Military

SLAMRAAM [Surfaced-Launched Advanced Medium Range Air-to-Air Missile]

The Surfaced-Launched Advanced Medium Range Air-to-Air Missile (SLAMRAAM) is the Army's future shortrange air defense weapon. The SLAMRAAM program is intended to eventually replace all the Army's shortrange air defense weapon systems that employ the Stinger missile. The SLAMRAAM system intends to give the Army the capability to engage targets (including cruise missiles and helicopters) to beyond line-of-sight and at greater ranges than the Stinger-based systems. SLAMRAAM is also intended to defend against the evolving air threat from unmanned aerial vehicles (UAVs) and cruise missiles.

The SLAMRAAM fire unit consists of four to six ready-to-fire AIM-120C-7 AMRAAMs mounted on an Army High Mobility Multi-Wheeled Vehicle (HMMWV). The SLAMRAAM system also consists of a Battle Management Command, Control, Computers, Communications, and Intelligence (BMC4I) system. The BMC4I system will include the sensors, command posts, and communications systems necessary to pass targeting data to the SLAMRAAM fire units. The United States Marine Corps (USMC) was also developing a surfaced-launched AMRAAM system called the Complementary Low-Altitude Weapon System (CLAWS). The USMC CLAWS program is also an HMMWV-based fire unit capable of launching AIM-120C AMRAAM missiles. The operational requirements for the Army's SLAMRAAM and USMC's CLAWS programs are very similar, but not identical.

Advanced Medium Range Air to Air Missile, or AMRAAM, is initially directed toward a target after launching by an aircraft and guided during mid-course flyout by a targeting aid such as a radar that is locked onto the target. The targeting aid is not onboard the missile, but instead is on the launch aircraft or at some other location. The targeting aid can give the approximate position of the target at great distances. The approximate position of the target as determined by the targeting aid is communicated to the missile and its guidance system by radio.

A gimballed seeker, such as an infrared sensor, within the missile can determine the position of the target very accurately, but only from a relatively short distance. During the portion of the missile flight when the target is beyond the range of the seeker, the seeker is pointed toward the target by the movement of the gimbal. The seeker does not, however, actively control the flight of the missile until the missile nears the target. During the final stages of the flight of the missile when the target is within the range of the seeker, the seeker locks onto the target, takes over control of the guidance of the missile, and provides the information to guide the missile to the target.

Initial attempts to use such an air-to-air missile of the AMRAAM type as a ground-to-air missile by launching it from a fixed ground location instead of a fast-moving aircraft, in many instances the mission was unsuccessful and the missile did not intercept the target. This is unfortunate, as the AMRAAM-type missile had proved to be very valuable in the air-to-air role, and its many features could desirably be used in the ground-to-air mission.

These problems can be avoided by delaying the initiation of the active missile guidance to the target until the ground-launched missile has reached a preselected velocity. The principal relevant difference in the operation of the air-launched missile and the ground-launched missile is that the ground launched missile starts from zero velocity rather than a relatively high velocity, typically about Mach 0.9, characteristic of the air-launched missile. At such an air-launched speed, the missile makes only relatively small directional corrections initially, so that the seeker is not forced to make large, rapid movements to continue to point toward the target.

According to DOT&E, two issues were critical to an adequate assessment of the operational effectiveness and suitability of the SLAMRAAM program. The first issue is the ability of the AIM-120C AMRAAM missile to perform against the targets of interest to the Army, namely, UAVs, cruise missiles, and helicopters. Firings against these types of targets have not been done throughout the long history of the AMRAAM test program conducted by the Air Force and Navy.

Second, the integration of the BMC4I is critical to the success of SLAMRAAM. The SLAMRAAM system, unlike the Stinger-based weapons, cannot autonomously engage targets. The SLAMRAAM fire unit must receive targeting data from the BMC4I system, including targeting data acquired from sensors operated by other Services. The BMC4I system must also provide target identification of friendly aircraft. This becomes critical since SLAMRAAM provides a beyond line-of-sight engagement capability that cannot rely on visual identification means to distinguish friendly aircraft from enemy threats. The BMC4I system must also be mobile enough to keep up with rapidly advancing maneuver forces.