Visual Requirements for Landing on the Moon

Abstract

An analysis was conducted to determine some of the visual requirements for landing a shuttle spacecraft on the surface of the moon and subsequently achieving rendezvous with the command module in orbit. The major questions investigated were: (1) Is the astronaut capable of perceiving moon landmarks while in orbit in order to detect and identify a desired landing area? (2) Can the astronaut perceive the command module from the moon during all phases of its orbit from lunar horizon to entering the moon's shadow? To evaluate these questions, the properties of the moon landmarks were examined in terms of size (visual angle subtended), contrast, and velocity of the moving imagery. In addition, stellar magnitude and luminance data were calculated for the command module and the earth as seen from the moon for different phase angles and albedos. Finally, the effects of glare on the discrimination of the command module were discussed.