In this historical photo from the U.S. space agency, a rear/side view of the Linear Aerospike SR Experiment (LASRE) pod on NASA SR-71, tail number 844 is shown. This photo was taken during the fit-check of the pod on Feb. 15, 1996, at Lockheed Martin Skunkworks in Palmdale, California.

The LASRE experiment was designed to provide in-flight data to help Lockheed Martin evaluate the aerodynamic characteristics and the handling of the SR-71 linear aerospike experiment configuration. The goal of the project was to provide in-flight data to help Lockheed Martin validate the computational predictive tools it was using to determine the aerodynamic performance of a future reusable launch vehicle.

The joint NASA, Rocketdyne (now part of Boeing), and Lockheed Martin Linear Aerospike SR-71 Experiment (LASRE) completed seven initial research flights at Dryden Flight Research Center.

Each weekday, SPACE.com looks back at the history of spaceflight through photos (archive).