Movement of Surveyor 3 spacecraft

Abstract

An examination of the position of the Surveyor 3 spacecraft as it appeared in the photographs taken by astronauts C. Conrad and A. Bean of the Apollo 12 lunar mission in November 1969 suggested that some changes had occurred in the spacecraft's attitude since the Surveyor operation of April 1967. A detailed study was made by simulating in the laboratory the position of one of the Surveyor spacecraft's footpads and its imprints in the lunar surface. Photographs were taken both from the location of the original Surveyor television camera and from the estimated position of the astronauts. It was found to be impossible to match the footpad and imprint positions and attitude in pictures taken from the two points of view. Consequently, it is tentatively concluded that the Surveyor spacecraft moved a few inches at some time between May 1967 and November 1969. It seems most likely that this movement occurred as a result of a relatively sudden failure of one or two of the shock absorbers on Surveyor's landing gear, since 2 out of the 3 shock absorbers were collapsed at the time of the astronauts' visit.