SSLs are being developed by multiple parts of the Department of Defense (DOD), not just the Navy. SSLs, EMRG, and HVP, moreover, have potential application to military aircraft and ground forces equipment, not just surface ships. And SSLs, EMRG, and HVP can be used for missions other than defending against ASCMs and ASBMs.
SSLs, EMRG, and HVP offer a potential for dramatically improving depth of magazine and the cost exchange ratio:
* Depth of magazine. SSLs are electrically powered, drawing their power from the ship’s overall electrical supply, and can be fired over and over, indefinitely, as long as the SSL continues to work and the ship has fuel to generate electricity. The EMRG’s projectile and the HVP (which are one and the same—see next section) can be stored by the hundreds in a Navy surface ship’s weapon magazine.
* Cost exchange ratio. An SSL can be fired for a marginal cost of less than one dollar per shot (which is the cost of the fuel needed to generate the electricity used in the shot), while the EMRG’s projectile/HVP has an estimated unit procurement cost of about $25,000.
The laser on the USS Ponce has a reported beam power of 30 kilowatts (kW), which is strong enough to counter small boats and UAVs. As a follow-on effort to LaWS and MLD, the Navy initiated the SSL Technology Maturation (SSL-TM) program, in which industry teams led by BAE Systems, Northrop Grumman, and Raytheon are competing to develop a shipboard laser with a beam power of 100 kW to 150 kW, which would provide increased effectiveness against small boats and UAVs. Boosting beam power further—to something like 200 kW or 300 kW—could permit a laser to counter at least some ASCMs. Improving to several hundred kW, if not one megawatt (MW) or more—could improve a laser’s effectiveness against ASCMs and enable it to counter ASBMs.
The EMRG is a cannon that uses electricity rather than chemical propellants (i.e., gunpowder charges) to fire a projectile. EMRG uses magnetic fields created by high electrical currents accelerate a sliding metal conductor. or armature, between two rails to launch projectiles at [speeds of] 4,500 mph to 5,600 mph,” or roughly Mach 5.9 to Mach 7.4 at sea level. Like SSLs, EMRG draws its power from the ship’s overall electrical supply.
The two industry-built prototypes are designed to fire projectiles at energy levels of 20 to 32 megajoules, which is enough to propel a projectile 50 to 100 nautical miles. (Such ranges might refer to using the EMRG for NSFS missions. Intercepts of ASCMs and ASBMs might take place at much shorter ranges.)
HVP - High Velocity Projectile
As the Navy was developing EMRG, it realized that the guided projectile being developed for EMRG could also be fired from 5-inch and 155mm powder guns.
When fired from 5-inch powder guns, the projectile achieves a speed of roughly Mach 3, which is roughly half the speed it achieves when fired from EMRG, but more than twice the speed of a conventional 5-inch shell fired from a 5-inch gun. This is apparently fast enough for countering at least some ASCMs. The Navy states that “The HVP—combined with the MK 45 [5-inch gun]—will support various mission areas including naval surface fire support, and has the capacity to expand to a variety of anti-air threats, [and] anti-surface [missions], and could expand the Navy's engagement options against current and emerging threats.