Contamination Control for the Aspera FUV SmallSat

Aspera is a NASA Pioneers Mission designed to measure faint OVI emission around nearby galaxies with unprecedented sensitivity. The SmallSat payload consists of two identical co-aligned spectrographs, both operating in the Far Ultraviolet (FUV) between 1030 -1040 Angstrom. Missions operating at FUV wavelengths are particularly sensitive to contamination, as short wavelengths are easily scattered and absorbed by contaminants deposited on payload optical surfaces. A strict contamination control plan is critical to avoiding a severe loss in FUV throughput. Aspera contamination control efforts have been tailored to fit within the scope of a sub-Class D mission, a challenge that has become increasingly relevant as advances in FUV optics/detectors drive an uptick in smaller platform, contamination sensitive UV payloads. Contamination monitoring is used to audit the cleanroom environment, avoid outgassing contaminants under vacuum, and assess contaminant levels on payload optics. We present a detailed contamination budget for the mission lifetime as well as our ongoing contamination monitoring efforts. We discuss protocols implemented for minimizing contamination-related performance loss.