This photograph shows a ground cold flow test of the linear aerospike rocket engine mounted on the rear fuselage of an SR-71.

The NASA SR-71A successfully completed its first cold flow flight as part of the NASA/Rocketdyne/Lockheed Martin Linear Aerospike SR-71 Experiment (LASRE) at NASA's Dryden Flight Research Center, Edwards, California on March 4, 1998. During a cold flow flight, gaseous helium and liquid nitrogen are cycled through the linear aerospike engine to check the engine's plumbing system for leaks and to check the engine operating characterisitics. Cold-flow tests must be accomplished successfully before firing the rocket engine experiment in flight. 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. "I think all in all we had a good mission today," Dryden LASRE Project Manager Dave Lux said. Flight crew member Bob Meyer agreed, saying the crew "thought it was a really good flight." Dryden Research Pilot Ed Schneider piloted the SR-71 during the mission. Lockheed Martin LASRE Project Manager Carl Meade added, "We are extremely pleased with today's results. This will help pave the way for the first in-flight engine data-collection flight of the LASRE."

A NASA SR-71 successfully completed its first flight 31 October 1997 as part of the NASA/Rocketdyne/Lockheed Martin Linear Aerospike SR-71 Experiment (LASRE) at NASA's Dryden Flight Research Center, Edwards, California. 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 before landing at Edwards at 10:21 a.m. PST, successfully validating the SR-71/linear aerospike experiment configuration. The goal of the first flight was to evaluate the aerodynamic characteristics and the handling of the SR-71/linear aerospike experiment configuration. The engine was not fired during the flight.

A NASA SR-71 takes off Oct. 31, making its first flight as part of the NASA/Rocketdyne/Lockheed Martin Linear Aerospike SR-71 Experiment (LASRE) at NASA's Dryden Flight Research Center, Edwards, California. 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 before landing at Edwards at 10:21 a.m. PST, successfully validating the SR-71/linear aerospike experiment configuration. The goal of the first flight was to evaluate the aerodynamic characteristics and the handling of the SR-71/linear aerospike experiment configuration. The engine was not fired during the flight.

A NASA SR-71 made its successful first flight Oct. 31 as part of the NASA/Rocketdyne/Lockheed Martin Linear Aerospike SR-71 Experiment (LASRE) at NASA's Dryden Flight Research Center, Edwards, California. 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 before landing at Edwards at 10:21 a.m. PST, successfully validating the SR-71/linear aerospike experiment configuration. The goal of the first flight was to evaluate the aerodynamic characteristics and the handling of the SR-71/linear aerospike experiment configuration. The engine was not fired during the flight.

This photograph shows the SR-71 with the Linear Aerospike SR-71 Experiment on the rear fuselage as seen from above. The photo was taken on the first flight of the aircraft with the experiment aboard, which took place on 31 October 1997.

This photograph shows the LASRE pod on the upper rear fuselage of an SR-71 aircraft during take-off of the first flight to experience an in-flight cold flow test. The flight occurred on 4 March 1998.

A NASA SR-71 refuels with an Edwards Air Force Base KC-135 during the first flight of the NASA/Rocketdyne/ Lockheed Martin Linear Aerospike SR-71 Experiment (LASRE). The flight took place Oct. 31 at NASA's Dryden Flight Research Center, Edwards, California. 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 before landing at Edwards at 10:21 a.m. PST, successfully validating the SR-71/linear aerospike experiment configuration. The goal of the first flight was to evaluate the aerodynamic characteristics and the handling of the SR-71/linear aerospike experiment configuration. The engine was not fired during the flight.

A NASA SR-71 successfully completed its first flight 31 October 1997 as part of the NASA/Rocketdyne/Lockheed Martin Linear Aerospike SR-71 Experiment (LASRE) at NASA's Dryden Flight Research Center, Edwards, California. 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 before landing at Edwards at 10:21 a.m. PST, successfully validating the SR-71/linear aerospike experiment configuration. The goal of the first flight was to evaluate the aerodynamic characteristics and the handling of the SR-71/linear aerospike experiment configuration. The engine was not fired during the flight.

A NASA SR-71 made its successful first flight Oct. 31 as part of the NASA/Rocketdyne/ Lockheed Martin Linear Aerospike SR-71 Experiment (LASRE) at NASA's Dryden Flight Research Center, Edwards, California. 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 before landing at Edwards at 10:21 a.m. PST, successfully validating the SR-71/linear aerospike experiment configuration. The goal of the first flight was to evaluate the aerodynamic characteristics and the handling of the SR-71/linear aerospike experiment configuration. The engine was not fired during the flight.

The test of twin Linear Aerospike XRS-2200 engines, originally built for the X-33 program, was performed on August 6, 2001 at NASA's Sternis Space Center, Mississippi. The engines were fired for the planned 90 seconds and reached a planned maximum power of 85 percent. NASA's Second Generation Reusable Launch Vehicle Program , also known as the Space Launch Initiative (SLI), is making advances in propulsion technology with this third and final successful engine hot fire, designed to test electro-mechanical actuators. Information learned from this hot fire test series about new electro-mechanical actuator technology, which controls the flow of propellants in rocket engines, could provide key advancements for the propulsion systems for future spacecraft. The Second Generation Reusable Launch Vehicle Program, led by NASA's Marshall Space Flight Center in Huntsville, Alabama, is a technology development program designed to increase safety and reliability while reducing costs for space travel. The X-33 program was cancelled in March 2001.