Military hypersonic technology in the US

No doubt that the word “hypersonic” has become a buzzword in the military realm. After a public presentation of Russian programs on March 1, 2018, the US defense industry and military doubled down on obtaining funding for development of own hypersonic weapons, resulting in a number of parallel programs one can easily become confused in.

The “New Defense Order. Strategy” prepared a brief guide for readers on this matter.

The foreword suggests a general talk about the present-day hypersonic weapons, their potential and types, as well as whether the excitement about them is justified and what reasons there are for it; however, these are subjects for other articles. We will only speak about American developments, and the goal of this review is to provide the reader with information about subjects of future news about testing of new US defense products.

We will briefly note that, for the purpose of this review, hypersonic weapons only mean those capable of actively maneuvering in the atmosphere at high speeds (more than 5 M), both powered and unpowered. The latter are more widely known by the word “glider”, since the term “guided hypersonic gliding head” used in Russia is a bit awkward. We should also clarify that all the systems mentioned below are only being developed in non-nuclear versions, at least at the current stage (which does not prevent from retrofitting them with nuclear charges or developing nuclear carriers on their basis).


US aerial missile programs

Air-Launched Rapid Response Weapon (ARRW). It’s a program for a glider-equipped aerial missile officially developed by Lockheed Martin according to a $480 million contract awarded to the US Air Force on August 13, 2018. Later on, the amount of the missile development contract was increased to almost $1 billion. It is probably based on the company’s earlier developments conducted together with DARPA (Defense Advanced Research Projects Agency). This explains the extremely tight project deadline: it is planned to reach the initial combat deployment stage as soon as in 2022.

It is one of the few weapon systems mentioned in the article that has official images, both weight and size mockup photos taken in June 2019 and some concept art showing the missile in flight with the nose cone ejected and demonstrating the glider, published at the end of February 2020 when the missile design was reviewed. At this time, the ARRW can be called the priority hypersonic weapon program at least for the US Air Force and potentially for the Pentagon. This is described, for instance, by the telling fact that only this missile has a publicly disclosed military index AGM-183A. The program name acronym was transformed into the unofficial missile name Arrow.

The AGM-183A is a fairly light missile (it has a starting weight of about 3–3.5 tons) with a maximum launch range of 1000 km, according to unofficial assessment. It looks like a missile with conventional proportions, but the “body” is, in fact, a solid booster that is jettisoned in flight, and the flat glider that kills the target is hidden under the nose cone. The glider dimensions are apparently very small and do not allow for a very powerful head. It is possible, the missile does not have a head at all, with only the kinetic effect of a high-speed impact used for killing the target, but this would set extremely high requirements to accuracy and limit the list of targets that could be killed.

The strategic bombers B-52H Stratofortress will probably be used as the carrier for the AGM-183A missiles at the initial stage, however, other aircraft are planned to be used for this purpose in the future, including at least the B-21 Raider bombers and even the F-15E/EX Strike Eagle fighters – if the weight and dimensions can be kept moderate, one missile could be suspended under the fighter fuselage.



ARRW Launch


Hypersonic Conventional Strike Weapon (HCSW). Until lately, the ARRW had a parallel “sister”, an also gliding guided high-precision head using a solid booster. The main difference would be the head type: the missile would utilize a “common” type-independent glider Common-Hypersonic Glide Body (C-HGB), which has a conical shape and noticeably larger dimensions. There are several photos of C-HGB concepts and mockups. It is probably based on the glider developed according to the common US Army and DARPA program Advanced Hypersonic Weapon (AHW), which included a successful test launch for a range of about в 3,700 km in 2011.

The potential dimensions of the resulting HCSW including the booster could only be guessed, but they would apparently be much larger than the AGM-183A dimensions. It is perhaps for this missile that the development of wing pylons for the B-52H bombers with a possibility to suspend multiple weapons with a maximum weight of 9 tons each started in 2018.

It would probably have larger range than the ARRW, and a definitely larger list of targets that could be killed, both thanks to its higher weight and due to a possibility to install a more advanced guiding system within the volume. The missile got the unofficial name Hacksaw. In 2018, Lockheed Martin was awarded a contract for its development, approximately amounting to $928 m. Similar to the ARRW case, it was planned to deliver the missile for service within the minimum time possible. However, at the beginning of 2020, a decision was made to abandon the program after a formal project review, which would be utilized to accumulate useful experience, and to redistribute the funds for the ARRW program.

Why did the “common” glider that was touted by the Pentagon as a very important unification not save the HCSW program? It is probably the matter of the dimensions: the US Air Force decided to concentrate on more compact ARRW, which would be used from tactical aircraft or in large numbers from bombers. Perhaps, the problem was not even the final price but a less definite tactical niche – if the question is killing an extremely important target, the Army and Navy would have the C-HGB carriers within a few thousand kilometers, and the B-52H would be unnecessary.

Tactical Boost Glide (TBG). Besides programs that would result in the development of a new weapon system, a large number of other projects aimed at technical solution testing and experience accumulation are underway in the US. These include, for instance, the X-60A, a mutual NASA and US Air Force program for the development of a booster that could be launched from the Gulfstream III business jet and could accelerate various payloads to hypersonic speeds.

Even more characteristic example would be the TBG program mutually conducted by DARPA and the US Air Force with a goal to design a glider for refining technical solutions that would be used in the AGM-183A. The program was commenced in 2015 and includes competing projects developed by Raytheon and Lockheed Martin. Flight testing was slated for the end of 2019 but later delayed into 2020.

Hypersonic Air-breathing Weapon Concept (HAWC). It is another mutual research program by the US Air Force and DARPA, which has an important difference from those mentioned in this review. The HAWC is aimed at the development of a missile demonstrator with a hypersonic steady-flow ramjet engine (Scramjet), rather than another glider. Potentially, it is this area of research that should result in a “true” hypersonic technology with breakthrough capabilities, wider than those of a simply maneuvering ballistic missile heads. At present, the US has relatively successful programs of flying labs in this area, the X-43 reaching a speed of almost 9.7 M at a 33 km altitude and the X-51 with a 3.5-minute flight time record with the scramjet engine on (the X-43 was mostly accelerated using a solid booster, the hydrogen fuel reserve for its own engine was about 1 kilogram, which is sufficient for approximately 10 seconds of operation).

As part of the HAWC program being implemented since 2016, it is planned to design a more advanced aircraft with a scramjet engine, with dimensions and capabilities close to fully functional weapons. The contenders are a Raytheon/Northrop team and the omnipresent Lockheed Martin. It was reported that ground testing of missile systems had been conducted, with flight testing slated for 2020. It is planned that the HAWC would be able to evolve into a light missile in the near future. Lockheed Martin demonstrated F-35 concepts with a pair of missiles (probably anti-ship ones) under the wing, while bombers would be able to carry up to 15–20 light scramjet missiles. The American military have a conservative view of deployment of long-range guided missiles with hypersonic engines and speeds of 5+ Mach – this would be in the next decade.


US Army ground missile systems

Long Range Hypersonic Weapon (LRHW). Along with the aerial ARRW, this is the highest priority military hypersonic program in the US. As part of this program, it is planned to design a new mobile system with an intermediate-range guided missile, practically a new Pershing II, but with a non-nuclear high-precision glider as the payload, the “common” C-HGB mentioned above. It would not be a great exaggeration to say that the US left the Intermediate-Range Nuclear Forces (INF) Treaty in 2019 to be able to create such a weapon system.

In its current state, the program was probably started in the second half of 2018. The LRHW efforts are spread among a number of individual contracts; the total development stage costs could be estimated at approximately one and a half billion dollars. Again, Lockheed Martin takes on the main designer’s role, gliders are being developed by Dynetics operating according to a contract for the production of a test lot including twenty C-HGB for the Army and Navy. The deadline is extremely ambitious: the first battery would be deployed for testing and combat duty as soon as in 2023.

Although the LRHW system is not ready yet, a lot is known about it as a weapon system. The missile battery would include four launchers and a command post vehicle. The launcher is a М870 semi-trailer (similar to that used for the Patriot AA missile system) with two transportation and launch containers that are about 10 m long and the four-axle all-wheel drive tractor Oshkosh M983A4. Each container has a two-stage missile with a diameter of about 0.88 m and a C-HGB glider under the nose cone. The LRHW range is anyone’s guess at the moment, but it would at least be 2,000 km (potentially, up to 4,000 km).

The deployment of the new missile system would provide the US Army with an instrument for independent killing of targets deep in the enemy territory, which was lost with the signing of the INF Treaty. This time, the instrument would be non-nuclear, that is in a more applicable version. The priority targets for the LRHW should be intermediate-range missile systems and anti-access and area denial (A2/AD) equipment: AA systems and coastal missile systems with anti-ship missiles, while the range would allow to have entire regions in sights.


Flying laboratory X-51


Operational Fires (OpFires). The Army and DARPA’s mutual program that is likely to be in the same position to the LRHW as the TBG is to the ARRW: this is a simplified demonstrator (probably with smaller dimensions, in this case) of technology for refining ground system and glider solutions.

The main contractor of the third program stage that is underway at the moment, as part of which flight testing is planned in 2022, is Lockheed Martin. The two previous phases concentrated on the development and ground testing of compact solid missile engines and included such participants as Aerojet Rocketdyne, Dynetics, Exquadrum and Sierra Nevada.

Strategic Long Range Cannon (SLRC). The most exotic system in this review would probably be the “thousand-mile cannon” developed for the US Army, with a planned firing range of up to 1,800 km. It is evident that there is no conventional weapon, let alone with reasonable dimensions, capable of sending shells to such a distance. In fact, the system in question is an exotic launcher that would provide initial acceleration to a small missile shell, which, in turn, would be equipped with a power plant (with possible versions ranging from a solid booster to a compact ramjet engine). Besides that, it is apparent that the missile shell must be guided.

Although we are not clear about exact solutions that would enable such a firing range at the moment, the general system design is unknown: the weapon would be transported using the standard tank-towing tractor Oshkosh M1070, and must be suitable to be carried by aircraft; the crew of a single weapon includes eight persons, the battery would consist of four weapons (and, apparently, charging and command vehicles). The intended timeframe for full-scale prototype testing is 2023, while a full battery would be deployed two years after that. If the shot price is acceptable, the “thousand-mile gun” should be a natural complement to the LRHW with its extremely expensive missiles. Besides that, compact and multiple missile shells would be capable of overloading the enemy’s AA system.

Apparently, saying that the SLRC is hypersonic weapon would be a stretch because it is unknown to what extent the missile shells would have gliding and maneuvering performance, if any. It is possible that they will only be guided in the sense that it would be possible to control deviation from the target due to firing errors and the atmosphere effect.

However, it would be difficult to not include such an exotic-looking project that is actually being implemented. Besides that, while different from the other projects from the technical point of view, their tactical performance allows us to classify them as short- and intermediate-range missile systems.


US Navy program

Intermediate Range Conventional Prompt Strike (IRCPS). Details are only known about a single hypersonic program by the Navy, aimed at the development of an intermediate-range missile with the C-HGB glider. The current program was probably launched in the middle of the present decade, while its roots go back to the Navy part of intertype research on the Prompt Global Strike (PGS) subject popular at the turn of the century. While such proposals as developing non-nuclear ICBM modifications, widely discussed at that time, did not gain any traction, works on an initially non-nuclear intermediate-range ballistic submarine missile that is smaller than the Trident II have never stopped. Thus, in October 2017, the first missile test including a launch for a distance “exceeding 3,700 km” was conducted as part of these works. The next test launch is slated for 2020.


Model submarine type "Virginia"
with VPM missile compartment


By current estimations, the IRCPS and LRHW missiles will be virtually identical. In this case, synergy between the Navy and the Army is evident, with the former providing a booster that has been in development for many years and the latter making available the glider, also in development for quite a long time. The costs would be split in this case, with the Navy, probably, bearing the most part: more than $1 billion has been requested for FY 2021 alone. The Army would deploy the system earlier and would be capable to accumulate operating experience and help eliminate initial-phase drawbacks. The Navy is only planning to deploy the IRCPS starting in 2028, which can be explained by the need to obtain and learn to operate the carriers, the multipurpose Virginia series 5 submarines with an extra missile compartment, the so-called Virginia Payload Module (VPM). Initially, four VPM silos should be able to house 28 Tomahawk missiles designed for installation in the future IRCPS. Surface ships, in particular, Zumwalt destroyers, are regarded as potential carriers of the new missiles.

Obtaining a high-speed and high-precision means for killing targets deep within the continent would allow the Navy to keep its position as a force that could be lost if it were behind the Army and Air Force actively seeking to deploy hypersonic weapons.


Author - Aleksandr Ermakov


Translated by EGO Translating



©New defence order. Strategy  №5 (64) 2020

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