Picture of the moment of separation from the carrier of the HSSW hypersonic missile. The US Air Force intends to move from development to a program to deploy this weapon system after a demonstration flight planned for 2020 year.
Hypersound becomes the next key parameter of weapons and surveillance platforms and therefore it is worth taking a closer look at the research conducted 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 the head of the department of high-speed systems in the research laboratory of the US Air Force (AFRL) Robert Mercier, two near goals are hypersonic weapon, the technological readiness of which is expected at the beginning of the 20-s, and the unmanned surveillance vehicle, which will be ready for deployment at the end of the 20-s or the beginning of the 30-s, and hypersonic devices will follow in the more distant future.
“Space exploration using air-jet engines is a much more distant prospect,” he said in an interview. “It is unlikely that hypersonic spacecraft will be ready before 2050’s.” Mercier added that the general development strategy is to start with small weapons and then, with the development of technologies and materials, expand to air and spacecraft.
Spiro Lekudis, director of the weapons systems, procurement, technology and supply department at the Ministry of Defense, confirmed that the hypersonic weapon is likely to be the first procurement program to appear after the technology has been developed by the ministry and its partner organizations. “The aircraft is definitely a much more long-term project than a weapon,” he said in an interview. The US Air Force is expected to demonstrate the HSSW (High Speed Strike Weapon) high-speed strike weapons - a joint development with the Advanced Defense Studies Directorate (DARPA) - around 2020, then the Pentagon will decide how best to transfer this technology to the development and purchases hypersonic rocket.
“There are two major research projects aimed at demonstrating HSSW technology,” says Bill Gillard, developer of plans and programs at the AFRL. “The first is the tactical overclocking program TBG (Tactical BoosWSIide) developed by Lockheed Martin and Raytheon, and the second is the hypersonic concept of a HAWC (Hypersonic Air-breathing Weapon Concept) jet-powered weapon, headed by Boeing.”
“Meanwhile, the AFRL lab is conducting another fundamental study to supplement the DARPA and US Air Force projects,” Gillard noted. For example, within the framework of testing the concept of the hypersonic reusable apparatus REACH (reusable aircraft concept for hypersonics), in addition to the study of basic materials, several experiments were conducted with small and medium ramjet engines. "Our goal is to promote the database and develop and demonstrate technologies that can be taken to create new systems." Long-term fundamental research AFRL in the field of improving the ceramic-matrix composite and other heat-resistant materials are extremely important for the creation of promising hypersonic devices.
AFRL and other Pentagon laboratories are intensively working on two main aspects of promising hypersonic devices: reusability and increase in their size. “In the AFRL laboratory, there is even a certain tendency aimed at promoting the development of the concept of reusable and larger hypersonic systems,” Gillard said. “We focused all of these technologies on projects like X-51, and REACH will be another.”
Hypersonic cruise missile X-51А WaveRider
“A demonstration of the Boeing X-51A WaveRider development in 2013 year will form the basis of the US Air Force hypersonic vehicle armament plans,” says John Leger, chief engineer of aerospace projects in the weapons department of the AFRL laboratory. “We study the experience gained in developing the X-51 project and use it in developing the HSSW.”
Simultaneously with the X-51 hypersonic cruise missile project, 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 observation, reconnaissance, and information-gathering platforms and atmospheric cruise missiles,” said Gillard. “And ultimately in our plans to move on to the 100 figure, which will allow us to gain access to space using air-reactive systems.”
The AFRL is also exploring the possibility of integrating a hypersonic ramjet with a high-speed turbine engine or a rocket in order to have enough driving force to achieve large Mach numbers. “We are exploring all the possibilities to improve the efficiency of the engines of a supersonic device. The conditions in which they are 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. Pratt & Whitney's Rocketdyne division developed the engine for the WaveRider. This unit was later sold to Aerojet, which continues to work on hypersonic propulsion systems, but does not provide any details on this topic.
From the 2003 to 2011 year, Lockheed Martin worked with DARPA on the original concept of the Falcon Hypersonic Technology Vehicle-2 hypersonic device. The Minotaur IV light rocket served as the booster for these vehicles, which were launched from Vandenberg Air Base in California. The first flight of the HTV-2 in 2010 year allowed us to collect data that demonstrated progress in aerodynamic performance, heat-resistant materials, thermal protection systems, autonomous flight safety systems, and long-duration hypersonic flight guidance and control systems.
Two demonstration launches were successfully carried out in April 2010 of the year and August of 2011 of the year, but, according to DARPA statements, both times the Falcon vehicles during the flight, trying to achieve the planned speed 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 as part of two demonstration programs: HAWC and TBG. DARPA issued in April 2014 to Raytheon and Lockheed Martin companies to continue the development of the TBG program. Companies received 20 and 24 million dollars respectively. And the Boeing company, meanwhile, is developing the HAWC project. She and DARPA refuse to give any details about this contract.
Figure of the detached high-speed strike weapons HSSW (High Speed Strike Weapon) in flight, the US Air Force hopes to demonstrate the system (joint development with the DARPA Office) around 2020 year
The company Lockheed Martin with 2003 on 2011 year worked with DARPA on the previous concept of hypersonic device Falcon Hypersonic Technology Vehicle-2. The picture shows the detached Falcon in flight.
The goal of the TBG and HAWC programs is to accelerate weapons systems up to speed M = 5 and their further planning on their target. Such weapons should be maneuverable and extremely resistant to heat. Ultimately, these systems can reach an altitude of almost 60 km. A warhead developed for a hypersonic missile has a mass of 76 kg, which is approximately equal to the mass of a small-diameter SDB (Small Diameter Bomb) bomb.
While the integration of the aircraft and the hypersonic engine was successfully demonstrated in the X-51A project, the focus in the TBG and HAWC projects would be on advanced guidance and control, which was not fully implemented in the Falcon or WaveRider projects. Homing head subsystems (GOS) are engaged in several US Air Force weapons laboratories to further enhance the capabilities of hypersonic systems. In March, 2014 of the year, a DARPA statement said that within the framework of the TBG project, which should be completed with a demonstration flight by 2020, partner companies are trying to develop technologies for a tactical hypersonic planning system with a rocket accelerator launched from a carrier aircraft.
“The program will focus on solving the problems associated with the system and the technologies necessary to create a hypersonic planning system with a rocket accelerator. These include the development of concepts of the apparatus with the necessary aerodynamic and aero-thermodynamic characteristics; manageability and reliability in a wide range of operating conditions; system and subsystem characteristics required for efficiency in appropriate 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 plans at speeds up to M = 10 and more.
Meanwhile, in the framework of the HAWC program following the X-51A project, a hypersonic cruise missile with ramjet propulsion at lower speeds will be demonstrated, approximately M = 5 and higher. “HAWC technologies can expand to promising reusable hypersonic aerial platforms that can be used as reconnaissance vehicles or access to outer space,” the DARPA said in a statement. Neither DARPA nor the main contractor of Boeing disclose all the details of their joint program.
Although the main goals of the Ministry of Defense in the field of hypersound are weapon systems and intelligence platforms, DARPA launched a new program in 2013 to develop a reusable unmanned hypersonic accelerator to launch small-sized 1360-2270 kg satellites into a low orbit, which will also serve as a testing laboratory for hypersonic devices. According to a congressional statement, in July 2015, the Office issued a contract to Boeing and its partner Blue Origin, which cost 6,6 a million dollars to continue work on the XS-1 experimental spacecraft Experimental Spaceplane. In August 2014, Northrop Grumman announced that in collaboration with Scaled Composites and Virgin Galactic, she was also working on a technical project and demonstration flight plan for the XS-1 program. The company received a 13-month contract worth 3,9 million dollars.
It is expected that the XS-1 will have a reusable starting accelerator, which, in combination with a one-time acceleration stage, will provide an affordable 1360 kg vehicle for delivery to a low near-earth orbit. In addition to the cheap launch, estimated at one tenth of the cost of the current launch of a heavy rocket, the XS-1 is also likely to serve as a testing laboratory for new hypersonic devices.
DARPA would like to run XS-1 every day at a price of less than 5 millions per flight. Management wants to get a machine that can reach speeds above 10 Mach numbers. The requested "like an airplane" principles of operation include horizontal landing on standard landing strips, in addition, the launch must be carried out from a lifting 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 year.
After several unsuccessful attempts by NASA, which began back in the 80s, to develop a system like the XS-1, military researchers now believe that the technology has already developed enough and this is due to progress in light and cheap composite materials and improved thermal protection.
XS-1 is one of several Pentagon projects aimed at reducing the cost of launching satellites. In connection with the reduction of the US defense budget and the building up of the capabilities of other countries, routine access to space is becoming an increasingly priority for national security. The use of heavy rockets to launch satellites is expensive and requires an elaborate strategy against the background of a few possibilities. Such traditional launches can cost hundreds of millions of dollars and require maintenance of expensive infrastructure. Due to the fact that the United States Air Force insists that lawmakers issue a resolution to suspend the use of Russian RD-180 rocket engines for launching American satellites, DARPA’s research in the field of hypersound will significantly shorten the path that needs to be taken, relying only on its own forces and means.
(top) During the last fourth flight, the X-51A WaveRider rocket reached Mach 5,1 and flew 230 nautical miles in just six minutes. This is the longest hypersonic flight with ramjet today; (center) a drawing of the XS-1 aerospace aircraft offered by Northrop Grumman, although the main goals of the Ministry of Defense in the development of hypersonic systems are weapons and reconnaissance vehicles; (below) the concept of the space launch vehicle Boeing XS-1. In addition to the low launch cost, estimated at one tenth of the launch of a heavy rocket, it is expected that the XS-1 will also serve as a flying laboratory for new hypersonic devices.
Russia: catch up time
At the end of the existence of the Soviet Union, the engineering design bureau of the ICD Raduga from Dubna designed the GELA (Hypersonic Experimental Aircraft), which was supposed to be the prototype of the strategic launch aircraft X-90 ("Product 40") with a ramjet engine Product 58 »Development of TMKB (Turaev Machine-Building Design Bureau)“ Soyuz ”. The missile should have been able to accelerate to a speed of 4,5 Mach numbers and have a range of 3000 km. Two standard X-160 missiles were to be included in the standard armament of the upgraded Tu-90M strategic bomber. Work on the X-90 supersonic cruise missile was discontinued in 1992 at the laboratory sample stage, and the GELA device itself was shown in 1995 at aviation MAX exhibition.
The most comprehensive information about the current programs of air launch hypersonic weapons was presented to the former commander of the General Staff of the Russian Air Force Alexander Zelin at a lecture given by him at the conference of aircraft manufacturers in Moscow in April 2013. According to Zelin, Russia is carrying out a two-stage program for developing a hypersonic rocket. The first stage envisages the development of a rocket sub-strategic level of air launch by 2020 with a range of 1500 km and a speed of approximately M = 6. Further in the next decade, a rocket should be developed at a speed of 12 Mach numbers capable of reaching any point on the globe.
Most likely, the 6 Max speed rocket, mentioned by Zelin, is a “75 Product”, also designated GZUR (Hypersonic Guided Missile), which is currently at the stage of technical design in the Tactical Missile Corporation. The “75 product” appears to have a length of 6 meters (the maximum size that the Tu-95MS bomb compartment can take; it can also be placed in the weapons compartment of the Tu-22М bomber) and weighs about 1500 kg. It should be set in motion by a ramjet “Product 70” developed by TMKB “Soyuz”. Its active radar homing head, the Gran-75, is currently developing the DCPPDB in Kamensk-Uralsky, while the broadband passive GOS is manufactured by Omsk TsKBA.
In 2012, Russia began flight tests of an experimental hypersonic vehicle mounted on a suspension of a long-range supersonic bomber Tu-23MZ (NATO designation “Backfire”). Not before 2013, this unit made its first free flight. The hypersonic device is installed in the nose compartment of the X-22 rocket (AS-4 "Kitchen"), used as a starting accelerator. This combination has a length of 12 meters and weighs about 6 tons; hypersonic component has a length of about 5 meters. In 2012, the Dubna Machine-Building Plant completed the construction of four X-22 supersonic airborne anti-ship missiles (without GOS and combat units) to be used in testing hypersonic vehicles. The rocket is launched from the Tu-22MZ underwing suspension at speeds up to 1,7 Mach and altitudes up to 14 km and accelerates the test apparatus to Mach 6,3 speed and 21 km altitude before launching the test component, which apparently develops Mach speed 8.
It was expected that Russia took part in similar flight tests of the French hypersonic MBDA LEA device with launch from Backfire. However, according to available data, the test hypersonic component is a primordially Russian project.
In October-November 2012, Russia and India concluded a preliminary agreement on work on the BrahMos-II hypersonic rocket. The cooperation scheme includes NPO Mashinostroeniya (rocket), TMKB Soyuz (engine), TsAGI (aerodynamics research) and TsIAM (engine development).
Russian experimental hypersonic rocket passes flight tests with 2012 year
India: new player on the field
After the agreement on joint development with Russia in 1998, the Indian BrahMos rocket program was launched. According to the agreement, the main partners were the Russian NPO Mashinostroeniya and the Indian Defense Research and Development Organization (DRDO).
Its first version is a supersonic cruise two-stage rocket with radar guidance. A solid-fuel first-stage engine accelerates a rocket to supersonic speeds, while a second-stage liquid ramjet accelerates a rocket to a speed of M = 2,8. BrahMos, in fact, is the Indian version of the Russian Yakhont missile.
While the BrahMos rocket was already delivered to the Indian army, navy, and air force, the decision to start development by the already established partnership of the BrahMos-II hypersonic version of the rocket was made in 2009 year.
In accordance with the technical design, BrahMos-ll (Kalam) will fly at speeds above 6 Mach numbers and have higher accuracy than the BrahMos-A variant. The rocket will have a maximum range of 290 km, which is limited to the Missile Technology Control Regime signed by Russia (it limits the development of missiles with a range of more than 300 km for a partner country). In order to increase the speed of the BrahMos-2 rocket, a hypersonic ramjet will be used and, according to a number of sources, the Russian industry is developing special fuel for it.
For the BrahMos-II project, a key decision was made to retain the physical parameters of the previous version so that the new rocket could use the already developed launchers and other infrastructure.
The set of targets defined for the new version includes reinforced targets, such as underground shelters and warehouses with weapons.
The scale model of the BrahMos-II rocket was shown at the Aero India 2013 exhibition, and the prototype tests should begin in the 2017 year. (At the recently held Aero India 2017 exhibition, the Su-30MKI fighter with the Brahmos rocket on the underwing pylon was introduced). In an interview with 2015, Brahmos Aerospace CEO Kumar Mishra said in an interview that the exact configuration still needs to be approved and that a full-scale prototype is expected no earlier than 2022.
Su-30MKI with BrahMos rocket at Aero India 2017
One of the main problems is to find constructive solutions for the BrahMos-II, which would allow the rocket to withstand the extreme temperatures and loads acting during hypersonic flight. Among the hardest problems - finding the most suitable materials for the manufacture of this rocket.
DRDO is assumed to have invested roughly 250 million dollars in the development of a hypersonic rocket; So far, tests of the hypersonic WFD have been conducted in the laboratory of modern systems in Hyderabad, where, in a wind tunnel, the speed M = 5,26 was reported. Further tests of the BrahMos-II Technology Demonstrator Hypersonic Technology Demonstrator Vehicle are taking place at a Bangalore Scientific Institute, whose hypersonic wind tunnel plays a key role in simulating the speed required to test various elements of a rocket design.
It is clear that the hypersonic rocket will be delivered only 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 defines the trends of developments in the field of hypersound, but countries such as Russia and India do not allow them to go far into the lead.
The US Air Force High Command in 2014 announced that in the coming decade hypersonic capabilities will come out on top in the top five priority developments. Hypersonic weapons will be difficult to intercept, it will provide an opportunity to strike at long ranges faster than current missile technologies allow.
In addition, this technology is considered by some as the successor to the stele technology, since weapons moving at high speeds and at high altitudes will have a better survivability than slow low-flying systems, that is, it can hit targets in a challenged space with limited access. Owing to the progress in the field of air defense technologies and their rapid spread, it is vital to search for new ways to penetrate enemy cordons.
To this end, US lawmakers are pushing the Pentagon to promote hypersonic technology at an accelerated pace. Many of them point to developments in China, Russia and even in India as a justification for more aggressive US efforts in this direction. The House of Representatives of the Congress, in its version of the law on defense spending, stated that "they are aware of the rapidly evolving threat associated with the development of hypersonic weapons in the camp of potential opponents."
They mention there "several recent tests of hypersonic weapons conducted in China, as well as developments in this field in Russia and India" and call for "moving ahead energetically." “The Chamber believes that rapidly growing opportunities may become a threat to national security and our existing troops,” the law says. In particular, it also states that the Pentagon must use the "remaining from previous hypersonic technology tests" to continue the development of this technology.
US Air Force officials predict that reusable hypersonic aircraft can enter service by the 40 years and experts in military research laboratories confirm these estimates. Coming out with a competitive solution before 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 applied in the development of weapons and reconnaissance aircraft, the big question arises - in which direction the Pentagon will move first. Both the Pentagon project, the arsenal aircraft project, which was first talked about by Defense Minister Carter in February 2016, and the new Long-Range Strike Bomber (LRS-B) / B-21 long-range bomber, are platforms that can carry useful hypersonic load, whether weapons or means of reconnaissance and surveillance.
For the rest of the world, including Russia and India, the way forward is less clearly defined when it comes to long development cycles and the future deployment of hypersonic technology and hypersonic platforms.
A preliminary model of the Russian-Indian BrahMos-II rocket, shown in 2013 year as a demonstration of intentions to jointly develop a hypersonic rocket