Congress directed the Department of Defense (DOD) to prepare a master plan to develop laser technologies for potential weapons applications in the National Defense Authorization Act for Fiscal Year 2000. In response to this legislation, the High Energy Laser (HEL) Executive Review Panel was formed and issued the HEL Master Plan on March 24, 2000. This plan recommended that DOD implement a new management structure for HEL technologies and increase the funding allocated to HELs to achieve a better balance between large demonstration programs and the enabling science and technology projects. Subsequently, in the Floyd D. Spence National Defense Authorization Act of Fiscal Year 2001, Congress directed the Secretary of Defense to implement the management and organizational structure specified in the Master Plan. Congress asked us to review the extent to which DOD has implemented the recommendations of the HEL Master Plan, by assessing (1) whether DOD has achieved more balance between large demonstration projects and the enabling science and technology base projects; (2) whether the DOD funding process focuses on the most critical HEL issues; and (3) what impact the new management structure has had on the coordination and redundancy of HEL technology efforts DOD-wide.

The U.S. Government Accountability Office (GAO) is an independent agency that works for Congress. The GAO watches over Congress, and investigates how the federal government spends taxpayers dollars. The Comptroller General of the United States is the leader of the GAO, and is appointed to a 15-year term by the U.S. President. The GAO wants to support Congress, while at the same time doing right by the citizens of the United States. They audit, investigate, perform analyses, issue legal decisions and report anything that the government is doing. This is one of their reports.

The Navy is developing three new ship-based weapons that could improve the ability of Navy surface ships to defend themselves against missiles, unmanned aerial vehicles (UAVs), and surface craft: the Surface Navy Laser Weapon System (SNLWS), the electromagnetic railgun (EMRG), and the gun-launched guided projectile (GLGP), previously known as the hypervelocity projectile (HVP). The Navy refers to the initial (i.e., Increment 1) version of SNLWS as HELIOS, an acronym meaning high-energy laser with integrated optical dazzler and surveillance. EMRG could additionally provide the Navy with a new naval surface fire support (NSFS) weapon for attacking land targets in support of Marines or other friendly ground forces ashore. The Department of Defense is exploring the potential for using GLGP across multiple U.S. military services. Any one of these three new weapons, if successfully developed and deployed, might be regarded as a "game changer" for defending Navy surface ships against enemy missiles and UAVs. If two or three of them are successfully developed and deployed, the result might be considered not just a game changer, but a revolution. Rarely has the Navy had so many potential new types of surface-ship air-defense weapons simultaneously available for development and potential deployment. Although the Navy in recent years has made considerable progress in developing technologies for these new weapons, a number of significant development challenges remain. Overcoming these challenges will require additional development work, and ultimate success in overcoming them is not guaranteed. The issue for Congress is whether to approve, reject, or modify the Navy's funding requests and proposed acquisition strategies for these three potential new weapons. Potential oversight questions for Congress include the following: Using currently available air-defense weapons, how well could Navy surface ships defend themselves in a combat scenario against an adversary such as China that has or could have large numbers of missiles and UAVs? How would this situation change if Navy surface ships in coming years were equipped with SNLWS, EMRG, GLGP, or some combination of these systems? How significant are the remaining development challenges for SNLWS, EMRG, and GLGP? Are current schedules for developing SNLWS, EMRG, and GLGP appropriate in relation to remaining development challenges and projected improvements in enemy missiles and UAVs? When does the Navy anticipate issuing roadmaps detailing its plans for procuring and installing production versions of SNLWS, EMRG, and GLGP on specific Navy ships by specific dates? Will the kinds of surface ships that the Navy plans to procure in coming years have sufficient space, weight, electrical power, and cooling capability to take full advantage of SNLWS and EMRG? What changes, if any, would need to be made in Navy plans for procuring large surface combatants (i.e., destroyers and cruisers) or other Navy ships to take full advantage of SNLWS and EMRGs? Given the Navy's interest in HPV, how committed is the Navy to completing the development of EMRG and eventually deploying EMRGs on Navy ships? Are the funding line items for SNLWS, EMRG, and GLDP sufficiently visible for supporting congressional oversight?

Physics at the beginning of the twenty-first century has reached new levels of accomplishment and impact in a society and nation that are changing rapidly. Accomplishments have led us into the information age and fueled broad technological and economic development. The pace of discovery is quickening and stronger links with other fields such as the biological sciences are being developed. The intellectual reach has never been greater, and the questions being asked are more ambitious than ever before. Physics in a New Era is the final report of the NRC's six-volume decadal physics survey. The book reviews the frontiers of physics research, examines the role of physics in our society, and makes recommendations designed to strengthen physics and its ability to serve important needs such as national security, the economy, information technology, and education.

The National Defense Authorization Act of 2016 mandates a review of missile defeat policy, strategy, and capability to be completed by January 2018. This upcoming Missile Defeat Review (MDR) represents an opportunity for the Trump administration to articulate a vision for the future of air and missile defense. This collection of expert essays explores how the strategic environment for missile defense and defeat has evolved since 2010 and offers recommendations to help guide and inform the MDR’s development.