Optical Sensor Prototypes: WASSS (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 could 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 the Air Force Research Laboratory, SSI developed and demonstrated a sensor prototype with 4 x 60 degrees field-of-view 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 for 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.