Hypersonic missiles travel at least five times the speed of sound (Mach 5 or 6,125 kilometers per hour) or more. Flying along the edge of space while gliding and maneuvering these missiles would strike targets with unprecedented speed and precision. Once operational, these missiles would make current strategic missile defenses systems obsolete, they will be able to avoid triggering early-warning systems or detection by radar as well their speed shall complicate interception.
Militaries are now developing various defensive strategies and solutions to counter the threat of hypersonic weapons. Glide Breaker intends to advance the United States’ means to counter hypersonic vehicles. According to a DARPA Broad Agency Announcement, released on 6 November 2018, Glide Breaker will develop an enabling technology that “is critical for enabling an advanced interceptor capable of engaging manoeuvring hypersonic threats in the upper atmosphere”.
“The objective of the Glide Breaker program is to further the capability of the United States to defend against supersonic and the entire class of hypersonic threats,” DARPA said in an announcement for the July 2018 “Proposers Day.” “Of particular interest are component technologies that radically reduce risk for development and integration of an operational, hard-kill system.”
Glide Breaker could be used against new Russian and Chinese weapons, including Moscow’s new Mach 27 Avangard hypersonic missile. Glide Breaker’s core objective is deterrence. “A key figure of merit is deterrence: the ability to create large uncertainty for the adversary’s projected probability of mission success and effective raid size,” DARPA said in its Proposers Day notice.
Now the U.S. Defense Advanced Research Projects Agency (DARPA) is ready for Phase 2 of the program, which was first announced in 2018. The agency is seeking proposals “to conduct wind tunnel and flight testing of jet interaction effects,” DARPA officials announced(opens in new tab) on April 15.
Participants in Phase 1 of the program included, at the least, Northrop Grumman (which received a contract valued at $13 million(opens in new tab), disclosed in January 2020) and Aerojet Rocketdyne ($12 million(opens in new tab), disclosed in February 2020.)
DARPA) has awarded Aerojet Rocketdyne a contract to develop enabling propulsion technology for the Glide Breaker hypersonic defence interceptor programme. The contract, awarded in February 2020 and worth up to USD19.6 million, is for the research, development, test, and evaluation of propulsion technology for the base period of the Glide Breaker programme. Work is expected to be completed in February 2021.
Aerojet Rocketdyne supplies both solid-fuelled and air-breathing propulsion systems for hypersonic flight. The company delivered both system types for the joint US Air Force-DARPA-NASA X-51A WaveRider programme, which completed the first practical hypersonic flight of a hydrocarbon-fuelled and -cooled scramjet-powered vehicle in May 2010, and achieved its longest duration powered hypersonic flight in May 2013.
More recently, the company completed a series of subscale propulsion-system test firings as part of DARPA’s Operational Fires (OpFires) programme – a joint DARPA/US Army initiative to develop and demonstrate a novel ground-launched system, enabling hypersonic boost glide weapons to penetrate modern enemy air defences, and rapidly and precisely engage critical time-sensitive targets from a highly mobile launch platform.
DARPA awarded Northrop Grumman a USD13 million contract in Jan 2020 for the base period of the Glide Breaker programme. The contract provides for “research, development and demonstration of a technology that is critical for enabling an advanced interceptor capable of engaging maneuvering hypersonic threats in the upper atmosphere.”
SPARC to deliver propulsion design for hypersonic interceptor weapon
SPARC Research has received a contract for the propulsion design of a future hypersonic interceptor weapon system. Having received the contract award from the US not-for-profit research and development organisation Draper Laboratory, SPARC will also be responsible for delivering analysis support for the weapon. The project concept is based on advanced air-breathing propulsion technologies, which are expected to provide the hypersonic weapon with extended flight at increased speeds that have yet remained unachieved. In order to meet the challenge, SPARC Research will leverage its in-house experience and analysis tools.
The system uses an air-breathing engine to burn the stored missile fuel with atmospheric air instead of propellant ingredients that would be carried in a traditional rocket, significantly increasing the speed and range. The flight system needs specialised knowledge of the air properties entering the engine and ability to model fuel combustion at speeds greater than the speed of sound as encountered in a supersonic combustion ramjet (SCRAMJET) engine. Using modern multi-physics modelling tools, SPARC Research is focused on advancing the advanced rocket and air-breathing technology development, preliminary design and prototype demonstration. In August, the company collaborated with ANSYS and F1 Computer Solutions in order to modify and modernise missile propulsion design.
“In Phase 1 of the Glide Breaker program, two DACS prototypes capable of achieving the desired performance objectives were designed and are being fabricated and demonstrated,” DARPA stated.
“Testing in Phase 1 includes component tests and static hot-fire demonstrations of the integrated DACS prototypes,” the agency added, noting that participating in Phase 1 is not a prerequisite for joining Phase 2.
Phase 2 of the Glidebreaker program in April 2022
Phase 1 was a critical step, but did not address endoatmospheric effects such as controlling the KV in the presence of JI between the DACS jets and the hypersonic cross flow. JI in this regime is complex and dependent on a large number of factors. The Advanced Interceptor Technology (AIT) program in the 1990’s was one of the few projects that have gathered data in this regime.
AIT showed that JI effects are highly dependent on outer mold line geometry (including nosecone angle), jet placement, jet geometry, jet thrust, and chemistry effects resulting from unburned propellant reacting with the crossflow. Glide Breaker Phase 2 seeks to develop the knowledge required to enable a DACS-propelled KV to intercept threats during glide phase in the presence of JI effects. If successful, the results of Phase 2 will provide the foundation for a future program of record interceptor.
DARPA is seeking innovative proposals to conduct wind tunnel and flight testing of jet interaction effects for Phase 2 of the Glide Breaker program. The overall goal of Glide Breaker is to advance the United States’ ability to counter emerging hypersonic threats. Phase 1 of the program focused on developing and demonstrating a divert and attitude control system (DACS) that enables a kill vehicle to intercept hypersonic weapon threats during their glide phase.
Phase 2 will focus on quantifying aerodynamic jet interaction effects that result from DACS plumes and hypersonic air flows around an interceptor kill vehicle. The Glide Breaker Phase 2 Broad Agency Announcement (BAA) can be found at this link.
“Glide Breaker Phase 1 developed the propulsion technology necessary to achieve hit-to-kill against highly-maneuverable hypersonic threats. Phase 2 of the Glide Breaker program will develop the technical understanding of jet interactions necessary to enable design of propulsion control systems for a future operational glide-phase interceptor kill vehicle.
A major goal of Phase 2 involves further developing a “divert and attitude control system” (DACS), which allows an “interceptor kill vehicle” to target hypersonic missiles in flight. The first phase did not consider effects such as hypersonic air flows, nor plumes from the control system, DARPA officials noted.
A solid propellant Divert Attitude Control System (DACS) is a quick reaction propulsion system providing control over positions of missiles, satellites, and spacecraft. Regarding missiles, whether a ballistic measure, counter measure or defensive measure, DACS allows for interception of its target with greater accuracy and reliability.
Phase 2 performer(s) shall execute wind tunnel and flight testing of a Demonstration System (DS) payload to characterize and quantify the effect of JI on a DACS-propelled kill vehicle. The primary deliverable for Phase 2 is a data set from the wind tunnel and flight tests that enables validation of models and informs future design activities
4. Demonstration System
Phases 1 and 2 together fill the technology gaps necessary for the U.S. to develop a robust defense against hypersonic threats,” said Major Nathan Greiner, program manager in DARPA’s Tactical Technology Office