Hypersonic Weapons: Background and Issues for Congress

Updated August 7, 2024

Congressional Research Service

https://crsreports.congress.gov

R45811

Congressional Research Service

SUMMARY

Hypersonic Weapons: Background and Issues for Congress

The United States has actively pursued the development of hypersonic weapons—maneuvering weapons that fly at speeds of at least Mach 5—as a part of its conventional prompt global strike program since the early 2000s. In recent years, the United States 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 former 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 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 advances in these technologies in Russia and China, both of which have a number of hypersonic weapons programs and have likely fielded operational hypersonic glide vehicles—potentially armed with nuclear warheads. Most U.S. hypersonic weapons, in contrast to those in Russia and China, are not being designed for use with a nuclear warhead. As a result, U.S. hypersonic weapons will likely require greater accuracy and will be more technically challenging to develop than nuclear-armed Chinese and Russian systems.

The Pentagon’s FY2025 budget request for hypersonic research was $6.9 billion—up from $4.7 billion in the FY2023 request. The Pentagon declined to provide a breakout of funding for hypersonic-related research in FY2024, but requested $11 billion for long-range fires—a category that includes hypersonic weapons. The Missile Defense Agency additionally requested $182.3 million for hypersonic defense in FY2025, down from its $190.6 million request in FY2024 and $225.5 million request in FY2023. 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 mission requirements for the systems or long-term funding plans. Indeed, as former Principal 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 hypersonic weapons be used for? Are hypersonic weapons the most cost-effective means of executing these potential missions? How will 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 the fielding of hypersonic weapons affect strategic stability?

• Is there a need for risk-mitigation measures, such as expanding New START, negotiating new multilateral arms control agreements, or undertaking transparency and confidence-building activities?

R45811

August 7, 2024

Kelley M. Sayler Specialist in Advanced Technology and Global Security

Hypersonic Weapons: Background and Issues for Congress

Congressional Research Service

Contents

Introduction ..................................................................................................................................... 1 Background ..................................................................................................................................... 2

United States ............................................................................................................................. 4

Programs ............................................................................................................................. 4 Infrastructure ..................................................................................................................... 12

Russia ...................................................................................................................................... 15

Programs ........................................................................................................................... 15 Infrastructure ..................................................................................................................... 17

China ....................................................................................................................................... 17

Programs ........................................................................................................................... 18 Infrastructure ..................................................................................................................... 19

Issues for Congress ........................................................................................................................ 22

Mission Requirements ............................................................................................................. 22

Funding and Management Considerations .............................................................................. 23

Industrial Base and Supply Chain ........................................................................................... 24 Strategic Stability .................................................................................................................... 25 Arms Control ........................................................................................................................... 26

Figures

Figure 1. Terrestrial-Based Detection of Ballistic Missiles vs. Hypersonic Glide Vehicles ............ 3

Figure 2. Artist Rendering of Avangard ......................................................................................... 16

Figure 3. Lingyun-1 Hypersonic Cruise Missile Prototype ........................................................... 20

Tables

Table 1. Summary of Selected U.S. Hypersonic Weapons RDT&E Funding ............................... 10 Table 2. Summary of U.S. Hypersonic Weapons Procurement Funding ........................................ 11

Table A-1. DOD Hypersonic Ground Test Facilities ..................................................................... 28

Table A-2. DOD Open-Air Ranges................................................................................................ 29 Table A-3. DOD Mobile Assets ..................................................................................................... 29

Table A-4. NASA Research-Related Facilities .............................................................................. 30

Table A-5. Department of Energy Research-Related Facilities ..................................................... 30

Table A-6. Industry/Academic Research-Related Facilities .......................................................... 30

Appendixes

Appendix. U.S. Hypersonic Testing Infrastructure ....................................................................... 28

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Contacts

Author Information ........................................................................................................................ 32

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Introduction

The United States has actively pursued the development of hypersonic weapons as a part of its conventional prompt global strike program since the early 2000s.¹ 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 advances 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 likely fielded an operational capability.

Experts disagree on the potential impact of competitor hypersonic weapons on both strategic stability and the U.S. military’s competitive advantage. Nevertheless, former 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 Although the John S. McCain National Defense Authorization Act for Fiscal Year 2019 (FY2019 NDAA, P.L. 115- 232) 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 FY2025. However, most U.S. hypersonic weapons programs, in contrast to those in Russia and China, are not being designed for potential use with a nuclear warhead.³ As a result, U.S. hypersonic weapons will likely require greater accuracy and will be more technically challenging 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 Intelligence 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) 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, “Testimony of Michael Griffin,” Hearing on New Technologies to Meet Emerging Threats, April 18, 2018, at 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 solicitation 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 Trimble, “USAF Errantly Reveals Research on ICBM-Range Hypersonic Glide Vehicle,” Aviation Week, August 18, 2020, at https://aviationweek.com/defense-space/missile-defense-weapons/usaf-errantly-reveals-research-icbm-range- hypersonic-glide.

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(6) An assessment of the intent or willingness of adversaries to use such technology.⁴

This report was delivered to Congress in July 2019. Similarly, Section 1689 of the FY2019 NDAA requires the Director of the Missile Defense Agency (MDA) to produce a report on “how hypersonic missile defense can be accelerated to meet emerging hypersonic threats.”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 the Department of Defense’s (DOD’s) funding requests for U.S. hypersonic technology programs.

Background

Several countries are developing hypersonic weapons, which fly at speeds of at least Mach 5 (five times the speed of sound).⁶ There are two primary categories of hypersonic weapons:

• Hypersonic glide vehicles are launched from a rocket before gliding to a target.⁷

• Hypersonic cruise missiles are powered by high-speed, air-breathing engines, or “scramjets,” after acquiring their target.

Unlike ballistic missiles, hypersonic weapons do not follow a ballistic trajectory and can maneuver en route to their destination. As former 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.”⁸ Conventional hypersonic weapons use only kinetic energy—energy derived from motion—to destroy unhardened targets or, potentially, underground facilities.⁹

Hypersonic weapons could challenge detection and defense due to their speed, maneuverability, and low altitude of flight.¹⁰ For example, terrestrial-based radar cannot detect hypersonic weapons until late in the weapon’s flight.¹¹ Figure 1 depicts the differences in terrestrial-based radar detection timelines for ballistic missiles versus hypersonic glide vehicles.

4 P.L. 115-232, Section 2, Division A, Title II, §247.

5 P.L. 115-232, Section 2, Division A, Title XVI, §1689.

6 At a minimum, the United States, Russia, China, Australia, India, France, Germany, and Japan 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, at https://www.rand.org/pubs/research_reports/RR2137.html; and Mike Yeo, “Japan unveils its hypersonic weapons plans,” Defense News, March 14, 2020.

7 When hypersonic glide vehicles 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, “Testimony of John E. Hyten,” Hearing on United States Strategic Command and United States Northern Command, February 26, 2019, at 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, at https://www.defense.gov/Portals/1/Interactive/2018/11- 2019-Missile-Defense-Review/The%202019%20MDR_Executive%20Summary.pdf.

11 Richard H. Speier et al., Hypersonic Missile Proliferation: Hindering the Spread of a New Class of Weapons.

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Figure 1. T errestrial-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 decisionmakers assessing their response options and for a defensive system to intercept the attacking weapon—potentially permitting only a single intercept attempt.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 former USD(R&E) Griffin noting that “hypersonic targets are 10 to 20 times dimmer than what the U.S. normally tracks by satellites in geostationary orbit.”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 weapons¹⁴—could theoretically present viable options for defending against hypersonic weapons in the future.¹⁵ Indeed, the 2019 Missile Defense Review notes that “such sensors take advantage of the large area viewable from space for improved tracking and potentially targeting of advanced threats, including [hypersonic glide vehicles] and hypersonic cruise missiles.”¹⁶

12 Bradley Perrett et al., “U.S. Navy Sees Chinese HGV as Part of Wider Threat,” Aviation Week, January 27, 2014.

13 David Vergun, “DOD Scaling Up Effort to Develop Hypersonics,” DoD News, December 13, 2018, at https://dod.defense.gov/News/Article/Article/1712954/dod-scaling-up-effort-to-develop-hypersonics/. See also U.S. Congress, Senate Committee on Armed Services, “Testimony of Michael Griffin,” Hearing on New Technologies to Meet Emerging Threats, April 18, 2018, at https://www.armed-services.senate.gov/imo/media/doc/18-40_04-18-18.pdf, and U.S. Congress, Senate Committee on Armed Services, “Testimony of John E. Hyten,” Hearing on United States Strategic Command and United States Northern Command, February 26, 2019, at https://www.armed- services.senate.gov/imo/media/doc/Hyten_02-26-19.pdf.

14 Section 1664 of the FY2022 NDAA (P.L. 117-81) granted the “Director of the Missile Defense Agency the authority to budget for, direct, and manage directed energy programs applicable for ballistic and hypersonic missile defense missions, in coordination with other directed energy efforts of the Department of Defense.”

15 U.S. Congress, Senate Committee on Armed Services, “Testimony of Michael Griffin,” Hearing on New Technologies to Meet Emerging Threats, April 18, 2018, at https://www.armed-services.senate.gov/imo/media/doc/18- 40_04-18-18.pdf; and U.S. Congress, Senate Committee on Armed Services, “Testimony of John E. Hyten,” Hearing on United States Strategic Command and United States Northern Command, February 26, 2019, at https://www.armed- services.senate.gov/imo/media/doc/Hyten_02-26-19.pdf.

16 Department of Defense, 2019 Missile Defense Review, p. XVI, at https://www.defense.gov/Portals/1/Interactive/ 2018/11-2019-Missile-Defense-Review/The%202019%20MDR_Executive%20Summary.pdf.

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Other analysts have questioned the affordability, technological feasibility, and/or utility of wide- area hypersonic weapons defense.¹⁷ 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 areas. To defend the whole of the continental United States, you would need an unaffordable number of THAAD batteries.”¹⁸ 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.”¹⁹ (For additional information on hypersonic missile defense, see CRS In Focus IF11623, Hypersonic Missile Defense: Issues for Congress, by Jennifer DiMascio and Kelley M. Sayler.)

United States

DOD is currently developing hypersonic weapons under the Navy’s Conventional Prompt Strike (CPS) program, which is intended to provide the U.S. military with the ability to strike hardened or time-sensitive targets with conventional warheads, as well as through several Air Force, Army, and Defense Advanced Research Projects Agency (DARPA) programs.²⁰ Those who support these development efforts argue that hypersonic weapons could enhance deterrence, as well 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.²¹ In recognition of this, the 2018 National Defense Strategy identifies hypersonic weapons as one of the key technologies “[ensuring the United States] will be able to fight and win the wars of the future.”²² Similarly, the House Armed Services Committee’s bipartisan Future of Defense Task Force Report notes that hypersonic weapons could present challenges to the United States in the years to come.²³

Programs

Unlike programs in China and Russia, U.S. hypersonic weapons are to be conventionally armed. As a result, U.S. hypersonic weapons will likely require greater accuracy and will be more technically challenging to develop than nuclear-armed Chinese and Russian systems. Indeed,

17 See James M. Acton, “Hypersonic Weapons Explainer,” Carnegie Endowment for International Peace, April 2, 2018, at https://carnegieendowment.org/2018/04/02/hypersonic-weapons-explainer-pub-75957; and Margot van Loon, “Hypersonic Weapons: A Primer.”

18 Acton, “Hypersonic Weapons Explainer.”

19 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 Them),” Real Clear Defense, April 23, 2019, at https://www.realcleardefense.com/articles/2019/ 04/23/hypersonic_weapons__a_threat_to_national_security_114358.html.

20 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.

21 Roger Zakheim and Tom 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, Test and Evaluation, Volume II, Budget Activity 4, p. 580.

22 Department of Defense, “Summary of the 2018 National Defense Strategy of The United States of America,” p. 3, at https://dod.defense.gov/Portals/1/Documents/pubs/2018-National-Defense-Strategy-Summary.pdf.

23 House Armed Services Committee, Future of Defense Task Force Report 2020, September 2020, at https://armedservices.house.gov/_cache/files/2/6/26129500-d208-47ba-a9f7-25a8f82828b0/ 424EB2008281A3C79BA8C7EA71890AE9.future-of-defense-task-force-report.pdf.

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according to one expert, “a nuclear-armed glider would be effective if it were 10 or even 100 times less accurate [than a conventionally armed glider]” due to nuclear blast effects.²⁴

According to open-source reporting, the United States is conducting research, development, test, and evaluation (RDT&E) on a number of offensive hypersonic weapons and hypersonic technology programs, including the following (see Table 1):

• U.S. Navy—Conventional Prompt Strike (CPS);

• U.S. Navy—Offensive Anti-Surface Warfare Increment 2 (OASuW Inc 2), also known as Hypersonic Air-Launched OASuW (HALO);

• U.S. Army—Long-Range Hypersonic Weapon (LRHW); and

• U.S. Air Force—Hypersonic Attack Cruise Missile (HACM).

These programs are intended to produce operational prototypes, as there are currently no programs of record for hypersonic weapons.²⁵

U.S. Navy

In a June 2018 memorandum, DOD announced that the Navy would lead the development of a Common Hypersonic Glide Body for use across the services.²⁶ The glide body is being adapted from a Mach 6 Army prototype warhead, the Alternate Re-Entry System. The Navy’s CPS is expected to pair the glide body with a booster system to create a common All Up Round (AUR) for use by both the Navy and Army. The first test of the AUR, conducted in June 2022, resulted in failure.²⁷ Two subsequent flight tests, planned for March and September 2023, did not occur due to failed preflight checks.²⁸ DOD completed a test of the AUR in June 2024.²⁹

According to the Navy’s FY2025 budget documents, the service intends to deploy CPS on Zumwalt-class destroyers by the end of FY2025.³⁰ Although Navy officials have previously noted plans to achieve “limited operating capability” on Ohio-class submarines as early as 2025³¹ and

24 James M. Acton, “China’s Advanced Weapons,” Testimony to the U.S. China Economic and Security Review Commission, February 23, 2017, at https://carnegieendowment.org/2017/02/23/china-s-advanced-weapons-pub-68095.

25 Steve Trimble, “New Long-Term Pentagon Plan Boosts Hypersonics, but Only Prototypes,” Aviation Week, March 15, 2019, at https://aviationweek.com/defense/new-long-term-pentagon-plan-boosts-hypersonics-only-prototypes.

26 The 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, at https://breakingdefense.com/2020/02/army-ramps-up-funding-for-laser-shield-hypersonic-sword/.

27 Jon Herskovitz and Anthony Capaccio, “US Hypersonic Missile Fails in Test in Fresh Setback for Program,” Bloomberg, June 29, 2022, at https://www.bloomberg.com/news/articles/2022-06-30/us-hypersonic-missile-fails-in- test-in-fresh-setback-for-program.

28 Director, Operational Test and Evaluation, FY2023 Annual Report, January 2024, p. 168, at https://www.dote.osd.mil/Portals/97/pub/reports/FY2023/other/2023annual-report.pdf?ver= d7gusiIrcbYmxM0oDkPSFg%3d%3d.

29 See Department of Defense, “DOD Completes Flight Test of Hypersonic Missile,” June 28, 2024, at https://www.defense.gov/News/Releases/Release/Article/3821376/dod-completes-flight-test-of-hypersonic-missile/.

30 Department of Defense Fiscal Year (FY) 2025 Budget Estimates, Navy Justification Book of Research, Development, Test and Evaluation, Volume II, Budget Activity 4, p. 1395, at https://www.secnav.navy.mil/fmc/fmb/Documents/25pres/RDTEN_BA4_Book.pdf. Reports indicate that Zumwalt- class destroyers could carry up to 12 missiles each. See Sam LaGrone, “Navy Awards HII Planning Contract for Zumwalt Hypersonic Upgrades,” USNI News, January 9, 2023, at https://news.usni.org/2023/01/09/navy-awards-hii- planning-contract-for-zumwalt-hypersonic-upgrades?utm_campaign=dfn-ebb&utm_medium=email&utm_source= sailthru&SToverlay=2002c2d9-c344-4bbb-8610-e5794efcfa7d.

31 See Department of Defense Fiscal Year (FY) 2022 Budget Estimates, Navy Justification Book of Research, (continued...)

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on Virginia-class submarines by FY2028, as well as to eventually field hypersonic weapons on Burke-class destroyers, such plans are not reflected in current budget documents.³² The Navy is requesting $903.9 million for CPS RDT&E in FY2025—an increase from the FY2024 request of $901.1 million.³³ The Navy did not request funding for CPS procurement in FY2025.³⁴

The Navy is also developing the Offensive Anti-Surface Warfare Increment 2 (OASuW Inc 2), also known as Hypersonic Air-Launched OASuW (HALO)—a new start in FY2023.³⁵ Although few details about the program have been released publicly, HALO is likely to be compatible with the Navy’s F/A-18 fighter jet.³⁶ The Navy is requesting $178.6 million for HALO RDT&E in FY2025.³⁷

U.S. Army

The Army’s Long-Range Hypersonic Weapon (LRHW) program, also known as Dark Eagle, is expected to pair the common glide vehicle with the Navy’s booster system.³⁸ The system is intended to have a range of over 1,725 miles 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.”³⁹ The Army is requesting $538 million for

Development, Test and Evaluation, Volume II, Budget Activity 4, p. 1466, at https://www.secnav.navy.mil/fmc/fmb/ Documents/22pres/RDTEN_BA4_Book.pdf; Department of the Navy, “Highlights of the Department of the Navy FY 2021 Budget,” February 10, 2020, at https://www.secnav.navy.mil/fmc/fmb/Documents/21pres/Highlights_book.pdf; and Megan Eckstein, “Navy Says Hypersonic Weapons Coming to Subs in 5 Years,” USNI News, November 17, 2020, at https://news.usni.org/2020/11/17/navy-says-hypersonic-weapons-coming-to-subs-in-5-years.

32 David B. Larter, “All US Navy Destroyers Will Get Hypersonic Missiles, Says Trump’s National Security Adviser,” Defense News, October 21, 2020, at https://www.defensenews.com/naval/2020/10/21/all-us-navy-destroyers-will-get- hypersonic-missiles-trumps-national-security-advisor-says/. Budget documents do indicate that the Navy is continuing “non-recurring engineering (NRE) efforts associated with CPS payload hosting on Block V Virginia platforms.” See Department of Defense Fiscal Year (FY) 2025 Budget Estimates, Navy Justification Book of Research, Development, Test and Evaluation, Volume II, Budget Activity 4, p. 1378, at https://www.secnav.navy.mil/fmc/fmb/Documents/25pres/RDTEN_BA4_Book.pdf.

33 Department of Defense Fiscal Year (FY) 2025 Budget Estimates, Navy Justification Book of Research, Development, Test and Evaluation, Volume II, Budget Activity 4, p. 1369, at https://www.secnav.navy.mil/fmc/fmb/Documents/25pres/RDTEN_BA4_Book.pdf.

34 Department of Defense Fiscal Year (FY) 2025 Budget Estimates, Navy Justification Book of Weapons Procurement, p. 1, at https://www.secnav.navy.mil/fmc/fmb/Documents/25pres/WPN_Book.pdf. The Navy’s FY2024 request of $304 million was to support the procurement of eight CPS weapons.

35 Department of Defense Fiscal Year (FY) 2023 Budget Estimates, Navy Justification Book of Research, Development, Test and Evaluation, Volume II, Budget Activity 4, p. 1373, at https://www.secnav.navy.mil/fmc/fmb/ Documents/23pres/RDTEN_BA4_Book.pdf. Some reports indicate that, despite its name, HALO may not travel at hypersonic speeds, and thus may not qualify as a hypersonic weapon. See, for example, Jon Harper, “Navy’s Future HALO ‘Hypersonic’ Missile Might not Actually Be Hypersonic,” Defense Scoop, April 3, 2023, at https://defensescoop.com/2023/04/03/navys-future-halo-hypersonic-missile-might-not-actually-be-hypersonic/. It is included here for reference.

36 Joseph Trevithick, “Hypersonic Anti-Ship Cruise Missile Has To Be Ready by 2028 Navy Says,” The Drive, April 23, 2022, at https://www.thedrive.com/the-war-zone/hypersonic-anti-ship-cruise-missile-has-to-be-ready-by-2028- navy-says.

37 Department of Defense Fiscal Year (FY) 2025 Budget Estimates, Navy Justification Book of Research, Development, Test and Evaluation, Volume II, Budget Activity 4, p. 1285, at https://www.secnav.navy.mil/fmc/fmb/Documents/25pres/RDTEN_BA4_Book.pdf.

38 For additional information about LRHW, see CRS In Focus IF11991, The U.S. Army’s Long-Range Hypersonic Weapon (LRHW), by Andrew Feickert.

39 Sydney J. Freedberg Jr., “Army Discloses Hypersonic LRHW Range Of 1,725 Miles; Watch Out China,” Breaking Defense, May 12, 2021, at https://breakingdefense.com/2021/05/army-discloses-hypersonic-lrhw-range-of-1725-miles- (continued...)

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LRHW RDT&E in FY2025⁴⁰ and $744.2 million for the procurement of LRHW ground support equipment and AURs and canister.⁴¹ The Army has fielded prototype LRHW equipment and “intends to field two additional batteries of LRHW” by FY2027.⁴² Army officials have previously expressed plans to transition LRHW to a program of record in the fourth quarter of FY2024—a timeline that officials have termed “very, very aggressive” and that would require the program to take on “a lot of risk.”⁴³

U.S. Air Force

The AGM-183 Air-Launched Rapid Response Weapon (ARRW, pronounced “arrow”) was to leverage DARPA’s Tactical Boost Glide (TBG) technology to develop an air-launched hypersonic glide vehicle prototype capable of travelling at average speeds of between Mach 6.5 and Mach 8 at a range of approximately 1,000 miles.⁴⁴ ARRW successfully completed a “captive carry” test flight in June 2019. It then experienced three successive failures before completing three successful flight tests in 2022.⁴⁵ Although the first test of the full operational ARRW prototype in December 2022 was successful, ARRW’s flight testing record since then appears to have been mixed, with at least one 2023 test flight failure.⁴⁶ The Air Force declined to comment on the

watch-out-china/; https://breakingdefense.com/2019/03/army-sets-2023-hypersonic-flight-test-strategic-cannon- advances/; and Department of Defense Fiscal Year (FY) 2022 Budget Estimates, Army Justification Book of Research, Development, Test and Evaluation, Volume II, Budget Activity 4, p. 639, at https://www.asafm.army.mil/Portals/72/ Documents/BudgetMaterial/2022/Base%20Budget/rdte/RDTE_BA_4_FY_2022_PB.pdf.

40 Department of Defense Fiscal Year (FY) 2025 Budget Estimates, Army Justification Book of Research, Development, Test and Evaluation, Volume II, Budget Activity 5D, p. 82, at https://www.asafm.army.mil/Portals/72/Documents/BudgetMaterial/2025/Base%20Budget/Research,%20Development ,%20Test%20and%20Evaluation/RDTE%20-%20Vol%202%20-%20Budget%20Activity%205D.pdf; and Department of Defense Fiscal Year (FY) 2025 Budget Estimates, Army Justification Book of Research, Development, Test and Evaluation, Volume II, Budget Activity 4B, p. 264, at https://www.asafm.army.mil/Portals/72/Documents/BudgetMaterial/2025/Base%20Budget/Research,%20Development ,%20Test%20and%20Evaluation/RDTE%20-%20Vol%202%20-%20Budget%20Activity%204B.pdf.

41 Department of Defense Fiscal Year (FY) 2025 Budget Estimates, Army Justification Book of Missile Procurement, pp. 104, at https://www.asafm.army.mil/Portals/72/Documents/BudgetMaterial/2025/Base%20Budget/Procurement/Missile- Procurement-Army.pdf.

42 Director, Operational Test and Evaluation, FY2023 Annual Report, January 2024, p. 123, at https://www.dote.osd.mil/Portals/97/pub/reports/FY2023/other/2023annual-report.pdf?ver= d7gusiIrcbYmxM0oDkPSFg%3d%3d.

43 Jon Harper, DefenseScoop, October 10, 2022, at https://defensescoop.com/2022/10/10/army-assuming-a-lot-of-risk- as-it-moves-to-field-hypersonic-weapons-by-end-of-fiscal-year/. See also Department of Defense Fiscal Year (FY) 2023 Budget Estimates, Army Justification Book of Research, Development, Test and Evaluation, Volume II, Budget Activity 4, pp. 705-709, at https://www.asafm.army.mil/Portals/72/Documents/BudgetMaterial/2023/Base%20Budget/ rdte/vol_2-Budget_Activity_4.pdf.

44 ARRW is expected to be launched initially from the B-52H strategic bomber. Thomas Newdick, “Air Force Says New Hypersonic Missile Will Hit Targets 1,000 Miles Away in Under 12 Minutes,” The Drive, October 13, 2020, at https://www.thedrive.com/the-war-zone/37045/air-force-says-new-hypersonic-missile-will-hit-targets-1000-miles- away-in-under-12-minutes.

45 Oriana Pawlyk, “Air Force’s Hypersonic ARRW Missile Fails First Flight Test,” Military.com, April 6, 2021, at https://www.military.com/daily-news/2021/04/06/air-forces-hypersonic-arrw-missile-fails-first-flight-test.html#:~:text= In%20June%202019%2C%20the%20service,early%202020s%2C%20the%20release%20states; John A. Tirpak, “Hypersonic ARRW Flies Successfully for Second Time, Completing Booster Tests,” Air Force Magazine, July 13, 2022, at https://www.airforcemag.com/hypersonic-arrw-flies-successfully-for-second-time-completing-booster-tests/.

46 Ilka Cole, “Air Force Conducts First ARRW Operational Prototype Missile Test,” U.S. Air Force, December 12, 2022, at https://www.af.mil/News/Article-Display/Article/3243194/air-force-conducts-first-arrw-operational-prototype- missile-test/; and Stephen Losey, “US Air Force Fires Hypersonic ARRW in First Test Since March Failure,” (continued...)

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outcome of a second 2023 test, noting only that it “gained valuable new insights into [ARRW’s] capabilities.”⁴⁷ Following the March 2023 failure, Secretary of the Air Force Frank Kendall stated that the Air Force is “more committed to HACM at this point in time than [it is] to ARRW.”⁴⁸ The Air Force conducted its final test of ARRW in March 2024 but also declined to discuss the results of that test.⁴⁹ The Air Force did not request funds for ARRW in FY2025 and budget documents characterized the program as “completed.”⁵⁰

In February 2020, the Air Force announced that it had cancelled its second hypersonic weapon program, the Hypersonic Conventional Strike Weapon (HCSW), which had been expected to use the common glide vehicle and booster system, due to budget pressures that forced it to choose between ARRW and HCSW.⁵¹ Then-Air Force acquisition chief Will Roper explained that ARRW was selected because it was more advanced and gave the Air Force additional options. “[ARRW] is smaller; we can carry twice as many on the B-52, and it’s possible it could be on the F-15,” he explained.⁵² A senior Air Force official has since noted that a B-52 could potentially carry four ARRWs.⁵³

Finally, in FY2022, the Air Force launched the Hypersonic Attack Cruise Missile (HACM) program to develop a hypersonic cruise missile that integrates Air Force and DARPA technologies.⁵⁴ Some reports indicate that HACM is intended to be launched from both bombers and fighter aircraft,⁵⁵ with a senior Air Force official noting that a B-52 could potentially carry 20 HACMs or more.⁵⁶ According to the Air Force, “the ability to execute HACM development is

C4ISRNet, August 21, 2023, at https://www.c4isrnet.com/battlefield-tech/space/2023/08/21/us-air-force-fires-arrw- hypersonic-in-first-test-since-march-failure/.

47 Stephen Losey, “US Air Force Fires Hypersonic ARRW in First Test Since March Failure,” C4ISRNet, August 21, 2023, at https://www.c4isrnet.com/battlefield-tech/space/2023/08/21/us-air-force-fires-arrw-hypersonic-in-first-test- since-march-failure/.

48 John A. Tirpak, “Kendall: Air Force ‘More Committed’ to HACM After Latest Unsuccessful ARRW Test,” Air and Space Forces Magazine, March 28, 2023, at https://www.airandspaceforces.com/kendall-air-force-hacm-unsuccessful- arrw-test/.

49 See, for example, Michael Marrow, “Air Force conducts final test of ARRW hypersonic missile, won’t discuss ‘specific’ results,” Breaking Defense, March 20, 2024, at https://breakingdefense.com/2024/03/air-force-conducts- final-test-of-arrw-hypersonic-missile-wont-discuss-specific-results/.

50 Department of Defense Fiscal Year (FY) 2025 Budget Estimates, Air Force Justification Book of Research, Development, Test and Evaluation, Volume II, p. 183, at https://www.saffm.hq.af.mil/LinkClick.aspx?fileticket=jQCmIF-YLMg%3d&portalid=84.

51 Valerie Insinna, “US Air Force Kills One of Its Hypersonic Weapons Programs,” Defense News, February 10, 2020, at https://www.defensenews.com/smr/federal-budget/2020/02/10/the-air-force-just-canceled-one-of-its-hypersonic- weapons-programs/.

52 John A. Tirpak, “Roper: The ARRW Hypersonic Missile Better Option for USAF,” Air Force Magazine, March 2, 2020, at https://www.airforcemag.com/arrw-beat-hcsw-because-its-smaller-better-for-usaf/. Tirpak 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.”

53 John A. Tirpak, “Air Force Will Try Again to Launch ARRW Hypersonic Missile in July,” Air Force Magazine, June 3, 2021, at https://www.airforcemag.com/air-force-july-launch-arrw-hypersonic-missile/.

54 According to Air Force budget documents, “the program leverages Southern Cross Integrated Flight Research Experiment (SCIFiRE) investment, a bi-lateral U.S./Australian air-breathing hypersonic cruise missile prototyping effort which is a prelude to HACM.” Department of Defense Fiscal Year (FY) 2025 Budget Estimates, Air Force Justification Book of Research, Development, Test and Evaluation, Volume II, p. 191, at https://www.saffm.hq.af.mil/LinkClick.aspx?fileticket=jQCmIF-YLMg%3d&portalid=84.

55 FY2023 Air Force budget documents note that “the HACM program will prioritize integration on the F-15E platform to enable quick entry into flight test.”

56 John A. Tirpak, “Air Force Will Try Again to Launch ARRW Hypersonic Missile in July,” Air Force Magazine, June 3, 2021, at https://www.airforcemag.com/air-force-july-launch-arrw-hypersonic-missile/.

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contingent upon fully funded and successful predecessor capability development efforts.”⁵⁷ The Air Force requested $517 million for HACM in FY2025, up from the $382 million request in FY2024.⁵⁸

The Air Force is also developing the Expendable Hypersonic Air-Breathing Multi-Mission Demonstrator Program, alternatively known as Project Mayhem. According to then-Principal Director for Hypersonics Mike White, “Project Mayhem is to look at the next step in what the opportunity space allows relative to hypersonic cruise missile systems” and is intended to be capable of flying “significantly longer ranges than what we’re doing today.”⁵⁹ Some reports indicate that Project Mayhem may be developing an uncrewed hypersonic bomber capable of flying at Mach 10 and performing both strike and intelligence, surveillance, and reconnaissance missions.⁶⁰

DARPA

DARPA, in partnership with the Air Force, conducted tests of TBG, a wedge-shaped hypersonic glide vehicle capable of Mach 7+ flight that “[aimed] to develop and demonstrate technologies to enable future air-launched, tactical-range hypersonic boost glide systems.”⁶¹ TBG “also [considered] traceability, compatibility, and integration with the Navy Vertical Launch System” and is planned to transition to both the Air Force and the Navy. DARPA did not request funds for TBG in FY2025, describing the program as “completed.”⁶²

DARPA’s Operational Fires reportedly sought to leverage TBG technologies to develop a ground- launched system that will enable “advanced tactical weapons to penetrate modern enemy air defenses and rapidly and precisely engage critical time sensitive targets.” OpFires completed its first flight test in July 2022.⁶³ The OpFires program concluded in FY2022.⁶⁴

57 Department of Defense Fiscal Year (FY) 2022 Budget Estimates, Air Force Justification Book of Research, Development, Test and Evaluation, Volume II, p. 148, at https://www.saffm.hq.af.mil/Portals/84/documents/FY22/ RDTE_/FY22%20DAF%20J-Book%20-%203600%20-%20AF%20RDT%20and%20E%20Vol%20II.pdf?ver= KpJJbVq68o32dSvkjuv_Iw%3d%3d.

58 Department of Defense Fiscal Year (FY) 2025 Budget Estimates, Air Force Justification Book of Research, Development, Test and Evaluation, Volume II, p. 191, at https://www.saffm.hq.af.mil/LinkClick.aspx?fileticket=jQCmIF-YLMg%3d&portalid=84.

59 Mike White, Remarks at the Center for Strategic and International Studies, “Hypersonic Strike and Defense: A Conversation with Mike White,” June 10, 2021, at https://www.csis.org/analysis/hypersonic-strike-and-defense- conversation-mike-white.

60 See, for example, Darren Orf, “Project Mayhem, the Air Force's Secret Hypersonic Bomber, Has Begun Cooking,” Popular Mechanics, January 20, 2023, at https://www.popularmechanics.com/military/aviation/a42589676/air-forces- secret-hypersonic-bomber-project-mayhem-updates/; and Howard Altman and Joseph Trevithick, “Future Of Mayhem Hypersonic Strike-Recon Aircraft Program Murky,” The War Zone, February 16, 2024, at https://www.twz.com/news- features/future-of-mayhem-hypersonic-strike-recon-aircraft-program-murky.

61 “Tactical Boost Glide (TBG) 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, at https://aviationweek.com/defense/us-air-force-plans-road-map-operational-hypersonics.

62 Department of Defense Fiscal Year (FY) 2025 Budget Estimates, Defense Advanced Research Projects Agency, Defense-Wide Justification Book 1 of 5, p. 167, at https://comptroller.defense.gov/Portals/45/Documents/defbudget/FY2025/budget_justification/pdfs/03_RDT_and_E/R DTE_Vol1_DARPA_MasterJustificationBook_PB_2025.pdf.

63 DARPA, “Operational Fires Program Successfully Completes First Flight Test,” July 13, 2022, at https://www.darpa.mil/news-events/2022-07-13a.

64 Department of Defense Fiscal Year (FY) 2023 Budget Estimates, Defense Advanced Research Projects Agency, Defense-Wide Justification Book 1 of 5, p. 172, at https://comptroller.defense.gov/Portals/45/Documents/defbudget/ fy2023/budget_justification/pdfs/03_RDT_and_E/RDTE_Vol1_DARPA_MasterJustificationBook_PB_2023.pdf.

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DARPA has similarly concluded work on the Hypersonic Air-breathing Weapon Concept (HAWC), which, with Air Force support, sought “to develop and demonstrate critical technologies to enable an effective and affordable air-launched hypersonic cruise missile.”⁶⁵ DARPA successfully tested HAWC in March and July 2022 and in January 2023, launching the missile from a B-52 bomber.⁶⁶ Former Principal Director for Hypersonics Mike White has stated that hypersonic cruise missiles like HAWC would be smaller than hypersonic glide vehicles and could therefore launch from a wider range of platforms. Former Principal Director White has additionally noted that HAWC and other hypersonic cruise missiles could integrate seekers more easily than hypersonic glide vehicles.⁶⁷ HAWC’s successor program, More Opportunities with HAWC (MOHAWC), similarly sought to develop technologies for use in future air-launched hypersonic cruise missiles.⁶⁸ DARPA did not request funds for MOHAWC in FY2025, describing the program as “completed.”⁶⁹

Table 1. Summary of Selected U.S. Hypersonic Weapons RDT&E Funding

Title

FY2024 Request

($ in millions)

FY2024 Enacted

($ in millions)

PB2025

($ in millions) Schedule

Conventional Prompt Strike (CPS)

901 901 904 Platform deployment in FY2025

Hypersonic Air- Launched OASuW (HALO)

96 96 179 Achieve early operational capability by FY2029

Long-Range Hypersonic Weapon (LRHW)

943 943 538 Field two operational batteries by FY2027

Hypersonic Attack Cruise Missile (HACM)

382 382 517 Complete test and development in FY2027; continue follow-on development through FY2029

Source: Program information taken from U.S. Navy, Army, Air Force, and DARPA FY2024 and FY2025 Justification Books, available at https://comptroller.defense.gov/Budget-Materials/. Note: MOHAWC, a new start in FY2023, is the successor program to HAWC, which concluded in 2023.

65 “Hypersonic Air-breathing Weapon Concept (HAWC) Program Information,” DARPA, at https://www.darpa.mil/ program/hypersonic-air-breathing-weapon-concept.

66 Oren Liebermann, “US Tested Hypersonic Missile in mid-March but Kept It Quiet to Avoid Escalating Tensions with Russia,” CNN, April 5, 2022, at https://us.cnn.com/2022/04/04/politics/us-hypersonic-missile-test/index.html; Courtney Albon, “Raytheon Hypersonic Scramjet Missile Has Another Successful Flight Test,” Defense News, July 19, 2022, at https://www.defensenews.com/battlefield-tech/2022/07/19/darpas-hypersonic-scramjet-missile-logs-another- flight-test-success/?utm_source=sailthru&utm_medium=email&utm_campaign=dfn-ebb&SToverlay=2002c2d9-c344- 4bbb-8610-e5794efcfa7d; and DARPA, “Final Flight of HAWC Program Screams Through the Sky,” January 30, 2023, at https://www.darpa.mil/news-events/2023-01-30.

67 “Department of Defense Press Briefing on Hypersonics,” March 2, 2020, at https://www.defense.gov/Newsroom/ Transcripts/Transcript/Article/2101062/department-of-defense-press-briefing-on-hypersonics/.

68 Ibid.

69 Department of Defense Fiscal Year (FY) 2025 Budget Estimates, Defense Advanced Research Projects Agency, Defense-Wide Justification Book 1 of 5, p. 168, at https://comptroller.defense.gov/Portals/45/Documents/defbudget/FY2025/budget_justification/pdfs/03_RDT_and_E/R DTE_Vol1_DARPA_MasterJustificationBook_PB_2025.pdf.

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Table 2. Summary of U.S. Hypersonic Weapons Procurement Funding

Title

FY2024 Request

($ in millions)

FY2024 Enacted

($ in millions)

PB2025

($ in millions) Status

CPS 341 341 0 FY2024 request was

to procure eight

AURs

LRHW 157 157 744 Request would

procure LRHW ground support

equipment and eight

AURs plus canister

Source: Program information taken from U.S. Navy and Army FY2024 and FY2025 Justification Books, available at https://comptroller.defense.gov/Budget-Materials/.

Hypersonic Missile Defenses⁷⁰

DOD is also investing in counter-hypersonic weapons capabilities. In September 2018, MDA— which in 2017 established a Hypersonic Defense Program pursuant to Section 1687 of the FY2017 NDAA (H.Rept. 114-840)—commissioned 21 white papers to explore hypersonic missile defense options, including interceptor missiles, hypervelocity projectiles, laser guns, and electronic attack systems.⁷¹ In January 2020, MDA issued a draft request for prototype proposals for a Hypersonic Defense Regional Glide Phase Weapons System interceptor intended to be fielded in the mid-2030s; however, the program was later cancelled in favor of an alternative solution, the Glide Phase Intercept (GPI).⁷² According to MDA FY2024 budget documents, the agency sought to field a regional, sea-based GPI capability in FY2034.⁷³ Section 1666 of the FY2024 NDAA (P.L. 118-31) directed MDA to accelerate this timeline to achieve initial operational capability by December 31, 2029, and full operational capability by December 31, 2032; however, MDA’s FY2025 budget documents state that GPI is to be delivered in FY2035.⁷⁴ On May 15, 2024, MDA announced that it had formalized a Cooperative Development Project Arrangement to co-develop GPI with Japan.⁷⁵

70 For additional information about hypersonic missile defense, see CRS In Focus IF11623, Hypersonic Missile Defense: Issues for Congress, by Jennifer DiMascio and Kelley M. Sayler.

71 H.Rept. 114-840, Section 2, Division A, Title XVI, §1687; Hudson and Trimble, “Top U.S. Hypersonic Weapon Program”; and Steve Trimble, “A Hypersonic Sputnik?,” p. 21.

72 Missile Defense Agency, “Draft Request for Prototype Proposal: Hypersonic Defense Regional Glide Phase Weapon System,” January 30, 2020, p. 8; and Steve Trimble, “MDA Unveils GPI In Retooled Counter-Hypersonic Plan,” Aviation Week, February 4, 2021, at https://aviationweek.com/defense-space/missile-defense-weapons/mda-unveils- gpi-retooled-counter-hypersonic-plan.

73 Steve Trimble, “MDA Unveils GPI In Retooled Counter-Hypersonic Plan,” Aviation Week, February 4, 2021, at https://aviationweek.com/defense-space/missile-defense-weapons/mda-unveils-gpi-retooled-counter-hypersonic-plan.

74 Department of Defense Fiscal Year (FY) 2025 Budget Estimates, Missile Defense Agency, Defense-Wide Justification Book 2a of 5, pp. 643, at https://comptroller.defense.gov/Portals/45/Documents/defbudget/FY2025/budget_justification/pdfs/03_RDT_and_E/R DTE_Vol2_MDA_RDTE_PB25_Justification_Book.pdf.

75 Per the arrangement, MDA is to “provide hypersonic missile defense capability during the glide-phase portion of hypersonic flight,” while Japan is to “lead development of rocket motors and propulsion components of GPI.” DOD, “U.S. Department of Defense Statement on the Signing of the Glide Phase Interceptor Cooperative Development,” May 15, 2024, at https://www.defense.gov/News/Releases/Release/Article/3775546/us-department-of-defense-statement-on- the-signing-of-the-glide-phase-intercepto/.

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In addition, MDA is developing the Hypersonic and Ballistic Tracking Space Sensor (HBTSS) in an effort to improve the agency’s ability to detect and track incoming missiles.⁷⁶ MDA requested $76 million for HBTSS in FY2025 and $182.3 million for hypersonic defense.⁷⁷ Finally, DARPA is working on a program called Glide Breaker, which “will develop critical component technology to support a lightweight vehicle designed for precise engagement of hypersonic threats at very long range.”⁷⁸ DARPA requested $38 million for Glide Breaker in FY2025.⁷⁹

Infrastructure

According to a study mandated by the FY2013 National Defense Authorization Act (P.L. 112- 239) and conducted by the Institute for Defense Analyses (IDA),⁸⁰ 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 2030.⁸¹ These specialized facilities, which simulate the unique conditions experienced in hypersonic flight (e.g., speed, pressure, heating),⁸² included 10 DOD hypersonic ground test facilities, 11 DOD open-air ranges, 11 DOD mobile assets, 9 National Aeronautics and Space Administration (NASA) facilities, 2 Department of Energy (DOE) facilities, and 5 industry or academic facilities.⁸³ In its 2014 evaluation of U.S. hypersonic test and evaluation infrastructure, 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 characteristics above Mach 8.”

Since the 2014 study report was published, there have been a number of changes in U.S. hypersonic test infrastructure. For example, the University of Notre Dame has opened Mach 6 and Mach 10 quiet wind tunnels, Purdue University has opened a Mach 8 quiet wind tunnel, and

76 Department of Defense Fiscal Year (FY) 2023 Budget Estimates, Missile Defense Agency, Defense-Wide Justification Book 2a of 5, p. 841, at https://comptroller.defense.gov/Portals/45/Documents/defbudget/fy2023/ budget_justification/pdfs/03_RDT_and_E/RDTE_Vol2_MDA_RDTE_PB23_Justification_Book.pdf; and Defense Budget Overview: United States Department of Defense Fiscal Year 2023 Budget Request, Office of the Under Secretary of Defense (Comptroller)/Chief Financial Officer, April 2022, p. 2-15, at https://comptroller.defense.gov/ Portals/45/Documents/defbudget/FY2023/FY2023_Budget_Request_Overview_Book.pdf; and Sandra Erwin, “Pentagon agencies team up in upcoming launch of hypersonic tracking satellites,” Space News, December 28, 2023, at https://spacenews.com/pentagon-agencies-team-up-in-upcoming-launch-of-hypersonic-tracking-satellites/.

77 Department of Defense Fiscal Year (FY) 2025 Budget Estimates, Missile Defense Agency, Defense-Wide Justification Book 2a of 5, pp. 643 and 852, at https://comptroller.defense.gov/Portals/45/Documents/defbudget/FY2025/budget_justification/pdfs/03_RDT_and_E/R DTE_Vol2_MDA_RDTE_PB25_Justification_Book.pdf.

78 Department of Defense Fiscal Year (FY) 2021 Budget Estimates, Defense Advanced Research Projects Agency, Defense-Wide Justification Book 1 of 5, p. 164.

79 Department of Defense Fiscal Year (FY) 2025 Budget Estimates, Defense Advanced Research Projects Agency, Defense-Wide Justification Book 1 of 5, p. 160, at https://comptroller.defense.gov/Portals/45/Documents/defbudget/FY2025/budget_justification/pdfs/03_RDT_and_E/R DTE_Vol1_DARPA_MasterJustificationBook_PB_2025.pdf.

80 P.L. 112-239, Section 2, Division A, Title X, §1071.

81 A more recent report by the Government Accountability Office states that there are “26 DOD, DOE, NASA, and private U.S. wind tunnel facilities capable of supporting hypersonic research.” Government Accountability Office, Hypersonic Weapons: DOD Should Clarify Roles and Responsibilities to Ensure Coordination Across Development Efforts, GAO-21-378, March 22, 2021, p. 15, at https://www.gao.gov/products/gao-21-378.

82 These conditions additionally require the development of specialized materials such as metals and ceramics.

83 This 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 Systems Development: Summary Analysis and Assessment, Institute for Defense Analyses, September 2014. Permission to use this material has been granted by the Office of Science and Technology Policy.

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at least one hypersonic testing facility has been inactivated.⁸⁴ In addition, the University of Arizona modified one of its wind tunnels to enable Mach 5 testing, while Texas A&M University—in partnership with Army Futures Command—is constructing a kilometer-long Mach 10 wind tunnel.⁸⁵ 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.⁸⁶ (For an illustrative list of U.S. hypersonic test assets and their capabilities, see the Appendix.)

In February 2022, DOD’s Office of Inspector General announced that it had concluded its two- year-long evaluation of current ground test and evaluation facilities to determine if the capability and capacity would be sufficient to execute DOD’s planned test schedule; however, DOD did not release the evaluation to the public.⁸⁷ Similarly, the FY2022 Director, Operational Test & Evaluation (DOT&E) Annual Report evaluated the sufficiency of U.S. hypersonic weapons test infrastructure.⁸⁸ The DOT&E report concluded that “additional missile test range modernization efforts are needed to support an increase in the tempo of testing and the development of new capabilities to measure hypersonic missile flight performance in increasingly complex threat environments.”⁸⁹ Congress appropriated $47.5 million to USD(R&E) and DOT&E in FY2022 for hypersonic test infrastructure; however, the FY2023 DOT&E Annual Report notes that at least one hypersonic weapon program’s “flight test schedule [was still] continually challenged due to the limited availability and numbers of hypersonic flight corridors, target areas, and test support assets.”⁹⁰ Congress may consider whether additional funds would be required to address DOT&E’s FY2022 recommendation.

DOD reportedly plans to expand hypersonic test infrastructure in the coming years. In January 2019, the Navy announced plans to reactivate its Launch Test Complex at China Lake, CA, to

84 Jessica Sieff, “University of Notre Dame Adds Two New Hypersonics Research Facilities,” Notre Dame News, June 6, 2022, at https://news.nd.edu/news/university-of-notre-dame-adds-two-new-hypersonics-research-facilities/; and Evamarie Socha, “Purdue Applied Research Institute Opens $41M Hypersonics and Applied Research Facility,” Purdue University News, June 7, 2023, at https://www.purdue.edu/newsroom/releases/2023/Q2/purdue-applied- research-institute-opens-41m-hypersonics-and-applied-research-facility.html.

85 University of Arizona, “Mach 5 Quiet Ludwieg Tube,” at https://transition.arizona.edu/facilities/qlt5?_ga= 2.62515882.768526379.1582843192-983632914.1582843192; and Ashley Tressel, “Army to Open Hypersonic Testing Facility at Texas 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, the California Institute of Technology, the Georgia Institute of Technology, the Air Force Academy, the University of Tennessee, and Virginia Polytechnic Institute and State University also maintain experimental hypersonic facilities or conduct hypersonic research.

86 (U//FOUO) Paul F. Piscopo et al., (U) Study on the Ability of the U.S. Test and Evaluation Infrastructure. For example, the Government Accountability Office reports that HACM is to be tested “both in Australia from Australian Air Force F-18s, and in the United States from F-15Es.” See Government Accountability Office, Hypersonic Weapons: DOD Could Reduce Cost and Schedule Risks by Following Leading Practices, July 2024, p. 14, at https://www.gao.gov/assets/gao-24-106792.pdf.

87 See Department of Defense Office of Inspector General, “Memorandum for Distribution: Evaluation of the Ground Test and Evaluation Infrastructure Supporting Hypersonic Capabilities (Project No. D2020-DEV0SN-0106.000),” April 13, 2020, at https://media.defense.gov/2020/Apr/14/2002280826/-1/-1/1/D2020-DEV0SN-0106.000.PDF; and Department of Defense Office of Inspector General,” Evaluation of the Ground Test and Evaluation Infrastructure Supporting Hypersonic Capabilities (DODIG-2022-056),” February 3, 2022, at https://www.dodig.mil/reports.html/ Article/2921419/evaluation-of-the-ground-test-and-evaluation-infrastructure-supporting-hyperson/.

88 DOT&E, FY2022 DOT&E Annual Report, January 2023, pp. 18-19, at https://www.dote.osd.mil/Portals/97/pub/ reports/FY2022/FY22DOTEAnnualReport.pdf?ver=UBO7t2O1FkRuvrB-nJDZ-g%3d%3d.

89 Ibid., p. 18.

90 Ibid., p. 19; and DOT&E, FY2022 DOT&E Annual Report, January 2024, pp. 18-19, at https://www.dote.osd.mil/ Portals/97/pub/reports/FY2023/other/2023annual-report.pdf?ver=d7gusiIrcbYmxM0oDkPSFg%3d%3d.

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improve air launch and underwater testing capabilities for the CPS program.⁹¹ DOD has also announced the development of the Multi-Service Advanced Capability Hypersonics Test Bed (MACH-TB), which is to “increase domestic capacity for hypersonic flight testing and leverage multiple commercially-available launch vehicles for ride-along hypersonic payloads.”⁹² DOD successfully tested components of MACH-TB in November 2023.⁹³ According to an assessment conducted by the Government Accountability Office, DOD has dedicated approximately $1 billion to hypersonic facility modernization from FY2015 to FY2024.⁹⁴

Congress has also continued to express interest in hypersonic weapons infrastructure. Section 222 of the FY2021 NDAA (P.L. 116-283) required the Under Secretary of Defense for Research and Engineering, in consultation with the Director of Operational Test and Evaluation, to submit to the congressional defense committees “an assessment of the sufficiency of the testing capabilities and infrastructure used for fielding hypersonic weapons, and a description of any investments in testing capabilities and infrastructure that may be required to support in-flight and ground-based testing for such weapons.”⁹⁵ Section 225 of the FY2022 NDAA (P.L. 117-81) requires the Secretary of Defense to identify the hypersonic facilities and capabilities of the Major Range and Test Facility Base and brief the congressional defense committees on a plan for improvement. Similarly, Section 237 of the FY2023 NDAA (P.L. 117-263) directs the Secretary of Defense to both assess DOD’s capacity to test and evaluate hypersonic capabilities and “[identify] test facilities outside the Department of Defense that have potential to be used to expand [DOD] capacity ... including test facilities of other departments and agencies of the Federal Government, academia, and commercial test facilities.” Section 218 of the FY2024 NDAA (P.L. 118-31) directs the Secretary to update this assessment at least once every two years. It additionally directs the Secretary to conduct a study to evaluate at least two possible locations in the United States that “have potential to be used as additional corridors for long-distance hypersonic system testing” and to submit to the congressional defense committees an annual report on DOD funding and investments in hypersonic capabilities.

Finally, 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

91 “Update: US Navy to Develop China Lake to Support CPS Weapon Testing,” Jane’s (subscription required), February 12, 2019, at https://janes.ihs.com/Janes/Display/FG_1644858-JMR.

92 U.S. Department of Defense, “DoD Announces New Contract to Increase Hypersonic Flight Testing Tempo,” October 6, 2022, at https://www.defense.gov/News/Releases/Release/Article/3182305/dod-announces-new-contract-to- increase-hypersonic-flight-testing-tempo/. According to a Dynetics press release, Dynetics is to lead a MACH-TB team composed of over 20 partners, including Peraton, Kratos Defense & Security Solutions, Stratolaunch, JRC Integrated Systems, NineTwelve Institute, Corvid, SpinLaunch, Varda, Kitty Hawk Technologies, Systima Division of Karman Space and Defense, Sandia National Laboratories, Oak Ridge National Laboratory, X-Bow Systems, RLNS and other hypersonic experts. See PRNewswire, “Dynetics Awarded New Contract to Increase Hypersonic Flight Testing Tempo,” October 20, 2022, at https://www.prnewswire.com/news-releases/dynetics-awarded-new-contract-to-increase- hypersonic-flight-testing-tempo-301654753.html.

93 U.S. Navy, “Department of Defense Demonstrates Advanced Hypersonic Technologies,” November 16, 2023, at https://www.navy.mil/Press-Office/News-Stories/Article/3591504/department-of-defense-demonstrates-advanced- hypersonic-technologies/.

94 Government Accountability Office, Hypersonic Weapons: DOD Should Clarify Roles and Responsibilities to Ensure Coordination Across Development Efforts, GAO-21-378, March 22, 2021, p. 27, at https://www.gao.gov/products/gao- 21-378.

95 This report was delivered to the committees on December 16, 2021.

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chain.⁹⁶ DOD has also amended its “5000 series” acquisition policy in order to enhance supply chain resiliency and reduce sustainment costs.⁹⁷

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-Ballistic Missile Treaty in 2001.⁹⁸ Detailing Russia’s concerns, President Putin stated that “the US is permitting constant, uncontrolled growth of the number of anti-ballistic missiles, improving their quality, and creating new missile launching areas. If we do not do something, eventually this will result in the complete devaluation of Russia’s nuclear potential. Meaning that all of our missiles could simply be intercepted.”⁹⁹ 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.¹⁰⁰

Programs

Russia is pursuing two hypersonic weapons programs—the Avangard and the 3M22 Tsirkon (or Zircon)—and has reportedly fielded the Kinzhal (“Dagger”), a maneuvering air-launched ballistic missile.¹⁰¹

Avangard (Figure 2) is a hypersonic glide vehicle launched from an intercontinental ballistic missile (ICBM), giving it “effectively ‘unlimited’ range.”¹⁰² Reports indicate that Avangard is currently deployed on the SS-19 Stiletto ICBM, though Russia plans to eventually launch the vehicle from the Sarmat ICBM. Sarmat reportedly entered combat duty in September 2023.¹⁰³ Avangard features onboard countermeasures and will reportedly carry a nuclear warhead. It was

96 Aaron Mehta, “Pentagon Launches Hypersonic Industrial Base Study,” Defense News, March 3, 2020, at https://www.defensenews.com/pentagon/2020/03/02/pentagon-launches-hypersonic-industrial-base-study/.

97 C. Todd Lopez, “Rewrite of Acquisition Regulation Helps U.S. Build Hypersonic Arsenal More Quickly,” DOD News, October 30, 2020, at https://www.defense.gov/Explore/News/Article/Article/2400205/rewrite-of-acquisition- regulation-helps-us-build-hypersonic-arsenal-more-quickly/.

98 United Nations Office of Disarmament Affairs, Hypersonic Weapons: A Challenge and Opportunity for Strategic Arms Control, February 2019, at https://www.un.org/disarmament/publications/more/hypersonic-weapons-a-challenge- and-opportunity-for-strategic-arms-control/.

99 Vladimir Putin, “Presidential Address to the Federal Assembly,” March 1, 2018, at http://en.kremlin.ru/events/ president/news/56957.

100 In this instance, “strategic stability” refers to a “bilateral nuclear relationship of mutual vulnerability.” See Tong Zhao, “Conventional Challenges to Strategic Stability: Chinese Perceptions of Hypersonic Technology and the Security Dilemma,” Carnegie-Tsinghua Center for Global Policy, July 23, 2018, at https://carnegietsinghua.org/2018/07/23/ conventional-challenges-to-strategic-stability-chinese-perceptions-of-hypersonic-technology-and-security-dilemma- pub-76894.

101 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.

102 Steve Trimble, “A Hypersonic Sputnik?,” Aviation Week, January 14-27, 2019, p. 20.

103 Al Jazeera, “Russia Puts Advanced Sarmat Nuclear Missile System on ‘Combat Duty,’” September 2, 2023, at https://www.aljazeera.com/news/2023/9/2/russia-puts-advanced-sarmat-nuclear-missile-system-on-combat- duty#:~:text=Russia%20test%2Dfired%20the%20Sarmat,in%20Russia's%20far%20east%20region. Sarmat could reportedly accommodate at least three Avangard vehicles. See Malcolm Claus, “Russia unveils new strategic delivery systems,” Jane’s (subscription required), at https://janes.ihs.com/Janes/Display/FG_899127-JIR.

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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 2019.¹⁰⁴

Figure 2. Artist Rendering of Avangard

Source: https://janes.ihs.com/Janes/Display/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 maximum range of approximately 625 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.¹⁰⁵ These sources assert that Tsirkon was successfully launched from a Project 22350 frigate in January, October, and December 2020 and May 2022 and from a Project 885 Yasen-class submarine in October 2021.¹⁰⁶ Russia reportedly deployed Tsirkon on the Project 22350 frigate Admiral of the Fleet of the Soviet Union Gorshkov in January 2023 and first launched the missile into Ukraine in February 2024.¹⁰⁷

In addition, Russia has fielded Kinzhal, a maneuvering air-launched ballistic missile modified from the Iskander missile. Russia reportedly fired Kinzhal from a MiG-31 interceptor aircraft in

104 “First Regiment of Avangard Hypersonic Missile Systems Goes on Combat Duty in Russia,” TASS, December 27, 2019, at https://tass.com/defense/1104297.

105 “Russia Makes over 10 Test Launches of Tsirkon Seaborne Hypersonic Missile,” TASS, December 21, 2018, at http://tass.com/defense/1037426. See also Russia Military Power: Building a Military to Support Great Power Aspirations, Defense Intelligence Agency, 2017, p. 79, at https://www.dia.mil/portals/27/documents/news/ military%20power%20publications/russia%20military%20power%20report%202017.pdf.

106 “TASS: Russia Conducts First Ship-Based Hypersonic Missile Test,” Reuters, February 27, 2020, at https://www.voanews.com/europe/tass-russia-conducts-first-ship-based-hypersonic-missile-test; Samuel Cranny-Evans, “Russia conducts first submarine test launches of Tsirkon hypersonic missile,” Jane’s (subscription required), October 4, 2021; and Isabel van Brugen, “Putin to Give Navy Hypersonic Missiles as Russia Beats U.S. in Arms Race,” Newsweek, July 18, 2022, at https://www.newsweek.com/putin-russian-navy-hypersonic-missiles-zircon-1725426.

107 Guy Faulconbridge, “Putin Deploys New Zircon Hypersonic Cruise Missiles to Atlantic,” Reuters, January 4, 2023, at https://www.reuters.com/world/europe/putin-sends-off-frigate-armed-with-new-hypersonic-cruise-missile-2023-01- 04/; and Brad Lendon, “Russia used an advanced hypersonic missile for the first time in recent strike, Ukraine claims,” CNN, February 13, 2024, at https://www.cnn.com/2024/02/13/europe/ukraine-russia-zircon-hypersonic-missile-intl- hnk-ml/index.html.

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Ukraine¹⁰⁸ and additionally plans to deploy the missile on the Su-34 long-range strike fighter¹⁰⁹ and the Tu-22M3 strategic bomber, although the slower-moving bomber may face challenges in “accelerating the weapon into the correct launch parameters.”¹¹⁰ 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 as of striking both ground and naval targets, and could eventually be fitted with a nuclear warhead. However, such claims regarding Kinzhal’s performance characteristics have not been publicly verified by U.S. intelligence agencies, and have been met with skepticism by a number of analysts.¹¹¹

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.¹¹²

China

According to Tong Zhao, a fellow at the Carnegie-Tsinghua Center for Global Policy, “most 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,” such as U.S. missile defenses.¹¹³ 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 conduct a retaliatory strike against the United States.¹¹⁴

As General Terrence O’Shaughnessy, then-commander of United States Northern Command (USNORTHCOM) and North American Aerospace Defense Command (NORAD), testified in a February 2020 hearing before the Senate Armed Services Committee, China is “testing a [nuclear-capable] intercontinental-range hypersonic glide vehicle” that could evade U.S. missile

108 Roxana Tiron, “Hypersonic Weapons: Who Has Them and Why It Matters,” Washington Post, April 6, 2022, at https://www.washingtonpost.com/business/hypersonic-weapons-who-has-them-and-why-it-matters/2022/04/05/ 1f6d0280-b557-11ec-8358-20aa16355fb4_story.html.

109 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.

110 Dave Majumdar, “Russia: New Kinzhal Aero-Ballistic Missile Has 3,000 km Range If Fired from Supersonic Bomber,” The National Interest, July 18, 2018, at https://nationalinterest.org/blog/buzz/russia-new-kinzhal-aero- ballistic-missile-has-3000-km-range-if-fired-supersonic-bomber.

111 David Axe, “Is Kinzhal, Russia’s New Hypersonic Missile, a Game Changer?,” The Daily Beast, March 15, 2018, at https://www.thedailybeast.com/is-kinzhal-russias-new-hypersonic-missile-a-game-changer.

112 “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, at 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, at http://russianforces.org/blog/2018/12/ avangard_system_is_tested_said.shtml.

113 Tong Zhao, “Conventional Challenges to Strategic Stability: Chinese Perceptions of Hypersonic Technology and the Security Dilemma.”

114 Tong Zhao, “Conventional Challenges to Strategic Stability”; and Lora Saalman, “China’s Calculus on Hypersonic Glide,” Stockholm International Peace Research Institute, August 15, 2017, at https://www.sipri.org/commentary/ topical-backgrounder/2017/chinas-calculus-hypersonic-glide.

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defense and warning systems.¹¹⁵ Reports additionally indicate that China may have tested a nuclear-capable hypersonic glide vehicle¹¹⁶—launched by a Long March rocket—in August 2021.¹¹⁷ In contrast to the ballistic missiles that China has previously used to launch hypersonic glide vehicles, the Long March, a fractional orbital bombardment system (FOBS), launches the hypersonic glide vehicle into orbit before the hypersonic glide vehicle deorbits to its target. This could provide China with a space-based global strike capability and further reduce the amount of target warning time prior to a strike.¹¹⁸

China has also demonstrated a growing interest in Russian advances in hypersonic weapons technology, conducting flight tests of a hypersonic glide vehicle only days after Russia tested its own system.¹¹⁹ Furthermore, a January 2017 report found that over half of open-source Chinese papers on hypersonic weapons include references to Russian weapons programs.¹²⁰ 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 conventionally armed hypersonic glide vehicles with the DF-21 and DF-26 ballistic missiles in support of an anti- access/area denial strategy.¹²¹

Programs

China has conducted a number of successful tests of the DF-17, a medium-range ballistic missile specifically designed to launch hypersonic glide vehicles. U.S. intelligence analysts assess that the missile has a range of approximately 1,000 to 1,500 miles and may now be deployed.¹²² China has also tested the DF-41 ICBM, which could be modified to carry a conventional or nuclear hypersonic glide vehicle, 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.¹²³

115 General Terrence J. O’Shaughnessy, “Statement Before the Senate Armed Services Committee,” February 13, 2020, at https://www.armed-services.senate.gov/hearings/20-02-13-united-states-northern-command-and-united-states- strategic-command.

116 It is not clear if this nuclear-capable hypersonic glide vehicle is the same model as that referenced by General O’Shaughnessy.

117 Demetri Sevastopulo and Kathrin Hille, “China Tests New Space Capability with Hypersonic Missile,” October 16, 2021, at https://www.ft.com/content/ba0a3cde-719b-4040-93cb-a486e1f843fb. China’s Foreign Ministry Spokesperson Zhao Lijian has stated that “this was a routine test of [a] space vehicle,” rather than a test of a nuclear-capable hypersonic glide vehicle. Zhao Lijian, “Remarks at Regular Press Conference,” Ministry of Foreign Affairs of the People’s Republic of China, October 18, 2021, at https://www.fmprc.gov.cn/mfa_eng/xwfw_665399/s2510_665401/ t1915130.shtml.

118 Greg Hadley, “Kendall: China Has Potential to Strike Earth from Space,” Air Force Magazine, September 20, 2021, at https://www.airforcemag.com/global-strikes-space-china-frank-kendall/.

119 Lora Saalman, “China’s Calculus on Hypersonic Glide.”

120 Lora Saalman, “Factoring Russia into the US-China Equation on Hypersonic Glide Vehicles,” SIPRI, January 2017, at https://www.sipri.org/sites/default/files/Factoring-Russia-into-US-Chinese-equation-hypersonic-glide-vehicles.pdf.

121 Lora Saalman, “China’s Calculus on Hypersonic Glide”; and Malcolm Claus and Andrew Tate, “Chinese Hypersonic Programme Reflects Regional Priorities,” Jane’s (subscription required), March 12, 2019, at https://janes.ihs.com/Janes/Display/FG_1731069-JIR.

122 Ankit Panda, “Introducing the DF-17: China’s Newly Tested Ballistic Missile Armed with a Hypersonic Glide Vehicle,” The National Interest, December 28, 2017, at 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 Times, October 2, 2019, at https://www.washingtontimes.com/news/2019/oct/2/china-shows-df- 17-hypersonic-missile/.

123 U.S.-China Economic and Security Review Commission 2018 Annual Report, p. 235, at https://www.uscc.gov/sites/ default/files/annual_reports/2018%20Annual%20Report%20to%20Congress.pdf.

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China has tested the DF-ZF hypersonic glide vehicle (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 vehicle may be capable of performing “extreme maneuvers” during flight.¹²⁴ China reportedly fielded the DF-ZF in 2020.¹²⁵

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 2018.¹²⁶ China claims the vehicle reached top speeds of Mach 6 and executed a series of in-flight maneuvers before landing.¹²⁷ Unlike the DF-ZF, Starry Sky-2 is a “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 2025.¹²⁸ U.S. officials have declined to comment on the program.¹²⁹

Infrastructure

China has a robust research and development infrastructure devoted to hypersonic weapons. Then-USD(R&E) Michael Griffin stated in March 2018 that China has conducted 20 times as many hypersonic tests as the United States.¹³⁰ China tested three hypersonic vehicle models (D18-1S, D18-2S, and D18-3S)—each with different aerodynamic properties—in September 2018.¹³¹ 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.¹³²

124 “Gliding Missiles That Fly Faster Than Mach 5 Are Coming,” The Economist, April 6, 2019, at 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 Tests New Weapon Capable of Breaching US Missile Defense Systems,” The Diplomat, April 28, 2016, at https://thediplomat.com/2016/04/china-tests-new-weapon-capable-of-breaching-u-s- missile-defense-systems/.

125 Department of Defense, Military and Security Developments Involving the People’s Republic of China 2021, p. 60, at https://media.defense.gov/2021/Nov/03/2002885874/-1/-1/0/2021-CMPR-FINAL.PDF.

126 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, at https://media.defense.gov/2019/May/02/2002127082/-1/-1/1/ 2019_CHINA_MILITARY_POWER_REPORT.pdf.

127 Jessie Yeung, “China Claims to Have Successfully Tested Its First Hypersonic Aircraft,” CNN, August 7, 2018, at https://www.cnn.com/2018/08/07/china/china-hypersonic-aircraft-intl/index.html.

128 U.S.-China Economic and Security Review Commission Report 2015, p. 20.

129 Bill Gertz, “China Reveals Test of New Hypersonic Missile,” The Washington Free Beacon, August 10, 2018, at https://freebeacon.com/national-security/chinas-reveals-test-new-hypersonic-missile/.

130 U.S.-China Economic and Security Review Commission Report 2015, p. 20.

131 Malcolm Claus and Andrew Tate, “Chinese Hypersonic Programme Reflects Regional Priorities,” Jane’s (subscription required), March 12, 2019, at https://janes.ihs.com/Janes/Display/FG_1731069-JIR.

132 Jeffrey Lin and P.W. Singer, “China’s Hypersonic Military Projects Include Spaceplanes and Rail Guns,” Popular Mechanics, June 26, 2018, at https://www.popsci.com/chinas-hypersonic-work-speeds-up.

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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.”¹³³ For example, the China Aerodynamics Research and Development Center claims to have 18 wind tunnels, while the China Academy of Aerospace Aerodynamics is known to operate at least three hypersonic wind tunnels—the FD-02, FD-03, and FD-07—capable of reaching speeds of Mach 8, Mach 10, and Mach 12, respectively.¹³⁴ 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 15.¹³⁵ It reportedly completed construction of the JF-22 wind tunnel, capable of reaching speeds of Mach 30, in 2023.¹³⁶ In addition, China is known to have tested hypersonic weapons at the Jiuquan Satellite Launch Center and the Taiyuan Satellite Launch Center.

133 Andrew Tate, “China Conducts Further Tests with Hypersonic Vehicles,” Jane’s Defence Weekly (subscription required), October 2, 2018, at https://customer.janes.com/DefenceWeekly/Display/FG_1120806-JDW.

134 Kelvin Wong, “China Claims Successful Test of Hypersonic Waverider,” Jane’s (subscription required), August 10, at 2018, https://janes.ihs.com/Janes/Display/FG_1002295-JDW; and Ellen Nakashima and Gerry Shih, “China Builds Advanced Weapons Systems Using American Chip Technology,” Washington Post, April 9, 2021.

135 Jeffrey Lin and P.W. Singer, “A Look at China’s Most Exciting Hypersonic Aerospace Programs,” Popular Science, April 18, 2017, at https://www.popsci.com/chinas-hypersonic-technology.

136 Akhil Kadidal, “Chinese Hypersonic Wind Tunnel Passes Acceptance Check,” Janes Defence Weekly (subscription required), June 8, 2023, at https://www.janes.com/defence-news/news-detail/chinese-hypersonic-wind-tunnel-passes- acceptance-check.

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Global Hypersonic Weapons Programs

Although the United States, Russia, and China possess the most advanced hypersonic weapons programs, a number of other countries—including Australia, India, France, Germany, South Korea, North Korea, and Japan— are also developing hypersonic weapons technology. Since 2007, the United States has collaborated with Australia on the Hypersonic International Flight Research Experimentation (HIFiRE) program to develop hypersonic technologies. The most recent HIFiRE test, successfully conducted in July 2017, explored the flight dynamics of a Mach 8 hypersonic glide vehicle, while previous tests explored scramjet engine technologies. HIFiRE’s successor, the Southern Cross Integrated Flight Research Experiment (SCIFiRE) program, is to further develop hypersonic air-breathing technologies. SCIFiRE demonstration tests are expected by the mid-2020s. In addition to the Woomera Test Range facilities—one of the largest weapons test facilities in the world—Australia reportedly operates seven hypersonic wind tunnels and is capable of testing speeds of up to Mach 30. India has similarly collaborated with Russia on the development of BrahMos II, a Mach 7 hypersonic cruise missile. Although BrahMos II was initially intended to be fielded in 2017, news reports indicate that the program faces significant delays and is now scheduled to achieve initial operational capability between 2025 and 2028. Reportedly, India is also developing an indigenous, dual-capable hypersonic cruise missile as part of its Hypersonic Technology Demonstrator Vehicle program and successfully tested a Mach 6 scramjet in June 2019 and September 2020. India operates approximately 12 hypersonic wind tunnels and is capable of testing speeds of up to Mach 13. France also has collaborated and contracted with Russia on the development of hypersonic technology. Although France has been investing in hypersonic technology research since the 1990s, it has only recently announced its intent to weaponize the technology. Under the V-max (Experimental Maneuvering Vehicle) program, France is modifying its air-to-surface ASN4G supersonic missile for hypersonic flight, successfully testing the modified missile in June 2023. Some analysts believe that the V-max program is intended to provide France with a strategic nuclear weapon. France operates five hypersonic wind tunnels and is capable of testing speeds of up to Mach 21. Germany successfully tested an experimental hypersonic glide vehicle (SHEFEX II) in 2012; however, reports indicate that Germany may have pulled funding for the program. German defense contractor DLR continues to research and test hypersonic vehicles as part of the European Union’s ATLLAS II project, which seeks to design a Mach 5-6 vehicle. Germany operates three hypersonic wind tunnels and is capable of testing speeds of up to Mach 11. In addition, South Korea reportedly has been developing a ground-launched Mach 6+ hypersonic cruise missile, Hycore, since 2018. According to Janes, South Korea is developing the missile “in response to growing concern about North Korea military modernization” and plans to eventually develop sea- and air-launched variants. Although North Korea tested the Hwasong-8—which it identifies as a hypersonic glide vehicle—in September 2021, reports indicate that the vehicle may have reached speeds of only Mach 3. Similarly, North Korea claims to have tested a second hypersonic weapon in January 2022; however, experts believe that that weapon may instead be a maneuvering reentry vehicle. Finally, Japan is developing the Hypersonic Cruise Missile (HCM) and the Hyper Velocity Gliding Projectile (HVGP). It reportedly plans to field HVGPs for area suppression and neutralizing aircraft carriers. A high- supersonic HVGP is expected to enter service in 2026, with a more advanced, hypersonic version available by FY2030; HCM is expected to enter service in 2030. The Japan Aerospace Exploration Agency operates three hypersonic wind tunnels, with two additional facilities at Mitsubishi Heavy Industries and the University of Tokyo. According to DOD, Japan and the United States have agreed to conduct “a joint analysis focused on future cooperation in counter-hypersonic technology.” Other countries—including Iran, Israel, and Brazil—have conducted foundational research on hypersonic airflows and propulsion systems, but may not be pursuing a hypersonic weapons capability at this time. In addition, a number of countries are testing increasingly maneuverable systems that travel at hypersonic speeds but that do not qualify as “hypersonic weapons” as defined in this report. Note: For information about South Korea’s hypersonic weapons programs, see Jon Grevatt and Rahul Udoshi, “South Korea Develops Hycore Hypersonic Cruise Missile,” Janes (subscription required), January 25, 2022. For information about North Korea’s hypersonic weapons programs, see Choi Soo-hyang, “N. Korea's ‘Hypersonic Missile’ Appears to Be at Early Stage of Development: JCS,” Yonhap News Agency, September 29, 2021; and Ankit Panda, “The Real Danger of North Korea’s New Hypersonic Missile Is not Its Speed,” NK News, January 10, 2022. For information about Japan’s hypersonic weapons programs, see Gordon Arthur, “Japan reveals test launch of its hypersonic strike missile program,” Defense News, July 10, 2024. For additional information about global hypersonic weapons programs, see Richard H. Speier et al., Hypersonic Missile Proliferation.

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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, budget and management, and their implications for strategic stability and arms control. This section provides an overview of some of these questions.

Mission Requirements

Although DOD 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.¹³⁷ Indeed, as Principal Director for Hypersonics (USD[R&E]) Mike White has stated, DOD has not yet made a decision to acquire 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 challenges.”¹³⁸

Given the lack of mission requirements, DOD officials have expressed a number of competing perspectives about the potential costs and intended quantities of U.S. hypersonic weapons. For example, Secretary of the Air Force Frank Kendall has stated that “hypersonics are not going to be cheap anytime soon ... [and thus] we’re more likely to have relatively small inventories of [hypersonic missiles] than large ones.”¹³⁹ Conversely, a number of other senior defense officials have stated that DOD intends to buy large quantities of hypersonic weapons. Then-DOD Director of Defense Research & Engineering Mark Lewis has noted that DOD wants “to deliver hypersonics at scale.... That means hundreds of weapons in a short period of time in the hands of the warfighter.”¹⁴⁰ Similarly, Principal Director for Hypersonics Mike White has stated that DOD seeks to “[produce] hypersonics in mass, because you have to be able to deliver capability in meaningful numbers, even to defeat the high-end targets.”¹⁴¹ These perspectives appear to be grounded in differing assumptions about the affordability of hypersonic weapons. Likewise, they are likely to hold different implications for the unit cost of the weapons.

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 hypersonic weapons and alternative means of executing potential 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. For example, Section 1671 of the FY2021 NDAA (P.L. 116-283) directs the Chairman of the Joint Chiefs of Staff, in coordination with the Under Secretary of Defense for Policy, to submit to the congressional defense committees a report on strategic hypersonic weapons, including “a

137 Steve Trimble, “New Long-Term Pentagon Plan Boosts Hypersonics.”

138 Steve Trimble, “New Long-Term Pentagon Plan Boosts Hypersonics.”

139 John A. Tirpak, “Only Small Inventories of Hypersonic Missiles in USAF’s Future, due to Cost,” Air Force Magazine, February 15, 2022, at https://www.airforcemag.com/only-small-inventories-of-hypersonic-missiles-in-usafs- future-due-to-cost/.

140 Sydney J. Freedberg Jr., “Hypersonics: DoD Wants ‘Hundreds of Weapons’ ASAP,” Breaking Defense, April 24, 2020, at https://breakingdefense.com/2020/04/hypersonics-dod-wants-hundreds-of-weapons-asap/.

141 “Hypersonic Strike and Defense: A Conversation with Mike White,” Center for Strategic and International Studies, June 10, 2021, at https://www.csis.org/analysis/hypersonic-strike-and-defense-conversation-mike-white. See also Jon Harper, “Just in: Pentagon to Spend Billions Mass-Producing Hypersonic Weapons,” National Defense Magazine, March 4, 2020, at https://www.nationaldefensemagazine.org/articles/2020/3/4/pentagon-to-spend-billions-mass- producing-hypersonic-weapons.

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description of how the requirements for land and sea-based hypersonic weapons will be addressed with the Joint Requirements Oversight Council, and how such requirements will be formally provided to the military departments procuring such weapons.” This report is to additionally include “the potential target sets for hypersonic weapons ... and the required mission planning to support targeting by the United States Strategic Command and other combatant commands.”

Congress may also consider the conclusions of a Congressional Budget Office assessment of hypersonic weapons and their alternatives, including the following findings:

• “Both hypersonic and ballistic missiles are well-suited to operate outside potential adversaries’ anti-access and area-denial (A2/AD), or ‘keep-out,’ zones.”¹⁴²

• “Hypersonic missiles would probably not be more survivable than ballistic missiles with maneuverable warheads in a conflict, unless the ballistic missiles encountered highly effective long-range defenses.”¹⁴³

• “Hypersonic missiles could cost one-third more to procure and field than ballistic missiles of the same range with maneuverable warheads.”¹⁴⁴

Funding and Management Considerations

Principal Director for Hypersonics Mike White has noted that DOD is prioritizing offensive programs while it determines “the path forward to get a robust defensive strategy.”¹⁴⁵ This approach is reflected in DOD’s recent budget requests. For example, DOD requested $182.3 million for the hypersonic defense program element and $6.9 billion for offensive hypersonic weapons programs in FY2025.¹⁴⁶ Similarly, in FY2023, DOD requested $225.5 million for the hypersonic defense program element and $4.7 billion for offensive hypersonic weapons programs.¹⁴⁷ (Although DOD requested $190.6 million for the hypersonic defense program element in FY2024, the department has declined to provide a breakout of funding for offensive hypersonic weapons programs in FY2024.)

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

142 Congressional Budget Office, U.S. Hypersonic Weapons and Alternatives, January 2023, at https://www.cbo.gov/ publication/58255.

143 Ibid.

144 Ibid.

145 Aaron Mehta, “Is the Pentagon Moving Quickly Enough on Hypersonic Defense?” Defense News, March 21, 2019, at https://www.defensenews.com/pentagon/2019/03/21/is-the-pentagon-moving-quickly-enough-on-hypersonic- defense/.

146 DOD has noted that the total request for all programs related to hypersonic defense was $1.9 billion in FY2025. Department of Defense Fiscal Year (FY) 2025 Budget Estimates, Missile Defense Agency, Defense-Wide Justification Book 2a of 5, p. 643, at https://comptroller.defense.gov/Portals/45/Documents/defbudget/FY2025/budget_justification/pdfs/03_RDT_and_E/R DTE_Vol2_MDA_RDTE_PB25_Justification_Book.pdf; and CRS correspondence with the Office of the Under Secretary of Defense (Comptroller), March 13, 2024.

147 Department of Defense Fiscal Year (FY) 2023 Budget Estimates, Missile Defense Agency Defense-Wide Justification Book Volume 2a of 5, p. 631, at https://comptroller.defense.gov/Portals/45/Documents/defbudget/fy2023/ budget_justification/pdfs/03_RDT_and_E/RDTE_Vol2_MDA_RDTE_PB23_Justification_Book.pdf; and Defense Budget Overview: United States Department of Defense Fiscal Year 2023 Budget Request, Office of the Under Secretary of Defense (Comptroller)/Chief Financial Officer, April 2022, p. 2-16, at https://comptroller.defense.gov/ Portals/45/Documents/defbudget/FY2023/FY2023_Budget_Request_Overview_Book.pdf.

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hypersonic research has the potential to result in stove-piped, proprietary systems that duplicate capabilities and increase costs.”¹⁴⁸ To mitigate this concern, they appropriated $100 million for DOD to establish a Joint Hypersonics Transition Office (JHTO) 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.¹⁴⁹

DOD established the JHTO in April 2020 and announced on October 26, 2020, that it awarded Texas A&M University with a $20 million contract—renewable for up to $100 million—to manage a University Consortium for Applied Hypersonics (UCAH).¹⁵⁰ UCAH is to be overseen by a group of academic researchers from Texas A&M University, the Massachusetts Institute of Technology, the University of Minnesota, the University of Illinois at Urbana-Champaign, the University of Arizona, the University of Tennessee Space Institute, Morgan State University, the California Institute of Technology, Purdue University, the University of California-Los Angeles, and the Georgia Institute of Technology.¹⁵¹ The consortium is to “facilitate transitioning academic research into developing systems [as well as] work with the department to reduce system development timelines while maintaining quality control standards.”¹⁵²

In addition, Section 1671 of the FY2021 NDAA (P.L. 116-283) directs the Secretary of the Army and the Secretary of the Navy to jointly submit to the congressional defense committees a report on LRHW and CPS, including total costs of the programs, “the strategy for such programs with respect to manning, training, and equipping, including cost estimates, [and] a testing strategy and schedule for such programs.” It directs the Director of Cost Assessment and Program Evaluation to submit to the congressional defense committees an independent cost estimate of these programs.¹⁵³

Given the lack of defined mission requirements for hypersonic weapons, however, it may be challenging for Congress to evaluate the balance of funding for hypersonic weapons programs, enabling technologies, supporting test infrastructure, and hypersonic missile defense.

Industrial Base and Supply Chain

U.S. government officials have expressed ongoing concern about the ability of the industrial base to support future demand for hypersonic weapons—particularly if multiple weapons programs go

148 “Department of Defense Appropriations Act, 2020: Joint Explanatory Statement,” Defense Subcommittees of the Appropriations Committees, December 16, 2019, at https://appropriations.house.gov/sites/ democrats.appropriations.house.gov/files/HR%201158%20-%20Division%20A%20- %20Defense%20SOM%20FY20.pdf.

149 Ibid. The Joint Hypersonic Transition Office, then called the Joint Technology 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 Transition 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. The office went unfunded until FY2020 and was not established until April 2020.

150 David Vergun, “DOD Awards Applied Hypersonics Contract to Texas A&M University,” DOD News, October 26, 2020, at https://www.defense.gov/Explore/News/Article/Article/2394438/dod-awards-applied-hypersonics-contract-to- texas-am-university/.

151 Ibid.

152 Ibid.

153 The Government Accountability Office notes DOD’s difficulty in developing accurate cost estimates for hypersonic weapons programs. For example, between FY2019 and FY2020, estimates for CPS “almost doubled.” Government Accountability Office, Hypersonic Weapons: DOD Should Clarify Roles and Responsibilities to Ensure Coordination Across Development Efforts, GAO-21-378, March 22, 2021, p. 21, at https://www.gao.gov/products/gao-21-378.

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into production at the same time.¹⁵⁴ Indeed, a July 2022 DOD industry solicitation notes that “the expansion of industrial base capacity is required” [emphasis added] if DOD is to meet its goal of “[producing] the air-breathing engine constituent materials, subcomponents, components, and subsystems to support an initial integrated system production capacity of no less than 48 all-up- round (AUR) missiles (four to five units per month) and up to 72 AURs per year (six per month).”¹⁵⁵

Furthermore, a DOD report issued in response to Executive Order 14017 (“America’s Supply Chains”) recommends investments in the hypersonic industrial base.¹⁵⁶ The report notes that DOD is in the process of “developing a hypersonics industrial base roadmap to inform investments over the next five years, which will guide investment decisions over this period. The roadmap will address sub-tier supplier development, and where appropriate, develop and retain competition that enables affordable production.”¹⁵⁷ The report additionally recommends that DOD “identify partners and allies with capabilities to aid in the development and expansion of [the U.S.] hypersonics supply chain, especially for materials and components where domestic sources may not exist.”¹⁵⁸ Congress may wish to conduct oversight of DOD’s efforts to strengthen the industrial base and supply chain for hypersonic weapons.

Strategic Stability

Analysts disagree about the strategic implications of hypersonic weapons. Some have identified two factors that could hold significant implications for strategic 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’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.

Some analysts argue that unintended escalation could occur as a result of warhead ambiguity, or from the inability to distinguish between a conventionally armed hypersonic weapon and a nuclear-armed one. However, as a United Nations report notes, “even if a State did know that [a hypersonic glide vehicle] launched toward it was conventionally armed, it may still 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.”¹⁵⁹ Differences in threat perception and escalation ladders could thus result in unintended escalation. Such concerns have previously led Congress to restrict funding for CPS programs.¹⁶⁰

154 See, for example, Justin Katz, “Hypersonics Too Expensive, Industrial Base Too Small For Services to Go It Alone: Admiral,” Breaking Defense, November 3, 2022, at https://breakingdefense.com/2022/11/hypersonics-too-expensive- industrial-base-too-small-for-services-to-go-it-alone-admiral/.

155 Department of the Air Force, “Request for Information (RFI) on Supplier Based Initiative for Air-Breathing Engines for Hypersonic Systems,” at https://www.businessdefense.gov/ai/dpat3/docs/ AirBreathing%20Enginesfor%20HypersonicsRFFA8650225507.pdf.

156 Department of Defense, Securing Defense-Critical Supply Chains: An action plan developed in response to President Biden’s Executive Order 14017, February 2022, at https://media.defense.gov/2022/Feb/24/2002944158/-1/-1/ 1/DOD-EO-14017-REPORT-SECURING-DEFENSE-CRITICAL-SUPPLY-CHAINS.PDF.

157 Ibid.

158 Ibid.

159 United Nations Office of Disarmament Affairs, Hypersonic Weapons.

160 For a history of legislative activity on conventional prompt global strike, see CRS Report R41464, Conventional Prompt Global Strike and Long-Range Ballistic Missiles: Background and Issues, by Amy F. Woolf.

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Other analysts have argued that the strategic implications of hypersonic weapons are minimal. Pavel Podvig, a senior research fellow at the United Nations Institute for Disarmament Research, has noted that the weapons “don’t … change much in terms of strategic balance and military capability.”¹⁶¹ This, some analysts argue, is because U.S. competitors such as China and Russia already possess the ability to strike the United States with ICBMs, which, when launched in salvos, could overwhelm U.S. missile defenses.¹⁶² Furthermore, these analysts note that in the case of hypersonic weapons, traditional principles of deterrence hold: “it is 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 actually use—hypersonic weapons against the United States ... would end well.”¹⁶³

Section 1671 of the FY2021 NDAA (P.L. 116-283) directs the Chairman of the Joint Chiefs of Staff, in coordination with the Under Secretary of Defense for Policy, to submit to the congressional defense committees a report that examines

How escalation risks will be addressed with regards to the use of strategic hypersonic weapons, including whether any risk escalation exercises have been conducted or are planned for the potential use of hypersonic weapons, and an analysis of the escalation risks posed by foreign hypersonic systems that are potentially nuclear and conventional dual- use capable weapons.

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.¹⁶⁴

The New START Treaty, a strategic offensive arms treaty between the United States and Russia, does not currently cover weapons that fly on a ballistic trajectory for less than 50% of their flight, as do hypersonic glide vehicles and hypersonic cruise missiles.¹⁶⁵ However, Article V of the treaty states that “when a Party believes that a new kind of strategic offensive arm is emerging, that Party shall 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

161 Amy Mackinnon, “Russia’s New Missiles Are Aimed at the U.S.,” Foreign Policy, March 5, 2019, at https://foreignpolicy.com/2019/03/05/russias-new-missiles-are-aimed-at-you-weapons-hypersonic-putin-united-states- inf/.

162 David Axe, “How the U.S. Is Quietly Winning the Hypersonic Arms Race,” The Daily Beast, January 16, 2019, at 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.

163 Jyri Raitasalo, “Hypersonic Weapons Are No Game-Changer,” The National Interest, January 5, 2019, at https://nationalinterest.org/blog/buzz/hypersonic-weapons-are-no-game-changer-40632.

164 See United Nations Office of Disarmament Affairs, Hypersonic Weapon; and Richard H. Speier et al., Hypersonic Missile Proliferation.

165 In some cases, hypersonic glide vehicles may be launched from ICBMs that are already covered by New START, as is reported to be the case with Russia’s Avangard hypersonic glide vehicle. See Rachel S. Cohen, “Hypersonic Weapons: Strategic Asset or Tactical Tool?”

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the New START limits.¹⁶⁶ However, because New START is due to expire in 2026, this may be a short-term solution.¹⁶⁷

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.¹⁶⁸ 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.”¹⁶⁹ 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.”¹⁷⁰

166 James Acton notes: “[D]uring [New START] negotiations, Russia argued that boost-glide weapons might constitute ‘a new kind of strategic offensive arm,’ in which case they would trigger bilateral discussions about whether and how they would be regulated by the treaty—a position [then] rejected by the United States.” James M. Acton, Silver Bullet?: Asking the Right Questions About Conventional Prompt Global Strike, Carnegie Endowment for International Peace, 2013, p. 139, at https://carnegieendowment.org/files/cpgs.pdf.

167 CRS Report R41219, The New START Treaty: Central Limits and Key Provisions, by Amy F. Woolf.

168 Mark Gubrud, “Test Ban for Hypersonic Missiles?” Bulletin of the Atomic Scientists, August 6, 2015, at https://thebulletin.org/roundtable/test-ban-for-hypersonic-missiles/.

169 Tong Zhao, “Test Ban for Hypersonic Missiles?”

170 Rajaram Nagappa, “Test Ban for Hypersonic Missiles?”; see also James M. Acton, Silver Bullet?, pp. 134-138.

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Appendix. U.S. Hypersonic Testing Infrastructure¹⁷¹

Table A-1. DOD Hypersonic Ground T est Facilities

Facility Capability Location

Air Force Arnold Engineering and Development Complex (AEDC) von Karman Gas Dynamics Facility Tunnels A/B/C

Tunnel A: 40-inch Mach 1.5-5.5; up to 290 °F Tunnel B: 50-inch Mach 6 and 8; up to 900 °F Tunnel C: 50-inch Mach 10; up to 1700 °F

Arnold AFB, TN

Air Force AEDC High-Enthalpy Aerothermal Test Arc-Heated Facilities H1, H2, H3

Simulate thermal and pressure environments at speeds of up to Mach 8

Arnold AFB, TN

Air Force AEDC Tunnel 9 59-inch Mach 7, 8,10, 14, and18; up to 2900 °F

White Oak, MD

Air Force AEDC Aerodynamic and Propulsion Test Unit

Mach 3.1-7.2; up to 1300 °F Arnold AFB, TN

Air Force AEDC Aeroballistic Range G

Launches projectiles of up to 8 inches in diameter at speeds of up to Mach 20

Arnold AFB, TN

Holloman High Speed Test Track 59,971 ft. track; launches projectiles at speeds of up to Mach 8

Holloman AFB, NM

Air Force Research Laboratory (AFRL) Cells 18, 22

Mach 3-7 Wright-Patterson AFB, OH

AFRL Laser Hardened Materials Evaluation Laboratory (LHMEL)

High-temperature materials testing Wright-Patterson AFB, OH

AFRL Mach 6 High Reynolds Number (Re) Facility

10-inch Mach 6 Wright-Patterson AFB, OH

Test Resource Management Center Hypersonic Aeropropulsion Clean Air Test-bed Facility

Up to Mach 8; up to 4040 °F Arnold AFB, TN

Source: (U//FOUO) Paul F. Piscopo et al. Air Force AEDC Tunnel 9 was upgraded in 2019 to enable Mach 18 testing. See “Department of Defense Press Briefing on Hypersonics,” March 2, 2020, at https://www.defense.gov/ Newsroom/Transcripts/Transcript/Article/2101062/department-of-defense-press-briefing-on-hypersonics/.

171 The following information is largely derived from the 2014 report (U//FOUO) Paul F. Piscopo et al., (U) Study on the Ability of the U.S. Test and Evaluation Infrastructure, and therefore, may not be current. Permission to use this material has been granted by the Office of Science and Technology Policy. Additional information has been provided by Dee Howard Endowed Assistant Professor Dr. Christopher S. Combs (The University of Texas at San Antonio).

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Table A-2. DOD Open-Air Ranges

Range Location

Ronald Reagan Ballistic Missile Defense Test Site

Kwajalein Atoll, Republic of the Marshall Islands

Pacific Missile Range Facility (PMRF) Kauai, HI

Western Range, 30^th Space Wing Vandenberg AFB, CA

Naval Air Warfare Center Weapons (NAWC) Division

Point Mugu and China Lake, CA

White Sands Missile Range (WSMR) New Mexico

Eastern Range, 45^th Space Wing Cape Canaveral Air Force Station/Patrick AFB/Kennedy Space Center, FL

NASA Wallops Flight Facility Wallops Island, VA

Pacific Spaceport Complex (formerly Kodiak Launch Complex)

Kodiak Island, AK

NAWC Weapons Division R-2508 Complex

Edwards AFB, CA

Utah Test and Training Range Utah

Nevada Test and Training Range Nevada

Source: (U//FOUO) Paul F. Piscopo et al.

Table A-3. DOD Mobile Assets

Asset

Navy Mobile Instrumentation System

PMRF Mobile At-sea Sensor System

MDA Mobile Instrumentation System Pacific Collector

MDA Mobile Instrumentation System Pacific Tracker

Kwajalein Mobile Range Safety System 2

United States Navy Ship Lorenzen missile range instrumentation ship

Sea-based X-band Radar

Aircraft Mobile Instrumentation Systems

Transportable Range Augmentation and Control System

Re-locatable MPS-36 Radar

Transportable Telemetry System

Source: (U//FOUO) Paul F. Piscopo et al.

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Table A-4. NASA Research-Related Facilities

Facility Capability Location

Ames Research Center (ARC) Arc Jet Complex

High-temperature materials testing

Mountain View, CA

ARC Hypervelocity Free Flight Facilities

Launches projectiles at speeds of up to Mach 23

Mountain View, CA

Langley Research Center (LaRC) Aerothermodynamics Laboratory

31-inch Mach 10, 20-inch Mach 6, and 15-inch Mach 6

Hampton, VA

LaRC 8-foot High Temperature Tunnel

96-inch Mach 5 and Mach 6.5

Hampton, VA

LaRC Scramjet Test Complex Up to Mach 8 and up to 4740 °F

Hampton, VA

LaRC HyPulse Facility Currently inactive Long Island, NY

Glenn Research Center (GRC) Plumbrook Hypersonic Tunnel Facility Arc Jet Facility

Mach 5, 6, and 7 and up to 3830 °F

Sandusky, OH

GRC Propulsion Systems Laboratory 4

Mach 6 Cleveland, OH

GRC 1’ x 1’ Supersonic Wind Tunnel

12-inch Mach 1.3-6 (10 discrete airspeeds) and up to 640 °F

Cleveland, OH

Source: (U//FOUO) Paul F. Piscopo et al.

Table A-5. Department of Energy Research-Related Facilities

Facility Capability Location

Sandia National Laboratories Solar Thermal Test Facility

High-temperature materials testing and aerodynamic heating simulation

Albuquerque, NM

Sandia National Laboratories Hypersonic Wind Tunnel

18-inch Mach 5, 8, and 14 Albuquerque, NM

Source: (U//FOUO) Paul F. Piscopo et al.

Table A-6. Industry/Academic Research-Related Facilities

Facility Capability Location

CUBRC Large Energy National Shock (LENS)-1/-II/-XX Tunnels

LENS 1: Mach 6-22 LENS II: Mach 2-12 LENS XX: Atmospheric reentry simulation

Buffalo, NY

Boeing Polysonic Wind Tunnel 48-inch up to Mach 5 St. Louis, MO

Lockheed Martin High Speed Wind Tunnel

48-inch Mach .3-5 Dallas, TX

Boeing/Air Force Office of Scientific Research (AFOSR) Quiet Tunnel at Purdue University

9.5-inch Mach 6 West Lafayette, IN

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Facility Capability Location

AFOSR-University of Notre Dame Quiet Tunnel

24-inch Mach 6 Notre Dame, IN

Stratolaunch Carrier Aircraft Reusable Mach 6 test bed Mojave, CA

University of Texas at San Antonio Hypersonic Ludwieg Tube

8-inch x 8-inch Mach 7.2 San Antonio, TX

University of Texas at Austin Blowdown Wind Tunnel

6-inch x 7-inch Mach 2 & Mach 5 Austin, TX

Southwest Research Light-Gas Gun Quiet, flight enthalpy ballistic range up to Mach 20

San Antonio, TX

University of Texas at Arlington Aerodynamics Research Center

1.6 MW Mach 2-6 Arc Jet 13-inch Mach 4-16 Shock Tunnel

Arlington, TX

Texas A&M National Aerothermochemistry and Hypersonics Laboratory

7-inch Quiet Mach 6 36-inch Expansion Tunnel 9-inch x 14-inch variable Mach 5-8

College Station, TX

California Institute of Technology GALCIT

12-inch Mach 5.2 T5 Reflected Shock Tunnel 6-inch Hypervelocity (up to Mach 7.1) Expansion Tube

Pasadena, CA

University of Arizona Hypersonic Ludwieg Tube

15-inch Mach 5

Tucson, AZ

Air Force Academy Ludwieg Tube 20-inch Mach 6 Colorado Springs, CO

University of Tennessee Space Institute Ludwieg Tube

18-inch x 18-inch Mach 7 Tullahoma, TN

Maryland HyperTERP Reflected Shock Tunnel

12-inch x 12-inch Mach 6 College Park, MD

Florida State Polysonic Wind Tunnel

12-inch x 12-inch Mach 0.2-5 Tallahassee, FL

Princeton HyperBLaF Wind Tunnel 9-inch Mach 8 Princeton, NJ

Sources: (U//FOUO) Paul F. Piscopo et al.; Oriana Pawlyk, “Air Force Expanding Hypersonic Technology Testing”; and CRS correspondence with Dee Howard Endowed Assistant Professor Dr. Christopher S. Combs (The University of Texas at San Antonio), October 27, 2022. Notes: Hypersonic wind tunnels are under construction at the following universities: Texas A&M University (Mach 10 quiet tunnel), Purdue University (Mach 8 quiet tunnel), and the University of Notre Dame (Mach 10 quiet tunnel). Additional universities, such as the University of Maryland, the Georgia Institute of Technology, and Virginia Polytechnic Institute and State University, also maintain experimental hypersonic facilities or conduct hypersonic research.

Hypersonic Weapons: Background and Issues for Congress

Congressional Research Service R45811 · VERSION 39 · UPDATED 32

Author Information

Kelley M. Sayler Specialist in Advanced Technology and Global Security

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