LASRE was
NASA
The National Aeronautics and Space Administration (NASA ) is an independent agencies of the United States government, independent agency of the US federal government responsible for the civil List of government space agencies, space program ...
's Linear Aerospike SR-71 Experiment which took place at the
Dryden Flight Research Center
The NASA Neil A. Armstrong Flight Research Center (AFRC) is an aeronautical research center operated by NASA. Its primary campus is located inside Edwards Air Force Base in California and is considered NASA's premier site for aeronautical rese ...
at
Edwards Air Force Base, California, until November 1998. The experiment sought to provide flight data to help
Lockheed Martin validate and tune the computational predictive tools used to determine the
aerodynamic
Aerodynamics, from grc, ἀήρ ''aero'' (air) + grc, δυναμική (dynamics), is the study of the motion of air, particularly when affected by a solid object, such as an airplane wing. It involves topics covered in the field of fluid dyn ...
performance of the
Lockheed Martin X-33
The Lockheed Martin X-33 was a proposed uncrewed, sub-scale technology demonstrator suborbital spaceplane that was developed for a period in the 1990s. The X-33 was a technology demonstrator for the VentureStar orbital spaceplane, which was plan ...
lifting body
A lifting body is a fixed-wing aircraft or spacecraft configuration in which the body itself produces lift. In contrast to a flying wing, which is a wing with minimal or no conventional fuselage, a lifting body can be thought of as a fuselage ...
and linear
aerospike engine
The aerospike engine is a type of rocket engine that maintains its aerodynamic efficiency across a wide range of altitudes. It belongs to the class of altitude compensating nozzle engines. Aerospike engines have been studied for several years a ...
combination and to lay groundwork for a future
reusable launch vehicle
A reusable launch vehicle have parts that can be recovered and reflown, while carrying payloads from the surface to outer space. Rocket stages are the most common launch vehicle parts aimed for reuse. Smaller parts such as rocket engines and boos ...
.
LASRE was a small, half-span model of the X-33's lifting body with eight thrust cells of an
aerospike engine
The aerospike engine is a type of rocket engine that maintains its aerodynamic efficiency across a wide range of altitudes. It belongs to the class of altitude compensating nozzle engines. Aerospike engines have been studied for several years a ...
, rotated 90 degrees and mounted on the back of a
Lockheed SR-71 Blackbird aircraft, to operate like a kind of "flying
wind tunnel
Wind tunnels are large tubes with air blowing through them which are used to replicate the interaction between air and an object flying through the air or moving along the ground. Researchers use wind tunnels to learn more about how an aircraft ...
." 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 about 750 miles/hour (335 meter/second or 1207 km/h). Design refinements looked to minimize the interaction of the aerodynamic flow with the engine plume, which could create drag.
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 occurred 31 October 1997. The SR-71 took off at 8:31 a.m. (
Pacific Standard Time
The Pacific Time Zone (PT) is a time zone encompassing parts of western Canada, the western United States, and western Mexico. Places in this zone observe standard time by subtracting eight hours from Coordinated Universal Time ( UTC−08:00 ...
-PST).
The aircraft flew for 1:50 hour, reaching Mach 1.2 and an altitude of 33,000 feet (10,000 m), landing at Edwards AFB. The result validated the SR-71/pod configuration.
Five later 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 4 March 1998. The SR-71 took off at 10:16 a.m. PST. The aircraft flew for 1:57 hour, reaching Mach 1.58 before landing at Edwards AFB.
During three more flights in the spring and summer of 1998,
liquid oxygen
Liquid oxygen—abbreviated LOx, LOX or Lox in the aerospace, submarine and gas industries—is the liquid form of molecular oxygen. It was used as the oxidizer in the first liquid-fueled rocket invented in 1926 by Robert H. Goddard, an app ...
was cycled through the engine. In addition, two engine hot firings were conducted on the ground. Researchers decided against a hot-fire flight test because of 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.
LASRE Hardware
The experiment itself was a small, half-span model of a
lifting body
A lifting body is a fixed-wing aircraft or spacecraft configuration in which the body itself produces lift. In contrast to a flying wing, which is a wing with minimal or no conventional fuselage, a lifting body can be thought of as a fuselage ...
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
Hydrogen is the chemical element with the symbol H and atomic number 1. Hydrogen is the lightest element. At standard conditions hydrogen is a gas of diatomic molecules having the formula . It is colorless, odorless, tasteless, non-toxic ...
,
helium
Helium (from el, ἥλιος, helios, lit=sun) is a chemical element with the symbol He and atomic number 2. It is a colorless, odorless, tasteless, non-toxic, inert, monatomic gas and the first in the noble gas group in the periodic table. ...
, 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 lb. The experimental pod was mounted on a NASA SR-71.
Hardware and aircraft
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
The Orbital Sciences X-34 was intended to be a low-cost testbed for demonstrating "key technologies" that could be integrated into the Reusable Launch Vehicle program. It was intended to be an autonomous pilotless craft powered by a " Fastrac" li ...
technology testbed demonstrator were under the Space Transportation Program Offices at NASA Marshall Space Flight Center, Huntsville, AL. The air-launched, 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.
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Further reading
''Flight Testing the Linear Aerospike SR-71 Experiment (LASRE)'' Sept 1998
References
External links
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*{{cite web, url= http://www.nasa.gov/centers/dryden/pdf/88650main_H-2378.pdf , title=Propellant Feed System Leak Detection—Lessons Learned
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