CASSIOPeiA solar power satellite

摘要

This paper describes a new Solar Power Satellite (SPS) concept, based on the principle of wavelength-scale modular integration of all major functions, from solar collection through to beam-formation. Like the earlier HESPeruS [1] (Highly Elliptical Solar Power Satellite) concept, CASSIOPeiA (Constant Aperture, Solid-State, Integrated, Orbital Phased Array) has no rotating (or otherwise moving) parts, yet maintains a constant solar collecting area directly facing the Sun (no cosine losses), whilst its retrodirective microwave beam is steered to the terrestrial rectenna (rectifying antenna). The well-known beam steering limitations of planar phased arrays require other SPS concepts to have either physically rotating parts, redundant solar collector / RF transmitter area, or suffer cosine losses as the collector tilts away from the Sun. HESPeruS avoids this issue by operating from a highly-elliptical Molniya orbit. By contrast, the novel (patent pending) phased array of CASSIOPeiA permits beam steering through a full 360 degrees without degradation - allowing deployment along a multitude of orbits, including geosynchronous (GSO). The same ultralight physical substrate is re-used for efficient concentrated photovoltaics, power management / distribution, thermal dissipation and beam formation, with zero temporal redundancy of RF (Radio Frequency) elements. The structure exhibits sufficient self-rigidity to support itself in microgravity without additional trusses, yet is able to deploy from a highly compact stowed configuration - offering the enticing possibility of a fully functional SPS deployed as a single payload. The paper concludes with a roadmap for staged implementation, offering delivered power from 200 kW (near-space, daylight hours), through 90 MW (3 hour orbit, 23+ hours), to 430 MW of utility-scale baseload power (GSO, 24 hours).