Linear Aerospike Lockheed SR-71A Blackbird

 aircraft on display  Add category

Serial Number: N844NA
Construction Number: 2013

LASRE was NASA\'s Linear Aerospike SR-71 Experiment which took place at the Dryden Flight Research Center at Edwards Air Force Base, California and concluded November 1998. The experiment\'s goal was to provide in-flight data to help Lockheed Martin validate the computational predictive tools they are using to determine the aerodynamic performance of a future potential reusable launch vehicle. Information from the LASRE experiment helped Lockheed Martin maximize its design for a future potential reusable launch vehicle. It gave Lockheed an understanding of the performance of the X-33 lifting body and linear aerospike engine combination.

LASRE was a small, half-span model of the X-33\'s lifting body with eight thrust cells of an aerospike engine, rotated 90 degrees and mounted on the back of an SR-71 Blackbird aircraft, to operate like a kind of "flying wind tunnel." The experiment focused on determining how a reusable launch vehicle\'s engine plume would affect the aerodynamics of its lifting body shape at specific altitudes and speeds reaching approximately 750 miles per hour (335 meters per second). The interaction of the aerodynamic flow with the engine plume could create drag; design refinements looked to minimize that interaction.

During the flight research program the aircraft completed seven research flights. Two initial flights were used to determine the aerodynamic characteristics of the LASRE apparatus on the back of the aircraft. The first of those two flights occurred October 31, 1997. The SR-71 took off at 8:31 a.m. PST. The aircraft flew for one hour and fifty minutes, reaching a maximum speed of Mach 1.2 and a maximum altitude of 33,000 feet (10,000 m) before landing at Edwards at 10:21 a.m. PST, successfully validating the SR-71/pod configuration.

Five follow-on flights focused on the experiment; two were used to cycle gaseous helium and liquid nitrogen through the experiment to check its plumbing system for leaks and to check engine operation characteristics. The first of these flights occurred March 4, 1998. The SR-71 took off at 10:16 a.m. PST. The aircraft flew for one hour and fifty-seven minutes, reaching a maximum speed of Mach 1.58 before landing at Edwards at 12:13 p.m. PST.

During three more flights in the spring and summer of 1998, liquid oxygen was cycled through the engine. In addition, two engine hot firings were conducted on the ground. It was decided not to do a final hot-fire flight test due to the liquid oxygen leaks in the test apparatus. The ground firings and the airborne cryogenic gas flow tests provided enough information to predict the hot gas effects of an aerospike engine firing during flight

The Lockheed SR-71, unofficially known as the Blackbird and by its crews as the Habu, was an advanced, long-range, Mach 3 strategic reconnaissance aircraft developed from the Lockheed YF-12A and A-12 aircraft by the Lockheed Skunk Works (also responsible for the U-2). It flew from 1964–1998. The legendary "Kelly" Johnson, in particular, was the man behind many of the design's advanced concepts. The SR-71 was one of the first aircraft to be shaped to have an extremely low radar signature. The aircraft flew so fast and so high that if the pilot detected a surface-to-air missile launch, the standard evasive action was simply to accelerate. During its entire operational life no SR-71 was ever shot down.