Hypersonic Weapons: Background and Issues August 27, 2020 for Congress Kelley M. Sayler The United States has actively pursued the development of hypersonic weapons— Analyst in Advanced maneuvering weapons that fly at speeds of at least Mach 5—as a part of its conventional Technology and Global prompt global strike program since the early 2000s. In recent years, the United States Security has focused such efforts on developing hypersonic glide vehicles, which are launched from a rocket before gliding to a target, and hypersonic cruise missiles, which are powered by high-speed, air-breathing engines during flight. As Vice Chairman of the Joint Chiefs of Staff and former Commander of U.S. Strategic Command General John Hyten has stated, these weapons could enable "“responsive, long-range, strike options against distant, defended, and/or time-critical threats [such as road-mobile missiles] when other forces are unavailable, denied access, or not preferred."” Critics, on the other hand, contend that hypersonic weapons lack defined mission requirements, contribute little to U.S. military military capability, and are unnecessary for deterrence.

Funding for hypersonic weapons has been relatively restrained in the past; however, both the Pentagon and Congress have shown a growing interest in pursuing the development and near-term deployment of hypersonic systems. This is due, in part, to the growing interest in these technologies in Russia and China, both of which have a number of hypersonic weapons programs and are expected to field an operational hypersonic glide vehicle—potentiallypotential y armed with nuclear warheads—as early as 2020. The United StatesMost U.S. hypersonic weapons, in contrast to those in Russia and China, is not currently considering or developing hypersonic weaponsare not being designed for use with a nuclear warhead. As a result, U.S. hypersonic weapons will likely wil likely require greater accuracy and will be more technically challengingwil be more technical y chal enging to develop than nuclear-armed Chinese and Russian systems.

The Pentagon'’s FY2021 budget request for all al hypersonic-related research is $3.2 billionbil ion—up from $2.6 billionbil ion in the FY2020 request—including $206.8 millionmil ion for hypersonic defense programs. At present, the Department of Defense (DOD) has not established any programs of record for hypersonic weapons, suggesting that it may not have approved either requirements for the systems or long-term funding plans. Indeed, as Assistant Director for Hypersonics (Office of the Under Secretary of Defense for Research and Engineering) Mike White has stated, DOD has not yet made a decision to acquire hypersonic weapons and is instead developing prototypes to assist in the evaluation of potential weapon system concepts and mission sets.

As Congress reviews the Pentagon'’s plans for U.S. hypersonic weapons programs, it might consider questions about the rationale for hypersonic weapons, their expected costs, and their implications for strategic stability and arms control. Potential questions include the following:

•  What mission(s) will wil hypersonic weapons be used for? Are hypersonic weapons the most cost- effective means of executing these potential missions? How will wil they be incorporated into joint operational doctrine and concepts?
•  Given the lack of defined mission requirements for hypersonic weapons, how should Congress evaluate funding requests for hypersonic weapons programs or the balance of funding requests for hypersonic weapons programs, enabling technologies, and supporting test infrastructure? Is an acceleration of research on hypersonic weapons, enabling technologies, or hypersonic missile defense options both necessary and technologically feasible?
• How, if at all, will technological y feasible?  How, if at al , wil the fielding of hypersonic weapons affect strategic stability?
•  Is there a need for risk-mitigation measures, such as expanding New START, negotiating new multilateral multilateral arms control agreements, or undertaking transparency and confidence-building activities? Congressional Research Service link to page 4 link to page 5 link to page 7 link to page 7 link to page 12 link to page 13 link to page 14 link to page 15 link to page 15 link to page 16 link to page 17 link to page 19 link to page 19 link to page 20 link to page 20 link to page 21 link to page 6 link to page 14 link to page 18 link to page 11 link to page 23 link to page 24 link to page 24 link to page 25 link to page 25 link to page 25 link to page 23 link to page 26 Hypersonic Weapons: Background and Issues for Congress Contents Introduction ................................................................................................................... 1 Background.................................................................................................................... 2 United States ............................................................................................................ 4 Programs ............................................................................................................ 4 Infrastructure ....................................................................................................... 9 Russia.................................................................................................................... 10 Programs .......................................................................................................... 11 Infrastructure ..................................................................................................... 12 China..................................................................................................................... 12 Programs .......................................................................................................... 13 Infrastructure ..................................................................................................... 14 Issues for Congress ....................................................................................................... 16 Mission Requirements .............................................................................................. 16 Funding Considerations ............................................................................................ 17 Strategic Stability .................................................................................................... 17 Arms Control .......................................................................................................... 18 Figures Figure 1. Terrestrial-Based Detection of Bal istic Missiles vs. Hypersonic Glide Vehicles .......... 3 Figure 2. Artist Rendering of Avangard............................................................................. 11 Figure 3. Lingyun-1 Hypersonic Cruise Missile Prototype ................................................... 15 Tables Table 1. Summary of U.S. Hypersonic Weapons Programs .................................................... 8 Table A-1. DOD Hypersonic Ground Test Facilities............................................................ 20 Table A-2. DOD Open-Air Ranges................................................................................... 21 Table A-3. DOD Mobile Assets ....................................................................................... 21 Table A-4. NASA Research-Related Facilities ................................................................... 22 Table A-5. Department of Energy Research-Related Facilities .............................................. 22 Table A-6. Industry/Academic Research-Related Facilities .................................................. 22 Appendixes Appendix. U.S. Hypersonic Testing Infrastructure .............................................................. 20 Contacts Author Information ....................................................................................................... 23 Congressional Research Service Hypersonic Weapons: Background and Issues for Congress Introduction activities?

The United States has actively pursued the development of hypersonic weapons as a part of its conventional prompt global strike (CPGS) program since the early 2000s.¹1 In recent years, it has focused such efforts on hypersonic glide vehicles and hypersonic cruise missiles with shorter and intermediate ranges for use in regional conflicts. Although funding for these programs has been relatively restrained in the past, both the Pentagon and Congress have shown a growing interest in pursuing the development and near-term deployment of hypersonic systems. This is due, in part, to the growing interest in these technologies in Russia and China, leading to a heightened focus in the United States on the strategic threat posed by hypersonic flight. Open-source reporting indicates that both China and Russia have conducted numerous successful tests of hypersonic glide vehicles, and both are expected to field an operational capability as early as 2020.

. Experts disagree on the potential impact of competitor hypersonic weapons on both strategic stability and the U.S. military'’s competitive advantage. Nevertheless, currentformer Under Secretary of Defense for Research and Engineering (USD [R&E]) Michael Griffin has testified to Congress that the United States does not "“have systems which can hold [China and Russia] at risk in a corresponding manner, and we don'’t have defenses against [their] systems."²”2 Although the John S. McCain National Defense Authorization Act for Fiscal Year 2019 (FY2019 NDAA, P.L. 115-232232) accelerated the development of hypersonic weapons, which USD (R&E) identifies as a priority research and development area, the United States is unlikely to field an operational system before 2023. However, the United Statesmost U.S. hypersonic weapons programs, in contrast to those in Russia and China, is not currently considering or developing hypersonic weaponsare not being designed for use with a nuclear warhead.3 As a result, U.S. hypersonic weapons will likely wil likely require greater accuracy and will be more technically challenging wil be more technical y chal enging to develop than nuclear-armed Chinese and Russian systems.

In addition to accelerating development of hypersonic weapons, Section 247 of the FY2019 NDAA required that the Secretary of Defense, in coordination with the Director of the Defense IntelligenceIntel igence Agency, produce a classified assessment of U.S. and adversary hypersonic weapons programs, to include the following elements:

(1) An evaluation of spending by the United States and adversaries on such technology.

(2) An evaluation of the quantity and quality of research on such technology.

(3) An evaluation of the test infrastructure and workforce supporting such technology.

(4) (4) An assessment of the technological progress of the United States and adversaries on such technology.

(5) Descriptions of timelines for operational deployment of such technology.

1 For details, see CRS Report R41464, Conventional Prompt Global Strike and Long-Range Ballistic Missiles: Background and Issues, by Amy F. Woolf. 2 U.S. Congress, Senate Committee on Armed Services, “T estimony of Michael Griffin,” Hearing on New T echnologies to Meet Emerging T hreats, April 18, 2018, https://www.armed-services.senate.gov/imo/media/doc/18-40_04-18-18.pdf. 3 Until recently, the United States was not believed to be considering the development of nuclear-armed hypersonic weapons; however, a since-revoked Air Force solicit ation sought ideas for a “ thermal protection system that can support [a] hypersonic glide to ICBM ranges.” Senior defense officials responded to news reports of the revocation, stating that DOD “remains committed to non-nuclear role for hypersonics.” See Steve T rimble, “USAF Errantly Reveals Research on ICBM-Range Hypersonic Glide Vehicle,” Aviation Week, August 18, 2020, https://aviationweek.com/defense-space/missile-defense-weapons/usaf-errantly-reveals-research-icbm-range-hypersonic-glide. Congressional Research Service 1 link to page 6 Hypersonic Weapons: Background and Issues for Congress (6) An assessment of the intent or willingness of adversaries to use such technology.4 (6) An assessment of the intent or willingness of adversaries to use such technology.³

This report was delivered to Congress in July 2019. Similarly, Section 1689 of the FY2019 NDAA requires the Director of the Missile Defense Agency to produce a report on "“how hypersonic missile defense can be accelerated to meet emerging hypersonic threats."⁴”5 The findings of these reports could hold implications for congressional authorizations, appropriations, and oversight.

The following report reviews the hypersonic weapons programs in the United States, Russia, and China, providing information on the programs and infrastructure in each nation, based on unclassified sources. It also provides a brief summary of the state of global hypersonic weapons research development. It concludes with a discussion of the issues that Congress might address as it considers DOD'’s funding requests for U.S. hypersonic technology programs.

Background

Background Several countries are developing hypersonic weapons, which fly at speeds of at least Mach 5 (five times the speed of sound), but none have yet introduced them into their operational military forces.⁵ forces.6 There are two primary categories of hypersonic weapons

•  Hypersonic glide vehicles (HGV) are launched from a rocket before gliding to a target.⁶
• target.7  Hypersonic cruise missiles are powered by high-speed, air-breathing engines, or " “scramjets,"” after acquiring their target.

Unlike ballistic Unlike bal istic missiles, hypersonic weapons do not follow a ballisticbal istic trajectory and can maneuver en route to their destination. As Vice Chairman of the Joint Chiefs of Staff and former Commander of U.S. Strategic Command General John Hyten has stated, hypersonic weapons could enable "“responsive, long-range, strike options against distant, defended, and/or time-critical threats [such as road-mobile missiles] when other forces are unavailable, denied access, or not preferred."⁷”8 Conventional hypersonic weapons use only kinetic energy—energy derived from motion—to destroy unhardened targets or, potentiallypotential y, underground facilities.⁸

9 Hypersonic weapons could challengechal enge detection and defense due to their speed, maneuverability, and low altitude of flight.⁹10 For example, terrestrial-based radar cannot detect hypersonic weapons until late in the weapon'’s flight.¹⁰11 Figure 1 depicts the differences in terrestrial-based radar detection timelines for ballisticbal istic missiles versus hypersonic glide vehicles.

Figure 1. Terrestrial-Based Detection of Ballistic Missiles vs. Hypersonic Glide Vehicles

Source: CRS image based on an image in "Gliding missiles that fly faster than Mach 5 are coming," The Economist, 4 P.L. 115-232, Section 2, Division A, T itle II, §247. 5 P.L. 115-232, Section 2, Division A, T itle XVI, §1689. 6 T he United States, Russia, China, Australia, India, France, and Germany are developing hypersonic weapons technology. See Richard H. Speier et al., Hypersonic Missile Proliferation: Hindering the Spread of a New Class of Weapons, RAND Corporation, 2017, https://www.rand.org/pubs/research_reports/RR2137.html. 7 When HGVs are mated with their rocket booster, the resulting weapon system is often referred to as a hypersonic boost -glide weapon. 8 U.S. Congress, Senate Committee on Armed Services, “T estimony of John E. Hyten ,” Hearing on United States Strategic Command and United States Northern Command, February 26, 2019, https://www.armed-services.senate.gov/imo/media/doc/Hyten_02-26-19.pdf. 9 Richard H. Speier et al., Hypersonic Missile Proliferation: Hindering the Spread of a New Class of Weapons, p. 13. 10 See Department of Defense, 2019 Missile Defense Review, https://www.defense.gov/Portals/1/Interactive/2018/11-2019-Missile-Defense-Review/T he%202019%20MDR_Executive%20Summary.pdf. 11 Richard H. Speier et al., Hypersonic Missile Proliferation: Hindering the Spread of a New Class of Weapons. Congressional Research Service 2 Hypersonic Weapons: Background and Issues for Congress Figure 1. Terrestrial-Based Detection of Ballistic Missiles vs. Hypersonic Glide Vehicles Source: CRS image based on an image in “Gliding missiles that fly faster than Mach 5 are coming,” The Economist, April 6, 2019, https://www.economist.com/science-and-technology/2019/04/06/gliding-missiles-that-fly-faster-than-mach-5-are-coming.

. This delayed detection compresses the timeline for decision-makers assessing their response options and for a defensive system to intercept the attacking weapon—potentiallypotential y permitting only a single intercept attempt.¹¹

12 Furthermore, U.S. defense officials have stated that both terrestrial- and current space-based sensor architectures are insufficient to detect and track hypersonic weapons, with USD R&Eformer USD(R&E) Griffin noting that "“hypersonic targets are 10 to 20 times dimmer than what the U.S. normallynormal y tracks by satellitessatel ites in geostationary orbit."¹²”13 Some analysts have suggested that space-based sensor layers—integrated with tracking and fire-control systems to direct high-performance interceptors or directed energy weapons—could theoreticallytheoretical y present viable options for defending against hypersonic weapons in the future.¹³14 Indeed, the 2019 Missile Defense Review notes that " “such sensors take advantage of the large area viewable from space for improved tracking and potentially potential y targeting of advanced threats, including HGVs and hypersonic cruise missiles."¹⁴

”15 Other analysts have questioned the affordability, technological feasibility, and/or utility of wide- area hypersonic weapons defense.¹⁵16 As physicist and nuclear expert James Acton explains, "“point-defense systems, and particularly [Terminal High-Altitude Area Defense (THAAD)], could very plausibly be adapted to deal with hypersonic missiles. The disadvantage of those systems is that they can only defend small smal areas. To defend the whole of the continental United States, you 12 Bradley Perrett et al., “U.S. Navy sees Chinese HGV as part of Wider T hreat,” Aviation Week, January 27, 2014. 13 David Vergun, “ DOD Scaling Up Effort to Develop Hypersonics,” DoD News, December 13, 2018, https://dod.defense.gov/News/Article/Article/1712954/dod-scaling-up-effort-to-develop-hypersonics/; see also “T estimony of Michael Griffin”; and “T estimony of John E. Hyten.” 14 “T estimony of Michael Griffin”; and “T estimony of John E. Hyten.” 15 Department of Defense, 2019 Missile Defense Review, p. XVI, https://www.defense.gov/Portals/1/Interactive/2018/11-2019-Missile-Defense-Review/T he%202019%20MDR_Executive%20Summary.pdf. 16 See James M. Acton, “Hypersonic Weapons Explainer,” Carnegie Endowm ent for International Peace, April 2, 2018, https://carnegieendowment.org/2018/04/02/hypersonic-weapons-explainer-pub-75957; and Margot van Loon, “Hypersonic Weapons: A Primer.” Congressional Research Service 3 link to page 11 Hypersonic Weapons: Background and Issues for Congress areas. To defend the whole of the continental United States, you would need an unaffordable number of THAAD batteries."¹⁶”17 In addition, some analysts have argued that the United States'’ current command and control architecture would be incapable of "“processing data quickly enough to respond to and neutralize an incoming hypersonic threat."¹⁷ ”18 (A broader discussion of hypersonic weapons defense is outside the scope of this report.)

United States

The Department of Defense (DOD) is currently developing hypersonic weapons under the Navy's ’s Conventional Prompt Strike program, which is intended to provide the U.S. military with the ability ability to strike hardened or time-sensitive targets with conventional warheads, as well wel as through several Air Force, Army, and DARPA programs.¹⁸19 Those who support these development efforts argue that hypersonic weapons could enhance deterrence, as well wel as provide the U.S. military with an ability to defeat capabilities such as advanced air and missile defense systems that form the foundation of U.S. competitors'’ anti-access/area denial strategies.¹⁹20 In recognition of this, the 2018 National Defense Strategy identifies hypersonic weapons as one of the key technologies " “[ensuring the United States] will wil be able to fight and win the wars of the future."²⁰

Programs

Unlike China and Russia, the United States is not currently developing hypersonic weapons for use with a nuclear warhead”21 Programs Unlike programs in China and Russia, most U.S. hypersonic weapons are to be conventional y armed. As a result, U.S. hypersonic weapons will likely wil likely require greater accuracy and will be more technically challengingwil be more technical y chal enging to develop than nuclear-armed Chinese and Russian systems. Indeed, according to one expert, "“a nuclear-armed glider would be effective if it were 10 or even 100 times less accurate [than a conventionallyconventional y-armed glider]"” due to nuclear blast effects.²¹

22 According to open-source reporting, the United States has a number of major offensive hypersonic weapons and hypersonic technology programs in development, including the following (seesee Table 1):

• :  U.S. Navy—Conventional Prompt Strike (CPS);
•  U.S. Army—Long-Range Hypersonic Weapon (LRHW);
•  U.S. Air Force—AGM-183 Air-Launched Rapid Response Weapon (ARRW, pronounced "arrow");
• DARPA—Tactical Boost Glide (TBG);
• pronounced “arrow”);  DARPA—Tactical Boost Glide (TBG); 17 Acton, “Hypersonic Weapons Explainer.” 18 Margot van Loon, “Hypersonic Weapons: A Primer” in Defense Technology Program Brief: Hypersonic Weapons, American Foreign Policy Council, May 17, 2019. Some analysts have suggested that future command and control systems may require autonomous functionality to manage the speed and unpredictability of hypersonic weapons. See John L. Dolan, Richard K. Gallagher, and David L. Mann, “Hypersonic Weapons Are Literally Unstoppable (As in America Can’t Stop T hem),” Real Clear Defense, April 23, 2019, https://www.realcleardefense.com/articles/2019/04/23/hypersonic_weapons__a_threat_to_national_security_114358.html. 19 For a full history of U.S. hypersonic weapons programs, see CRS Report R41464, Conventional Prompt Global Strike and Long-Range Ballistic Missiles: Background and Issues, by Amy F. Woolf. 20 Roger Zakheim and T om Karako, “China’s Hypersonic Missile Advances and U.S. Defense Responses,” Remarks at the Hudson Institute, March 19, 2019. See also Department of Defense Fiscal Year (FY) 2020 Budget Estimates, Army Justification Book of Research, Development, T est and Evaluation, Volume II, Budget Activity 4, p. 580. 21 Department of Defense, “Summary of the 2018 National Defense Strategy of T he United States of America,” p. 3, https://dod.defense.gov/Portals/1/Documents/pubs/2018-National-Defense-Strategy-Summary.pdf. 22 James M. Acton, “China’s Advanced Weapons,” T estimony to the U.S. China Economic and Se curity Review Commission, February 23, 2017, https://carnegieendowment.org/2017/02/23/china-s-advanced-weapons-pub-68095. Congressional Research Service 4 Hypersonic Weapons: Background and Issues for Congress  DARPA—Operational Fires (OpFires); and  DARPA—Operational Fires (OpFires); and
• DARPA—Hypersonic Air-breathing Weapon Concept (HAWC, pronounced "hawk").

“hawk”). These programs are intended to produce operational prototypes, as there are currently no programs of record for hypersonic weapons.²²23 Accordingly, funding for U.S. hypersonic weapons programs is found in the Research, Development, Test, and Evaluation accounts, rather than in Procurement.

Procurement. U.S. Navy

In a June 2018 memorandum, DOD announced that the Navy would lead the development of a common glide vehicle for use across the services.²³24 The common glide vehicle is being adapted from a Mach 6 Army prototype warhead, the Alternate Re-Entry System, which was successfully tested in 2011 and 2017.²⁴25 Once development is complete, "“Sandia National Laboratories, the designer of the original concept, then will wil build the common glide vehicles…. Booster systems are being developed separately."²⁵

”26 The Navy'’s Conventional Prompt Strike (CPS) is expected to pair the common glide vehicle with a submarine-launched booster system, achieving initial operational capability (IOC) on a Virginia-class submarine with Virginia Payload Module in FY2028.²⁶27 The Navy is requesting $1 billion bil ion for CPS in FY2021—an increase of $415 million mil ion over the FY2020 request and $496 million mil ion over the FY2020 appropriation—and $5.3 billion bil ion across the five-year Future Years Defense Program (FYDP).²⁷

28 U.S. Army

The Army'’s Long-Range Hypersonic Weapon program is expected to pair the common glide vehicle with the Navy'’s booster system. The system is intended to have a range of 1,400 miles and " 23 Steve T rimble, “ New Long-T erm Pentagon Plan Boosts Hypersonics, But Only Prototypes,” Aviation Week, March 15, 2019, https://aviationweek.com/defense/new-long-term-pentagon-plan-boosts-hypersonics-only-prototypes. 24 T he services coordinate efforts on a Common Hypersonic Glide Body Board of Directors with rotating chairmanship. Sydney J. Freedberg, Jr., “Army Ramps Up Funding For Laser Shield, Hypersonic Sword,” Breaking Defense, February 28, 2020, https://breakingdefense.com/2020/02/army-ramps-up-funding-for-laser-shield-hypersonic-sword/. 25 Steve T rimble and Guy Norris, “Sandia’s Swerve Could Lead to First -gen Hypersonic Production Line,” Aviation Week, October 11, 2018, http://aviationweek.com/air-dominance/sandia-s-swerve-could-lead-first-gen-hypersonic-production-line; and Sydney J. Freedberg Jr., “ Army Warhead Is Key T o Joint Hypersonics,” Breaking Defense, August 22, 2018, https://breakingdefense.com/2018/08/army-warhead-is-key-to-joint-hypersonics/. 26 T rimble and Norris, “ Sandia’s Swerve.” 27 Department of the Navy, “Highlights of the Department of the Navy FY 2021 Budget,” February 10, 2020, https://www.secnav.navy.mil/fmc/fmb/Documents/21pres/Highlights_book.pdf. Vice Admiral T erry Benedict, former director of the Navy Strategic Systems Program, has stated that CPS will eventually be deployed on both Ohio - and Virginia-class submarines. Navy leadership has also discussed the possibility of deploying CPS on Arleigh Burke- and Zumwalt -class destroyers. See Jason Sherman and Lee Hudson, “ Navy reveals plans to put hypersonic strike weapons on submarines,” Inside Defense, November 8, 2017, https://insidedefense.com/inside-missile-defense/navy-reveals-plans-put-hypersonic-strike-weapons-submarines; and Paul McLeary, “ SecNav T ells Fleet Hypersonic Competition Demands ‘Sputnik Moment;’ Glide Body T est Set,” Breaking Defense, January 31, 2020, https://breakingdefense.com/2020/01/secnav-tells-fleet-hypersonic-competition-demands-sputnik-moment-glide-body-test-set/. 28 Department of Defense Fiscal Year (FY) 2021 Budget Estimates, Navy Justification Book of Research, Development, T est and Evaluation, Volume II, Budget Activity 4, p. 1419, https://www.secnav.navy.mil/fmc/fmb/Documents/21pres/RDT EN_BA4_Book.pdf; see also CRS In Focus IF10831, Defense Prim er: Future Years Defense Program (FYDP), by Brendan W. McGarry and Heidi M. Peters. Congressional Research Service 5 Hypersonic Weapons: Background and Issues for Congress and “provide the Army with a prototype strategic attack weapon system to defeat A2/AD capabilities, suppress adversary Long Range Fires, and engage other high payoff/time sensitive targets."²⁸”29 The Army is requesting $801 millionmil ion for the program in FY2021—$573 million mil ion over the FY2020 request and $397 million mil ion over the FY2020 appropriation—and $3.3 billion bil ion across the FYDP.²⁹30 It plans to conduct flight tests for LRHW from FY2021 to FY2023, field combat rounds in FY2023, and transition to a program of record in the fourth quarter of FY2024.³⁰

31 U.S. Air Force

The The AGM-183 Air-LaunchedAir-Launched Rapid Response Weapon is expected to leverage DARPA'’s Tactical Boost Glide technology to develop an air-launched hypersonic glide vehicle prototype capable of travellingtravel ing at speeds up to Mach 20 at a range of approximately 575 miles.³¹32 Despite testing delays due to technical challengeschal enges, ARRW completed a successful flight test in June 2019 and is expected to complete flight tests in FY2022.³²33 The Air Force has requested $382 millionmil ion for ARRW in FY2021—up from $286 millionmil ion in the FY2020 request and appropriation—and $581 million mil ion across the FYDP, with no funds requested beyond FY2022.³³34 ARRW is a project under the Air Force'’s Hypersonics Prototyping Program Element, which is intended to demonstrate concepts "“to [enable] leadership to make informed strategy and resource decisions … for future programs."³⁴

programs.”35 In February 2020, the Air Force announced that it had cancelledcancel ed its second hypersonic weapon program, the Hypersonic Conventional Strike Weapon (HCSW), which had been expected to use the common glide vehicle, due to budget pressures that forced it to choose between ARRW and HCSW.³⁵36 Air Force acquisition chief Will Wil Roper explained that ARRW was selected because it was more advanced and gave the Air Force additional options. "“[ARRW] is smallersmal er; we can carry 29 Department of Defense Fiscal Year (FY) 2020 Budget Estimates, Army Justification Book of Research, Development, T est and Evaluation, Volume II, Budget Activity 4, pp. 579 -584, https://www.asafm.army.mil/documents/BudgetMaterial/fy2020/rdte_ba4.pdf; and Sydney J. Freedberg Jr., “ Army Sets 2023 Hypersonic Flight T est; Strategic Cannon Advances,” Breaking Defense, March 19, 2019, https://breakingdefense.com/2019/03/army-sets-2023-hypersonic-flight-test-strategic-cannon-advances/. 30 Department of Defense Fiscal Year (FY) 2021 Budget Estimates, Army Justification Book of Research, Development, T est and Evaluation, Volume II, Budget Activity 4, p. 613, https://www.asafm.army.mil/Portals/72/Documents/BudgetMaterial/2021/Base%20Budget/rdte/RDT E_BA_4_FY_2021_PB_RDT E_Vol%202_Budget_Activity_4.pdf. 31 Department of the Army, “FY 2021: President’s Budget Highlights,” February 2020, p. 18, https://www.asafm.army.mil/Portals/72/Documents/BudgetMaterial/2021/pbr/Overview%20and%20Highlights/Army_FY_2021_Budget_Highlights.pdf. 32 Stephen T rimble, “ Lockheed Martin claims both USAF hypersonic programmes,” Flight Global, August 7, 2018, https://www.flightglobal.com/news/articles/lockheed-martin-claims-both-usaf-hypersonic-programm-450968/. 33 T he Air Force’s budget request notes that “further schedule details can be provided in the appropriate forum.” Department of Defense Fiscal Year (FY) 2021 Budget Estimates, Air Force Justification Book of Research, Development, T est and Evaluation, Volume II, p. 128. See also Lee Hudson and Steve T rimble, “ T op U.S. Hypersonic Weapon Program Facing New Schedule Pressure,” Aviation Week, January 11, 2019, http://aviationweek.com/defense/top-us-hypersonic-weapon-program-facing-new-schedule-pressure. 34 Department of Defense Fiscal Year (FY) 2021 Budget Estimates, Air Force Justification Book of Research, Development, T est and Evaluation, Volume II, p. 121, https://www.saffm.hq.af.mil/Portals/84/documents/FY21/RDT E_/FY21%20Air%20Force%20Research%20Development%20Test%20and%20Evaluation%20Vol%20II.pdf?ver=2020-02-12-145218-377. 35 Ibid., p. 121. 36 Valerie Insinna, “ US Air Force kills one of its hypersonic weapons programs,” Defense News, February 10, 2020, https://www.defensenews.com/smr/federal-budget/2020/02/10/the-air-force-just-canceled-one-of-its-hypersonic-weapons-programs/. Congressional Research Service 6 Hypersonic Weapons: Background and Issues for Congress ; we can carry twice as many on the B-52, and it'’s possible it could be on the F-15,"” he explained.³⁶37 The Air Force will Force wil continue its technical review of HCSW through March 2020.³⁷

38 DARPA DARPA, in partnership with the Air Force, continues to test Tactical Boost Glide, a wedge-shaped hypersonic glide vehicle capable of Mach 7+ flight that "“aims to develop and demonstrate technologies to enable future air-launched, tactical-range hypersonic boost glide systems."³⁸ TBG will "”39 TBG wil “also consider traceability, compatibility, and integration with the Navy Vertical Launch System"System” and is planned to transition to both the Air Force and the Navy. DARPA has requested $117 millionmil ion—down from the $162 million mil ion FY2020 request and the $152 million FY2020 mil ion FY2020 appropriation—for TBG in FY2021.³⁹

DARPA'40 DARPA’s Operational Fires reportedly seeks to leverage TBG technologies to develop a ground-launched system that will wil enable "“advanced tactical weapons to penetrate modern enemy air defenses and rapidly and precisely engage critical time sensitive targets."” DARPA has requested $40 mil ion $40 million for OpFires in FY2021—down from the $50 millionmil ion FY2020 request and appropriation—and intends to transition the program to the Army.⁴⁰

41 In the longer term, DARPA, with Air Force support, is continuing work on the Hypersonic Air- breathing Weapon Concept, which "“seeks to develop and demonstrate critical technologies to enable an effective and affordable air-launched hypersonic cruise missile."⁴¹”42 Assistance Director for Hypersonics Mike White has stated that such a missile would be smallersmal er than DOD's ’s hypersonic glide vehicles and could therefore launch from a wider range of platforms. Director White has additionally additional y noted that HAWC and other hypersonic cruise missiles could integrate seekers more easily than hypersonic glide vehicles.⁴²43 DARPA requested $7 millionmil ion to develop HAWC in FY2021—down from the $10 millionmil ion FY2020 request and $20 mil ion FY2020 appropriation.44 37 John A. T irpak, “Roper: T he ARRW Hypersonic Missile Better Option for USAF,” March 2, 2020, https://www.airforcemag.com/arrw-beat-hcsw-because-its-smaller-better-for-usaf/. T irpak additionally notes that “ the F-15 could accelerate the ARRW to Mach 3 before launch, potentially reducing the size of the booster needed to get the weapon to hypersonic speed.” 38 Ibid. 39 “T actical Boost Glide (T BG) Program Information,” DARPA, https://www.darpa.mil/program/tactical-boost-glide; and Guy Norris, “U.S. Air Force Plans Road Map to Operational Hypersonics,” Aviation Week, July 27, 2017, https://aviationweek.com/defense/us-air-force-plans-road-map-operational-hypersonics. 40 DARPA states that the decline in the budget request “reflects completion of full-scale testing and final program reporting.” Department of Defense Fiscal Year (FY) 2021 Budget Estimates, Defense Advanced Research Projects Agency, Defense-Wide Justification Book 1 of 5, pp. 162-164, https://comptroller.defense.gov/Portals/45/Documents/defbudget/fy2021/budget_just ification/pdfs/03_RDT _and_E/RDT E_Vol1_DARPA_MasterJustificationBook_PB_2021.pdf . 41 Department of Defense Fiscal Year (FY) 2021 Budget Estimates, Defense Advanced Research Projects Agency, Defense-Wide Justification Book 1 of 5, p. 165, https://comptroller.defense.gov/Portals/45/Documents/defbudget/fy2021/budget_justification/pdfs/03_RDT _and_E/RDT E_Vol1_DARPA_MasterJustificationBook_PB_2021.pdf . 42 “Hypersonic Air-breathing Weapon Concept (HAWC) Program Information,” DARPA, https://www.darpa.mil/program/hypersonic-air-breathing-weapon-concept. 43 “Department of Defense Press Briefing on Hypersonics,” March 2, 2020, https://www.defense.gov/Newsroom/T ranscripts/T ranscript/Article/2101062/department -of-defense-press-briefing-on-hypersonics/. 44 Department of Defense Fiscal Year (FY) 2021 Budget Estimates, Defense Advanced Research Projects Agency, Defense-Wide Justification Book 1 of 5, p. 165, https://comptroller.defense.gov/Portals/45/Documents/defbudget/fy2021/budget_justification/pdfs/03_RDT _and_E/RDT E_Vol1_DARPA_MasterJustificationBook_PB_2021.pdf . Congressional Research Service 7 Hypersonic Weapons: Background and Issues for Congress Table 1. Summary of U.S. Hypersonic Weapons Programs FY2020 PB2021 Title ($ in millions) ($ in millions) Schedule Conventional Prompt 512 1,008 IOC in FY2028 Strike (CPS) Long-Range Hypersonic 404 801 Flight tests through 2023 Weapon (LRHW) AGM-183 Air-Launched 286 382 Flight tests through 2022 Rapid Response Weapon (ARRW) Hypersonic Conventional 290 0 Cancel ed in 2020 Strike Weapon (HCSW) Tactical Boost Glide 152 117 Testing through at least (TBG) 2021 Operational Fires 50 40 Testing through at least (OpFires) FY2020 request and $20 million FY2020 appropriation.⁴³

Hypersonic Missile Defenses

Defenses45 DOD is also investing in counter-hypersonic weapons capabilities, although USD R&E former USD(R&E) Michael Griffin has stated that the United States will wil not have a defensive capability against hypersonic weapons until the mid-2020s, at the earliest.⁴⁴46 In September 2018, the Missile Defense Agency (MDA)—which in 2017 established a Hypersonic Defense Program pursuant to Section 1687 of the FY2017 NDAA (P.L. 114-840)—commissioned 21 white papers to explore hypersonic missile defense options, including interceptor missiles, hypervelocity projectiles, laser guns, and electronic attack systems.⁴⁵47 In January 2020, MDA issued a draft request for prototype proposals for a Hypersonic Defense Regional Glide Phase Weapons System interceptor. This effort is intended to "“reduce interceptor key technology and integration risks, anchor modeling and simulation in areas of large uncertainty, and to increase the interceptor technology readiness levels (TRL) to level 5."⁴⁶ MDA has also awarded four companies—Northrop Grumman, Raytheon, Leidos, and L3Harris—with $20 million ” (validating components in a relevant environment).48 MDA has also 45 For additional information about hypersonic missile defense, see CRS In Focus IF11623, Hypersonic Missile Defense: Issues for Congress, by Kelley M. Sayler, Stephen M. McCall, and Quintin A. Reed. 46 “Media Availability With Deputy Secretary Shanahan and Under Secretary of Defense Griffin at NDIA Hypersonics Senior Executive Series,” U.S. Department of Defense, December 13, 2018, https://dod.defense.gov/News/T ranscripts/T ranscript -View/Article/1713396/media-availability-with-deputy-secretary-shanahan-and-under-secretary-of-defens/. 47 P.L. 114-840, Section 2, Division A, T itle XVI, §1687; and Hudson and T rimble, “T op U.S. Hypersonic Weapon Program”; Steve T rimble, “A Hypersonic Sputnik?,” p. 21. 48 Missile Defense Agency, “Draft Request for Prototype Proposal: Hypersonic Defense Regional Glide Phase Weapon System,” January 30, 2020, p. 8. T RL measures a technology’s level of maturity; T RL 5 requires validation in a relevant environment. For information about specific T RLs, see T roy Carter, “The 9 T echnology Readiness Levels of Congressional Research Service 8 Hypersonic Weapons: Background and Issues for Congress awarded four companies—Northrop Grumman, Raytheon, Leidos, and L3Harris—with $20 mil ion contracts to design prototype space-based (low-Earth orbit) sensors by October 31, 2020.⁴⁷49 Such sensors could theoreticallytheoretical y extend the range at which incoming missiles could be detected and tracked—a critical requirement for hypersonic missile defense, according to USD Griffin.⁴⁸then-USD(R&E) Griffin.50 MDA requested $206.8 millionmil ion for hypersonic defense in FY2021—up from its $157.4 millionmil ion FY2020 request—and $659 millionmil ion across the FYDP.⁴⁹51 In addition, DARPA is working on a program calledcal ed Glide Breaker, which "will “wil develop critical component technology to support a lightweight vehicle designed for precise engagement of hypersonic threats at very long range."⁵⁰”52 DARPA requested $3 millionmil ion for Glide Breaker in FY2021—down from $10 millionmil ion in FY2020.⁵¹

53 Infrastructure

According to a a study mandated by the FY2013 National Defense Authorization Act (P.L. 112-239)239) and conducted by the Institute for Defense Analyses (IDA),⁵²,54 the United States had 48 critical hypersonic test facilities and mobile assets in 2014 needed for the maturation of hypersonic technologies for defense systems development through 2030. These specialized facilities, which simulate the unique conditions experienced in hypersonic flight (e.g., speed, pressure, heating),⁵³ 55 included 10 DOD hypersonic ground test facilities, 11 DOD open-air ranges, 11 DOD mobile assets, 9 NASA facilities, 2 Department of Energy facilities, and 5 industry or academic facilities.⁵⁴ 56 In its 2014 evaluation of  U.S. hypersonic test and evaluation infrastructure, IDA noted that "IDA noted that “no current U.S. facility can provide full-scale, time-dependent, coupled aerodynamic and thermal-loading environments for flight durations necessary to evaluate these  these characteristics above  Mach 8." ” Since the 2014  study report was published,  the University of Notre Dame has opened a Mach 6 hypersonic wind tunneltunnel and at least one hypersonic testing facility has been inactivated. DevelopmentDevelopment of Mach 8 and Mach 10 wind tunnels at Purdue University and the University of Notre Dame, respectively, is ongoing.⁵⁵57 In addition, the the University of Arizona plans to modify one of its wind tunnels to enable Mach 5 testing by early 2021, while2021, while Texas A&M University—in partnership with Army Futures Command—plans to in partnership with Army Futures Command—plans to the DOD,” T echLink, https://techlinkcenter.org/technology-readiness-level-dod/. 49 Sandra Erwin, “ Missile Defense Agency selects four companies to develop space sensors,” Space News, October 30, 2019, https://spacenews.com/missile-defense-agency-selects-four-companies-to-develop-space-sensors/. Experts disagree on the cost and technological feasibility of space-based missile defense. 50 Media Availability With Deputy Secretary Shanahan and Under Secretary of Defense Griffin .” 51 Missile Defense Agency, Budget Estimates Overview: Fiscal Year 2021, p. 12, https://www.mda.mil/global/documents/pdf/budgetfy21.pdf. 52 Department of Defense Fiscal Year (FY) 2021 Budget Estimates, Defense Advanced Research Projects Agency, Defense-Wide Justification Book 1 of 5, p. 164. 53 Ibid. 54 P.L. 112-239, Section 2, Division A, T itle X, §1071. 55 T hese conditions additionally require the development of specialized materials such as metals and ceramics. 56 T his list is taken directly from a 2014 Institute for Defense Analysis report and, therefore, may not be current. See (U//FOUO) Paul F. Piscopo et al., (U) Study on the Ability of the U.S. Test and Evaluation Infrastructure to Effectively and Efficiently Mature Hypersonic Technologies for Defense System s Developm ent: Sum mary Analysis and Assessm ent, Institute for Defense Analyses, September 2014. Permission to use this material has been granted by the Office of Science and T echnology Policy. 57 Oriana Pawlyk, “ Air Force Expanding Hypersonic T echnology T esting at T wo Indiana Universities,” Military.com, April 23, 2019, https://www.military.com/daily-news/2019/04/23/air-force-expanding-hypersonic-technology-testing-two-indiana-universities.html. Congressional Research Service 9 link to page 23 Hypersonic Weapons: Background and Issues for Congress complete construction of a kilometer-long Mach 10 wind tunnel by 2021.⁵⁶ (.58 (For a list of U.S. hypersonic test assets and their capabilities, see thethe Appendix.) )

The United States also uses the Royal Australian Air Force Woomera Test Range in Australia and the Andøya Rocket Range in Norway for flight testing.⁵⁷59 In January 2019, the Navy announced plans to reactivate its Launch Test Complex at China Lake, CA, to improve air launch and underwater testing capabilities for the conventional prompt strike program.⁵⁸

60 In April 2020, DOD’s Office of Inspector General announced that it would be evaluating current ground test and evaluation facilities to determine if the capability and capacity would be sufficient to execute DOD’s planned test schedule.61 In addition, in March 2020, DOD announced that it had established a "“hypersonic war room"” to assess the U.S. industrial base for hypersonic weapons and identify "“critical nodes"” in the supply chain.⁵⁹62 Initial findings are to be released in mid-2020.⁶⁰

63 Russia

Although Russia has conducted research on hypersonic weapons technology since the 1980s, it accelerated its efforts in response to U.S. missile defense deployments in both the United States and Europe, and in response to the U.S. withdrawal from the Anti-BallisticBal istic Missile Treaty in 2001.⁶¹ 64 Detailing Russia'’s concerns, President Putin stated that "“the US is permitting constant, uncontrolled growth of the number of anti-ballisticbal istic missiles, improving their quality, and creating new missile launching areas. If we do not do something, eventually this will eventual y this wil result in the complete devaluation of Russia'’s nuclear potential. Meaning that all al of our missiles could simply be intercepted."⁶²”65 Russia thus seeks hypersonic weapons, which can maneuver as they approach their targets, as an assured means of penetrating U.S. missile defenses and restoring its sense of strategic stability.⁶³

Programs

66 58 University of Arizona, “Mach 5 Quiet Ludwieg T ube,” https://transition.arizona.edu/facilities/qlt5?_ga=2.62515882.768526379.1582843192 -983632914.1582843192; and Ashley T ressel, “ Army to open hypersonic testing facility at T exas A&M,” Inside Defense, October 13, 2019, https://insidedefense.com/daily-news/army-open-hypersonic-testing-facility-texas-am. Additional universities such as the University of Maryland, th e California Institute of T echnology, the Georgia Institute of T echnology, the Air Force Academy, the University of T ennessee, and Virginia Polytechnic Institute and State University also maintain experimental hypersonic facilities or conduct hypersonic research. 59 (U//FOUO) Paul F. Piscopo et al., (U) Study on the Ability of the U.S. Test and Evaluation Infrastructure. 60 “Update: US Navy to develop China Lake to support CPS weapon testing,” Jane’s (subscription required), February 12, 2019, https://janes.ihs.com/Janes/Display/FG_1644858-JMR. 61 See Department of Defense Office of Inspector General, “Memorandum for Distribution: Evaluation of the Ground T est and Evaluation Infrastructure Supporting Hypersonic Capabilities (Project No. D2020 -DEV0SN-0106.000),” April 13, 2020, https://media.defense.gov/2020/Apr/14/2002280826/-1/-1/1/D2020-DEV0SN-0106.000.PDF. 62 Aaron Mehta, “Pentagon launches hypersonic industrial base study,” Defense News, March 3, 2020, https://www.defensenews.com/pentagon/2020/03/02/pentagon-launches-hypersonic-industrial-base-study/. 63 Ibid. 64 United Nations Office of Disarmament Affairs, Hypersonic Weapons: A Challenge and Opportunity for Strategic Arm s Control, February 2019, https://www.un.org/disarmament/publications/more/hypersonic-weapons-a-challenge-and-opportunity-for-strategic-arms-control/. 65 Vladimir Putin, “Presidential Address to the Federal Assembly,” March 1, 2018, http://en.kremlin.ru/events/president/news/56957. 66 In this instance, “strategic stability” refers to a “bilateral nuclear relationship of mutual vulnerability.” See T ong Zhao, “Conventional Challenges to Strategic Stability: Chinese Perceptions of Hypersonic T echnology and the Security Dilemma,” Carnegie-T singhua Center for Global Policy, July 23, 2018, https://carnegietsinghua.org/2018/07/23/conventional-challenges-to-strategic-stability-chinese-perceptions-of-hypersonic-technology-and-security-dilemma- Congressional Research Service 10 link to page 14 Hypersonic Weapons: Background and Issues for Congress Programs Russia is pursuing two hypersonic weapons programs—the Avangard and the 3M22 Tsirkon (or Zircon)—and has reportedly fielded the Kinzhal ("Dagger" (“Dagger”), a maneuvering air-launched ballistic missile.⁶⁴

bal istic missile.67 Avangard (Figure 2) is a hypersonic glide vehicle launched from an intercontinental ballistic bal istic missile (ICBM), giving it "“effectively 'unlimited' range."⁶⁵‘unlimited’ range.”68 Reports indicate that Avangard is currently deployed on the SS-19 Stiletto ICBM, though Russia plans to eventuallyeventual y launch the vehicle from the Sarmat ICBM. Sarmat is still stil in development, although it may be deployed by 2021.⁶⁶ 2021.69 Avangard features onboard countermeasures and will wil reportedly carry a nuclear warhead. It was successfully tested twice in 2016 and once in December 2018, reportedly reaching speeds of Mach 20; however, an October 2017 test resulted in failure. Russian news sources claim that Avangard entered into combat duty in December 2019.⁶⁷

70 Figure 2. Artist Rendering of Avangard

Source: https://janes.ihs.com/Janes/Display/FG_899127-JIR.

FG_899127-JIR. In addition to Avangard, Russia is developing Tsirkon, a ship-launched hypersonic cruise missile capable of traveling at speeds of between Mach 6 and Mach 8. Tsirkon is reportedly capable of striking both ground and naval targets. According to Russian news sources, Tsirkon has a range of between approximately 250 and 600 miles and can be fired from the vertical launch systems mounted on cruisers Admiral Nakhimov and Pyotr Veliky, Project 20380 corvettes, Project 22350 frigates, and Project 885 Yasen-class submarines, among other platforms.⁶⁸71 These sources assert pub-76894. 67 Although the Kinzhal is a maneuvering air-launched ballistic missile rather than a hypersonic glide vehicle or hypersonic cruise missile, it is often included in reporting of Russia’s hypersonic weapons program. For this reason —and because it poses defensive challenges that are similar to other hypersonic weapons—it is included here for reference. 68 Steve T rimble, “A Hypersonic Sputnik?,” Aviation Week, January 14-27, 2019, p. 20. 69 Ibid. Sarmat could reportedly accommodate at least three Avangard vehicles. See Malcolm Claus, “Russia unveils new strategic delivery systems,” Jane’s (subscription required), https://janes.ihs.com/Janes/Display/FG_899127-JIR. 70 “First regiment of Avangard hypersonic missile systems goes on combat duty in Russia,” TASS, December 27, 2019, https://tass.com/defense/1104297. 71 “Russia makes over 10 test launches of T sirkon seaborne hypersonic missile,” TASS, December 21, 2018, http://tass.com/defense/1037426. See also Russia Military Power: Building a Military to Support Great Power Aspirations, Defense Intelligence Agency, 2017, p. 79, https://www.dia.mil/portals/27/documents/news/military%20power%20publications/russia%20military%20power%20report%202017.pdf. Congressional Research Service 11 Hypersonic Weapons: Background and Issues for Congress These sources assert that Tsirkon was successfully launched from a Project 22350 frigate in January 2020.⁶⁹ U.S. intelligence 72 U.S. intel igence reports indicate that the missile will wil become operational in 2023.⁷⁰

73 In addition, Russia has reportedly fielded Kinzhal, a maneuvering air-launched ballisticbal istic missile modified from the Iskander missile. According to U.S. intelligenceintel igence reports, Kinzhal was successfully test fired from a modified MiG-31 fighter (NATO code name: Foxhound) as recently as July 2018—striking a target at a distance of approximately 500 miles—and is expected by U.S. intelligence intel igence sources to become ready for combat by 2020.⁷¹74 Russia plans to deploy the missile on both the MiG-31 and the Su-34 long-range strike fighter.⁷²75 Russia is working to mount the missile on the Tu-22M3 strategic bomber (NATO code name: Backfire), although the slower-moving bomber may face challenges in "chal enges in “accelerating the weapon into the correct launch parameters."⁷³

”76 Russian media has reported Kinzhal'’s top speed as Mach 10, with a range of up to 1,200 miles when launched from the MiG-31. The Kinzhal is reportedly capable of maneuverable flight, as well wel as of striking both ground and naval targets, and could eventuallyeventual y be fitted with a nuclear warhead. However, such claims regarding Kinzhal'’s performance characteristics have not been publicly verified by U.S. intelligenceintel igence agencies, and have been met with skepticism by a number of analysts.⁷⁴

Infrastructure

77 Infrastructure Russia reportedly conducts hypersonic wind tunnel testing at the Central Aero-Hydrodynamic Institute in Zhukovsky and the Khristianovich Institute of Theoretical and Applied Mechanics in Novosibirsk, and has tested hypersonic weapons at Dombarovskiy Air Base, the Baykonur Cosmodrome, and the Kura Range.⁷⁵

China

78 China According to Tong Zhao, a fellowfel ow at the Carnegie-Tsinghua Center for Global Policy, "“most experts argue that the most important reason to prioritize hypersonic technology development [in 72 “T ASS: Russia Conducts First Ship-Based Hypersonic Missile T est ,” Reuters, February 27, 2020, https://www.voanews.com/europe/tass-russia-conducts-first-ship-based-hypersonic-missile-test. 73 Amanda Macias, “ Russia again successfully tests ship-based hypersonic missile—which will likely be ready for combat by 2022,” CNBC, December 20, 2018, https://www.cnbc.com/2018/12/20/russia-tests-hypersonic-missile-that-could-be-ready-for-war-by-2022.html; and “ Russian Navy to accept latest T sirkon hypersonic missile for service in 2023—source,” TASS, March 20, 2019, http://tass.com/defense/1049572. 74 Amanda Macias, “Russia’s new hypersonic missile, which can be launched from warplanes, will likely be ready for combat by 2020,” CNBC, July 13, 2018, https://www.cnbc.com/2018/07/13/russia-new-hypersonic-missile-likely-ready-for-war-by-2020.html. 75 Mark B. Schneider, “Moscow’s Development of Hypersonic Missiles … and What It Means” in Defense Technology Program Brief: Hypersonic Weapons, American Foreign Policy Council, May 17, 2019. 76 Dave Majumdar, “ Russia: New Kinzhal Aero-Ballistic Missile Has 3,000 km Range if Fired from Supersonic Bomber,” The National Interest, July 18, 2018, https://nationalinterest.org/blog/buzz/russia-new-kinzhal-aero-ballistic-missile-has-3000-km-range-if-fired-supersonic-bomber. 77 David Axe, “ Is Kinzhal, Russia’s New Hypersonic Missile, a Game Changer?,” The Daily Beast, March 15, 2018, https://www.thedailybeast.com/is-kinzhal-russias-new-hypersonic-missile-a-game-changer. 78 “Aerodynamics,” Central Aerohydrodynamic Institute, http://tsagi.com/research/aerodynamics/; “Russia announces successful flight test of Avangard hypersonic glide vehicle,” Jane’s (subscription required), January 3, 2019, https://janes.ihs.com/Janes/Display/FG_1451630-JMR; and “ Avangard system is tested, said to be fully ready for deployment ,” Russian Strategic Nuclear Forces, December 26, 2018, http://russianforces.org/blog/2018/12/avangard_system_is_tested_said.shtml. Congressional Research Service 12 Hypersonic Weapons: Background and Issues for Congress experts argue that the most important reason to prioritize hypersonic technology development [in China] is the necessity to counter specific security threats from increasingly sophisticated U.S. military technology, including [hypersonic weapons]."⁷⁶” such as U.S. regional missile defenses.79 In particular, China'’s pursuit of hypersonic weapons, like Russia'’s, reflects a concern that U.S. hypersonic weapons could enable the United States to conduct a preemptive, decapitating strike on China'’s nuclear arsenal and supporting infrastructure. U.S. missile defense deployments could then limit China'’s ability to to conduct a retaliatory strike against the United States.⁷⁷

80 China has demonstrated a growing interest in Russian advances in hypersonic weapons technology, conducting flight tests of a hypersonic-glide vehicle (HGV) only days after Russia tested its own system.⁷⁸81 Furthermore, a January 2017 report found that over half of open-source Chinese papers on hypersonic weapons include references to Russian weapons programs.⁷⁹82 This could indicate that China is increasingly considering hypersonic weapons within a regional context. Indeed, some analysts believe that China may be planning to mate conventionallyconventional y armed HGVs with the DF-21 and DF-26 ballisticbal istic missiles in support of an anti-access/area denial strategy.⁸⁰83 China has reportedly not made a final determination as to whether its hypersonic weapons will weapons wil be nuclear- or conventionallyconventional y-armed—or dual-capable.

Programs

China has conducted a number of successful tests of the DF-17, a medium-range ballistic missile specificallybal istic missile specifical y designed to launch HGVs. U.S. intelligence intel igence analysts assess that the missile has a range of approximately 1,000 to 1,500 miles and could be deployed in 2020.⁸¹84 China has also tested the DF-41 intercontinental ballistic bal istic missile, which could be modified to carry a conventional or nuclear HGV, according to a report by a U.S. Congressional commission. The development of the DF-41 thus "“significantly increases the [Chinese] rocket force'’s nuclear threat to the U.S. mainland,"” the report states.⁸²

85 China has tested the DF-ZF HGV (previously referred to as the WU-14) at least nine times since 2014. U.S. defense officials have reportedly identified the range of the DF-ZF as approximately 1,200 miles and have stated that the missile may be capable of performing "“extreme maneuvers" during flight.⁸³ Although unconfirmed by intelligence agencies, some analysts believe the DF-ZF will ” 79 T ong Zhao, “ Conventional Challenges to Strategic Stability: Chinese Perceptions of Hypersonic T echnology and the Security Dilemma.” 80 T ong Zhao, “ Conventional Challenges to Strategic Stability”; and Lora Saalman, “China’s Calculus on Hypersonic Glide,” August 15, 2017, Stockholm International Peace Research Institute, https://www.sipri.org/commentary/topical-backgrounder/2017/chinas-calculus-hypersonic-glide. 81 Lora Saalman, “China’s Calculus on Hypersonic Glide.” 82 Lora Saalman, “Factoring Russia into the US-China Equation on Hypersonic Glide Vehicles,” SIPRI, January 2017, https://www.sipri.org/sites/default/files/Factoring-Russia-into-US-Chinese-equation-hypersonic-glide-vehicles.pdf. 83 Lora Saalman, “China’s Calculus on Hypersonic Glide”; and Malcolm Claus and Andrew T ate, “Chinese hypersonic programme reflects regional priorities,” Jane’s (subscription required), March 12, 2019, https://janes.ihs.com/Janes/Display/FG_1731069-JIR. 84 Ankit Panda, “ Introducing the DF-17: China’s Newly T ested Ballistic Missile Armed with a Hypersonic Glide Vehicle,” The National Interest, December 28, 2017, https://thediplomat.com/2017/12/introducing-the-df-17-chinas-newly-tested-ballistic-missile-armed-with-a-hypersonic-glide-vehicle/; and Bill Gertz, “ China’s new hypersonic missile,” Washington Tim es, October 2, 2019, https://www.washingtontimes.com/news/2019/oct/2/china-shows-df-17-hypersonic-missile/. 85 U.S.-China Economic and Security Review Commission 2018 Annual Report, p. 235, https://www.uscc.gov/sites/default/files/annual_reports/2018%20Annual%20Report%20to%20Congress.pdf. Congressional Research Service 13 link to page 18 Hypersonic Weapons: Background and Issues for Congress during flight.86 Although unconfirmed by intel igence agencies, some analysts believe the DF-ZF wil be operational as early as 2020.87 be operational as early as 2020.⁸⁴

According to U.S. defense officials, China also successfully tested Starry Sky-2 (or Xing Kong- 2), a nuclear-capable hypersonic vehicle prototype, in August 2018.⁸⁵88 China claims the vehicle reached top speeds of Mach 6 and executed a series of in-flight maneuvers before landing.⁸⁶ Unlike 89 Unlike the DF-ZF, Starry Sky-2 is a "waverider"“waverider” that uses powered flight after launch and derives lift from its own shockwaves. Some reports indicate that the Starry Sky-2 could be operational by 2025.⁸⁷ 2025.90 U.S. officials have declined to comment on the program.⁸⁸

Infrastructure

91 Infrastructure China has a robust research and development infrastructure devoted to hypersonic weapons. Then-USDUSD (R&E) Michael Griffin stated in March 2018 that China has conducted 20 times as many hypersonic tests as the United States.⁸⁹92 China tested three hypersonic vehicle models (D18-1S, D18-2S, and D18-3S)—each with different aerodynamic properties—in September 2018.⁹⁰ 93 Analysts believe that these tests could be designed to help China develop weapons that fly at variable speeds, including hypersonic speeds. Similarly, China has used the Lingyun Mach 6+ high-speed engine, or "“scramjet,"” test bed (Figure 3) to research thermal resistant components and hypersonic cruise missile technologies.⁹¹

Figure 3. Lingyun-1 Hypersonic Cruise Missile Prototype

Source: Photo accompanying Drake Long, "China reveals Lingyun-1 hypersonic missile 94 86 “Gliding missiles that fly faster than Mach 5 are coming,” The Economist, April 6, 2019, https://www.economist.com/science-and-technology/2019/04/06/gliding-missiles-that -fly-faster-than-mach-5-are-coming; and Franz-Stefan Gady, “ China T ests New Weapon Capable of Breaching US Missile Defense Systems,” The Diplom at, April 28, 2016, https://thediplomat.com/2016/04/china-tests-new-weapon-capable-of-breaching-u-s-missile-defense-systems/. 87 U.S.-China Economic and Security Review Commission 2015 Annual Report, p. 20, https://www.uscc.gov/sites/default/files/annual_reports/2015%20Annual%20Report%20to%20Congress.PDF. 88 Office of the Secretary of Defense, Annual Report to Congress: Military and Security Developments Involving the People’s Republic of China 2019, May 2, 2019, p. 44, https://media.defense.gov/2019/May/02/2002127082/-1/-1/1/2019_CHINA_MILIT ARY_POWER_REPORT.pdf . 89 Jessie Yeung, “ China claims to have successfully tested its first hypersonic aircraft . CNN, August 7, 2018, https://www.cnn.com/2018/08/07/china/china-hypersonic-aircraft-intl/index.html. 90 U.S.-China Economic and Security Review Commission Report 2015, p. 20. 91 Bill Gertz, “ China Reveals T est of New Hypersonic Missile,” The Washington Free Beacon, August 10, 2018, https://freebeacon.com/national-security/chinas-reveals-test-new-hypersonic-missile/. 92 U.S.-China Economic and Security Review Commission Report 2015, p. 20. 93 Malcolm Claus and Andrew T ate, “ Chinese hypersonic programme reflects regional priorities,” Jane’s (subscription required), March 12, 2019, https://janes.ihs.com/Janes/Display/FG_1731069-JIR. 94 Jeffrey Lin and P.W. Singer, “ China’s hypersonic military projects include spaceplanes and rail guns,” Popular Mechanics, June 26, 2018, https://www.popsci.com/chinas-hypersonic-work-speeds-up. Congressional Research Service 14 Hypersonic Weapons: Background and Issues for Congress Figure 3. Lingyun-1 Hypersonic Cruise Missile Prototype Source: Photo accompanying Drake Long, “China reveals Lingyun-1 hypersonic missile at National Science and Technology expo,"” The Defense Post, May 21, 2018.

According to Jane'’s Defence Weekly, "“China is also investing heavily in hypersonic ground testing facilities."⁹²”95 CAAA operates the FD-02, FD-03, and FD-07 hypersonic wind tunnels, which are capable of reaching speeds of Mach 8, Mach 10, and Mach 12, respectively.⁹³96 China also operates the JF-12 hypersonic wind tunnel, which reaches speeds of between Mach 5 and Mach 9, and the FD-21 hypersonic wind tunnel, which reaches speeds of between Mach 10 and Mach 15.⁹⁴97 China is expected to have an operational wind tunnel capable of reaching speeds of Mach 25 by 2020.⁹⁵98 China is known to have tested hypersonic weapons at the Jiuquan Satellite Satel ite Launch Center and the Taiyuan SatelliteSatel ite Launch Center. 95 T ate, “China conducts further tests.” 96 Kelvin Wong, “ China claims successful test of hypersonic waverider,” Jane’s (subscription required), August 10, 2018, https://janes.ihs.com/Janes/Display/FG_1002295-JDW. 97 Jeffrey Lin and P.W. Singer, “A look at China’s most exciting hypersonic aerospace programs,” Popular Science, April 18, 2017, https://www.popsci.com/chinas-hypersonic-technology. 98 T ate, “China conducts further tests.” Congressional Research Service 15 Hypersonic Weapons: Background and Issues for Congress Launch Center.

Issues for Congress

As Congress reviews the Pentagon'’s plans for U.S. hypersonic weapons programs during the annual authorization and appropriations process, it might consider a number of questions about the rationale for hypersonic weapons, their expected costs, and their implications for strategic stability and arms control. This section provides an overview of some of these questions.

Mission Requirements

Although the Department of Defense is funding a number of hypersonic weapons programs, it has not established any programs of record, suggesting that it may not have approved requirements for hypersonic weapons or long-term funding plans.⁹⁶99 Indeed, as Assistant Director for Hypersonics (USD [R&E]) Mike White has stated, DOD has not yet made a decision to acquire 99 Steve T rimble, “New Long-T erm Pentagon Plan Boosts Hypersonics.” Congressional Research Service 16 Hypersonic Weapons: Background and Issues for Congress hypersonic weapons and is instead developing prototypes to "“[identify] the most viable overarching weapon system concepts to choose from and then make a decision based on success and chal enges.”100and challenges."⁹⁷ As Congress conducts oversight of U.S. hypersonic weapons programs, it may seek to obtain information about DOD'’s evaluation of potential mission sets for hypersonic weapons, a cost analysis of alternative means of executing these mission sets, and an assessment of the enabling technologies—such as space-based sensors or autonomous command and control systems—that may be required to employ or defend against hypersonic weapons.

Funding Considerations

Assistant Director for Hypersonics (USD [R&E]) Mike White has noted that DOD is prioritizing offensive programs while it determines "“the path forward to get a robust defensive strategy."⁹⁸ ”101 This approach is reflected in DOD'’s FY2021 request, which allocatesal ocates $206.8 millionmil ion for hypersonic defense programs—of a total $3.2 billionbil ion request for all al hypersonic-related research.⁹⁹102 Similarly, in FY2020, DOD requested $157.4 millionmil ion for hypersonic defense programs—of a total $2.6 billion for all bil ion for al hypersonic-related research.

Although the Defense Subcommittees of the Appropriations Committees increased FY2020 appropriations for both hypersonic offense and defense above the FY2020 request, they expressed concerns, noting in their joint explanatory statement of H.R. 1158 " “that the rapid growth in hypersonic research has the potential to result in stove-piped, proprietary systems that duplicate capabilities and increase costs."¹⁰⁰”103 To mitigate this concern, they appropriated $100 millionmil ion for DOD to establish a Joint Hypersonic Transition Office to "“develop and implement an integrated science and technology roadmap for hypersonics"” and "“establish a university consortium for hypersonic research and workforce development"” in support of DOD efforts.¹⁰¹104 Given the lack of defined mission requirements for hypersonic weapons, it may be challengingchal enging for Congress to evaluate the balance of funding for hypersonic weapons programs, enabling technologies, supporting test infrastructure, and hypersonic missile defense.

Strategic Stability

Analysts disagree about the strategic implications of hypersonic weapons. Some have identified two factors that could hold significant implications for strategicstrategic stability: the weapon'’s short time-of-flight—which, in turn, compresses the timeline for response—and its unpredictable flight path—which could generate uncertainty about the weapon'and its unpredictable flight 100 Ibid. 101 Aaron Mehta, “Is the Pentagon Moving Quickly Enough on Hypersonic Defense?” Defense News, March 21, 2019, https://www.defensenews.com/pentagon/2019/03/21/is-the-pentagon-moving-quickly-enough-on-hypersonic-defense/. 102Department of Defense Fiscal Year (FY) 2021 Budget Estimates, Missile Defense Agency Defense -Wide Justification Book Volume 2a of 5, p. 10, https://comptroller.defense.gov/Portals/45/Documents/defbudget/fy2021/budget_justification/pdfs/03_RDT _and_E/RDT E_Vol2_MDA_RDT E_PB21_Justification_Book.pdf . 103 “Department of Defense Appropriations Act, 2020: Joint Explanatory Statement,” Defense Subcommittees of the Appropriations Committees, December 16, 2019, https://appropriations.house.gov/sites/democrats.appropriations.house.gov/files/HR%201158%20-%20Division%20A%20-%20Defense%20SOM%20FY20.pdf. 104 Ibid. T he Joint Hypersonic T ransition Office, then called the Joint T echnology Office on Hypersonics, was originally mandated by Section 218 of the FY2007 NDAA ( P.L. 109-364). The office was redesignated as the Joint Hypersonics T ransition Office and given additional authorities in Section 214 of the FY2018 NDAA (P.L. 115-91). Section 216 of the FY2020 NDAA (P.L. 116-92) further amended the office’s authorities to include the ability to enter into agreements with institutions of higher learning. T he office went unfunded until FY2020 and was not established until April 2020. Congressional Research Service 17 Hypersonic Weapons: Background and Issues for Congress path—which could generate uncertainty about the weapon’s intended target and therefore heighten the risk of miscalculation or unintended escalation in the event of a conflict. This risk could be further compounded in countries that co-locate nuclear and conventional capabilities or facilities.

facilities. Some analysts argue that unintended escalation could occur as a result of warhead ambiguity, or from the inability to distinguish between a conventionally conventional y armed hypersonic weapon and a nuclear-armed one. However, as a United Nations report notes, "“even if a State did know that an HGV launched toward it was conventionallyconventional y armed, it may still stil view such a weapon as strategic in nature, regardless of how it was perceived by the State firing the weapon, and decide that a strategic response was warranted."¹⁰²”105 Differences in threat perception and escalation ladders could thus result in unintended escalation. Such concerns have previously led Congress to restrict to restrict funding for conventional prompt strike programs.¹⁰³

106 Other analysts have argued that the strategic implications of hypersonic weapons are minimal. Pavel Podvig, a senior research fellowfel ow at the United Nations Institute for Disarmament Research, has noted that the weapons "don'“don’t … change much in terms of strategic balance and military capability."¹⁰⁴”107 This, some analysts argue, is because U.S. competitors such as China and Russia already possess the ability to strike the United States with intercontinental ballisticbal istic missiles, which, when launched in salvos, could overwhelm U.S. missile defenses.¹⁰⁵108 Furthermore, these analysts note that in the case of hypersonic weapons, traditional principles of deterrence hold: "“it is real yis really a stretch to try to imagine any regime in the world that would be so suicidal that it would even think threating to use—not to mention to actuallyactual y use—hypersonic weapons against the United States ... would end well."¹⁰⁶

wel .”109 Arms Control

Some analysts who believe that hypersonic weapons could present a threat to strategic stability or inspire an arms race have argued that the United States should take measures to mitigate risks or limit the weapons'’ proliferation. Proposed measures include expanding New START, negotiating new multilateral arms control agreements, and undertaking transparency and confidence-building measures.¹⁰⁷

measures.110 The New START Treaty, a strategic offensive arms treaty between the United States and Russia, does not currently cover weapons that fly on a ballisticbal istic trajectory for less than 50% of their flight, as do hypersonic glide vehicles and hypersonic cruise missiles.¹⁰⁸111 However, Article V of the treaty states that " 105 United Nations Office of Disarmament Affairs, Hypersonic Weapons. 106 For a history of legislative activity on conventional prompt global strike, see CRS Report R41464, Conventional Prom pt Global Strike and Long-Range Ballistic Missiles: Background and Issues, by Amy F. Woolf. 107 Amy Mackinnon, “ Russia’s New Missiles Are Aimed at the U.S.,” Foreign Policy, March 5, 2019, https://foreignpolicy.com/2019/03/05/russias-new-missiles-are-aimed-at-you-weapons-hypersonic-putin-united-states-inf/. 108 David Axe, “ How the U.S. Is Quietly Winning the Hypersonic Arms Race,” The Daily Beast, January 16, 2019, https://www.thedailybeast.com/how-the-us-is-quietly-winning-the-hypersonic-arms-race. See also Mark B. Schneider, “Moscow’s Development of Hypersonic Missiles,” p. 14. 109 Jyri Raitasalo, “ Hypersonic Weapons are No Game-Changer,” The National Interest, January 5, 2019, https://nationalinterest.org/blog/buzz/hypersonic-weapons-are-no-game-changer-40632. 110 See United Nations Office of Disarmament Affairs, Hypersonic Weapon; and Richard H. Speier et al., Hypersonic Missile Proliferation. 111 In some cases, hypersonic glide vehicles may be launched from intercontinental ballistic missiles that are already covered by New ST ART , as is reported to be the case with Russia’s Avangard HGV. See Rachel S. Cohen, Congressional Research Service 18 Hypersonic Weapons: Background and Issues for Congress states that “when a Party believes that a new kind of strategic offensive arm is emerging, that Party shall shal have the right to raise the question of such a strategic offensive arm for consideration in the Bilateral Consultative Commission (BCC)."” Accordingly, some legal experts hold that the United States could raise the issue in the BCC of negotiating to include hypersonic weapons in the New START limits.¹⁰⁹112 However, because New START is due to expire in 2021, unless extended through 2026, this solution is likely to be temporary.¹¹⁰

113 As an alternative, some analysts have proposed negotiating a new international arms control agreement that would institute a moratorium or ban on hypersonic weapon testing. These analysts argue that a test ban would be a "“highly verifiable"” and "“highly effective"” means of preventing a potential arms race and preserving strategic stability.¹¹¹114 Other analysts have countered that a test ban would be infeasible, as "“no clear technical distinction can be made between hypersonic missiles and other conventional capabilities that are less prompt, have shorter ranges, and also have the potential to undermine nuclear deterrence."¹¹²”115 These analysts have instead proposed international transparency and confidence-building measures, such as exchanging weapons data; conducting joint technical studies; "“providing advance notices of tests; choosing separate, distinctive launch locations for tests of hypersonic missiles; and placing restraints on sea-based tests."¹¹³

Appendix. U.S. Hypersonic Testing Infrastructure¹¹⁴