Jacqueline Riddle, Elizabeth Beesley, Lisa Young, and Malcolm Collum
Abstract
In preparation for the first lunar landing, the National Aeronautics and Space Administration sent seven robotic Surveyor spacecraft to the Moon between June 1966 and January 1968. These spacecraft provided crucial information to the Apollo 11mission that put the first humans on the Moon in July 1969. The Smithsonian acquired a full-scale Surveyor engineering model in 1970, continuously displaying it from 1976 until 2017. In 2013, a leaking pipe damaged the alpha scattering instrument on the spacecraft, which was subsequently disassembled, treated for extensive magnesium corrosion, and reinstalled on the spacecraft. By 2017, the corrosion had reoccurred, galvanically aided by the gold components in the instrument. This paper outlines the re-treatment of the highly reactive magnesium alloy, including disassembly of the component, mechanical and chemical corrosion removal, application of an industrial conversion coating, and insertion of isolating layers. The treatment decision making is presented, providing justification for the use of industrial grade products when previous treatments have failed. Overall, the treatment choices demonstrate how the presence of unusual modern materials with no established conservation treatment methodologies can lead to the use of more restorative techniques.