Reaction Engines Ltd. is pleased to announce its collaboration with the United Kingdom Defence Science and Technology Laboratory (‘Dstl’).
The collaboration commenced in December 2013 and provides a framework for Dstl to assess the military utility of Reaction Engines’ Synergetic Air-Breathing Rocket Engine (‘SABRE’) and its enabling technologies. In particular, the collaboration aims to explore and evaluate the potential defence applications of REL’s heat exchanger technology.
Varunjay Ahluwalia, Technical Lead for the collaboration at Dstl, stated - “The technological advances being made by Reaction Engines could open up exciting new opportunities for defence. As part of MOD’s wider investment in disruptive technology, our collaboration with REL will enable us to explore the impact that SABRE technologies could have to current or future defence systems.”
Ben Gallagher, Business Development Lead at Reaction Engines Ltd, commented - “We are pleased to be working with Dstl to analyse and explore potential applications for our SABRE engine and heat exchanger technologies. This collaboration is a welcome addition to the portfolio of technology partnerships that Reaction Engines is participating in and we look forward to growing the relationship into the future.”
A group of researchers at NASA Ames conducts aerodynamic modelling of the Skylon SSTO at hypersonic speeds, which suggests that engine plume impingement on the aft fuselage may cause thermal issues:
An independent partial assessment is provided of the technical viability of the Skylon aerospace plane concept, developed by Reaction Engines Limited (REL). The objectives are to verify REL's engineering estimates of airframe aerodynamics during powered flight and to assess the impact of Synergetic Air-Breathing Rocket Engine (SABRE) plumes on the aft fuselage. Pressure lift and drag coefficients derived from simulations conducted with Euler equations for unpowered flight compare very well with those REL computed with engineering methods. The REL coefficients for powered flight are increasingly less acceptable as the freestream Mach number is increased beyond 8.5, because the engineering estimates did not account for the increasing favorable (in terms of drag and lift coefficients) effect of underexpanded rocket engine plumes on the aft fuselage. At Mach numbers greater than 8.5, the thermal environment around the aft fuselage is a known unknown-a potential design and/or performance risk issue. The adverse effects of shock waves on the aft fuselage and plumeinduced flow separation are other potential risks. The development of an operational reusable launcher from the Skylon concept necessitates the judicious use of a combination of engineering methods, advanced methods based on required physics or analytical fidelity, test data, and independent assessments.
The European Commission has found that a £50 million (around €71 million) grant that the UK authorities intend to provide for designing a SABRE space launcher engine is in line with EU state aid rules. SABRE is a research and development (R&D) project carried out by UK company Reaction Engines Limited (REL). The project aims to develop an engine that would power a reusable airframe to launch satellites into low Earth orbit, significantly reducing the costs of such space missions. The Commission found that the measure fosters aerospace R&D in Europe while limiting distortions of competition in the Single Market.
Commissioner in charge of competition policy Margrethe Vestager commented: "I am glad that we have approved public funding for the SABRE project. It supports crucial R&D in the challenging area of satellite launches into low Earth orbit - the most difficult and costly step in any space mission. It can lead to significant technological advances that would benefit consumers using products and services depending on these satellites, such as mobile communications, broadcasting, and navigation."
The UK notified plans in January 2015 to support the SABRE project for the design, engineering and assembling of key engine components for integration in a new type of space launcher. The new engine would enable a vehicle to reach orbital velocity and altitude from the Earth's surface without jettisoning any hardware. The objective is to render the technology less risky by significantly improving each of SABRE's numerous components and subsystems. If successful, the engine would be used to power the prototype of a reusable airframe, SKYLON, for flights into low Earth orbit, drastically reducing launch costs and enabling a step change in outer-space transportation technology.
The Commission assessed the project under its 2014 Framework on state aid for Research, Development and Innovation (R&D&I), which requires that state aid is proportionate to the objective and limited to the minimum necessary to avoid crowding out private investors. It concluded that the funding raised at this stage from private equity is insufficient to bring the project to completion. This is mainly because private investors are unable to fully apprehend the risk and opportunities of the endeavour due to a lack of information on these. The £50 million grant, along with money raised by REL from private investors, will allow the project to advance.
The UK authorities have also committed to ensure that private investors participate in each stage of the project so as the limit the use of public money in line with EU state aid rules. Furthermore, the risk of competition distortions is presently minor as the aided project is relatively remote from the market and REL is currently not active in the space launcher engine market.
The Commission therefore concluded that the project's contribution to common EU R&D&I goals clearly outweighs any potential distortion of competition brought about by the public financing.
Aviation Week discusses some of the results of the recent examination of the Reaction Engines SABRE airbreathing rocket concept by the US Air Force Research Laboratory (AFRL):
AFRL program manager Barry Hellman says analysis “confirmed the feasibility and potential performance of the Sabre engine cycle. While development of the Sabre represents a substantial engineering challenge, the engine cycle is a very innovative approach and warrants further investigation.”
Sam Hutchison, director of corporate development at Reaction Engines: “AFRL signing off on the Sabre engine is potentially game-changing".
“Enough people now say the Sabre cycle works and it looks compelling. Now the question is what will we do with it?” says Hutchison. “As an engine class, it straddles both air and space, so we have to optimize a system to take advantage of that for a given application. As we structure the development plan going forward, we can figure out what the first use is going to be. So over the next six months we will be closing in on that application.”
REL is currently scoping a full-scale Block 1 SABRE ground demonstrator engine, which is expected to be operational by 2018-19.
Highlighting the work done by Reaction Engines on 3D-printing an injector plate for the STOIC rocket engine, as part of the development of the SABRE air-breathing engine for the Skylon SSTO spaceplane:-
Details of the proprietary frost-control technology behind the SABRE airbreathing rocket propulsion system SABRE were publicly revealed for the first time by the developer Reaction Engines. The SABRE engine is designed to power an aerospace vehicle from a standing start to Mach 5.5 in airbreathing mode, and then onwards to low Earth orbit in pure rocket mode. A crucial component of the engine is the precooler, a complex heat-exchanger made of miles of fine tubing, which allows oxygen to be taken for rocket combustion directly from the ambient air.
The precooler chills incoming air from over 1000C to -150C in less than 0.01 seconds, before passing the cooled air through a turbo-compressor and into the rocket combustion chamber, where it is cooled with subcooled liquid hydrogen. The critical technical hurdle has been preventing the rapid buildup of ice on the precooler as the vehicle flies through moist air.
Speaking at at the American Institute of Aeronautics and Astronautics International Space Planes and Hypersonics conference in Glasgow, Reaction Engines technical director and chief designer Richard Varvill described a system of methanol injection which functions as antifreeze. The methanol is not simply injected into the airflow, as the air temperature drops below the point where methanol itself would freeze.
To make the methanol system work, Reaction Engines has “borrowed a trick from the chemical process industry,” Varvill says. “We inject the methanol at one of the coldest points and we effectively get the mix of water and methanol to flow forward in the matrix – against the direction of the airflow.” While conceding this could seem counterintuitive, Varvill says the system achieves this by catching the water-methane mix and re-injecting it farther upstream. “We have multiple injection and extraction points in the matrix, but the overall effect is the mix of methanol and water is actually flowing forward in the matrix against the airflow direction.”
Reaction Engines has decided to publish the frost control technology because of pending patent applications. “The trigger for patenting was the awareness that to execute this program we are going to have to involve other companies,” says Mark Thomas, former chief engineer for technology and future programs at Rolls-Royce, who recently took the reins as managing director of Reaction Engines. “You can’t keep trade secrets very long in that situation, so it is better to be protected formally and legally on the clever stuff.” Thomas adds that Reaction is close to “having those approved.”
The Reaction Engines team are celebrating the installation and current commissioning of a new state-of-the-art high vacuum furnace at Culham Science Centre, Oxfordshire. Representatives from the UK Space Agency, Department of BIS and the European Space Agency recently visited Reaction Engines’ new pre-cooler manufacturing centre at Culham Science Centre. This state-of-the-art facility is capable of achieving temperatures up to 1200°C and a vacuum level of less than one ten billionth of the Earth’s atmosphere (10-10atm). The bespoke furnace was designed and commissioned by Reaction Engines and produced by Consarc Engineering Ltd, based in Holytown, Scotland.
With an internal diameter of nearly 3m, and a total internal volume of 25m3, this equipment is optimised for the manufacture of the full-scale SABRE pre-cooler technology which will be built, tested and validated over the course of the SABRE Engine Demonstrator Programme. The furnace was jointly funded by Reaction Engines’ private capital, alongside European Space Agency ‘General Support Technology Programme’ (GSTP) funding.
Simon Hanks, Head of Advanced Manufacturing at Reaction Engines, commented: “The furnace represents enabling technology that is virtually unique in the UK. With its exceptionally clean processing environment and a highly responsive thermal performance, REL has the means to build world-leading heat exchanger technology. This is exemplified in the full-scale pre-coolers that are soon to be manufactured and tested. With efforts underway to demonstrate the performance of the full SABRE engine cycle on a static test bed, the pre-cooler manufacturing capability will form a critical part of that undertaking”