Lockheed Martin-designed craft will demonstrate technology for reusable, unmanned hypersonic cruise vehicle
Lockheed Martin is proceeding with design of a hypersonic test vehicle (HTV) after the US Defense Advanced Research Projects Agency (DARPA) exercised the option to enter the next phase of its Falcon programme to develop technology for a global-range strike system.
The HTV will demonstrate technology for a reusable, unmanned hypersonic cruise vehicle (HCV) that could enter US Air Force service around 2025. The autonomous HCV would be capable of taking off from a conventional runway, carrying a 5,450kg (12,000lb) payload and reaching a distance of 16,600km (9,000nm) in under 2h.
Lockheed Martin has received an initial $10.6 million contract for Phase 2b of Task 2 of the DARPA/USAF programme. Task 2 covers the design, construction and testing of a series of increasingly capable HTVs to be launched by the small launch vehicle (SLV) being developed under Task 1 of the Falcon programme.
Three vehicles are planned, starting with the expendable HTV-1 capable of cruising for 800s at Mach 10 after release from the SLV, rising to 45min for the expendable HTV-2. All the test vehicles are planned to be unpowered, although the reusable HTV-3 could test an advanced scramjet engine.
Advances in hypersonic aerodynamics, thermal protection, and guidance, navigation and control will allow each 3.5-4.5m-long, 900kg vehicle to fly longer. Each will be more waverider-like, and more like the HCV. Hypersonic lift-to-drag ratio (L/D) will increase from 2.5 for the HTV-1, to 3.5-4 for the HTV-2 and 4-5 for the HTV-3. The HCV will require an L/D of 6-7 at M10 and 130,000ft (40,000m).
DARPA plans to fly the HTV-1 in 2007, to be followed in a proposed Phase 3 by two HTV-2s and three launches of two reusable HTV-3s by 2009. The Falcon effort is only a technology demonstration, and there would need to be a follow-on programme to build a prototype HCV, says the agency.
GRAHAM WARWICK/WASHINGTON DC
Source: Flight International