Lockheed Martin’s Skunk Works says the replacement it’s proposing for the SR-71 spy plane, the SR-72, is a Mach 6 drone that doesn’t need to be stealthy because it’s so fast. Aviation Week and Space Technology got an exclusive on the public unveiling of the project, which it quotes a Lockheed Martin spokesperson as saying could be operational within 10 years and since it uses some off-the-shelf technology won’t break the defense budget. The Skunk Works has been working with Aerojet Rocketdyne for the past seven years to develop a method to integrate an off-the-shelf turbine with a scramjet to power the aircraft from standstill to Mach 6 plus, Brad Leland, portfolio manager for air-breathing hypersonic technologies, told AW&ST.
The drone will launch and recover from conventional runways and use jet engines to get it to Mach 4. A scramjet second stage would get the blended wing aircraft to Mach 6 with a variety of spy gear or weapons. The company said it didn’t worry too much about stealth because at more than 4,000 mph the speed itself is the cover. Lockheed Martin said the key to the success of the program is the combination turbine and scramjet engine that supplies the ponies. Leland says the method of making the two vastly different engine technologies work together “is proprietary.” The SR-71 Blackbird, a Mach 3 high altitude manned spy plane, was retired in 1998 after a 30-year career.
