3

Testing for Future Combat: Multi-Domain Operations, Connected Concurrent Kill Chains, and Mitigating Encroachment

Critical to success in a dynamic warfighting environment is the seamless integration of multiple systems and technologies working in concert across multiple domains (land, air, sea, cyberspace, and space); therefore, it is necessary that the operational effectiveness and suitability of emergent technologies are tested in such an environment so that they can be applied to their greatest effect. This critical point was articulated when former Department of Defense (DoD) Director of Operational Testing and Evaluation (OT&E), Hon. Robert Behler, addressed the committee at their opening meeting in December 2020:

Historically, OT&E has focused on the performance of individual programs and systems by making sure that they achieve desired outcomes under conditions similar to those that would be encountered in combat. Although operational plans may involve the use of multiple systems working together, their collaborative effects are not typically a major test

___________________

¹ From remarks delivered at December 4, 2020, committee meeting; recording available at https://www.nationalacademies.org/our-work/assessing-the-physical-and-technical-suitability-of-dod-test-and-evaluation-ranges-and-infrastructure.

requirement, nor are the results of large scale and integrative tests fed back into a program’s design. Consequently, if operational issues arise during a multi-system test, there may not be a mechanism to use those results to modify a system’s design.

Integration is an increasingly important aspect of military weapons and systems. As stated in the 2018 National Defense Strategy, “Success no longer goes to the country that develops a new technology first, but rather to the one that better integrates it and adapts its way of fighting” (DoD, 2018a, p. 10). The increasing interconnectedness and complexity of systems-of-systems is becoming the operational norm and better aligns with the concept of “testing like we fight” than does testing systems separately.

The requirement that systems be able to work collaboratively to satisfy mission objectives results in a need to represent a variety of systems, both friendly and adversary, under test conditions. A relevant example of this system collaboration was reflected in the 2020 Director of Operational Test and Evaluation (DOT&E) Annual Report, which recognized that in the case of a National Space Test and Training Range (NSTTR), currently referred to as a National Space Test and Training Complex, operationally representative threats must simultaneously include “cyber, directed-energy, kinetic, and electronic-warfare threats, as well as natural hazards.” (DOT&E, 2020, p. 3). Additionally, understanding the impact of emerging technologies on mission accomplishment is only understood in the context of its value added to collaborative effects. Measuring and evaluating collaboration between systems as well as the effectiveness and suitability of the resulting system-of-systems (SoS) has become more operationally relevant than testing the capability of any one system in isolation.

The emphasis of this chapter is on the range capabilities needed to assess these systems-of-systems working collaboratively across multiple domains (land, air, sea, space, and cyberspace) and across multiple technologies. The context for this chapter is about improving test range capabilities to support the assessment of multiple concurrent kill chains of systems and technologies and how those systems are connected together within a command-and-control structure to verify and understand the combat effectiveness and suitability within a multi-domain environment. The understanding of kill chains is paramount in assessing a system’s operational effectiveness and suitability as well as the integration of new systems into existing kill chains.

TESTING FOR THE MULTI-DOMAIN BATTLESPACE

The multi-domain battlespace can be represented in a variety of operational views. The operational view depicted in Figure 3.1 is a

representation of how different systems in different domains share information to accomplish an objective or set of objectives.

In the future multi-domain battlespace, “shooters” and sensors both collect data, share that data, information is derived from that data, the data prompts a timely human or autonomous decision, and an appropriate effects-based action results from the data-driven decision. This collaboration of systems represents what the range infrastructure, to include virtual range infrastructure, must support moving forward. DoD ranges must be able to connect with each other, as they gather and analyze data to verify these assumptions, to inform system designs, digital models, acquisition decisions, tactics, techniques and procedures (TTPs), and operational employment decisions.

This committee calls out specific range capabilities and additional enterprise needs that enable these range capabilities in supporting multi-domain and multiple concurrent kill chains. While some of these range capabilities have been highlighted in various reports, the committee paid particular attention to the challenges raised by test range personnel in the site visits and program representatives from the public workshop. The needed test range capabilities to support operational testing of multi-domain systems and multiple concurrent kill chains include:

• High-bandwidth connectivity across ranges, with multi-level security provisions, and common data standards for interoperability (Eglin, Edwards, and Wright-Patterson Air Force bases; Missile Defense Agency [MDA]; Atlantic Test Range at Patuxent River;

Point Mugu; Nevada Test and Training Range [NTTR]) (NASEM, 2021).

• An overarching, cross-range data strategy, processes, and procedures for collecting, storing, managing, and sharing test data (Aberdeen, MDA, Atlantic Test Range at Patuxent River) (NASEM, 2021).
• Capabilities and success criteria for measuring and evaluating collaboration among systems, and end-to-end SoS performance (Eglin, Edwards, and Wright-Patterson Air Force bases).
• The emulation of physical or threat environments that could affect closure of the kill chain in an operational setting (Joint Simulation Environment) (NASEM, 2021).

The enabling enterprise needed to support the above capabilities includes:

• The identification of a process and oversight body for defining kill chain and multi-domain operation (MDO) doctrines and concepts of operation as well as creating cross-program and multi-system test requirements to ultimately drive range capability requirements.
• A defined funding approach to support the execution of “beyond program” multi-domain and multiple concurrent kill chain testing.
• A defined funding approach for sustaining the MDO/kill chain joint infrastructure on the test ranges to last beyond the program funding that originally built the capability.

As DoD advances capabilities in areas such as hypersonics, directed energy, cyber, and artificial intelligence, there will be aspects of multi-domain effects that are essential for understanding how DoD can use these technologies in concert to achieve a desired outcome.

Defining Multi-Domain Operations

Warfighting has long involved multiple domains. For example, Union troops used balloons in the Civil War to help direct artillery (American Battlefield Trust, n.d.). What is different today is how capabilities in different domains are tightly integrated, how much more effective operations can be by taking advantage of such integration, the speed at which information is exchanged, and how new technologies affect the effectiveness of this integrated capability.

In order to modernize range infrastructure to support the operational testing objectives of connected systems in the multi-domain battlespace,

it is necessary for the DoD services to agree on how to define MDOs. In this context the committee refers to the term MDO as a more general description of the concept, rather than the Army’s vision or the joint vision (joint all-domain operations), both of which have appeared with increasing frequency over the past decade. MDO describes operations that extend over more than a single war-fighting domain—land, sea, air, cyber, and space—although the term has been used in other ways as well (Grest and Heren, 2019). For example, a ground mission with air support or the use of a satellite to guide munitions dropped from an airplane are considered MDOs (NASEM, 2018). MDOs can involve multiple platforms, multiple technologies, and the command-and-control systems that enable that integration across platforms or technologies. A true MDO is a tightly integrated combination of different technologies from different domains under command and control that results in a unified war-fighting operation.

Much that has been written over the past few years about MDOs has been in the context of multi-domain command-and-control, with little said about operations (Grest and Heren, 2019). Thus, many references to MDOs in military publications are actually referring to multi-domain command-and-control systems. In today’s military, however, integrated effects from multi-domain systems and command-and-control systems are so tightly coupled that there is little to be gained from distinguishing a difference between them. For example, an F-35 can be considered either a sensor or a shooter, depending on the situation at that moment. At this time, DoD has no formal definition for MDOs but there are multiple interpretations and applications of MDOs.

The Army has developed language to define how MDOs pertain to their domain. It defines MDOs as how they “as part of the joint force [Army, Navy, Air Force, and Marines] can counter and defeat a near-peer adversary capable of contesting the U.S. in all domains [air, land, maritime, space, and cyberspace] in both competition and armed conflict” (CRS, 2021a). Having a defined outcome for MDOs helps clarify strategies to meet Army objectives and provides guidance for congressional oversight. However, the committee noted that the Army’s definition does not specify what constitutes MDOs.

Developing a shared DoD vision on MDOs could align the services in a coordinated approach to ensure that corresponding investments are made in systems needed to successfully test in MDOs. Without a clear definition of MDOs, it is challenging to focus the test and evaluation (T&E) investment strategy to modernize range infrastructure in support of MDO testing. Using MDO objectives and the test parameters that accompany a program’s life cycle may help broaden the currently program-centric acquisition process as well, shaping program requirements and milestones that better align with mission objectives.

The lack of a common definition for MDO has been frequently cited as a challenge to joint force efforts, which are critical for coordinating the services as they work to deter and win future conflicts (NASEM, 2018; CRS, 2021a). A common definition for MDOs will also provide improved coordination for joint allied efforts, such as joint targeting to synchronize fires with multiple military capabilities across allied nations (NATO, 2016). In an effort to develop a common definition, the committee highlights a definition shared at a National Academies of Sciences workshop in November 2018 on multi-domain command and control by Brig. Gen. B. Chance Saltzman (U.S. Air Force) that suits the complex multi-faceted nature of this term:

Multi-domain operations require integration of capabilities in different domains, effectiveness of operations from this integration, and speed of information exchange. These capabilities are achieved by new systems that closely integrate hardware and software while implementing new technological advances. These new types of systems create a new type of system complexity that requires further definition.

Defining Cyber-Physical Systems

A key comment that the director of DOT&E shared when he addressed the committee was that DoD has no definition of complex systems that have both hardware and software components and that software is a major aspect of almost all new weapon systems. The term “cyber-physical system” (CPS) captures the integration of these technologies. CPSs are complex systems consisting of both hardware and software components. This term deserves particular consideration because of its growing relevance to military systems. The F-35 Joint Strike Fighter and AEGIS systems are good examples; both are software-intensive systems with significant platform integration. Both have real-time command and control communications inherent in the successful performance of their desired effects as well as a reliance on other systems to provide sensor information for adequate situational awareness for successful completion of kill chains.

The complex interactions between software and hardware can sometimes be difficult to predict and pose challenges to operational assessment and range capabilities. For example, maintaining positive control and range safety for emerging non-deterministic, learning artificial intelligence (AI) systems is a challenge for test ranges. Aegis’ cooperative engagement capability (CEC) takes advantage of digital communications to enable air, land, and sea forces to share target information in real time; however, software updates to this system can pose challenges to the overall effective operation of the system-of-systems.

While DoD does not currently have a formal definition of CPS, the National Science Foundation issued the following definition in its program solicitation:

This definition could be further expanded for defense purposes to include small and closed systems, such as an on-board oxygen generation system, or a very large, complex, and interconnected system, such as for a networked system on a multi-domain battlefield. Such a definition emphasizes the predominance of software in military systems today and highlights the fact that any combined test, experiment, or exercise for MDO, at its core, is looking at the data connections and vulnerabilities of those connections in understanding mission capability, as illustrated by the F-35 Joint Strike Fighter (JSF) and Aegis systems examples.

Testing Kill Chains

The “kill chain” is a DoD term describing a process of military engagement. Christian Brose’s 2020 book The Kill Chain describes it as

___________________

² National Science Foundation, 2021, Solicitation 21-551, Cyber-Physical Systems (CPS), https://www.nsf.gov/pubs/2021/nsf21551/nsf21551.htm.

“gaining understanding about what is happening . . . making a decision about what to do . . . [and] taking action that creates an effect to achieve an objective” (Brose, 2020, p. xviii). There are different models in use to describe the kill chain; one common model is F2T2EA (find, fix, track, target, engage, assess), but foundationally the processes are the same (Tirpak, 2000). Operational tests can examine how a system integrates into a kill chain and how information is received, processed, and used to create the desired effect.

Developmental test objectives for complex systems often drive significant instrumentation requirements with large amounts of data required to understand how a system behaves. Operational test objectives often have the additional challenge of gathering data across multiple systems as part of an operational environment or chain of events. These developmental and operational test objectives inform test infrastructure requirements for the ranges. However, emerging military technologies in areas such as directed energy weapons and hypersonic missiles are increasing the physical and technical demands on the nation’s test ranges that affect the ranges’ abilities to successfully conduct operational testing that examines a full engagement kill chain.

The committee separated the assessment of test range capabilities from the perspective of testing a kill chain around a single system and then the additional challenge of a full multi-domain test, which involves the convergence of multiple kill chains across several systems. Traditionally, programs test parts of a kill chain in isolation in order to satisfy their programmatic decision needs. For instance, a test may focus on whether a given target could be identified and located, initiating a decision to attack it with a particular weapons system. In this case, the objective of the test is understanding if the weapon functions as intended. This focused testing is important, but to ensure operational effectiveness it is also crucial to test the entire kill chain as an integrated system to look for weaknesses in how the various pieces of the kill chain fit together.

As an example, for an aircraft-mounted high energy laser system a developmental test objective could be to assess the performance of the system from the power output compared to the design requirement against a given target. An operational kill chain test objective would examine how that directed energy system receives target information from different sensors, determines decisions to engage a target, interfaces with an operator, understands the engagement itself, and uses information to assess the effectiveness of that engagement. The operational test would also represent the physical and threat environment the system under test could encounter.

Figure 3.2 illustrates a kill chain testing scenario. In the figure, a friendly aircraft targets an enemy (red) ballistic missile transporter erector

launcher (TEL) through the MDO connected, concurrent kill chain cyber-physical system construct. Examination of this scenario through an observe-orient-decide-act (OODA) kill chain framework, the test evolves as follows:

Observe:

• A reconnaissance drone operated by forward deployed special operations team finds, locates, and transmits the TEL information (labeled A) to the joint command and control (C2) network.
• A reconnaissance drone, potentially operated by forward Special Operations Forces (SOF), or even as part of an automated C2 system orchestrating the find, fix, track, target (F2T2) activities of multiple sensors across domains.

Orient:

• Space and aerial electro-optical and infrared (EO/IR) sensors are tasked and attempt to identify viable time critical TEL target and, once it is identified, to provide information to the C2 network.
• Space sensor assets are tasked and, aided by EO/IR and other sensors, track of target is obtained among representative ground clutter.
• Geo-location is handed off to F-35 and C2 network.
• A land- or sea-based radar emitter provides signal for F-35 passive radar with synchronization of emitter and receiver over the network.

• F-35 tracks red TEL via passive radar among representative clutter.

Decide:

• Advanced C2 framework gathers sensor data, assesses available capabilities, and designated authority makes decision to employ F-35 to take action to strike TEL.

Act:

• F-35 deploys a small swarm or kinetic weapon while wing-men execute non-kinetic electronic or cyber-attack to confuse or degrade radar operations long enough for strike to be successful.
• Cognitive electronic warfare (EW) jamming of enemy representative radars (labeled B) occurs throughout mission, requiring active deconfliction with blue communications and radar signal.

Post/concurrent kill chain and assessment:

• Fighter aircraft (Air Force or Navy) intercept and destroy enemy aircraft (red outlined aerial targets in Figure 3.2, labeled C) over the critical area of a combat zone.

The MDO connected, concurrent kill chain, cyber-physical system construct requires that test planning accounts for more dynamics and blue and red force assets than traditional testing. In addition to the red force assets described in Figure 3.2, the scenario requires space-based sensors, airborne sensors, airborne jamming, land- or sea-based radar emitters, strike aircraft, and space-based communications assets be considered in test range planning.

Some range-based capabilities required for the MDO connected, concurrent kill chain cyber-physical system construct example are that Range 1, Range 2, and the Virtual Range, as depicted in Figure 3.2, are connected with adequate bandwidth, availability of type and quantity representations of red capabilities, blue and red force monitoring for truth data, range coordination command and control, adequate distance for weapon type, and adequate electromagnetic spectrum for communications, radar, and jamming. Some range measurement capabilities are also required for sensor performance, communication performance, command and control performance, weapon effects, environmental factors and situational awareness of blue forces. These combined capabilities are currently limited for operational testing.

There are additional limitations to DoD test range capabilities for conducting end-to-end testing of kill chains. In testimony provided to the committee, Lt. Gen. Neil Thurgood, Director for Hypersonics, Directed Energy, Space and Rapid Acquisition in the Office of the Assistant Secretary of the Army, shared how a lack of a secure communications network among the test ranges is one of several challenges that constrains

testing for hypersonic programs. Since hypersonic vehicles can travel thousands of miles, multiple test ranges need to collaborate throughout a vehicle’s trajectory. Thurgood pointed out that the ranges were not originally developed for concurrent and collaborative testing; most ranges are not connected via secure communication lines and there is a lack of common processes or procedures for ranges to collect, store, manage, or share test data.

In a virtual site visit to the Eglin/Edwards/Wright-Patterson Air Force bases, representatives agreed that the ranges face rapidly growing operational needs to conduct end-to-end and concurrent kill chain testing. In future combat, systems will need to connect and interact with other systems across multiple domains and in a multi-player environment. This need was one of the factors that led to the creation of the Emerald Flag exercise in 2020. Emerald Flag exercises, which to date have been conducted at Eglin Air Force Base, provide a realistic operating environment linking ground, air, and space systems together to demonstrate joint and multi-domain operational capabilities, while identifying tangible shortcomings to these systems.

Representatives from Eglin/Edwards/Wright-Patterson shared how Emerald Flag is a promising example of how ranges can test and evaluate connected and concurrent kill chain reactions. However, these exercises both produce and require large volumes of test data, and most test range infrastructure is currently inadequate for conducting simultaneous data-intensive activities. A further challenge to testing concurrent kill chains is combining data across multiple levels of security. This is especially the case for providing real-time data, since several ranges reported challenges with data sharing both from a policy perspective on what data is exchanged and technical perspective in terms of sufficient bandwidth. Chapter 4 provides a more detailed description about the data challenges facing the test ranges.

While the Emerald Flag exercises bring testing a step closer to “testing like we fight,” these exercises are rare, and test ranges do not currently have the infrastructure or capacity to support similar comprehensive testing of connected and concurrent kill chains. Additionally, participation in Emerald Flag is voluntary and based on interest and availability at the program level—there is no oversight from service leadership or OT&E to coordinate programs or determine the objective of the exercises. It is essential for both program managers and leadership in the testing community to recognize that kill chains do not occur in a vacuum, but as a greater mission-oriented action often across multiple domains.

Connected, concurrent kill chains will increasingly become the norm as cyber-physical systems with new technology are developed. These systems will require test planning requirements to expand beyond those applying to a single program to achieve the required insight into the

systems’ effectiveness and suitability. Bridging siloed service tests and activities will require that a joint forces approach be developed.

A JOINT PROGRAM OFFICE TO SUPPORT DOD MULTI-DOMAIN TESTING NEEDS

A central feature of test and evaluation in DoD is that it is shaped by program requirements set during their acquisition process. This model works well in tailoring the ranges and range resources to support specific weapon systems or specific technology development but breaks down when cyber physical systems become more prominent and paradigm shifts in technology change the nature of warfare through greater interactions between individual weapon systems and technology.

DoD’s Central Test and Evaluation Investment Program (CTEIP), managed by the Test Resource Management Center (TRMC), is DoD’s corporate investment program which was established to modernize the DoD test infrastructure. Chapter 5 provides greater detail on test range funding, but it is worthwhile to note that a challenge for the current funding framework is that even if a network of test ranges secures CTEIP funds to build some infrastructure to support multi-domain and kill chain testing, there is no clear funding stream for the sustainment of that joint infrastructure and funding the execution of the testing if that infrastructure does not trace to program needs.³

___________________

³ Department of Defense (DoD), 2004, “Department of Defense Test Resource Management Center (TRMC),” DoD Directive 26 (DoDD) 5105.71, March 8, https://www.esd.whs.mil/Portals/54/Documents/DD/issuances/dodd/510571p.pdf.

Our nation’s superiority in future combat requires the appropriate fielding of programs and systems capable of seamlessly connecting kill chains in a multi-domain environment. The services and program managers overseeing current tests have overlapping and sometimes conflicting requirements and objectives tied to specific programs. Even when there is a recognized need for a test to demonstrate and evaluate the integration of a given system, a large scale test can be cost prohibitive for any one program. Additionally, if a program has funding for an integrated test, the test will likely be bounded to the objectives of the given program and not a full kill chain. There is a need for an environment that is available for programs to participate in to meet their objective but that can also address broader strategic questions related to the integration of multiple systems and technologies across a representative kill chain.

The testing of systems of systems is not new, and a finding of this study is that there are admirable emerging efforts like Orange Flag and Emerald Flag, which have been created to test systems of systems in a multi-domain environment. These have been executed thus far through dedicated efforts of key individuals and funded by pooling resources of participating programs with the objectives of a given exercise shaped by those programs. A concern from this study is how sustainable these efforts are without some dedicated program or office with associated funding to support the sustainment and growth of these capabilities and also how these tests can support not just the program objectives but broader Combatant Command, Joint Staff, or other DoD multi-service objectives. Based on testimony from the public workshop, the services and DOT&E agree that multi-systems testing is critically important, but those tests are ultimately limited by the specific scope of a given program (NASEM, 2021).

There is currently a Joint Test and Evaluation (JT&E) program, but its focus is on concepts of operations for specific use cases that are proposed and approved as stand-alone individual efforts. The primary objective of JT&E is to provide rapid solutions to operational deficiencies identified by the joint military community by developing new tactics, techniques, and procedures (TTPs) and rigorously measuring the extent to which their use improves operational outcomes.⁴ JT&E as it is currently organized is not a mechanism to connect mission threads, broad DOT&E test objectives, and the recurring execution of multi-system tests at events like Emerald Flag to address those objectives.

The committee determined that a need exists for a joint program office to enable experimentation and testing of connected concurrently executed kill chains across systems and technologies in a sustained manner to

___________________

⁴ DoD, “FY19 Joint Test and Evaluation (JT&E) Program,” https://www.dote.osd.mil/Portals/97/pub/reports/FY2019/other/2019jte.pdf?ver=2020-01-30-115602-597.

assess mission-level capabilities and operational employment. The intent is to provide the means for recurring test events that can provide a “sandbox” that various programs can participate in to meet their program needs and that can address broader strategic objectives. The services and Major Range and Test Facility Base (MRTFB) leadership would still have responsibility of the test execution. This joint program office would include joint service representatives and work with offices in the Joint Staff, Combatant Commands and efforts like the Innovation Steering Group to define key mission threads and information needs related to the integration of domains and emerging technologies in those mission threads. The TRMC and service T&E budgets would still fund the test infrastructure and modernization efforts, and the joint program office would help fund the sustainment of the capabilities for multi-domain tests and the execution of those test events. The program office would work with existing DoD agencies to address cross-service policy and standards that are barriers to these types of tests, to work with Joint Staff on mission threads and with operational and developmental test and evaluation experts on system-of-systems test objectives that will inform test infrastructure requirements, and to identify and provide funding for the execution of those tests that are not part of specific program objectives. This office would include representatives from Joint Staff, combatant commands (COCOMs), the services, the Office of the Secretary of Defense Research and Engineering (OSD (R&E)), and DOT&E.

The committee does not intend to be overly prescriptive concerning the structure of the joint program office because it expects the office will both want and need space to grow and adapt as needed over time, and its success will depend in no small measure on decisions regarding its funding and authorities. A potential location for a joint program office as described above is the Joint Staff J8 Force Structure, Resources, and Assessment Directorate, since COCOMs J8s similarly plan and oversee joint warfighter technology demonstrations. An alternative is that this is an office that falls under the oversight of DOT&E similar to the current JT&E office or it is a growth and expansion of the current JT&E mission. DOT&E currently has the authorities necessary to establish the recommended office.

The committee envisions that this effort would:

1. Reside in DOT&E and report to a committee chaired by the DOT&E and consists of representatives from the Joint Staff, COCOMs, the services, and R&E;
2. Establish clear definitions for “multi-domain operations” and “cyber-physical systems”;
3. Lead an effort across Joint Staff elements to define representative multi-domain use cases as well as OT&E objectives and range testing requirements;
4. Work with COCOMs on operational community needs for test information/results to inform operations;
5. Work with technology prototype efforts, e.g., Joint Capability Technology Demonstration, to understand and inform test objectives related to the integration of new technology to enable rapid capability integration;
6. Provide inputs to programs and services on needed future developments based on MDO test results;
7. Provide and advocate for funding to support execution of multi-domain test events and sustainment of capabilities needed to execute those events;
8. Assist with the prioritization of MDO and kill chain tests and associated test resources; and
9. Establish a shared, accessible, and secure modeling and simulation (M&S) and data ecosystem to drive integrated development and testing across the life cycles of multiple supporting programs.

Throughout the remainder of this report specific needs for testing MDOs and connected, concurrent kill chains will arise. The challenge of future testing will be the availability of the minimal set of range capabilities to adequately test the effectiveness and suitability of new systems within this environment. Specific range capabilities, as well as additional enterprise capabilities, are necessary to adequately achieve this minimal set of range capabilities. Box 6.1 in Chapter 6 provides a summary of the necessary range capabilities highlighted throughout this report that are critical for meeting operational testing needs through 2035.

MITIGATING ENCROACHMENT TO SUPPORT FUTURE COMBAT TESTING

Figure 3.2 illustrates the growing size and complexity of the battlespace. As the battlespace becomes larger and more dynamic to encompass interacting systems across multiple domains, the demand for mission

space for testing increases. With next-generation weapons that can fly, sail, or drive faster and farther than before, as well as interface with a variety of communication networks, test ranges require more mission space and broad access to the electromagnetic spectrum; however, the testing community is facing a reduction in mission space and a narrowing operating area within the electromagnetic (EM) spectrum.

The DOT&E, the Government Accountability Office (GAO), the TRMC, the Readiness and Environmental Protection Integration (REPI) program, and the MITRE Corporation have all recognized that retaining adequate mission space to meet test requirements is critical (DoD, 2020b; DOT&E, 2020; GAO, 2017; Lachman et al., 2007; MITRE, 2007, TRMC, 2010). The 2018 Sustainable Range Report also highlighted this challenge by noting that “emerging technologies such as hypersonics, autonomous systems, and advanced subsurface systems will require enlarged testing and training footprints.” (DoD, 2018b). This concern was echoed by the service test and evaluation executives and program representatives at the public workshop (NASEM, 2021), and representatives from the MDA and NTTR noted that encroachment was a growing concern for conducting operational tests at their locations.

In the context of DoD test ranges, encroachment refers to any factors that obstruct, impede, or suppress the ability of the test community to conduct operational test and training exercises. DoD Directive 3200.15 (DoD, 2013) defines encroachment as “external, as well as internal, DoD factors and influences that constrain or have the potential to inhibit the full access or operational use of the live training and test domain.” Encroachment inhibits full access to the live training and test domain by restricting access to the resources necessary to conduct tests. This can be the physical space, or ranges, controlled by the services, which provide the backbone of test area for the test and evaluation community. Because the majority of current and next-generation weapon systems are dependent on the electromagnetic spectrum, encroachment of the electromagnetic spectrum can also inhibit the operational use of these domains (CRS, 2021b).

Encroachment was recognized when GAO reported in 2002 that DoD lacked a comprehensive plan to manage encroachment on ranges that dealt with test and training operations (GAO, 2002). In an attempt to address emerging encroachment concerns, Congress established the Conservation Partnering Program (CPP) and Sustainable Ranges Initiative (SRI) to collaborate with community organizations and provide investments to create exclusion areas around test and training locations. The CPP is currently known as REPI.

A 2007 assessment of the REPI program by the RAND Corporation found that it appeared to be successful to that point but that more could

be done to protect DoD mission space (Lachman et al., 2007). The report’s recommendations included suggestions that DoD address fundamental causes of encroachment, increase OSD and service investments, and develop additional local partnerships. Following the release of the report, OSD, the services, and DOT&E developed mitigation efforts to address encroachment concerns. A 2016 GAO report outlined these efforts and provided a framework for implementing additional collaborative mechanisms to prevent and mitigate encroachment (GAO, 2016).

With mission space limited, which is a perennial issue for the test community, mission capability will be lost as programs become limited in what they are able to test on a live range. At the committee’s January workshop, Conrad Grant, the chief engineer at Johns Hopkins University Applied Physics Laboratory, explained that programs are not able to replicate live end-to-end testing for boost-glide hypersonic vehicles and ballistic missile defense systems (NASEM, 2021).

An example of a recent high-profile encroachment concern occurred at the Eastern Gulf Test and Training Range (EGTTR). Managed by Eglin Air Force Base, EGTTR controls more than 120,000 square miles of airspace and has historically been protected from encroachment under the 2006 Gulf of Mexico Energy and Security Act,⁵ which set a moratorium on oil and gas exploration near the EGTTR.⁶ This moratorium was set to expire in 2022 until the Trump administration issued a memo extending the moratorium to 2032.⁷ While this memo extended the moratorium, it highlights the fragility of the mission space available to DoD. This memo can be reversed at any time, leaving EGTTR vulnerable to the loss of critical mission space, even as plans are being put into place to expand the reach of EGTTR to allow for testing of 5th and 6th generation weapon systems through the Gulf Range Enhancement Program.

Persistent External Encroachment Threats

DoD Directive 3200.15 distinguishes between encroachment caused by external factors and encroachment caused by internal factors (DoD,

___________________

⁵ Gulf of Mexico Energy Security Act of 2006, United States Congress 1331, https://www.boem.gov/sites/default/files/oil-and-gas-energy-program/Energy-Economics/Econ/GOMESA.pdf.

⁶ Testimony from Protecting and Securing Florida’s Coastline Act of 2019, Congressional Record, Volume 165, Number 145, September 11, 2019, https://www.govinfo.gov/content/pkg/CREC-2019-09-11/html/CREC-2019-09-11-pt1-PgH7622.htm.

⁷ Presidential Memoranda, “Memorandum on the Withdrawal of Certain Areas of the United States Outer Continental Shelf from Leasing Disposition,” September 8, 2020, https://trumpwhitehouse.archives.gov/presidential-actions/memorandum-withdrawal-certain-areas-united-states-outer-continental-shelf-leasing-disposition/.

2013). Figure 3.3 illustrates the external encroachment threats identified by the REPI program from fiscal year 2020 (DoD, 2020b). Encroachment concerns have continued to rise in recent years, with noise complaints, residential and commercial growth, environmental impacts, and spectrum use the leading causes for concern (DoD, 2018b). Land encroachment, like construction projects, can bring residential areas closer to DoD ranges and threaten testing operations. For example, a rifle range at Camp Butner in North Carolina was shut down due to encroachment from noise complaints, and it is believed helicopter and other training operations will soon be restricted by further noise complaints (DoD, 2020b). Additionally, windmill farms can adversely impact military activies by interfering with air defense radars and increasing ambient seismic noise levels (DoD, 2006). Additional areas of external encroachment include peer and near-peer surveillance using drones, satellites, and other equipment as well as commercial customers using range telemetry and altimeter resources.

A recent example of external encroachment comes from NTTR. The Desert National Wildlife Range (DNWR) placed restrictions on operating areas for NTTR activities in 2016. The affected area, primarily on the south range, is used by NTTR to conduct flight testing, classified research and development projects, and weapons tests (Aftergood, 2020). A 2017 proposal that would have expanded protected areas for NTTR to operate was

denied.⁸ Often referred to as the NTTR Land Withdrawal Strategy, this proposal was intended to protect the land needed to conduct test operations. Representatives of NTTR expressed concern during the committee site visit that the rejection of this strategy will directly lead to the loss of mission capability (see Appendix B).

Naval test ranges face encroachment from windmill farms off the Virginia and North Carolina coasts, which threaten to infringe on the already limited available space on Atlantic test and training ranges (Niiler, 2019). Naval Base Kitsap also suffered from noise encroachment due to increased acoustic interference from surrounding vessels, forcing a response from the REPI program to ensure that missions at Naval Base Kitsap could continue (DoD, 2020b). Windmills also interfere with radars used in testing processes (DOE, 2018).

Electromagnetic Spectrum Encroachment

External encroachment also includes the declining access to various bands of the electromagnetic spectrum. Spectrum encroachment is not a new issue. A 2007 MITRE report identified a “crisis” of insufficient spectrum for the flight test community, which was affecting aeronautical telemetry for the transmission of real-time data during flight tests. Since then, a number of efforts have been undertaken to limit the sell-off or sharing of EM bands deemed critical to the T&E community for testing (MITRE, 2007). However, emerging technologies have complicated this mitigation process. The Radio Technical Commission for Aeronautics released a report in October 2020 recognizing that 5G transmitters cause interference with the radar altimeters used for commercial and military aircraft even though 5G has its own unique bands of operation separate from those used for radar altimeters (RTCA, 2020). This interference directly hinders the ability of the U.S. Air Force to conduct end-to-end system testing in a live setting.

During a committee site visit, representatives from NTTR said that they recognized that spectrum issues currently exist and that they expect them to become even more pressing in coming years. They noted that NTTR no longer receives requests for GPS jamming because they cannot obtain approval from commercial and other government agencies to conduct jamming tests.

The external encroachment from the loss of spectrum directly affects the ability to validate system performance against threat systems. As opposed to telemetry data use of the spectrum, DoD does not have control

___________________

⁸ “Proposal to Withdrawal and Reservations of Public Lands in Nevada to Support Military Readiness and Security,” https://fas.org/man/eprint/ndaa-2021-prop/04172020-nevada.pdf.

over where the threat frequencies of U.S. adversaries will operate in operational situations. As a result, frequency sell-off in certain wavelengths removes the ability to conduct operational testing against those threats in a live environment. In addition, the loss of spectrum will lead to fielding systems that have not undergone extensive testing in the EW and other spectrum-related arenas.

The committee recognizes that spectrum sharing for DoD is a necessity. This necessity, however, does not preclude the need for bands to be reserved solely for DOT&E testing of systems that require exclusive access to certain bands within the spectrum. Adopting a successful spectrum management strategy is critical to retaining control of the electromagnetic spectrum to ensure that systems have the required frequencies available for proper operation.

The development of a spectrum management strategy could be initiated by DOT&E by conducting a review and identifying critical bands within the spectrum that are necessary for the operational testing of next-generation weapon systems at live ranges. DOT&E would then collaborate with stakeholders and recommend action to protect those critical bands so that live testing of EW and other weapons will be able to take place on next-generation weapon systems. While previous studies have focused on spectrum loss from a telemetry data perspective, the following recommendation is focused on the need to identify operational risk and impact of threats that cannot be tested against in a live environment due to spectrum sell-off:

Internal Encroachment Challenges

Internal encroachment refers to actions taken by DoD that result in encroachment. Increased demand and tempo at ranges can lead to actions that restrict the ability of test groups to perform the full range of necessary tests. An example of this is when the 7th Special Forces Group was moved to Eglin AFB as a result of the 2005 Defense Base Closure and Realignment Commission, which recommended the move as “an opportunity to achieve outstanding joint training through its collocation with the Air Force Special Operations Command” (DBCRC, 2005). Personnel from the Eglin/Edwards/Wright Patterson Air Force bases site visit discussed how a new compound for the 7th SOG (Studies and Observations Group) was placed into the center of test space at Eglin Air Force Base. This action directly resulted in the cancellation of 29 operational test profiles, including major test programs like the F-16, Small Diameter Bomb test program, Joint Standoff Weapon, and several other classified test programs. There are examples where the movement of range equipment (both radiating and non-radiating), uncoordinated with test operations have resulted in test anomalies and “no test” results, causing significant unplanned analyses and the unnecessary consumption of critical test assets that have delayed the Initial Operating Capability (IOC) of major systems by months or even years.

As evidenced by the increase in encroachment concerns since 2001, external encroachment from business, residential, and foreign entities will be a constant challenge in the future and will require mitigation strategies spanning from the development of bladeless wind turbines to land preservation negotiations to mapping noise corridors (GAO, 2016). These strategies, however, are either already being pursued by programs such as REPI or are outside the scope of this study. While the committee recognizes the existence of external encroachment issues, efforts are under way to create frameworks and recommendations for mitigating these concerns.

There is, however, a lack of literature on internal encroachment issues and how they might be mitigated. By definition, internal encroachment is caused by DoD and thus offers DoD an opportunity to limit the impacts

of encroachment in coming years by restricting actions taken within the department to limit the space available for test and training operations.

Given that there already exists a program to identify and mitigate external encroachment issues facing the test ranges, rather than suggest the establishment of a new program, the committee recommends the following:

Encroachment Challenges for Next-Generation Systems

As next-generation weapon systems enter OT&E, their onboard systems and sensors, as well as the ability for multiple platforms to integrate and act collectively, exceed the capabilities of current ranges and the existing range capabilities constrain the ability to test these advanced systems. In the case of hypersonic weapons, the significant increase in sustained speed, distance, and impact of these weapons coupled with the number of programs pursuing this technology result in tests that exceed the capabilities of historic approaches and test locations. These constraints were voiced to the committee at their March 4, 2021, meeting by Michael White, the principal director for hypersonics, who used the phrase “string of pearls” to describe how testing will have to be conducted going forward. “String of pearls” refers to the integration of multiple ranges together in a single hypersonic test in order to track the hypersonic vehicle throughout the entire trajectory of the flight (Spravka and Jorris, 2015). This string-of-pearls issue also faces space testing, long-range precision fires, and intercontinental ballistic missile (ICBM) operational testing.

Spectrum encroachment issues will become more pronounced as next-generation weapon systems enter OT&E. Any further restriction on spectrum access will “directly impact DoD’s ability to conduct live

training” (DoD, 2018b). EW systems, for example, are classified as spectrum dependent systems (SDS) which require the use and control of spectrum resources. DOT&E testing generally contains requirements for systems to test using spectrum in the live environment for either electronic attack (EA), electronic protection (EP), or electronic warfare support (EWS). The loss of spectrum has resulted in nonrealistic training scenarios and limited the ability to execute TTPs.

Given the existing encroachment issues facing U.S. military ranges, the growing need for adequate physical and spectrum space in which to conduct tests, and the difficulty of expanding the physical and spectrum boundaries of ranges within the United States, one potential approach would be to cooperate with foreign allies to invest in additional test range space. As an example, Australia in particular has physical space that is expansive enough for hypersonic weapon testing, and a collaborative agreement could allow both countries to test new military technologies and scenarios over much larger areas than currently available to the United States. These efforts are permissible through 10 U.S. Code §2350l, which gives authority to the Secretary of Defense to enter an agreement with a foreign country to provide testing of U.S. defense equipment at that country’s test facilities.⁹ Military testing cooperations with foreign countries are overseen by the International Test and Evaluation Program (ITEP), which is managed by DOT&E. Given TRMC’s authority to maintain awareness of testing needs for current and future technologies, they are suitable for determining the use and investment strategies for testing military systems abroad.

___________________

⁹ United States Code, 2012 Edition, Supplement 2, Title 10 - ARMED FORCES. https://www.govinfo.gov/content/pkg/USCODE-2014-title10/pdf/USCODE-2014-title10.pdf. Accessed June 22, 2021.

REFERENCES

NASEM. 2021. Key Challenges for Effective Testing and Evaluation Across Department of Defense Ranges: Proceedings of a Workshop–In Brief. Washington, DC: The National Academies Press. https://doi.org/10.17226/26150.

NATO (North Atlantic Treaty Organization). 2016. AJP-3.9 “Allied Joint Doctrine for Joint Targeting.” https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/628215/20160505-nato_targeting_ajp_3_9.pdf.

Niiler, E. 2019. “The Military Is Locked in a Power Struggle with Wind Farms.” Wired. May 20. https://www.wired.com/story/the-military-is-locked-in-a-power-struggle-with-wind-farms/.

RTCA (Radio Technical Commission for Aeronautics). 2020. Assessment of C-Band Mobile Telecommunications Interference Impact on Low Range Radar Altimeter Operations. Washington, DC. https://www.rtca.org/wp-content/uploads/2020/10/SC-239-5G-Interference-Assessment-Report_274-20-PMC-2073_accepted_changes.pdf.

Spravka, J.J., and T.R. Jorris. 2015. Current Hypersonic and Space Vehicle Flight Test and Instrumentation. Edwards Air Force Base, California. https://apps.dtic.mil/sti/pdfs/ADA619521.pdf.

TRMC (Test Resource Management Center). 2010. FY2010 Annual Report. Washington, DC.

Tirpak, J.A. 2000. “Find, Fix, Track, Target, Engage, Assess.” Air Force Magazine. https://www.airforcemag.com/article/0700find/.