LSP Timer overbanking on the lunar surface

Abstract

Early in the preliminary design phase of the Lunar Seismic Profiling Experiment (LSP), it was recognized that the environmental conditions to which the timer watch movements would be exposed on the lunar surface would cause an increase in balance wheel amplitude; this could cause "overbanking" and possibly large timing errors in the fast direction. This, in turn, suggested the possibility of LSP timers running out while the astronauts were still on the lunar surface and caused the potential hazard to be categorized as "Safety Catastrophic." This report presents the results of the tests conducted to acquire a fundamental understanding of the problem in quantitative terms and to reduce the hazard potential to "Safety Negligible" in the flight hardware.