You know you’re living in the future when the US Navy starts installing laser weapons on its ships. You really know you are when you hear the reason why: Those laser cannons zapping sea- and airborne threats like something out of Star Trek? Using them is actually less expensive than using conventional weapons. In April, the Navy announced it would deploy an onboard solid-state laser capable of firing at swarming small boats or downing unmanned aircraft (See: Navy to Put Craft-Zapping Laser on a Ship in 2014). The Laser Weapon System (LaWS) — built from commercial fiber solid-state lasers — was temporarily installed on the USS Dewey to support an exercise off the coast of southern California during August 2012. A modified version of LaWS is scheduled to be installed on the USS Ponce during 2014 to support deployed operations in the Persian Gulf. The Navy has tested such weapons before — for example, the Maritime Laser Demonstrator it developed with Northrop Grumman (See: Laser Used at Sea to Set Boat Afire and A Brave New World of Photonics) — but the installation aboard the Ponce will mark the first time a laser defense system is actively deployed on a Navy ship at sea. Laser weapons offer a number of advantages over conventional shipboard weapons, but in announcing the installation on the Ponce, the Navy emphasized one in particular. In a statement, Rear Adm. Matthew Klunder, the chief of naval research, described the laser weapon as “a tremendously affordable answer to the costly problem of defending against asymmetric threats.” He went on to say that the technology — and associated cost reductions — are “crucial in a fiscally constrained environment.” How affordable? The Navy says laser weapons systems can protect a ship against swarming small boats and unmanned aircraft at a fraction of the cost of conventional weapons: A shot of directed energy costs under $1 while firing a missile can run up to hundreds of thousands of dollars. That’s quite a difference in cost. It makes sense, though, when you consider what goes into firing each type of weapon. Firing a laser requires only the energy involved in doing so, including the raw electrical power and the energy needed for cooling. This figure is negligible compared to the “All Up Round” (AUR) cost of firing a conventional weapon — that is, the cost of the article inserted into launcher or gun and then typically fired at a target. “Lasers in this regard are highly efficient, able to use already available resources (electricity) without requiring comparatively costly logistics required for explosives and propellants handling with conventional weapons,” Peter “Rollie” Morrison explained in an email. Morrison is the program officer for the Solid-State Laser Technology Maturation program (that includes LaWs) at the Office of Naval Research. Of course, there’s the cost of the hardware itself, which could offset any savings in the operation of the system. We’re just beginning to see studies of the cost advantages of lasers versus conventional weapons, Morrison said, taking into account the tradeoffs that come with each: A solid-state laser has the advantage in efficiency and in requiring only electricity and water cooling to fire them, for example. Conventional weapons offer a variety of other advantages, including the ability to reach over the horizon, beyond the line of sight.