Reaching Farther, Risking Less

Remotely Crewed Systems’ ISR Applications for Great Power Competition

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The Issue

As the world returns to great power competition, remotely crewed systems play an important role in intelligence, surveillance, and reconnaissance (ISR) work in contested spaces; this brief examines the Department of Defense’s development and procurement for remotely crewed systems, comparing its budget and strategy. While remotely crewed systems’ most important contribution is mitigating the risk of physical harm to the warfighter, they offer additional advantages including longer flight duration, increasing the number of passes craft can make and the fidelity of information obtained, and lower costs per effects, including both purchase costs and costs per flying hour. While the Air Force established an early lead in remotely crewed systems’ use and the majority of systems remain aerial, recent years have seen a steep decline in budget dedicated to Air Force remotely crewed systems, perhaps reflecting a shift to classified systems. Recent trendlines also indicate a marked increase in Navy spending, a portion of which has fueled growth in remotely crewed maritime systems.


Almost as soon as humans could become airborne, militaries have been searching for assets from the air.

The first military observation plane went into the air just six years after the Wright Brothers flew at Kitty Hawk—and from the first days of U-2 surveillance, finding the object of the mission while avoiding detection has centered on aerial assets flying higher and faster.1 Half a century after that first observation plane, remotely crewed systems made their first large-scale strategic appearance in the Vietnam War. Now, half a century after that finds a world returning to great power competition with an intense race to develop and build remotely crewed systems.2

A July 2021 paper by CSIS’s Seth Jones outlined one of the greatest challenges in great power competition as hiding and finding; that is, finding the assets and maneuvers our adversaries attempt to conceal.3Not only does this challenge place a greater weight on the intelligence, surveillance, and reconnaissance (ISR) mission set, but it also marks an operational shift toward contested spaces. As the focus of the ISR mission tightens around these challenges, more effort will be spent against adversaries and near-peer competition—a theme which shaped the March 2020 force postures of the U.S. Air Force, U.S. Army, and U.S. Navy. Their renewed emphasis on contested environments and classified systems, for both crewed and remotely crewed systems, would have felt familiar in the 1960s.

But while the challenges may rhyme, technology has changed the melody: remotely crewed systems represent an important opportunity for fewer people to be at risk even as the ISR mission penetrates farther into contested environments. While their most important use is removing service members from dangerous environments, remotely crewed systems also have the potential to reduce the cost per flying hour even while keeping machines in the air longer and increasing the range and fidelity of the information obtained. These benefits are particularly powerful for the ISR mission, where persistence and access are first-order priorities. With increased emphasis on rising great power competition amid declining troop numbers, remotely crewed systems have the demonstrated ability to help mend the gap while ensuring that the “finding” mission continues to succeed. If great power competition results in high intensity conflict, remotely crewed systems may provide additional advantages in terms of production costs and manufacturing time that would prove significant in a conflict with high attrition rates.

This brief examines the United States’ current and future plans for remotely crewed systems by performing a comprehensive review of the remotely crewed portfolio and providing a data source that tracks remotely crewed spending across the Department’s budget. While the paper focuses on the ISR mission set, it will identify and analyze trends across all types of remotely crewed systems. After establishing a definition for what is and is not a remotely crewed system, the brief establishes the growing intersection of remotely crewed systems and the ISR mission. While the overlap between the two is incomplete, over 90 percent of remotely crewed systems are used in support of ISR today. Some of the key challenges include contested environments, reduced manpower, and classified environments. The brief then analyzes the remotely crewed systems investment portfolio that might respond to those challenges, focusing specifically on system development and a few key technologies. This analysis will show what differences, if any, exist between the Department’s current strategy and the platforms it is currently developing and fielding.

Defining Terms

While “remotely crewed system” is often presumed to be a direct transliteration of unmanned aircraft system (UAS), for the purposes of this paper, the former is intended to be a far broader category. In this brief, remotely crewed systems include UASs, but also ground- and sea-based systems. As evidenced in Figure 1, aircraft may comprise the largest single subcategory of remotely crewed vehicles, but missile defense, ground systems, and shipbuilding also comprise substantial parts of the landscape.

The bounds of the category are systems that are primarily operated remotely (and so are not autonomous), can be controlled during their operation, and are intended to complete a return journey. This excludes equipment that is simply launched for a single, non-return journey, such as missiles. Satellites also share traits with remotely crewed systems but are excluded due to crucial differences that come with operating in space, where all military satellites are remotely crewed.

For budgetary purposes, this analysis looks at remotely crewed systems that have their own distinct budget line.4 This is a strict criterion that enables a comparison over a greater number of years, but that excludes a mix of support systems, payloads, integration efforts, and broader research topics that fund both remotely crewed and crewed systems. This approach also excludes optionally crewed vehicles, such as the Army’s Optionally Manned Fighting vehicle or Future Attack Reconnaissance Aircraft. These platforms are making major investments in remote capabilities but delivering a crewed vehicle on schedule may take priority for early iterations. A limitation of this approach is that it does not include a variety of portfolio-related programs, especially for counter-mine efforts, that group remotely crewed efforts among a variety of other programs.5This approach to the data also includes little Defense Advanced Research Projects Agency (DARPA) or Strategic Capabilities Office (SCO) funding for uncrewed systems. The former agency is especially notable as an important driver of early-stage research, but its budget lines often intermingle remotely and traditionally crewed development funds, precluding those lines from the exclusively remotely crewed definition used in this paper.

The data for this report is drawn primarily from budget requests from 1999 onward for the research, development, test, and evaluation (RDT&E) and procurement titles of the president’s budget, building on work done by the CSIS Defense Budget Analysis Program;6 a full list of all of the program elements (PEs)/line items the authors identified as being for uncrewed systems is included in the appendix. This paper uses March 2020 force posture statements as a bridge between posture statements historical enough to have affected multiple budget requests, yet recent enough to reflect current strategy.

Enabling the ISR Mission

The predominant use for remotely crewed systems has historically been ISR, and this section will discuss several of the ways that remotely crewed systems, including UASs, support the ISR mission. The services’ 2020 force posture statements reflect how critical remotely crewed systems will become. In a contested environment, these systems remove the risk of physical harm to the warfighter, while also offering additional competitive advantages for the return to great power competition. Remotely crewed systems also have the ability to stay in the air longer than their traditional counterparts, extending reach and increasing the volume of intelligence gathered, even as they can be deployed more cheaply per flying hour.7

Indeed, ISR is perhaps the primary driver of remotely crewed systems’ growth. The predominance of such systems in ISR applications makes sense: while transmitting operational commands from remote locations can lead to a damaging delay in combat situations, this typically does not have a significant effect on an ISR mission set, making remotely crewed systems leverageable with relatively little mission cost. The importance of remotely crewed systems in the ISR mission is also backed by market numbers. According to the Boston Consulting Group, in the last few years alone, investment in UAVs has grown “at roughly 5 percent per year since 2013, outpacing the growth rate of the total airborne ISR market (3.9 percent). . . . Demand, both global and domestic, continues to grow at a faster rate than overall defense spending.”8

In addition to posture statements from individual services, there is a robust need for remotely crewed ISR capabilities from Unified Combatant Commands (COCOMs). An integral part of meeting this need has come from ISR transfer funds rather than standard budget lines; the resulting lack of a comprehensive dataset presents a challenge to analysis. The 2020 Intelligence, Surveillance and Reconnaissance Request’s $100.3 million transfer includes several small remotely crewed aerial assets, as well as additional funds for high altitude assets, reflecting many of the overall budget patterns which will be discussed in more detail later in this brief.9 The ISR transfer fund was eliminated from the FY21 appropriations bill, and the Department of Defense (DoD) has not requested its inclusion in the FY22 request.

Contested Environments

When remotely crewed systems became more prominent in the early aughts, the post–Cold War order found the U.S. strategy suddenly bereft of a single defining adversary. While remotely crewed systems were able to prove their worth in counterterrorism and counterinsurgency operations in this period, questions remained whether that utility could be as readily applied against more sophisticated adversaries. As policy has more recently shifted back to great power competition, UAVs have found a crucial role in entering contested environments. The Air Force’s Next Generation ISR Dominance Flight Plan 2018–2028 “reorients the ISR Enterprise by aligning ends, ways, and an initial assessment of means to shift from a manpower-intensive permissive environment to a human-machine teaming approach in a peer threat environment.”10

In 2020, all services delivered force posture statements to Congress—and all their force postures proposed using remotely crewed systems to advance into contested space. In their statement to Congress on the Department of the Navy’s 2020 force posture, Acting Navy Secretary Thomas B. Modly, Admiral Michael M. Gilday, and General David H. Berger said the MQ-25, the Navy’s first unmanned carrier-based aircraft, will both extend the services reach and lay "the foundation for integrating unmanned air power into our carrier fleet,” which "extends the lethal strike range of the CVW into denied areas.”11

The Army statement by Hon. McCarthy and Gen. McConville said, “we will increase our competitive aviation advantage with next generation aircraft designed to penetrate contested airspace and support independent maneuver from greater distances through extended range, endurance and lifting capacity” as part of its Future Vertical Lift (FVL) modernization priority. The statement continued, stating that “over $800M is included in the FY21 President's Budget to develop initial designs and unmanned demonstration systems” under the FVL initiative.12 Some FVL systems may take substantial additional research before use, as, for example, current helicopters’ radar signals make them a challenge to use in contested airspace. Remotely crewed systems will likely act as the vanguard for future FVL systems in two key ways: they will be used years earlier than the FVL systems, which are slated for a first unit equipped in 2030,13 and remotely crewed systems will likely be sent into contested spaces first. Systems planned for that vanguard include the FVL’s Air-Launched Effects (ALE) systems, which are specifically designed to be remotely crewed; the Army is also developing remotely crewed ground systems.14

The majority of remotely crewed systems belong to the Air Force, which released a Next Generation ISR Dominance Flight Plan in addition to its force posture.15 That plan highlights how sharp the service expects the shift to contested spaces to be, swiftly overtaking traditional conflict.

Remotely crewed systems present several advantages for these contested spaces, including a greater number of flying hours. As Figure 2 shows, this can represent a greater number of passes over the target, which improves the quality of the images produced even in the face of declining manpower and reduced resources: remotely crewed systems’ longer flying hours create the potential for fewer flights to make an increased number of passes.16

Declining Manpower, Reduced Resources

The Boston Consulting Group’s recent analysis of the ISR market concluded that “demand [for ISR technologies], both global and domestic, continues to grow at a faster rate than overall defense spending.”17 Remotely crewed systems can represent substantial savings in purchase price and operating costs, creating potential to ameliorate this gap. This section will outline some of the ways that remotely crewed systems compare to traditional crewed systems.

The most important benefit of remotely crewed systems is people. The current generation of remotely crewed systems requires a roughly equivalent number of personnel to operate compared to traditionally crewed systems, as most personnel are dedicated to maintenance.

Over the medium to long term, new advancements may also reduce the number of troops needed per each remotely crewed platform, answering the challenge of declining troop numbers.18

Instead, remotely crewed systems present a more important personnel “savings”: their use keeps personnel out of contested environments, diminishing the risk to service members. Both the Air Force and Army March 2020 force postures, as well as the Air Force’s Next Generation ISR Dominance Flight Plan 2018–2028 forecast that the next 10 years will see the services rely more heavily on remotely crewed systems for balancing great powers and providing long-range capabilities in contested environments as a shift to missions that must be conducted with declining numbers of troops stationed abroad.19

Reducing the number of people crewing the mission may be a medium-term goal, but reducing the cost of the mission may already be here. In its report Usage Patterns and Costs of Unmanned Aerial Systems, the Congressional Budget Office (CBO) compared the Air Force’s unmanned RQ-4 and the Navy’s manned P-8.20 The report sought to examine UAVs’ oft-claimed cost advantages by analyzing the full life cycle, including costs per flying hour, to create a truer picture of the cost advantage(s) of remotely crewed craft. It found that the manned P-8 averaged approximately 40 percent fewer flying hours than the unmanned RQ-4 (589 hours vs. 945 hours) per aircraft.

In addition to logging 40 percent fewer flying hours, the P-8 was also more expensive than the remotely crewed RQ-4, with acquisitions costs slightly more than 20 percent higher. The RQ-4 “had an average acquisition cost of $239 million per aircraft compared with $307 million for a P-8.” In combination, the CBO calculated that “between 2014 and 2018, RQ-4s had a recurring cost per flying hour of about $18,700, or 62 percent of the projected cost of about $29,900 for the P-8.” This grounds the forecasted savings in the lifecycle cost of equipment. Remotely crewed systems may also realize ancillary savings including increased fuel economy and the ability to transition highly trained pilots to other missions, maximizing the impact of current personnel.21 As services look to train additional personnel, a recent CSIS analysis examined the potential effects of remotely crewed systems’ use on flying hours, costs, training and operations, and personnel management. It cites several sources that estimate the Air Force pilot pipeline training costs for remote systems as 95 percent lower than training costs for traditionally crewed systems—despite both systems being restricted to operators.22

These combined savings might shift the focus to reduce the number of crewed systems; however, the same CSIS analysis indicated that that is not the case. Rather, “the data indicate that remotely piloted AISR [airborne intelligence, surveillance, and reconnaissance] aircraft have not reduced demand for crewed aircraft. Rather, these new aircraft have been used to satisfy previously unmet demand that existing crewed aircraft could not surge to meet.” This is vividly demonstrated in Figure 3.

Comparing the two shows that there has been an increase in flying hours, but that the increase has come almost entirely from remotely crewed systems, while use of traditional craft has remained level. This suggests that remotely crewed systems represent a more scalable capacity, a more attractive capacity, or a combination of the two.

Thus, shifting to remotely crewed systems represents savings in both cost per hour flown and in training operators to fly. A recent CSIS analysis examined the ways services have integrated remotely crewed systems. It found that, in a world where DoD budgets are flat with inflation while the mission set expands, remotely crewed systems present a powerful mechanism with which to bridge the gap: “the DoD is instead looking for efficiency savings and reforms to free up funds within its budget to accommodate growing operation and sustainment costs for existing forces and lagging modernization needs.”23

Shift to Classified Systems

In March 2020 remarks to Congress on their force postures, both the Air Force and Navy flagged an imminent shift to more classified systems. As Senator Cotton remarked to Air Force General Goldfein when the latter presented a budget that seemingly reduced the amount spent on remotely crewed systems, budgets are “making cuts to the stuff that we can see and spending money on the stuff we cannot see.”

Shifting to classified systems aligns with the shift to operating in more highly contested environments and supports great power competition. When he was director of the Defense Department’s Strategic Capabilities Office, Dr. Will Roper described the case for classified systems: “One of the things we're going to have to remember—and that we did quite well in the Cold War—is to [maintain] a good balance between the capabilities that we show to the world for deterrence versus those that we keep behind the door for warfighting overmatch.” This is particularly relevant for great power competition, he continued: “You've got to expect the great powers, unlike lessor countries or terrorist groups, are going to be able to emulate that capability and potentially implement it, even if their operators aren't as good as ours.”24

This shift to classified systems may also present challenges for future analysis, as the systems most closely aligned with strategy are also the systems most likely to be classified. Funding for stealthy aircraft is often classified, which complicates an analysis of remotely crewed systems for the ISR mission set. While systems like the RQ-170 have since been revealed, there was no identifiable funding line for this system.25 This brief analyzes unclassified budget lines, which limits its ability to track all remotely crewed systems.

In summary, based on this policy rhetoric, we should expect to see growing remotely crewed systems portfolios across the services, with their growth fueled primarily by the ISR mission set. The case in favor of remotely crewed systems’ use is clear: as the mission moves to more contested theaters, these systems remove the warfighter from the greatest danger. With a focus on collecting greater data, remotely crewed systems extend the services’ reach: they allow birds to remain in the air for longer, and their ability to stay in the air across shift changes on the ground creates more flexibility in how they operate. Evidence from CBO data suggests that remotely crewed systems have a cost advantage, which is currently expressed in the cost per flying hour, but which could potentially be expressed by the cost per effects. This, in turn, multiplies the number of missions each service can accomplish with the same resources—and it might expand the number of personnel able to execute each mission, as pilots’ physical limitations are superseded by technology.

Budgetary Support for Remotely Crewed Systems

To understand the strategy is to understand the vision for remotely crewed systems; to understand the budget is to understand the current trajectory. Having discussed above the vision laid out in the March 2020 force postures, this brief analyzes the current and recent budget trends, and notes any differences from the vision. Budgets provide a substantive picture of the current status, including what has been funded to date, outlining the foundation on which future procurement, research, and development will build.

As there is often a two- to three-year lag between stating policy and enacting a presidential budget, it may be too soon to see all aspects of the policy vision reflected in budget implementation. After reviewing overall spending, this section will break out a few key case studies for further examination in an aim to assess the significance of the difference between the systems we have, and the systems that strategy demands.

Research, Development, Testing, and Evaluation

The RDT&E budget includes DoD funding for activities conducted by the Department itself (e.g., in government labs) or in universities, industry, or other federal labs.26

Within the RDT&E budget, spending is divided by budget activity level (BA level), which describes the type of research and development being conducted with those funds. BA levels break down as follows:27

  1. Basic Research
  2. Applied Research
  3. Advanced Technology Development
  4. Advanced Component Development and Prototypes
  5. System Development and Demonstration
  6. RDT&E Management Support
  7. Operational System Development

An eighth level, for Software and Digital Technology Pilot Programs, was introduced in Presidential Budget 2021, but as such does not have analyzable historical data.28 Thus, BA levels indicate a general level of development and readiness for a certain technology. Examining the BA levels of the past years’ spending, shown in Figure 4, provides an indication of the priorities of the current budget.

Until recent years, most identifiable remotely crewed system RDT&E was at the operational system development stage and typically tied to specific platforms. Basic research (levels 1 and 2) stage topics are broad: for example, relevant spending took place under Tactical Technology or Sensors and Electronic Survivability. As a result, only rarely is it possible to identify a budget line predominantly focused on remotely crewed systems.29

Funding at BA levels 4 and 5 has substantively expanded in the last two years, suggesting that additional weight has been put on the projects at that level. BA level 4 is used for new programs, which includes prototypes that have seen increasing use under the larger adaptable acquisition framework. That said, the robust system development and demonstration (BA level 5) spending through 2020 suggests that some of these systems are advancing to later stages of development. The budget lines that have grown significantly, been created, or both during the past two years under BA level 4 include many Navy technologies for developing remote mine hunting, remotely crewed undersea vehicles, and medium-to-large remotely crewed surface vessels. Three of the ten Navy funding lines at BA level 4 relate to remotely crewed aircraft systems, which would suggest that overwater ISR collection is not a Navy RDT&E priority. However, all the remotely crewed Navy systems at BA levels 5 and 7 are aerial, suggesting that the Navy is prioritizing moving remotely crewed systems past development and into production.

Overall, aerial systems account for RDT&E program elements that are exclusively devoted to remotely crewed systems. However, with the rise in Navy undersea and surface systems, that dynamic is shifting and in funding terms, requests for aerial systems dip to around half of funding in 2022, going as low as 46 percent in 2023.

The graph below shows RDT&E trends by service, with the Air Force being an early leader and responsible for more than half of the spending in almost every year through 2006. The notable exception is 2005, where the Joint Unmanned Combat Air Vehicle accounted for $450 million in constant dollars one year before the joint program was restructured and transferred to the services to attempt to develop a Navy carrier-based aircraft.30 That transfer coincided with a larger growth in Navy spending on exclusively remotely crewed RDT&E budget lines, doubling from a low point between 2006 and 2007 and doubling again from 2008 to 2009. In 2010, the Navy rose to $1 billion in annual spending in constant dollars as the MQ-4 Triton received its own funding line and was the top Navy line through 2015. During the 2006–2012 period, Army spending rose above $100 million a year in constant dollars, averaging more than a third of a billion dollars in constant dollars annually during this period. However, that bump was made possible in part by the remotely crewed aviation and ground vehicles for the Future Combat System, which outlived its 2009 cancellation. But as these efforts wound down, they were not replaced by research programs of comparable size. 

Air Force RDT&E during this past decade has primarily funded the MQ-9 Reaper and RQ-4 Global Hawk, and the decline in constant dollars from a peak of $488 million in 2017 to requests of under $100 million is due to the drawdown of those research programs in the absence of a replacement. This decline in Air Force spending and the future Navy and Army spending plans diversifying into maritime and ground vehicles signals that the services are changing the types of development being pursued for DoD remotely crewed vehicles. That said, the most important omission from Figure 6 is DARPA research taking place under broad research topics such as Tactical Technology or Algorithmic Warfare, the latter of which included Project Maven, which used artificial intelligence to process imagery from remotely crewed vehicles.


Procurement data shows remarkable growth since the early years of 1999, where the MQ-1 Predator was nearly the only remotely crewed system to merit its own budget line and the Global Hawk was in the president’s budget for 2001 but had not yet reached procurement. In the first decade of the twenty-first century, funding has spread across a greater variety of systems, although a small number of top programs drove the distribution among the military services. By 2007, in constant dollar terms, spending had increased tenfold from 201 million to 2.16 billion with the MQ-1 Predator and Global Hawk as the largest spenders but with the Army’s shadow system, combined special operations forces spending, and the Navy’s Fire Scout rounding out the top five. Spending dropped during the budget cap period, hitting a low in 2015 before being driven up the next year with the purchase of the Navy’s MQ-4 Triton, which by 2017 had risen higher than spending for the updated MQ-9 Reaper. From that point onward, Navy spending on remotely crewed systems has been comparable or greater than Air Force spending.

As seen in Figure 5, air vehicles are predictably but nonetheless remarkably dominant. Even though the Navy and Army have often been dominant players when it comes to systems that receive their own budget lines, aerial remotely crewed systems tend to dominate. This historical dominance is shifting in RDT&E with $456 million and $77 million in constant dollars respectively requested in 2021 for the Navy’s Medium and Large Unmanned Surface Vehicle program and Large Unmanned Undersea Vehicles. This trend still holds when looking at partial remotely crewed system lines, though there are six remotely crewed maritime system lines, including both surface and undersea, as well as a total of three cross-domain lines. That said, in the procurement budget, the Army’s ground-oriented Robotics and Applique Systems category is steadily growing in constant dollars, from $36 million spent in 2019 to a requested $232 million in 2025.

On the Horizon

The PB 2021 procurement budget shows a decline in constant dollars from the nearly $2 billion enacted in 2020 to a request for $1.2 billion in 2021. With rising Navy spending, primarily on the MQ-4 Triton, the out years do show a Navy bounce back, increasing 133 percent in constant dollars between 2021 and 2025 and reaching a new spending high. However, the marked decline in Air Force spending, dropping to only $29 million by 2025 in constant dollars, means that overall spending is expected to remain well below that of recent years. This phenomenon may reflect that current unclassified systems are being replaced by classified successors, as referenced by Senator Cotton in the Air Force’s March 2020 force posture hearing.31

Often, classified budget lines since revealed have been dedicated to stealth technology; these classified technologies may have been prioritized with the return to great power competition and a desire for technology that will “scare the Chinese,” in the words of Frank Kendall, secretary of the Air Force. Kendall also stated his desire to retire whole fleets of aircraft, an idea the Department has requested and Congress has rebuffed since the Obama administration. Such divestments could, if made, rapidly shift spending from unclassified to classified budget lines, although Kendall has said that efforts to date have not resulted in “real” savings.32 The shift to classified systems may represent some portion of the decline in Air Force spending. While this brief only covers unclassified lines, future analysis might track whether historical programs geared toward great power competition are cut without clear replacements.

In sum, an analysis of budget activity levels for current RDT&E spending shows increasing dollar amounts going toward more advanced budget activity levels over time, suggesting that some systems are advancing to higher stages of development. The majority of RDT&E funding by program elements goes to aerial systems, with five times as many aerial systems budget lines as maritime, which comprises the second largest number of budget lines. On procurement, aerial remotely crewed systems dominate again, with the domain supported by funding from the Air Force and, increasingly, the Navy. The forecast for procurement shows a tick downward as Air Force funding is projected to decline in the out years, suggesting that there may be fewer dollars to put to aerial remotely crewed systems’ budget lines in the unclassified space.

Having surveyed what is currently being developed and acquired, the next question is what the Department already has; comparing the two will illustrate where, if anywhere, there might be gaps to be filled. Following the broad catalog above, the next section will focus on a few key goals centered specifically on the use of remotely crewed systems for ISR in great power competition, examining key pieces of technology that might support those aims. By “finding” its present capabilities through the budget and comparing them to stated policy goals, this brief will be able to indicate whether the actuality of the budget supports the Department’s goals.

“Finding” Current Status

In 2020, the Congressional Research Service released a report examining how ISR can support great power competition—and within that, how remotely crewed systems can support the ISR mission area. Its ISR Design for Great Power Competition report outlined five paths to increased lethality: (1) high altitude, (2) penetrating, persistent, and multi-role remotely piloted aircraft, (3) ISR from/for space operations, (4) publicly available information (PAI), and (5) ISR from/for cyberspace operations.33 Of those, high altitude and penetrating, persistent, and multi-role remotely piloted aircraft have the greatest implications for remotely crewed systems supporting the ISR mission. There is currently a robust inventory of high-altitude equipment available, but many fewer options for multi-role remotely piloted aircraft.

While the unclassified summary of the Air Force’s multi-function remotely piloted aircraft does not specify a definition for multi-function aircraft, in practice this has been achieved by combining an ISR mission and a combat one. The database Janes, an open-source catalog of defense intelligence, lists several systems including the term multi-function under its remotely crewed systems tag, as shown in Table 1.34

One note on the Janes data is that it did not include the X-47, a carrier-based unmanned combat aerial vehicle, suggesting that the list may not include demonstration aircraft,35 or those undergoing testing and development outside the Department. This is an encouraging sign, as it suggests there may be more systems coming down the pike than otherwise might be expected; the X-47 began its purpose-built development in 2011. Still, if multi-function remotely crewed aircraft remain a priority for the Department, they should also remain a priority area for research and development.

Strikingly, few systems have been initially developed as dedicated multi-function platforms, which raises the question of whether this may be an area of particular focus for future development. Many systems developed in the last 20 years have been intended as replacements to existing systems, rather than all new capabilities.

One of the noted disadvantages of remotely crewed systems is the potential for lag time in command relays from the operator to the machine; it may be that an ISR mission does not face the same problems from a slight delay in command relays that a combat mission would. Additionally, according to the book Unmanned Aircraft Systems in the Cyber Domain, while “the payload should drive the platform this tends to be the reverse in reality. The platform creates compromised trade-offs between a higher quality sensor that weighs more and consumes power versus a lower quality sensor that is less expensive, lighter, but will require more passes to get useable information or will provide a less clean data set.”[36] Thus, multifunction platforms may begin from a combat mission because beginning from a combat chassis may mean beginning with engineering that has solved for that command relay delay—or may simply mean that the platforms are able to carry more weight.

What is clear is the trend for multifunction systems to represent adding an ISR capability to a combat platform, increasing the capacity of remotely crewed systems to conduct ISR. Because these systems add an ISR capacity where there was none, multifunction systems expand the number of platforms that can be used for ISR even should the total number of systems remain the same.

As outlined in the ISR Design for Great Power Competition report, the U.S. Air Force’s push for increased lethality and survivability includes both high-altitude and multi-function aircraft, but few remotely crewed systems land in both categories. Janes lists only a single system in that category: the RQ-4 Global Hawk. There are a few possible explanations for this.

First, it may be that adding an additional role to a high-altitude craft creates a requirements weight that drives costs too high to be widely deployed unless space to preposition craft is at a premium. If, for example, a commander can only access or store a limited number of assets, a multi-function craft may be more appealing than two specialist systems. An ancillary reason may be that the high altitude and multi-function use cases may be separate domains. Increased altitude has traditionally been a significant source of protection for surveillance craft, and while the commercial definition of high altitude begins at 25,000 feet,37 some military aircraft can fly from 70,000 to at least 90,000 feet.38 While modern surface-to-air missiles (SAMs) may pose a threat even at those heights, there may be relatively few threats in the high-altitude neighborhood—and with remotely crewed craft, no threats at all to the pilot.

By contrast, there is a much more robust inventory for high-altitude craft: Janes lists 31 entries for high-altitude, remotely crewed craft. There are several reasons that might explain the comparatively robust inventory of remotely crewed high-altitude craft. The Air Force has relied on altitude to deter attacks on its craft for decades; if, as the CBO report discussed above implies, remotely crewed systems also present a cost advantage, the one-two punch of a legacy priority representing cost savings may alone be sufficient to give it a significant presence.39 Remotely crewed systems may also present a greater advantage to high-altitude mission. As the CBO discussed, remotely crewed systems allow for a greater number of flying hours—which would translate into an increased range or an increased number of passes.40 High altitude flight also presents a greater number of physical challenges for pilots, presenting a greater chance that physical conditions will prevent crewed craft from completing a mission as scheduled. For non-combat missions that will not suffer from latency in the command and control link, remotely crewed craft may present many advantages with few, if any, disadvantages.

The combination of RDT&E spending, procurement spending, and current systems suggests that aerial systems will continue to comprise the majority of the remotely crewed ISR mission. The coming years may not see a robust increase in the number or type of new systems coming online as Air Force funding ticks downward, although Navy funding may make up some of the difference. This increases the emphasis on current systems, and two crucial capabilities for remotely crewed ISR collection in the face of great power competition are multi-function and high-altitude systems. An examination of the current remotely crewed aerial systems in these categories shows that some capabilities have a larger number of available programs than others, with a robust number of high-altitude craft types, and relatively few multi-function ones. This may be because multi-function craft are more narrowly useful—but if they become critical to the mission, more development is needed. As the United States looks to prepare for great power competition, its current capacity for ISR centers on Air Force and Navy aerial systems, with less RDT&E, procurement, and current capacity dedicated toward underwater and ground collection.


As the world shifts back to great power competition, remotely crewed systems represent a new capability on the global stage. The Air Force Next Generation Flight Plan predicts a sharp shift toward contested spaces for peer and near-peer competition. An analysis of the current strategy represents a robust capacity for remotely crewed systems to support the overarching mission—not just the Air Force mission, where they are perhaps most traditionally associated, but also the work of the Navy and Army.

Remotely crewed systems present significant advantages for ISR and other mission areas in the face of great power competition: they have the potential to extend our forces’ reach into contested spaces, bolster ISR, and lower costs. Remotely crewed systems remove the warfighter from contested spaces while making more passes through that space, increasing the fidelity of information gathered through longer loiter times while keeping service members safer collecting it. Remotely crewed systems allow craft to remain in the air longer, potentially across shift times, creating the capacity for longer missions that cover more ground. These systems represent a cost savings both at acquisition and by flying hour, making them cost effective as well as mission effective. Most importantly, remotely crewed systems keep warfighters out of both the extraordinary dangers of entering contested spaces and the more quotidian dangers of flight.

Budgets are the forebearers of tactical operations; where they go, capacity and strategy will follow. Through analyzing currently-funded systems and priorities, it is possible to identify potential gaps between policy and implementation—although as the mission continues to shift toward the classified space, unclassified data may become harder to interpret and yield fewer insights into plans for remotely crewed systems. RDT&E spending shows a strong move to more highly developed technologies and a continued dominance of remotely crewed aerial systems across both the Air Force and the Navy. While non-aerial systems may come to make up a larger proportion of procurement budget lines, this is due more to a decline in aerial spending than an uptick in other systems; if the Department would like more robust ground and maritime capacities, it will need to put muscle behind acquiring them.

As the U.S. government develops its current assets, there are a few areas it might prioritize to meet the goals laid out in the current force postures. Multifunction remotely crewed systems in particular seem to represent a smaller and older portion of the current inventory than strategy might call for, while enduring priorities like high-altitude craft have a robust catalog for the Department to draw on. The sharp decline in both RDT&E and procurement spending for aerial systems may represent a decline in overall spending—or indicate a shift to classified budget lines. Over the past decade, remotely crewed systems have been leveraged to meet an expanding mission set with a constant budget, but future budgets may find they need to devote more spending to remotely crewed systems as this return plateaus and developing programs reach levels of scalability.

As the world returns to great power competition and the United States must project its power further into contested spaces, remotely crewed systems offer a plethora of advantages to the mission, not least protecting the warfighter. The current inventory is robust and presents the armed forces many advantages that were not present in the last period of great power competition, including the ability to gather more assets from deeper in contested spaces with less risk to the warfighter. As we look to the future, remotely crewed systems represent a vast potential for finding what others are hiding.

Rose Butchart is a fellow with the Defense-Industrial Initiatives Group (DIIG) at the Center for Strategic and International Studies (CSIS) in Washington, D.C. Gregory Sanders is deputy director and fellow with DIIG at CSIS. Jill N. Cheney is an intern with DIIG at CSIS. Sevan Araz is a researcher with DIIG at CSIS.

This brief is made possible by support from General Atomics and general support to CSIS.  

CSIS Briefs are produced by the Center for Strategic and International Studies (CSIS), a private, tax-exempt institution focusing on international public policy issues. Its research is nonpartisan and nonproprietary. CSIS does not take specific policy positions. Accordingly, all views, positions, and conclusions expressed in this publication should be understood to be solely those of the author(s).

© 2021 by the Center for Strategic and International Studies. All rights reserved.

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Rose Butchart

Rose Butchart

Former Associate Fellow, Defense-Industrial Initiatives Group
Gregory Sanders
Deputy Director and Fellow, Defense-Industrial Initiatives Group

Jill N. Cheney

Intern, Defense-Industrial Initiatives Group

Sevan Araz

Researcher, Defense-Industrial Initiatives Group