By: Chris Alba
Approximate Reading Time: 18 minutes
Figure 1 (Featured Image Above):The Air-launched Rapid Response Weapon (ARRW) prototype on an external pylon of a B-52 during a flight test at Edwards AFB, CA. Photo: ARRW Program Office
The current DoD hypersonic weapon investment strategy is untenable over the next three to four years which will widen the capability gap with Russia and China. The investment strategy needs to be streamlined based on acquisition, test, and fiscal realities to field a hypersonic weapon by 2023. In order to enable success, the DoD should begin to consolidate the hypersonic weapon efforts to one per service to help alleviate budgets, focus requirements, and reduce competition at test facilities.
Current threat environments the United States (US) military will encounter in a near-peer contest are that of an anti-access/area-denial (A2/AD) environment. Hypersonic weapons are a disruptive technology that would enable US military operations in such an environment. They are not the solution to A2/AD environments but will be part of a family of solutions. In fact, hypersonic weapons have been identified in national strategy and budgetary documents as being critical capabilities to overcome emerging threats and win future conflicts. The Undersecretary of Defense for Research and Engineering, Dr. Michael Griffin, has made the development of hypersonic weapons a top Department of Defense (DoD) priority by nearly doubling long-term investments from $6 to $11.2 billion over the next five years and pushing to purchase “thousands” of weapons for a viable deterrent. Much of this urgency is likely due to the dissolution of the Intermediate-Range Nuclear Forces (INF) Treaty between the US and Russia on August 2, 2019, which had banned ground-launched cruise missiles with ranges between 500 and 5,500 kilometers. Many fear this will accelerate an arms race with Russia and China because hypersonic missile technology now makes intermediate range weapons more dangerous than ever.
There are currently multiple offensive and defensive hypersonic weapon programs between the military Services that are competing against each other for budgetary requirements in a time when there is also a huge swell of funding required for other weapon systems (e.g. nuclear modernization, new submarine, new bomber). Just as challenging as the fight over budgets may be the competition between these programs for prioritized access to the limited number of aging ground test facilities and flight test ranges. The DoD should re-evaluate its current approach to acquiring and fielding hypersonic weapon systems including prioritizing an offensive capability for an immediate deterrent. It has been shown that offensive capabilities, more than defensive capabilities, help shape the strategic environment, provide credibility to political statements, and prevent conflict escalation. Additionally, the DoD needs to immediately prioritize the recapitalization of the hypersonic test infrastructure (facilities and ranges) to support current and future investments. The current acquisition approach is unsustainable, and therefore, the DoD should begin to consolidate the hypersonic weapon efforts to one per Service to help alleviate budgets, focus requirements, and reduce competition at test facilities. This paper will discuss the benefit and rationale for pursuing hypersonic weapons, review DoD and near-peer hypersonic weapon investments, and recommend a revised investment strategy based on acquisition, test, and fiscal realities.
Figure 2. Operational flight information for hypersonic maneuvering weapons.
Source: A Threat to America’s Global Vigilance, Reach, and Power High-Speed, Maneuvering Weapons: Unclassified Summary, 2016
It is important to understand the distinct attributes of hypersonic weapons that make them attractive to the military and how they are different from current weapon systems. A general definition for a vehicle flying at hypersonic speed is considered to be traveling five times the speed of sound (Mach 5) or faster. To put that in another context, hypersonic weapons can fly faster than about one mile to five miles per second. As a comparison, it would take approximately one hour for a standard subsonic cruise missile flying at Mach 0.85 to travel 1,000 km whereas a hypersonic weapon traveling at Mach 10 would take approximately six minutes to travel 1,000 km. Current hypersonic weapons under development differ from ballistic missiles in that they have unpredictable trajectories due to their ability to maneuver during most phases of flight. Additionally, ballistic missiles spend most of their flight time, typically 80% or more, outside of the atmosphere. Whereas, a modern hypersonic weapon spends between 80-100% of its flight time within the atmosphere (Figure 3). This has the unique military advantage of delaying and potentially avoiding detection from adversary ground-based radars or other line-of-sight sensors due to the Earth’s curvature and the relative low flying altitude of a hypersonic weapon. Hence, hypersonic weapons can hold extremely large areas at risk and complicate defensive countermeasures.
Figure 3. Terrestrial based detection of ballistic missiles vs. hypersonic glide vehicles. Source (left): Congressional Research Service report on Hypersonic Weapons: Background and Issues for Congress, September 19, 2017. Ballistic reentry vehicle versus hypersonic glide vehicle trajectories. Source (right): RAND Analysis RR2137
Hypersonic weapons are being aggressively pursued by the US and other nations because of their unique military utility to penetrate most air defense systems due to speed, altitude, range, and maneuverability. First and foremost, hypersonic weapons offer increased effectiveness compared to current standoff munitions in heavily defended environments. This translates to a smaller force structure because of the fact that missions can be executed with fewer weapons and carriage platforms. Hypersonic weapons provide a faster response to time sensitive targets from safe standoff ranges. This becomes a force multiplier because the Services can utilize 4th generation assets in A2/AD environments without the need for a platform to penetrate a defended area. Lastly, offensive hypersonic weapons provide a credible deterrent without provocation. The US will be able to hold high value targets at risk beyond an adversary’s reach or capability to defend. Hypersonic weapons are not to be thought of as “silver bullets”, because like most high-end munitions, they will likely be in limited supply. There are other solutions to the A2/AD environment besides hypersonic weapons, but these weapons will provide the warfighter with responsive, time-sensitive, and penetrating strike options against advanced integrated air defense systems (IADS). For these reasons, both the US and near-peer countries, such as Russia and China, have been aggressively investing in hypersonic weapons and are in a race to make them operational.
Figure 4. Russian air-launched Kinzhal hypersonic missile being carried on a MiG-31. Source: Air Force Magazine, The Great Hypersonic Race, August 2018
Russia and China are currently outpacing the US and leading the development of hypersonic weapons. Recently, Russia has touted their hypersonic weapon capabilities with the announcement of three missiles that have entered production and are ready for operational use. The first is the Avangard hypersonic glide vehicle, which is ground-launched using an intercontinental ballistic missile (ICBM) booster and can carry either a conventional or nuclear warhead. The speed and range of the Avangard are unknown but considering that it uses an ICBM booster puts it into the strategic class. The second is the Kinzhal hypersonic glide vehicle, which is air-launched using a single-stage solid rocket booster and can also carry either a conventional or nuclear warhead (Figure 4). Missile defense analysts have estimated a range of more than 2,000 km with a speed of more than Mach 10. The third is the Zircon hypersonic cruise missile, which is ship-launched using a two-stage solid rocket booster and scramjet engine propulsion system. This is an anti-ship cruise missile with an estimated range of up to 1,000 km with a speed of approximately Mach 8. The Chinese are not too far behind the Russians in development and are projected to deploy their hypersonic weapon capabilities by 2020-2021. The main system reported on is the DF-ZF hypersonic glide vehicle, which is ground-launched using a DF-17 as the booster. The range is unknown but based on the DF-17, it is expected to be a medium range missile (2,000-3,000 km) with a speed somewhere between Mach 5 and Mach 10. The DF-ZF is expected to enter operational service in 2020. With these fielded or emerging capabilities entering the battlespace, the DoD has recognized that Russia and China now have an asymmetric advantage. This renewed sense of urgency spurred the DoD to put an investment strategy together near the beginning of 2017 with the goal to rapidly prototype and field hypersonic weapons within five years.
Figure 5. Artist concept of the Common Hypersonic Glide Body (C-HGB).
Source: Breaking Defense, https://breakingdefense.com/2019/08/hypersonics-army-awards-699m-to-build-first-missiles-for-a-combat-unit/
The DoD has led the development of US hypersonic weapons since the early 2000s as part of the conventional prompt global strike program that has involved the Army, Navy, and Air Force. In recent years, the program has re-branded as the conventional prompt strike (CPS) program focusing on both hypersonic glide vehicles and hypersonic cruise missiles with intermediate ranges. The current goal of the CPS program is to develop a common-hypersonic glide body (C-HGB) that can be utilized by the Army, Navy, and Air Force with the idea that this will save research and development (R&D) costs in the future (Figure 5). Additionally, the Defense Advanced Research Projects Agency (DARPA) has invested heavily in hypersonic technologies with the Falcon Hypersonic Technology Vehicle 2 (HTV-2) program in the late-2000s with the goal to develop a capability that can reach anywhere in the world in less than an hour. Since the mid-2010s, DARPA has expanded to four hypersonic technology programs each with unique goals. The DARPA Tactical Boost Glide (TBG) program aims to demonstrate an air-launched, tactical-range hypersonic boost glide system. The DARPA Hypersonic Air-breathing Weapon Concept (HAWC) aims to demonstrate an air-launched hypersonic cruise missile. The DARPA Operational Fires (OpFires) program aims to demonstrate a ground-launched hypersonic boost glide weapon. The DARPA Advanced Full Range Engine (AFRE) is developing a reusable aircraft that can reach hypersonic speeds. Note that a few of these DARPA demonstrations are linked to Service efforts, specifically the Air Force and Army, but are still considered technology demonstrators and not operational capabilities. As such, the Services recognized that if the US are to catch up to Russian and Chinese systems, they needed to accelerate hypersonic weapon development beyond technology demos.
Figure 6. Artist concept of a hypersonic glide vehicle.
Photo: ARRW Program Office
Each Service has recently implemented rapid prototyping programs with the ultimate goal to field a operational capability within the 2022-2023 timeframe. The Air Force awarded contracts for two efforts in 2018 called the Air-launched Rapid Response Weapon (ARRW) and the Hypersonic Conventional Strike Weapon (HCSW). These are both air-launched hypersonic boost-glide weapons that vary in size and range but are described as having complementary capabilities. The HCSW program is expected to use the C-HGB from the CPS program, and the ARRW program is leveraging the glide body used by the DARPA TBG demonstration. The Navy plans to start the Intermediate Range Conventional Prompt Strike Weapon (IR CPS) in Fiscal Year (FY) 2020 which will also use the C-HGB with a submarine-launched booster system. The Army plans to start the Land-Based Hypersonic Missile (or Long-Range Hypersonic Weapon) in FY 2020 which will again use the C-HGB with a two-stage ground-launched booster system. The DoD is also investing in hypersonic weapon defensive capabilities through the Missile Defense Agency (MDA) which began soliciting white papers in 2018 to explore defensive options. All of this information is highlighting that, within the DoD, there are currently 8-9 hypersonic weapon programs executing concurrently with most having the same goal of fielding a residual operational capability in the next 2-4 years. This puts an enormous strain on government and contractor manpower, testing infrastructure, and budget priorities.
The current strategy of using a joint program to develop a common piece of technology is noble in practice but could be disastrous in reality. The development of the C-HGB under the CPS program for use by three different Service-specific weapon systems has the potential for program delays and cost overruns experienced by the F-35 Joint Strike Fighter and F-111 programs. The issue boils down to Service-specific requirements that will be imposed on each program. For example, the storage, carriage, and handling requirements will be different depending upon whether these weapons need to integrate with a bomber, submarine, or ground-based launcher. The operational environments are also drastically different depending whether a weapon needs to function properly at -60°F while carried under the wing of a B-52 at 40,000 ft or at 110°F while sitting in a rocket launcher in the desert. The operational flight trajectories are also different between the Services necessitating tailored thermal protection system requirements. These differences all lead to extensive test programs to qualify components and systems for the Service-specific requirements. The problem is exacerbated when a re-design becomes necessary due to a component failing qualification. Therefore, the idea of a “common” glide body becomes impractical. History on the F-35 and F-111 programs have shown that a “one size fits all” does not work. It likely would save time and money over the course of a program to develop a Service-specific glide body at program initiation instead of inheriting the limitations of a previous design.
Due to the number of programs, the demand for prioritized access and support from hypersonic test facilities and ranges is larger than the current supply and capacity can sustain. Dr. Griffin stated during testimony before the House Armed Services Committee in March 2019 that the DoD intends to conduct approximately 40 flight tests over the next few years. This would be an incredible inflection point for the hypersonic test community that has not experienced this level of activity likely since the initial development of ICBMs. Reviewing past hypersonic test flights from the X-43A (2004), X-51 (2010, 2011, 2012, 2013), HTV-2 (2010, 2011), Army Advanced Hypersonic Weapon (2011, 2014), and Navy Intermediate Range Conventional Prompt Strike Flight Experiment-1 (2017) shows that the US has been averaging less than one test flight per year over the past 15 years. Additionally, all of these test flights flew over the Pacific Ocean because it is extremely challenging to clear a flight corridor over the continental United States due to the long ranges of these systems. Many of these early systems were technology demonstrators meaning that recovery or assessing accuracy of hitting a ground target were not test objectives. As the DoD moves to operational prototypes, it will be a requirement to assess terminal and warhead effectiveness. Hence, these weapons can no longer terminate missions into the ocean but must impact a ground or surface target.
Figure 7. The Army Advanced Hypersonic Weapon demonstrator was launched successfully on its first flight in 2011, but had a failed test flight in 2014.
Source: IHS Jane’s Military & Security Assessments Intelligence Centre, https://www.janes.com/images/assets/515/67515/Hypersonics_disrupt_global_strategic_stability.pdf
Currently, the primary Pacific test range facility is the Reagan Test Site in the Marshall Islands operated by Army Space and Missile Defense Command. Scheduling 40 flight tests at the Reagan Test Site over the next few years is guaranteed to be a tremendous hurdle to overcome considering all the necessary preparations required for telemetry, instrumentation, communication, and airborne assets. Traditionally, these tests have used dozens of surface vessels to aid with telemetry and data collection, which becomes expensive and time-consuming considering transit time to locations in the vast Pacific Ocean. However, the Air Force has recently purchased three RQ-4 Global Hawks to alleviate the dependence on surface vessels to conduct hypersonic flight testing. The use of Global Hawks may help to decrease the amount of time needed to prepare for a test, but there will still be competing interests over which program gets prioritized access to the range if the 40 tests holds true to prediction. An even bigger roadblock to hypersonic weapon development may be access to a limited number of ground test facilities.
Ground testing hypersonic weapons prior to flight is pivotal to reduce risk and increase confidence for success, but aging infrastructure and limited number of facilities will cause program delays. Many of the existing large hypersonic wind tunnel facilities were built in the 1950s and 1960s to support ICBM development. In 2005, RAND conducted an inventory of US ground test facilities and identified approximately 15 hypersonic wind tunnels with varying Mach numbers, test section diameters, and run times. Since it takes one to two decades to build a new facility, this is likely still an accurate estimate of current inventory. The main omission from this RAND report were hypersonic arc jet facilities to test high temperature materials and structures in extreme aeroheating environments. Currently, there are two US hypersonic arc jet facilities located at NASA Ames Research Center and Arnold Engineering Development Center operated by the Air Force.
Figure 8. Mach 18 nozzle at Arnold Engineering Development Center Hypervelocity Wind Tunnel 9 in White Oak, Maryland.
Source: Arnold Air Force Base News Article, https://www.arnold.af.mil/News/Article-Display/Article/1899789/hypervelocity-capabilities-advance-to-new-highs-at-aedc-tunnel-9/
The target flight Mach number of the hypersonic weapons will also limit the number of available facilities. For example, if the weapon is designed to fly at Mach 10 or faster, the US only has approximately five facilities with that capability. There are even more facility discriminators such as run test times, model size, Reynolds number, and tunnel noise to consider. Therefore, it is straightforward to conclude that the US lacks an abundant amount of hypersonic ground test infrastructure to accommodate 8-9 concurrently executing programs. The other concern is the maintainability of these facilities. There are likely no off-the-shelf replacement parts from a structure that was built in 1960. A looming fear must be the amount of scheduled and unscheduled maintenance time required to keep these facilities operational. Any prolonged down time will have a multiplying and cascading effect on all weapon programs that are waiting to use those tunnels causing delays to not only one program but maybe five or six. The repercussion of schedule delays of this magnitude only strain and increase the budgets for these programs.
Hypersonic weapons are still a very new technology that is being accelerated into the acquisition world, which has the consequence of program cost estimates bordering on educated guesses to rough orders of magnitude. There is no historical analogy or parametric trend to build upon for an accurate operational hypersonic weapon cost estimate. It is literally a brand-new industry. However, the DoD is beginning to understand how much these weapons will cost both in development and production after one year of execution with the initial Air Force rapid prototyping efforts through recent budget requests. Unfortunately, the response seems to be an increase in cost from initial estimates. A Center for Strategic and Budgetary Assessments report estimated program costs for a ground launched hypersonic weapon of $1.1 billion for development and $21 million each for procurement. For comparison, the Joint Air-to-Surface Standoff Missile Extended Range (JASSM-ER) and Tomahawk Land Attack Missile (TLAM) have estimated procurement costs of $1.38 million and $1.51 million each, respectively. The goal of purchasing thousands of hypersonic weapons seems unrealistic with this order of magnitude cost increase for one program. Therefore, it is prudent to assess the risk posture of this current acquisition approach along with the context that fielding hypersonic weapons are a top priority for the DoD.
The current acquisition approach across the DoD of using rapid prototyping to field a hypersonic weapon capability as quickly as possible is innovative but may ultimately hinder itself due to the volume of efforts undertaken simultaneously. This aggressive investment strategy is attempting to reduce the risk of failure, such that if one program fails, then there are other efforts executing simultaneously that still have a chance to succeed. It is similar to the analogy if you throw enough darts at a dartboard, one of them is likely to hit the bullseye. Additionally, if a prototyping effort fails, then at least it was not a major defense acquisition program that the DoD is stuck with for decades. The Air Force’s Service Acquisition Executive, Dr. Will Roper, has aggressively pushed to field hypersonic weapons within five years and has promoted the slogan of “failing fast and failing forward”. Dr. Roper would like the Air Force rapid prototyping efforts, ARRW and HCSW, to test extensively and allow for intelligent failure in order to learn something and make future improvements. Therefore, the issue is not with allowing for failure, it is not being able to test aggressively and extensively. The current test environment has all of these programs competing against each other for resources and access. Furthermore, a senior leader within the DoD will have to make a determination about which program has priority to use those test facilities or even bump other programs from the schedule. The emphasis is on a DoD senior leader because all three Services, DARPA, and MDA are competing for these resources. Lastly, it is unclear if the DoD has an appetite to pay for all of these efforts over the next five years, especially if the estimated average development cost for one program is over a billion dollars. Again, any program delay or missed test event equates to an increase in cost. These programs will not get cheaper. Therefore, if the ultimate goal is to field a hypersonic weapon capability by 2022-2023, then the current investment strategy is high risk to meet that date unless it becomes streamlined.
In order to enable success, the DoD should begin to consolidate the hypersonic weapon efforts to one per Service which helps to alleviate budgets, focus requirements, and reduce competition at test facilities. First, while the DARPA demonstration efforts were tremendous at advancing hypersonic technologies, they unfortunately do not heavily focus on any Service-specific requirements. If the Services are planning to use some of these technologies, they will still have to requalify (i.e. test) components to their specific environments. In the spirit of rapid prototyping, it is more practical to focus on the Service-specific requirements than continue with the associated DARPA efforts. The foundational vision for DARPA is to prevent technological surprise, and one could argue that we are beyond that point for hypersonic weapons. Second, Services with multiple programs, like the Air Force, should down-select to one program. Again, the goal is to field as early as possible because the US is already behind Chinese and Russian capabilities. It is not practical to have programs within a Service competing for budgets when one program could likely become fully funded without having to spread the costs. Third, this consolidation of programs would ease the burden on the limited hypersonic test infrastructure. With the number of tests planned over the next few years, it is recommended to take a portion of this money freed up from program consolidation and to invest immediately into modernizing the hypersonic test infrastructure. Plus, it is time to modernize hypersonic test facilities and ranges to ensure performance is measured accurately and verified in the real world. Test modernization will come at a price though, because it will cause temporary shutdowns of facilities. However, this “strategic pause” in the near-term is necessary to ensure future success and reliability. Last, while it is not recommended to completely ignore a defensive capability, the DoD should prioritize fielding an offensive hypersonic weapon prior to investing large sums of money into the MDA. The current MDA approach of requesting white papers and initial design concepts is appropriate. There is a lot of data to be collected and lessons learned that the MDA can leverage from the upcoming tests.
The current hypersonic weapon investment strategy is untenable over the next three to four years and will delay the fielding of these weapons widening the capability gap with Russia and China. If the plan is to potentially purchase thousands of hypersonic weapons, then the DoD needs to immediately consolidate the number of existing programs to one per Service considering the estimated per unit price tag of $21 million. This consolidation of programs will alleviate the competition for limited resources and test facility access. Instead of pitting programs against each other to compete for budgets, the Services could likely fully fund each program and prevent any schedule delays due to funding. The savings recouped from consolidation should be invested immediately into the modernization of hypersonic test infrastructure. Due to the limited number of facilities and ranges, the government should strive to maximize availability and minimize maintenance down time. The goal is to have enough time to complete all required testing and prevent the facilities and ranges from getting over crowded. It is recommended that the DoD streamline its current hypersonic weapon investment approach to increase the chances of successfully fielding a weapon by 2022-2023. This will demonstrate that the US has parity or even surpassed Chinese and Russian capabilities and provide an immediate deterrent.
Major Christopher Alba is currently a student in the Multi-Domain Operational Strategist concentration at Air Command and Staff College. He is an Acquisitions Officer with over twelve years of experience in program and technical management of advanced systems research and development for high-speed weapons and re-entry vehicles. He holds an Aerospace Engineering PhD from the Air Force Institute of Technology with a concentration in hypersonic aerothermodynamics. His last position was as the Deputy Program Manager for the AGM-183A Air-launched Rapid Response Weapon (ARRW) rapid prototyping program at Eglin AFB, FL.
The views expressed are those of the author and do not necessarily reflect the official policy or positions of the Department of the Air Force or the U.S. Government.