Last month, the U.S. Missile Defense Agency successfully destroyed an ICBM in mid-flight, in a direct collision over the Pacific—a test likened to hitting one bullet with another. What if lasers could knock down missiles even sooner, when they’re still rising off the ground? In that case we might not need as many bullets.
The Missile Defense Agency is working on that very technology, which may become the most important mission given to future UAVs: the destruction of nuclear ballistic missiles. Richard Matlock, Program Executive for Advanced Technology at the MDA, said in a May interview that the ultimate goal is “to destroy rockets in the boost phase using speed-of-light lasers.” Progress will be incremental, however. “We’re working on scaling up the solid-state lasers, with the goal of eventually employing these kill lasers, as well as tracking lasers, on unmanned air vehicles.”
As part of its development program, the MDA has modified MQ-9 Reapers by adding Raytheon’s Multi-Spectral Targeting System to track missiles as they rise into the atmosphere. Currently, missiles are tracked, and their trajectories identified, primarily by shore- and ship-based radars. With the Reapers doing this from the air, missile tracking will extend hundreds of miles beyond the radar range. In other words, the Reapers will be able to see missiles before they climb above the horizon where radars can pick them up.
Instead of mounting Raytheon’s optical sensors on the bottom of the aircraft, as is standard on ground-surveilling Reapers, they are mounted on the aircraft’s chin so they can look up as well as down. The nice thing about these sensors, says Matlock, is that they operate in the same part of the spectrum as the optical/infrared sensors on ground-based missile interceptors. “So it will be a bit easier for us to directly transfer the kind of tracking information that we’re getting from the Reapers” to the interceptors, he says.
The MDA successfully tested a pair of modified Reapers off the coast of Hawaii during a Navy exercise last summer. Testing has since moved stateside, and the Raytheon sensor package is being upgraded to include a laser rangefinder. That will allow the Reaper to predict a launch trajectory without using radar.
“Assuming [the sky] is clear we can track them—given the right positioning—from the launch pad” to beyond apogee (the highest point in their trajectory), says Matlock. And if weather is a problem, “certainly we can track them once they break through whatever cloud layer there is local to the launch pad.”
Matlock emphasizes that this tracking ability of Reapers is just a steppingstone to the ability to shoot lasers, but that will require more advanced drones. “We’re looking at unmanned aerial vehicles, and manned vehicles, that will operate higher than [30,000 feet] and give us the kind of payload capacity that we need. There’s no unmanned aerial vehicle platform today that operates under all those conditions.” Kill lasers on UAS aircraft “are probably years away,” he adds. “Our goal is eventually to have these ‘ray guns’ on drones operating here in the next decade.”
In the meantime, missile defense will be largely restricted to the midcourse and terminal phase of a missile flight, with the latter taking place uncomfortably close to an intended target. A spokesman for the MDA points out, “If I can destroy [a missile] before it gets over my territory, the further back towards the bad guy who shoots at me, the better.”