Spacecraft and Constellation Design for a Continuous Responsive Imaging System in Space

Abstract

Natural disasters and military conflicts have demonstrated the ongoing need for high resolution imagery with nearly continuous coverage on short notice. Current satellite systems do not meet this need because they suffer from low resolution (high altitude orbits and/or small optics) or intermittent coverage (low orbits). The Continuous Responsive Imaging System in Space (CRISIS) optimizes the trade between resolution and coverage by utilizing a constellation of small, inexpensive, rapidly deployable Earth observation satellites. Initial mission analysis has demonstrated that a constellation of eight satellites at 600 km altitude evenly distributed throughout two perpendicular planes can satisfy resolution and responsiveness requirements simultaneously. Total development cost for the entire system is comparable to that of a single traditional commercial Earth-observing satellite and the individual CRISIS spacecraft are within the mass and volume limits of low-cost launch vehicles such as the Pegasus XL or Falcon 1e. This configuration was selected from a trade space of 1350 different architectures using a parameterized model implemented in Matlab and Satellite Toolkit.