This is a low poly model that is perfect for games. I have included one untextured model with the landing gear, and one model without the landing gear. The landing gear can easily be added to the textured model. UV Mapping is already done for both models, so the included texture works for both in blender.
The North American X-15 was a hypersonic rocket-powered aircraft operated by the United States Air Force and the National Aeronautics and Space Administration as part of the X-plane series of experimental aircraft. The X-15 set speed and altitude records in the 1960s, reaching the edge of outer space and returning with valuable data used in aircraft and spacecraft design. The X-15’s official world record for the highest speed ever recorded by a manned, powered aircraft, set in October 1967 when William J. Knight flew Mach 6.72 at 102,100 feet (31,120 m), a speed of 4,520 miles per hour (7,274 km/h; 2,021 m/s), has remained unchallenged as of November 2018.