Aerobraking as a potential planetary capture mode.

The synthesis of manned aerobraking spacecraft for missions to Mars and Venus is described. Pertinent data derived from performance, weights, heating, and heat shield design analyses conducted to support the synthesis are presented. The sequential approach that was used, in which aerobraker mission-system requirements were establised and candidate vehicle arrangements were prepared, is discussed. Sensitivity analyses and selected configurations are presented along with the evolved modular approach to aerobraker spacecraft design. Considerable commonality between the Mars and Venus vehicles and requirements for elliptical parking orbit missions using modular designs is shown. Comparisons of the aerobraking and retrobraking modes of orbital capture at Mars and Venus are presented to show that a chemically (FLOX/CELi) propelled aerobraker vehicle system requires less mass on Earth orbit than a nuclear (LH^) retrobraker for all mission opportunities from 1980 to 2000.