The Evolution of the Space Shuttle

This set of five detailed X planes portraying the evolution of the Space Shuttle through 2004. The box has details on each of the space craft. Extreme Machines. X-15: 1959-1968 Max Speed: Mach 6.7 (4,520 mph) Maximum Altitude: 67 Miles Number in Fleet: 3- one was destroyed on a mission X-24A: 1969-1971 Max Speed: Mach 1.6 (1,100 mph) Maximum Altitude: 13.5 miles Number in Fleet: 3-two never flew and the flying version was converted into an X-24B Number of Flights: 28 X-20 Dyna-Soar: 1965 Never Flew, Canceled 1963, Expected Top Speed: Mach 15-21 (11,000-15,000 mph) Maximum Altitude: Low Earth Orbit Booster: Modified Titan Rocket X-38: 2004 Designed to test the emergency Crew Return Vehicle (CRV) concept of the International Space Station Dimensions: 24.5 ft long, 11.6 ft. wide, and 8.4 ft. high Number in Fleet: 4- One for space related tests, three for atmospheric tests Shuttle Enterprise Orbiter: 1977-Present Used to test Space Shuttle systems Number of Flights: 8 Captive Flights atop