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Optical Sensor Prototypes: WASSS - the Wide Area Space Surveillance System

The Wide Area Space Surveillance System is a concept for persistent deep space surveillance from a low-earth-orbit (LEO) platform. The principal applications would be rare event detection and early warning for GEO transfer and GEO insertion events. Wide angle sensors with very high stray light rejection would allow observation close to the sun. A system of two or more LEO platforms would provide continuous coverage of the entire GEO belt, with no solar exclusion, and refresh rates of less than an hour. This would provide ten opportunities to detect and gain custody of a new GEO satellite prior to its reaching GEO altitude.

In a Phase II SBIR program sponsored by AFRL, SSI developed and demonstrated a sensor prototype with a 4 x 60 degrees FOV and high stray light rejection, which would allow viewing to within 5 degrees of the sun. Shot noise-limited detection of GEO objects was demonstrated in a series of ground-based observations.

Working in cooperation with Orbital Sciences, SSI has developed a conceptual design for a demonstration experiment which would fit on a Pegasus launch vehicle. Two sensors oriented North/South, but with different longitudinal orientations, would allow 360 degree coverage with at least one observation per orbit. A third sensor would provide long-term observations of GEO objects, enabling characterization of their optical signatures.