Lunar Orbiter mission design.

Abstract

The primary objectives of the Lunar Orbiter Program were to obtain photographic coverage of potential Apollo and Surveyor landing sites on the moon and to contribute to the scientific knowledge of the moon. An additional objective was to obtain information on the gravitational field of the moon. The landing site search at 1-m resolution was essentially completed by the end of the third flight; remaining flights provided a 100-m resolution map of the lunar front side and closeup views of scientifically interesting sites. The lunar back side was covered at about 1 km resolution. In this paper the lunar orbit design is developed in terms of mission requirements and predicted effects due to Earth and lunar gravitational fields. Errors experienced in predicting the spacecraft trajectory during the flight are indicated to be due to large irregularities in the lunar gravitational field.