NASA 

National Aeronautics and 

Facts

Space Administration 

Dryden Flight Research Center 

P.O. Box 273

Edwards, California 93523 

AC 661-276-3449 

FAX 661-276-3566 

pao@dfrc.nasa.gov FS-2002-09-043 DFRC 

LASRE Project 

Linear Aerospike experiment takes 

flight. A NASA SR-71 successfully 

completed its first flight as part of 

the NASA/Rocketdyne/Lockheed 

Martin Linear Aerospike SR-71 

Experiment (LASRE) Oct. 31, 

1997, at NASA’s Dryden Flight 

Research Center, Edwards, Calif. 

The goal of the first flight was to 

evaluate the aerodynamic characteristics and the handling of the SR-71/ 

linear aerospike experiment 

configuration. The aerospike engine 

was not fired during the flight. 

(NASA photo EC97-44295-99) 

The LASRE project concluded its flight operations phase in November 1998. 

The goal of the experiment was to provide in-flight data to help Lockheed Martin validate the computational predictive tools it has 

been using to determine the aerodynamic performance of a future potential reusable launch vehicle. 

LASRE included a 20-percent-scale, half-span model of the X-33 (minus the fins) that was rotated 90 degrees and equipped with eight 

thrust cells of an aerospike engine. The experiment, mounted on the back of an SR-71 aircraft, simulated the operation of the X-33. 

The experiment focused on determining how a reusable launch vehicle’s engine plume would affect the aerodynamics of its liftingbody shape at specific altitudes and at speeds reaching approximately 750 miles per hour. 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 from NASA’s Dryden Flight Research Center, 

Edwards, Calif. 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 Oct. 31, 1997. The SR-71 took off at 8:31 a.m. PST. The aircraft flew for one hour and 

50 minutes, reaching a maximum speed of Mach 1.2 and a maximum altitude of 33,000 feet 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 57 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. 

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A final hot-fire flight test did not take place 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. 

Hardware and Aircraft 

The experiment itself was a small, half-span model of a lifting 

body shape. The model contained eight thrust cells of an 

aerospike engine and was mounted on a housing known as the 

“canoe,” which contained the gaseous hydrogen, helium, and 

instrumentation gear. 

The model, engine, and canoe together were called the “pod.” 

The entire pod was 41 feet in length and weighed 14,300 pounds. 

The experimental pod was mounted a NASA SR-71. 

NASA and Space Transportation 

Lockheed Martin may have used information gained from 

LASRE and the X-33 Advanced Technology Demonstrator to 

develop a potential future reusable launch vehicle. NASA and 

Lockheed Martin were partners in the X-33 program through a 

cooperative agreement. 

The goal of the X-33 program, and a major goal for NASA’s 

Office of Aero-Space Technology, was to enable significant 

reductions in the cost of access to space, and to promote the 

creation and delivery of new space services and other activities 

that would improve U.S. economic competitiveness. The program 

implemented the National Space Transportation Policy, which is 

designed to accelerate the development of new launch technologies and concepts to contribute to the continuing commercialization of the national space launch industry. 

Both the X-33 and the smaller X-34 technology testbed demonstrator were under the Space Transportation Program Offices at 

NASA Marshall Space Flight Center, Huntsville, Ala. The airlaunched, winged X-34 also was to demonstrate technologies 

applicable to future-generation reusable launch vehicles designed 

to dramatically lower the cost of access to space. 

SR-71 with aerospike experiment. 

Normal Bell-Nozzle Linear Aerospike 

Rocket Engine Rocket Engine

Rocket engines. 

Pod design. Three view of SR-71 with pod. 

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