Hypersound is emerging as the next key parameter for weapons and surveillance platforms, and therefore it is worth taking a closer look at the research being carried out in this area by the United States, Russia and India
The US Department of Defense and other government agencies are developing hypersonic technology for two immediate and one long-term goals. According to Robert Mercier, head of high-speed systems at the US Air Force Research Laboratory (AFRL), the two near targets are hypersonic weapons, which are expected to be technologically ready in the early 1920s, and an unmanned surveillance vehicle, which will be ready for deployment in the late 1920s. or the early 30s, and hypersonic vehicles will follow in the more distant future.
“Space exploration with the help of spacecraft with an air-jet engine is a much more distant prospect,” he said in an interview. "It is unlikely that hypersonic spacecraft will be ready before the 2050s." Mercier added that the overall development strategy is to start with small weapons and then, as technology and materials develop, expand to air and space vehicles.
Spiro Lekoudis, director of the Department of Weapons Systems, Procurement, Technology and Supply at the Ministry of Defense, confirmed that hypersonic weapons are likely to be the first procurement program that will emerge after the development of this technology by the ministry and its partner organizations. “The aircraft is definitely a much longer term project than a weapon,” he said in an interview. The U. S. Air Force is expected to demonstrate the High Speed Strike Weapon (HSSW) - a joint development with the Defense Advanced Research Projects Agency (DARPA) - around 2020, when the Pentagon will decide how best to bring this technology into the development program and purchases of hypersonic missiles.
“There are two main research papers that are aimed at demonstrating HSSW technology,” said Bill Gillard, plan and program designer at AFRL. "The first is Lockheed Martin and Raytheon's TBG (Tactical BoosWSIide) tactical acceleration-planning program, and the second is the HAWC (Hypersonic Air-breathing Weapon Concept), led by Boeing."
“Meanwhile, AFRL is conducting another fundamental study to complement the DARPA and US Air Force projects,” Gillard said. For example, within the framework of validation of the concept of the reusable aircraft concept for hypersonics (REACH), in addition to the study of basic materials, several experiments were carried out with small and medium-sized ramjet engines. "Our goal is to promote the database and develop and demonstrate technologies that can be taken to create new systems." AFRL's long-term fundamental research in the field of improving ceramic-matrix composite and other heat-resistant materials is extremely important for the creation of promising hypersonic vehicles.
AFRL and other Pentagon laboratories are intensively working on two main aspects of promising hypersonic vehicles: reusability and increased size.“There is even a trend at AFRL to promote the concept of reusable and larger hypersonic systems,” Gillard said. "We've focused all of these technologies on projects like the X-51, and REACH will be another one."
"The 2013 demonstration of Boeing's X-51A WaveRider missile will form the basis of the US Air Force's hypersonic armament plans," said John Leger, chief aerospace project engineer at AFRL's weapons department. "We are studying the experience gained during the development of the X-51 project and use it in the development of the HSSW."
Simultaneously with the project of the X-51 hypersonic cruise missile, various research organizations also developed larger (10x) ramjet engines (ramjet), which "consume" 10 times more air than the X-51 engine. "These engines are ideal for systems such as high-speed surveillance, reconnaissance and intelligence platforms and atmospheric cruise missiles," Gillard said. "And, ultimately, our plans are to move further towards the number 100, which will allow access to space using air-breathing systems."
AFRL is also exploring the possibility of integrating a hypersonic ramjet engine with a high-speed turbine engine or rocket in order to have sufficient propulsion to achieve large Mach numbers. “We are exploring all the possibilities to improve the efficiency of the supersonic apparatus engines. The conditions in which they have to fly are not entirely favorable."
On May 1, 2013, the Kh-51A WaveRider rocket successfully passed flight tests. The experimental apparatus undocked from the B-52H aircraft and accelerated using a rocket accelerator to a speed of 4.8 Mach numbers (M = 4, 8). Then the X-51A separated from the accelerator and started its own engine, accelerated to Mach 5, 1 and flew 210 seconds until all the fuel was burned out. The Air Force collected all telemetry data for 370 seconds of flight. The Rocketdyne division of Pratt & Whitney has developed the engine for the WaveRider. Later, this division was sold to Aerojet, which continues to work on hypersonic power plants, but does not provide any details on this topic.
Previously, from 2003 to 2011, Lockheed Martin worked with DARPA on the initial concept of the Falcon Hypersonic Technology Vehicle-2. The booster for these vehicles, which were launched from the Vandenberg airbase in California, was a Minotaur IV light rocket. The HTV-2's maiden flight in 2010 generated data that demonstrated progress in aerodynamic performance, refractory materials, thermal protection systems, autonomous flight safety systems, and long-range hypersonic flight guidance, navigation and control systems.
Two demonstration launches were successfully carried out in April 2010 and August 2011, but, according to DARPA statements, both times Falcon vehicles during flight, trying to reach the planned speed of M = 20, lost contact with the control center for several minutes.
The results of the X-51A program are now used in the HSSW project. The armament and guidance system are being developed in the framework of two demonstration programs: HAWC and TBG. DARPA awarded contracts to Raytheon and Lockheed Martin in April 2014 to continue developing the TBG program. The companies received $ 20 and 24 million, respectively. Meanwhile, Boeing is developing the HAWC project. She and DARPA refuse to give any details about this contract.
The goal of the TBG and HAWC programs is to accelerate weapons systems to a speed of M = 5 and further plan them for their own purpose. Such weapons must be maneuverable and extremely resistant to heat. Ultimately, these systems will be able to reach an altitude of almost 60 km. The warhead, being developed for a hypersonic missile, has a mass of 76 kg, which is approximately equal to the mass of a small-diameter bomb SDB (Small Diameter Bomb).
While the X-51A project successfully demonstrated the integration of an aircraft and a hypersonic engine, the TBG and HAWC projects will focus on advanced guidance and control, which was not fully implemented in the Falcon or WaveRider projects. Seeker subsystems (GOS) are engaged in several US Air Force weapons laboratories in order to further enhance the capabilities of hypersonic systems. In March 2014, DARPA said in a statement that under the TBG project, which is due to complete a demonstration flight by 2020, partner companies are trying to develop technologies for a tactical hypersonic gliding system with a rocket booster, launched from a carrier aircraft.
“The program will address the system and technology problems required to create a hypersonic gliding system with a rocket booster. These include the development of concepts for an apparatus with the necessary aerodynamic and aerothermodynamic characteristics; controllability and reliability in a wide range of operating conditions; the characteristics of the system and subsystem necessary for efficiency in the relevant operating conditions; finally, approaches to reduce the cost and increase the affordability of the experimental system and future production systems,”the statement said. The aircraft for the TBG project is a warhead that separates from the accelerator and glides at speeds up to M = 10 or more.
Meanwhile, as part of the HAWC program, following the X-51A project, a hypersonic cruise missile with a ramjet engine will be demonstrated at lower speeds - approximately M = 5 and higher. "HAWC's technology could expand to promising reusable hypersonic airborne platforms that can be used as reconnaissance vehicles or access to outer space," DARPA said in a statement. Neither DARPA nor Boeing's parent contractor have disclosed all the details of their joint program.
While the Department of Defense's primary hypersonic targets are weapons systems and reconnaissance platforms, DARPA began a new program in 2013 to develop a reusable unmanned hypersonic booster to launch small satellites weighing 1,360-2270 kg into low orbit, which will simultaneously serve as a test laboratory for hypersonic vehicles. In July 2015, the Office awarded Boeing and its partner Blue Origin a $ 6.6 million contract to continue work on the XS-1 Experimental Spaceplane, according to a Congressional statement. In August 2014, Northrop Grumman announced that it was also working with Scaled Composites and Virgin Galactic on a technical design and a flight plan for the XS-1 program. The company received a 13-month contract worth $ 3.9 million.
The XS-1 is expected to have a reusable launch booster that, when combined with a one-time booster stage, will provide affordable delivery of a 1,360 kg class vehicle into low Earth orbit. In addition to a cheap launch, estimated at one-tenth the cost of a current heavy rocket launch, the XS-1 is likely to also serve as a test laboratory for new hypersonic vehicles.
DARPA would like to launch the XS-1 every day in the future at a cost of less than 5 million per flight. Management wants to get a device that can reach speeds of more than 10 Mach numbers. The requested operating principles "like an airplane" include horizontal landings on standard runways, in addition, the launch must be from a lift launcher, plus there must be a minimum infrastructure and ground personnel and a high level of autonomy. The first test orbital flight is scheduled for 2018.
After several failed attempts by NASA, beginning in the 1980s, to develop a system like the XS-1, military researchers now believe that the technology has matured enough due to advances in lightweight and cheap composites and improved thermal protection.
XS-1 is one of several Pentagon projects aimed at reducing the cost of launching satellites. With the cuts in the US defense budget and the increase in the capabilities of other countries, routine access to space is becoming an increasingly high priority for national security. Using heavy rockets to launch satellites is expensive and requires an elaborate strategy with few options. These traditional launches can cost hundreds of millions of dollars and require expensive infrastructure to be maintained. As the US Air Force insists that lawmakers issue a decree to suspend the use of Russian RD-180 rocket engines to launch American satellites, DARPA's hypersonic research will help significantly shorten the path that will need to be traveled, relying only on its own forces and means.
Russia: making up for lost time
At the end of the existence of the Soviet Union, the machine-building design bureau MKB "Raduga" from Dubna designed GELA (Hypersonic Experimental Aircraft), which was to become the prototype of the X-90 strategic air launch missile ("Product 40") with a ramjet engine "Product 58 "Developed by TMKB (Turaevskoe machine-building design bureau)" Soyuz ". The rocket was supposed to be able to accelerate to a speed of 4.5 Mach numbers and have a range of 3000 km. The set of standard weapons of the modernized strategic bomber Tu-160M was supposed to include two X-90 missiles. Work on the Kh-90 supersonic cruise missile was discontinued in 1992 at the laboratory stage, and the GELA apparatus itself was shown in 1995 at the MAKS aviation exhibition.
The most comprehensive information on the current hypersonic air launch programs was presented by the former commander of the General Staff of the Russian Air Force, Alexander Zelin, in a lecture he gave at a conference of aircraft manufacturers in Moscow in April 2013. According to Zelin, Russia is carrying out a two-stage program to develop a hypersonic missile. The first stage provides for the development by 2020 of a sub-strategic air launch missile with a range of 1,500 km and a speed of approximately M = 6. Further in the next decade, a rocket with a speed of 12 Mach numbers should be developed, capable of reaching anywhere in the world.
Most likely, the Mach 6 missile mentioned by Zelin is Product 75, also designated GZUR (HyperSonic Guided Missile), which is currently at the technical design stage at the Tactical Missiles Corporation. "Product 75", apparently, has a length of 6 meters (the maximum size that the bomb bay of the Tu-95MS can take; it can also fit in the armament compartment of the Tu-22M bomber) and weighs about 1,500 kg. It should be set in motion by the Product 70 ramjet engine developed by Soyuz TMKB. Its active radar seeker Gran-75 is currently being developed by the Detal UPKB in Kamensk-Uralsky, while the broadband passive homing head is being manufactured by the Omsk Central Design Bureau.
In 2012, Russia began flight tests of an experimental hypersonic vehicle attached to the suspension of a Tu-23MZ long-range supersonic bomber-bomber (NATO designation "Backfire"). Not earlier than 2013, this device made its first free flight. The hypersonic apparatus is installed in the nose section of the X-22 rocket (AS-4 "Kitchen"), which is used as a launch booster. This combination is 12 meters long and weighs about 6 tons; the hypersonic component is about 5 meters long. In 2012, the Dubna Machine-Building Plant completed the construction of four X-22 supersonic air-launched cruise anti-ship missiles (without seeker and warheads) to be used in tests of hypersonic vehicles. The rocket is launched from a Tu-22MZ underwing suspension at speeds up to Mach 1, 7 and altitudes up to 14 km and accelerates the test vehicle to Mach 6, 3 and an altitude of 21 km before launching the test component, which apparently develops a speed of 8 Mach numbers.
Russia was expected to take part in similar flight tests of the French MBDA LEA hypersonic vehicle launched from the Backfire. However, according to available data, the test hypersonic component is a primordially Russian project.
In October-November 2012, Russia and India signed a preliminary agreement to work on the BrahMos-II hypersonic missile. The cooperation scheme includes NPO Mashinostroeniya (rocket), TMKB Soyuz (engine), TsAGI (aerodynamics research) and TsIAM (engine development).
India: a new player on the field
Following an agreement on joint development with Russia, India's BrahMos rocket program was launched in 1998. According to the agreement, the main partners were the Russian NPO Mashinostroyenia and the Indian Defense Research and Development Organization (DRDO).
Its first version is a two-stage supersonic cruise missile with radar guidance. The solid-propellant engine of the first stage accelerates the rocket to supersonic speeds, while the liquid-propellant ramjet of the second stage accelerates the rocket to the speed of M = 2. 8. BrahMos is, in fact, the Indian version of the Russian Yakhont missile.
While the BrahMos rocket had already been delivered to the Indian army, navy and aviation, the decision to start developing a hypersonic version of the BrahMos-II rocket by the already established partnership was made in 2009.
In accordance with the technical design, BrahMos-ll (Kalam) will fly at speeds in excess of Mach 6 and have higher accuracy compared to the BrahMos-A variant. The missile will have a maximum range of 290 km, which is limited by the Missile Technology Control Regime signed by Russia (which limits the development of missiles with a range of more than 300 km for a partner country). In order to increase the speed in the BrahMos-2 rocket, a hypersonic ramjet engine will be used and, according to a number of sources, the Russian industry is developing a special fuel for it.
For the BrahMos-II project, a key decision was made to maintain the physical parameters of the previous version so that the new rocket could use the already developed launchers and other infrastructure.
The target set for the new variant includes fortified targets such as underground shelters and weapons depots.
A scale model of the BrahMos-II rocket was shown at Aero India 2013, and prototype testing is due to begin in 2017. (At the recently held exhibition Aero India 2017, a Su-30MKI fighter with a Brahmos rocket on an underwing pylon was presented). In 2015, in an interview, the executive director of Brahmos Aerospace, Kumar Mishra, said that the exact configuration still needs to be approved and that a full-fledged prototype is expected no earlier than 2022.
One of the main challenges is finding design solutions for the BrahMos-II that would allow the rocket to withstand the extreme temperatures and loads of hypersonic flight. Among the most difficult problems is the search for the most suitable materials for the manufacture of this rocket.
DRDO is estimated to have invested approximately $ 250 million in the development of a hypersonic missile; at the moment, tests of a hypersonic VRM have been carried out in the laboratory of modern systems in Hyderabad, where, according to reports, a speed of M = 5, 26 was achieved in a wind tunnel. The hypersonic wind tunnel plays a key role in simulating the speed required to test various structural elements of a rocket.
It is clear that the hypersonic missile will only be supplied to India and Russia and will not be available for sale to third countries.
There is a leader
As the most powerful military and economic power in the world, the United States is driving hypersonic development trends, but countries such as Russia and India are holding back.
The US Air Force High Command announced in 2014 that hypersonic capabilities will come out on top in the top five development priorities for the next decade. Hypersonic weapons will be difficult to intercept and will enable them to deliver long-range strikes faster than current missile technology allows.
In addition, this technology is seen by some as a successor to the stele technology, since weapons moving at high speeds and at high altitudes will have better survivability than slow low-flying systems, meaning they will be able to engage targets in contested limited access space. Due to the progress in the field of air defense technologies and their rapid proliferation, it is vital to find new ways to penetrate the "enemy cordons".
To this end, US lawmakers are forcing the Pentagon to accelerate the advancement of hypersonic technology. Many of them point to developments in China, Russia and even India as justification for more aggressive US efforts in this direction. The House of Representatives in its version of the defense spending bill said that "they are aware of the rapidly evolving threat posed by the development of hypersonic weapons in the camp of potential adversaries."
They mention there "several recent tests of hypersonic weapons carried out in China, as well as developments in this area in Russia and India" and urge "to move forward vigorously." “The Chamber believes that rapidly growing capabilities could pose a threat to national security and our active forces,” the law says. In particular, it also states that the Pentagon should use "technology leftover from previous hypersonic tests" to continue the development of this technology.
US Air Force officials predict that reusable hypersonic aircraft may enter service by the 1940s, and experts from military research laboratories confirm these estimates. Coming out with a competitive solution ahead of potential adversaries would put the United States in an advantageous position, especially in the Pacific, where long distances prevail and high speeds at high altitudes will be preferred.
Since the technology, which should "mature" in the near future, can be used in the development of weapons and reconnaissance aircraft, a big question arises - in which direction the Pentagon will move first. Both the Pentagon's projects, the "arsenal aircraft" project pioneered by Defense Secretary Carter in February 2016, and the new Long-Range Strike Bomber (LRS-B) / B-21, are platforms that can carry a useful hypersonic load, whether it be weapons or reconnaissance and surveillance equipment.
For the rest of the world, including Russia and India, the path forward is less clear-cut when it comes to long development cycles and future deployments of hypersonic technology and hypersonic platforms.
