Rolls-Royce completes initial test of engine for supersonic cruise missile programme

Indianapolis: Rolls-Royce has announced it has successfully completed an initial test of its advanced, high-specific thrust YJ102R engine at the Indianapolis, Indiana facility. This test is the first of a series to be performed by LibertyWorks, the company's research unit, and is designed to validate critical performance criteria under its High Speed Turbine Engine Demonstration (HiSTED) contract with the US Air Force Research Laboratory (AFRL).

Phil Burkholder, chief operating officer for LibertyWorks, said: "Partnering with the Department of Defense to create this new capability is an exciting opportunity for LibertyWorks. The unique, power dense design of this engine has the potential to take high-Mach propulsion to the next level. Validating the progress achieved to date is a significant milestone and critical for the HiSTED program."

LibertyWorks, known officially as Rolls-Royce North American Technologies Inc., has a long history of service to the US military. Based in Indianapolis, Indiana, US, LibertyWorks - previously known as Allison Advanced Development Co. (AADC) - has contributed technology to the F-35 Lightning II LiftFan and F136 engine; IHPTET (Integrated High Performance Turbine Engine Technology) programme; and the RATTLRS supersonic missile.

HiSTED is a joint DARPA/Air Force initiative to design, fabricate and ground test a high Mach expendable turbine engine. The engine is also expected to power Lockheed Martin's Revolutionary Approach to Time-critical Long Range Strike (RATTLRS) vehicle. The RATTLRS program is a supersonic, science and technology missile flight demonstrator effort sponsored by the Office of Naval Research.

Additional engine testing is scheduled to demonstrate its ability to achieve transonic acceleration and Mach 3+ cruise speed. The success of these tests will lead to a first flight demonstration of the RATTLRS vehicle.

The programme is designed to supply similar supersonic cruise missile capabilities as the Russian Granit and the Indo-Russian BrahMos missiles.

The HiSTED engine is a high-temperature, moderate-pressure-ratio, single-spool, dry (non-afterburning) turbojet. It incorporates Lamilloy technology, designed by Rolls-Royce to enable engines to run at higher temperatures, allowing for greater fuel economy.

RATTLRS
The RATTLRS (Revolutionary Approach To Time Critical Long Range Strike Project) program, led by the U.S. Navy's ONR (Office of Naval Research), was begun in early 2004 with Lockheed Martin receiving the contract to design, build and fly the RATTLRS flight test vehicle. The programme's goal is to build a vehicle, which has the potential to be developed into a tactical missile system.

The missile system, in the same class as the Russian Granit and the Indo-Russian BrahMos is expected to have the following characteristics: it will use a turbine engine, accelerate with 0.25g from subsonic speed to at least Mach 3, and cruise at Mach 3 for at least 5 minutes.

Lockheed Martin's RATTLRS vehicle will be air-launched by a fighter aircraft, and will be powered by an Allison YJ102R turbojet engine. The YJ102R covers a speed range similar to that of the 1960s' J58 used in the SR-71, but is much smaller and lighter than the older engine and uses less fuel. e.g., no afterburner will be necessary to accelerate RATTLRS to Mach 3.

If RATTLRS is to be further developed into a tactical missile, performance goals include a speed of Mach 4+, 0.5g acceleration, and 15+ minutes cruise time (implying a range of 1000+ km). A typical payload for such a weapon would be a penetrating warhead which can use the missile's speed to particular advantage.

Lockheed Martin has already successfully tested penetrator designs which could be used with a RATTLRS-type missile.