Command module Base diameter 3.90 m. (12.8 ft.) Length 3.66 m. (12 ft.) Weight 5896 kg. (13,000 lb.) Service module Diameter 3.9 m. (12.8 ft.) Length 6.71 m. (22 ft.) Weight at launch 24,947 kg. (55,000 lb.) Docking module Diameter 1.52 m. (5 ft.) Length 3.05 m. (10 ft.) Weight 1882 kg. (4155 lb.) _Soyuz_ Orbital module Diameter 2.29 m. (7.5 ft.) Length 2.65 m. (8.7 ft.) Weight 1224 kg. (2700 lb.) Descent module Diameter 2.29 m. (7.5 ft.) Length 2.20 m. (7.2 ft.) Weight 2802 kg. (6200 lb.) Instrument module Diameter 2.77 m. (9.75 ft.) Length 2.29 m. (7.5 ft.) Weight 2654 kg. (5850 lb.) M2-F3 Lifting Body [Illustration: 81. Three chase planes salute the M2-F3 wingless lifting body following one of its rocket-powered flights. The blunt-nosed M2-F3 achieves its aerodynamic lift from the shape of its body.] This wingless craft is called a lifting body, because it derives its lift from the fuselage rather than from wings. Removing the wings reduces the weight of the craft, but adds significant control problems. The lifting body concept was developed early in the last decade to explore the problems of aerodynamic heating and vehicle control during reentry from earth orbit. These are the problems that will be especially critical in the space shuttle of the 1980s. The M2-F3 tested flight behavior of wingless craft over a wide range of speeds. The M2-F3’s forerunner, the M2-F2, made 16 flights—all unpowered—between July 1966 and May 1967. On May 10, it crashed on landing, partly due to control instability. The craft was rebuilt, and the center fin was added. This modification effectively solved the control problem, and the new craft, designated M2-F3, logged 27 more flights by December 1972. Some of the M2-F3’s flights were powered by a 3630-kilogram (8000-pound) thrust rocket which boosted the craft to a higher altitude. The M2-F3 was launched from a B-52 bomber at a height of about 13,300 meters (45,000 feet) and a usual speed of 730 kilometers (450 miles) per hour. The maximum altitude achieved was 21,800 meters (71,500 feet). The M2-F3’s record speed was 1718 kilometers (1066 miles) per hour. The M2-F3 was built by Northrop. The craft on exhibit is from the National Aeronautics and Space Administration. Length 6.8 m. (22 ft., 2 in.) Span 2.9 m. (9 ft., 7 in.) Height 2.5 m. (8 ft., 10 in.) Weight 2720 kg. (6000 lb.) empty; 4540 kg. (10,000 lb.) fueled Speed 1718 km. per hr. (1066 m. per hr.) max. achieved Altitude 21,800 m. (71,500 ft.) max. achieved Mach number 1.5 max. achieved