New programmes launched by Pentagon organisation take up technologies abandoned by US space agency
The US Defense Advanced Research Projects Agency (DARPA) is emerging as the engine for government-funded aerospace research and development. This fiscal year's $3bn budget has several new programmes that take up technologies dropped by NASA as it focuses on space exploration.
The new projects include hypersonic propulsion; high-energy laser and magnetohydrodynamic weapons; sea-launched unmanned air vehicles and UAV killers; blended wing-body aircraft and ultra-large airships.
DARPA's high-speed/hypersonic reusable demonstration initiative "continues work to design, develop and demonstrate a combined-cycle engine" and could lead to flight tests of a reusable hypersonic vehicle. The project is aligned with the agency's Rascal programme to develop an aircraft-based microsatellite launcher and the Falcon initiative to develop a global-range strike system.
NASA recently cancelled development by General Electric of a Mach 4+ turbine engine, the Revolutionary Turbine Accelerator (RTA), which had been the baseline low-speed propulsion system for the unmanned, reusable hypersonic cruise vehicle foreseen under the Falcon programme. The RTA was to be combined with a supersonic-combustion ramjet to power the now-cancelled M7 reusable combined-cycle flight demonstrator.
DARPA is also backing long-running work on the blended wing-body concept, with a project to demonstrate a 40-50% scale model of a modular multirole aircraft that would be reconfigurable on the flight line between bomber, tanker or transport in less than 24h.
The Walrus programme, meanwhile, plans a hybrid aircraft demonstrator, combining aerodynamic and buoyant lift, as a forerunner of a vehicle able to lift 500t "from fort to fight" over intercontinental distances.
Other new DARPA programmes include Hellads, to develop a 150kW-class higher-energy liquid laser weapon with a weight goal of less than 5kg/kW, making it suitable for use on tactical aircraft and UAVs.
The Air Laser project will develop a 100kW-class weapon based on direct diode pumping of liquid oxygen, which provides both amplification and cooling.
The high-power fibre lasers programme aims to demonstrate 1kW from a single fibre aperture, which can then be scaled up to hundreds of kilowatts by bundling many fibres.
DARPA says its Mahem project will demonstrate a self-shaping anti-armour/ hard-target precision munition. When the munition "explodes" an intense magnetic field is created.
This magnetohydrodynamic process shapes and directs metal jets to burn through softer targets and produces fragments that become harder target penetrators.
GRAHAM WARWICK / WASHINGTON DC
Source: Flight International
