HL-20 Personnel Launch System - Lifting Body Development

Lifting Body Development

Predating and influencing the design of the Space Shuttle, several lifting body craft including M2-F2, M2-F3, HL-10, X-24A, and X-24B were flown by test pilots from 1966 through 1975. The M2-F2 and the HL-10 were proposed in the 1960s to carry 12 people to a space station following launch on a Saturn IB. The HL-20 PLS concept was evolved from these early shapes, being further influenced by the Russian Kosmos-1445 and Kosmos-1374 and later MiG-105. The "HL" designation stands for horizontal lander, and "20" reflects Langley's long-term involvement with the lifting body concept, which included the Northrop HL-10.

A lifting-body spacecraft would have several advantages over other shapes. With higher lift characteristics during flight through the atmosphere while returning from orbit, the spacecraft can reach more land area, and the number of available landing opportunities to specific sites would be increased. Deceleration loading during entry would be limited to about 1.5 G. This is important when returning sick, injured, or deconditioned Space Station crew members to Earth. Wheeled runway landings would be possible, permitting simple, precision recovery at many sites around the world, including the Kennedy Space Center launch site.