Overview of the HST Contamination Engineering Program at 15 Years: A Cleanliness Metric for Success with Optical Satellites

Over the past two decades, the Hubble Space Telescope (HST) contamination control program has evolved from a ground-based integration program to a space-based science-sustaining program. On-orbit, the primary contamination requirement for the telescope was maintaining a low contamination flux in the optical path of the instrument. In addition, to maintain the scientific capability of the telescope, the contamination requirements and specific contamination controls from the second- and third-generation scientific instruments and orbital replacement units were captured within the HST contamination control program. Contamination controls involving the Orbiter, astronauts, and mission were developed for on-orbit operations and four servicing missions. Long-term on-orbit scientific data has shown that these contamination controls successfully protected the HST from contamination.