F-15B #837 (Retired 2009)
The F-15B research aircraft (tail number 837), the first two-seat F-15 built by McDonnell Douglas, was used initially for developmental testing and evaluation. In the mid 1980's, the aircraft was extensively modified for the Air Force's Short Takeoff and Landing Maneuvering Technology Demonstrator (S/MTD) program.
Those modifications included equipping the aircraft with a digital fly-by-wire control system, canards (modified F-18 horizontal stabilators) ahead of the wings and two-dimensional thrust-vectoring, thrust-reversing nozzles which could redirect engine exhaust either up or down, giving the aircraft greater pitch control and aerodynamic braking capability.
After being loaned to NASA for the Advanced Control Technology for Integrated Vehicles (ACTIVE) program, the twin-engine F-15 was equipped with a powerful research computer, higher-thrust versions of the Pratt & Whitney F-100 engine and axisymmetric thrust-vectoring engine exhaust nozzles that are capable of redirecting the engine exhaust in any direction, not just in the pitch (up and down) axis or direction.
Other projects using this aircraft as a testbed included the High Stability Engine Control (HISTEC) project, High-Speed Research Acoustics, Intelligent Flight Control Systems (IFCS), and the Space-Based Range Demonstration and Certification project under the Exploration Communications and Navigation Systems program (SBRDC/ECANS).