Anglo-French missile development group extends research program
Missile research in France and the U.K. is organized around the Materials and Components for Missiles Innovation and Technology Partnership (MCM ITP). Founded in 2007 and slated to run six years, the 89 partners—industry, small and medium-sized businesses, laboratories and universities—work under the umbrella of MBDA, the Anglo-French-Italian missile group, with an annual budget of €14 million ($18.7 million) shared equally by France and the U.K.
This successful collaboration will be extended from 2014-19, with the goal of developing advanced technologies to generate disruptive responses and address future U.K./French missile capability requirements in the 2020 timeframe. An intergovernmental agreement for this period is being concluded; then, MBDA will launch a tranche of research and an annual call for proposals.
One difference between ITP1 and ITP2 is that in the latter, the British and French defense ministers will validate the orientation taken by research projects, to be organized around 16 technical domains instead of eight in the first phase. These were: systems and electronics (both led by MBDA); radiofrequency sensors (); electro-optic sensors (Selex); rocket propulsion (Roxel); air-breathing propulsion ( Microturbo); warheads (Nexter); and fuzes, safety and arming units (Thales).
Among projects presented at the MCM ITP conference in Lille, France, in May, was the nosecone demonstrator that won a breakthrough project prize. One difficulty in achieving high supersonic and hypersonic speeds is the resultant aerodynamic heating, which means the skin temperature of the vehicle can exceed 1,000C (1,832F). Traditional aerospace materials cannot tolerate such heat, so hypersonic airframes must be fabricated from expensive—and heavy—heat-resistant materials such as titanium or ceramic matrix composites (CMC).
MBDA and two French research institutes, Onera and Institut Prisme, used a proprietary high-temperature carbon fiber called HVN-CMC, which maintains structural integrity at 1,100C for several minutes, and demonstrated that the material can be formed into complex shapes with the manufacture of a full-size hypersonic missile nosecone. Michel Blin, project head, says that in five years they were able to bring the project from Technology Readiness Level (TRL) 1 to TRL 4, validation in a laboratory environment.
“We have a patent pending on our HVN-CMC material, which we derived from repeated impregnation and pyrolysis of a low-cost polysiloxane polymer,” he says. This project is likely to continue under ITP2 to find a material that resists higher temperatures for longer periods and costs less.
Winner of the best demonstration/trial prize was the 3-D manufacturing process developed by the University of Birmingham and Loughborough University in the U.K., and by Safran Microturbo. Moataz Attallah of Birmingham's College of Engineering and Physical Sciences says his team used 3-D printing to manufacture parts within the missile's engine. “The lead time drops from two years to less than six months using this process,” he explains.
The process was developed in the framework of the project to investigate low-cost materials and manufacturing processes for the cold-section components of a current turbojet engine for missiles. Two aluminum alloys were selected for printing, one low cost for low temperature and one using a nickel super alloy that is more expensive, but maintains properties above 200C. Among the advantages of this manufacturing process is no waste, he says, although “surface properties can be improved,” Attallah adds. The project is at TRL 3.
Limiting collateral damage caused by missiles changing their shape or the material they are made of, while maintaining penetration capability, is a key area of warhead research. Trials have been undertaken using composites and/or copper, the difficulty being that the weapons must also maintain insensitive properties, be easy to manufacture and low cost. The problem with copper warheads is that the copper stretched further than predicted and broke up.
MCM ITP also sidelines technologies. The concept of scalable volumetric detonation, which involves placing a pulse of electrical energy into a conductive cellular matrix that contains an energetic, will not be pursued, given that the potential penalties in mass, volume, complexity and price were not offset by increased performance.