Alpha-Scattering Chemical Analysis

Composition of surface materials was also determined from data obtained by the alpha-scattering instrument. The alpha-scattering surface analyzer was designed to measure directly the abundances of the major elements of the lunar surface.

This instrument was carried by Surveyor 5, 6, and 7 to allow chemical analysis of the lunar surface material. The alpha-scattering surface analyzer performed as designed, and provided excellent data. From the three Surveyor spacecraft that carried the alpha-scattering surface analyzer, six lunar samples were examined. The Surveyor 5, 6, and 7 missions provided the first chemical analysis of lunar surface material.

In summary, five Surveyor spacecraft landed successfully on the lunar surface. Four of these examined widely separated mare sites in the Moon’s equatorial belt. The fifth investigated a region within the southern highlands. Four spacecraft sur­vived the extreme cold of the lunar night and operated for more than one day/night cycle. In total, the five spacecraft operated for a combined elapsed time of about 17 months, transmitted 87,000 pictures, performed 6 separate chemical analyses of surface and near-surface samples, dug into and otherwise manipulated and tested lunar material, measured its mechanical properties, and obtained a wide variety of other data that greatly increased our knowledge of the Moon.