	Why This Issue Is Important for Congress

Active Protection Systems (APSs) are subsystems integrated into or installed on a combat vehicle to automatically acquire, track, and respond with hard or soft kill capabilities to a variety of threats, including rocket-propelled grenades (RPGs) and anti-tank guided missiles (ATGMs). APS technologies are not new, and a number of nations have already employed APS on the battlefield. The U.S. military is now beginning to include APS as part of its formal combat vehicle modernization plans and, if the initial deployment of APS proves successful, could expand the use of APS to potentially thousands of tactical military vehicles—a complex and potentially costly undertaking. Proliferation of Advanced RPGs and ATGMs

			RPGs

The proliferation of advanced RPGs and ATGMs is of concern to some defense officials and policymakers alike. These weapons—RPGs in particular—have been especially popular with insurgents because they are readily available, relatively inexpensive, and require little training. The 2006 Israel-Lebanon War and the 2014 Gaza Conflict

Some experts cite Israeli combat experiences in 2006 and 2014 as demonstrative of the value of APS. Basic APS Considerations and Theory

		Proposed Criteria for a Successful APS

It has been suggested that an APS should meet both technical and operational criteria to be effective, including 
be able to work under extremely demanding circumstances and compressed timelines; be robust against countermeasures; minimize the threat to friendly forces and civilians; fit in the space and power allocated to it on the vehicle; and be affordable. A Brief History of Selected U.S. APS Efforts

According to the U.S. Army Tank-Automotive Research, Development, and Engineering Center (TARDEC), "Active Protection Systems have been in the design and development stages since the early 1950s, but none have successfully made the transition from development to integration on a [U.S.] platform." Current U.S. Army and Marine Corps APS Efforts

		General74

Both Army and Marine officials emphasized to CRS that their respective APS efforts are not in any sense either acquisition programs or Programs of Record by DOD definition. The Army's APS Effort76

The Army is currently involved in two separate parallel and distinct APS efforts—the Expedited, Non-Developmental Item (NDI) APS effort and the Modular Active Protection System (MAPS) effort. The Marine Corps APS Effort81

The Marines describe their APS efforts as a "technology demonstration" whereby the Marines would attempt to install an existing Trophy on the M-1A1 tank in coordination with the Army Expedited NDI effort. Potential Issues for Congress

		Are Current NDI APSs Effective and Safe Enough for Operational Use? What Are the Benefits of MAPS Relative to Non-Developmental Efforts? How Does MAPS Affect NDI APS Performance and Costs? What Are the Army's and Marines' Detailed Plans for APS Fielding?
Active Protection Systems (APSs) are subsystems integrated into or installed on a combat vehicle to automatically acquire, track, and respond with hard or soft kill capabilities to a variety of threats, including rocket-propelled grenades (RPGs) and anti-tank guided missiles (ATGMs). APS technologies are not new, and a number of nations have already employed APS on the battlefield. The U.S. military is now beginning to include APS as part of its formal combat vehicle modernization plans and, if the initial deployment of APS proves successful, could expand the use of APS to potentially thousands of tactical military vehicles—a complex and potentially costly undertaking.
The proliferation of advanced RPGs and ATGMs is of concern to some defense officials and policymakers, including Congress. These weapons—RPGs in particular—have been particularly popular with insurgents because they are readily available, relatively inexpensive, and require little training. Israel's experiences with RPGs and ATGMs in the 2006 Israel-Lebanon War and the 2014 Gaza Conflict and growing concerns with Russian military capabilities and activities in Eastern Europe have possibly served as catalysts for intensifying U.S. APS efforts. Technical and operational challenges to APS include being able to work under extremely demanding circumstances and compressed timelines, robustness against countermeasures, minimizing the threat to friendly forces and civilians, being compatible with the space and power allocated to it on the vehicle, and affordability.
A number of nations have operationally deployed APS on combat vehicles—Russia and Israel most notably—and some experts characterize U.S. efforts as somewhat lagging. U.S. military officials contend there are still a number of developmental and safety challenges that must be overcome before current APS systems are suitable for battlefield deployment.
According to the U.S. Army Tank-Automotive Research, Development, and Engineering Center (TARDEC), "Active Protection Systems have been in the design and development stages since the early 1950s, but none have successfully made the transition from development to integration on a platform."
The Army's and Marines' current APS efforts are described as technology demonstrations and have not progressed to formal Programs of Record. The Army and Marines are coordinating their respective efforts, although no joint program currently exists. The Army is currently involved in two separate parallel and distinct APS efforts—the Expedited, Non-Developmental Item (NDI) APS effort and the Modular Active Protection System (MAPS) effort. The Marines describe their APS efforts as a "technology demonstration" whereby the Marines would attempt to install a Trophy APS on the M-1A1 tank in coordination with the Army's Expedited NDI effort. The Marines have a number of unique APS requirements—including the ability to be transported by ship and withstand salt water corrosion—which will also factor into their eventual APS plans.
Potential issues for Congress include whether current NDI APSs are effective and safe enough for operational use, the benefits of MAPS relative to non-developmental efforts, MAPS' impacts on NDI APS performance and costs, the Army's and Marines' detailed plans for APS fielding, and APS adaptability to future threats.