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This Defense Intelligence Reference Document from the Defense Intelligence Agency, dated 1 November 2010, was produced under the Advanced Aerospace Weapon System Applications (AAWSA) Program. It describes nanosatellite technologies and proposes launching nanosats into orbit with laser Lightcraft propulsion. It also covers a weapon mission selection study and multi-megawatt laser options. The author recommends that the Department of Defense and NASA bring Lightcraft R&D back to the United States and restart the X-50LR flight demonstration program.
“Masse”33 pages
UNCLASSIFIED/ /P&tl err1e1xc 65£ 911[ I 0.001 duty cycle, has a helical film antenna that increases its gain and doubles as a solar sail for infrequent stationkeeping maneuvers, and has a tether for coarse gravity gradient stabilization. A SO km tether supports the feed, transmitter, and DGPS reference assembly against a counterweight. The antenna lens is 2 km x 4 km. The effective area of the array is the same as that of a SO m diameter filled aperture. The total effective RF radiated power of the system is 3 GW peak and 3 MW average. Although specific performance calculations have not been done for this concept, these powers are so large that the radar should have the sensitivity from its location in GEO for detecting and tracking many targets simultaneously and most "low observable" targets as well because they are all designed and oriented so as to have their low observables in near-horizontal directions. Three constellations would provide essentially complete global coverage. The entire constellation weighs about 11,000 kg in GEO (this could be reduced in the future to 110 kg if Buckytubes are used to construct the system) and can be emplaced and replaced incrementally using laser- powered Lightcraft launch vehicles or even small conventional launch vehicles. It could even be funded incrementally. Simple, Distributed, Hyperspectral Sensor This concept presents an unconventional method of implementing a hyperspectral sensor of great spectral and spatial resolution. Its implementation would allow the detection of very many spectral intervals simultaneously, and it has a small field of view from GEO so that the instrument can dwell on and resolve particular targets of interest. It also has a large field of regard so that one spacecraft covers a significant fraction of a hemisphere. The concept uses a Fresnel zone plate, which is oriented roughly parallel to the local horizontal just below GEO. It is supported by a tether that extends well above the GEO altitude, and may or may not have a counterweight at the top end. The gravity gradient causes the ensemble to remain Earth pointing along the local vertical, with its center of mass in GEO. The Fresnel zone plate has a long focal length, and thus the surface and ring locations can be imprecise compared with conventional optics. In addition, the lens is a thin film membrane and will be light and inexpensive. It is highly frequency dispersive, and thus its focal length is a sensitive function of wavelength. Small, self-contained optical sensor nanosats are placed on the tether at many locations with each nanosat's optics filtered for response at only that narrow spectral region focused at its distance from the lens. The nanosats can transmit directly to the ground or their signals can be combined in one transceiver, also on the tether. This system has a 100 km long tether, which weighs only a few kilograms in GEO. The Fresnel zone plate is 100 m in diameter, has a collecting aperture equivalent to a 30 m filled aperture, and requires only a surface accuracy of centimeters in the visible light region. It is constructed of thin film with deposited aluminum rings and is an adaptive piezoelectric membrane kept flat by an electron beam in response to an optical figure sensor. MEMS FEEP thrusters are at the sensor's periphery for attitude control, with 40 UNCLASSIFIED//FQII. QFFUiiliR.I! l!llilii 8111:¥
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Report, from the dia collection. The PDF is mirrored here; the original link is under it. 77 pages are in the text index: search them above, or from the library's search.