Computer Controlled Operation of Ultraviolet Spectrometer and Polarimeter on Solar Maximum Mission Satellite

The Ultraviolet Spectrometer and Polarimeter (UVSP) is one of the instruments on NASA's Solar Maximum Mission (SMM) satellite. This instrument has four optical path mechanisms which control and select solar light reaching a set of sensitive photodetectors. The light is controlled in wavelength, polarization, spatial source, and spatial area. All of the optical path mechanisms are electronically interfaced to a computer (CPU) which is part of the UVSP instrument. The motions and settings of the mechanisms are defined as experiments which are controlled by the CPU. The CPU software executes experiments according to directions stored in the memory, which are supplied from scientists on the ground. During experiment execution, the CPU software annotates the science data with header and block messages.