allow the marksman to hit a target moving even with a cross speed of 60 km/h. Additionally, the technology will allow less experienced personnel to obtain spot-on hits, increasing their accuracy with less training.
EDR On-Line understood that ISL is aiming at making the round compatible with 12.7×99 mm sniper rifles. No date was provided for the final tests, which will bring the project to TRL5, at which point ISL will look for an industrial partner, transferring its expertise to bring the demonstrator to product level.
Photo by P. Valpolini