Solar Power Satellite Microwave Power Transmission System Description Executive Summary

The history of the concept of microwave power beaming to Earth is reviewed with emphasis on transmission frequency selection. Constraints on the system power level results from (1) required rejection of waste heat resulting from inefficiencies in the cover conversion of dc electric power to microwave power; (2) the rf power intensity in the ionosphere; and (3) the effect of sidelobe level on aperture illumination factors. Transmitter arrangement, the power distribution system, attitude control, subarrays, waveguides, and alignment are discussed

Earth-to-orbit transportation for solar power satellites

The cargo transport capability and the cost of space transportation operations for transportation of solar power satellites (SPS) to space are addressed. The history of SPS launch vehicle evolution is shown. Alternative vehicle designs developed include: (1) a parallel burn, crossfeed configuration; (2) single stage to orbit airbreathing/rocket runway takeoff vehicle concept; and (3) a smaller HLLV concept. The smaller HLLV was analyzed to compare the nonrecurring cost benefits of a less challenging development with the recurring cost increases expected due to losses in efficiency associated with smaller vehicle size. The vehicle payload bay size was selected to be adequate to accommodate the SPS transmitter subarrays fully assembled. The resulting vehicle design is compared with the shuttle, the Saturn V, and the reference SPS HLLV. A nonrecurring savings of at least five billion dollars was obtained with a recurring cost penalty of 3% per SPS. The environmental benefits of the small vehicle were deemed more important than the slight increase in upper atmosphere propellant deposition. It is recommended that the small HLLV be adopted as the SPS reference launch system

High voltage systems (tube-type microwave)/low voltage system (solid-state microwave) power distribution

SPS satellite power distribution systems are described. The reference Satellite Power System (SPS) concept utilizes high-voltage klystrons to convert the onboard satellite power from dc to RF for transmission to the ground receiving station. The solar array generates this required high voltage and the power is delivered to the klystrons through a power distribution subsystem. An array switching of solar cell submodules is used to maintain bus voltage regulation. Individual klystron dc voltage conversion is performed by centralized converters. The on-board data processing system performs the necessary switching of submodules to maintain voltage regulation. Electrical power output from the solar panels is fed via switch gears into feeder buses and then into main distribution buses to the antenna. Power also is distributed to batteries so that critical functions can be provided through solar eclipses

Rectenna System Design

The fundamental processes involved in the operation of the rectenna system designed for the solar power satellite system are described. The basic design choices are presented based on the desired microwave rf field concentration prior to rectification and based on the ground clearance requirements for the rectenna structure. A nonconcentrating inclined planar panel with a 2 meter minimum clearance configuration is selected as a representative of the typical rectenna

Modified Reference SPS with Solid State Transmitting Antenna

The development of solid state microwave power amplifiers for a solar power satellite transmitting antenna is discussed. State-of-the-art power-added efficiency, gain, and single device power of various microwave solid state devices are compared. The GaAs field effect transistors and the Si-bipolar transistors appear potentially feasible for solar power satellite use. The integration of solid state devices into antenna array elements is examined and issues concerning antenna integration and consequent satellite configurations are examined

Emerging SPS Concepts

Four technologies were evaluated to determine their effect on Satellite Power System concepts. Two of these technologies, solid-state power amplifiers and magnetrons, are replacements for the Klystrons used for dc to RF conversion on the satellite. A third technology, laser power transmission, transmits the energy at laser frequencies rather than microwave frequencies. The fourth technology, multibandgap solar cells, has the promise of significantly increased solar to dc conversion efficienty as compared to the reference-concept silicon and gallium arsenide solar cells. The design characteristics of concepts resulting from application of these technologies are summarized

Pacemaker endocarditis due to Haemophilus parainfluenza : case report and literature review

This article reports a case of pacemaker infective endocarditis in a 14 month old girl, caused by Haemophilus parainfluenzae. There are no other cases in children reported in the literature. The issues surrounding the case and the evidence which influenced the management are discussedpeer-reviewe

Handling qualities requirements for control configured vehicles

The potential effects of fly by wire and control configured vehicle concepts on flying qualities are considered. Failure mode probabilities and consequences, controllability, and dynamics of highly augmented aircraft are among the factors discussed in terms of design criteria

Reframing safety: An analysis of perceptions of cycle safety clothing

This article contributes to debates around cycle safety clothing, specifically helmets and high-visibility clothing. In England such items are widely promoted in safety campaigns and in broader cycling publicity, particularly for children. However, the impact of this approach on cycling safety and cycling uptake is unclear and contested. This article uses a combined analysis of three sets of qualitative interview data to explore talk about cycle helmets and high-visibility clothing. A thematic analysis involved coding all references to such safety clothing, and within that coding meanings, experiences, interactions, and links to other safety equipment. Reported use of safety clothing was strongly associated with perceived threat from motor vehicles, but accompanied by scepticism about effectiveness. Many interviewees felt and/or exerted social pressure to wear a helmet, and, to a lesser extent, high-visibility clothing. Analysis identified a widespread dislike of safety clothing, sometimes linked to cycling less. We found evidence of resistance to social pressure, expressed in complaints about inconvenience, discomfort (helmets), and personal appearance. More interdisciplinary research is needed to explore the complex relationships between cycling safety, the promotion of safety clothing, and cycling uptake. However, our findings suggest that, policy-makers and practitioners should carefully consider how promoting safety clothing might impact cycling uptake and experiences. Policy goals of increasing cycling and making it more 'normal' and subjectively safer might imply reducing or even avoiding the use of such accessories in everyday utility cycling contexts.The Changing Commutes project was funded by the Economic and Social Research Council, Grant number ES/K004549/1. The projects from which the interviews come were funded as detailed in the appendix. The work was undertaken under the auspices of the Centre for Diet and Activity Research (CEDAR), a UKCRC Public Health Research Centre of Excellence which is funded by the British Heart Foundation, Cancer Research UK, Economic and Social Research Council, Medical Research Council, the National Institute for Health Research, and the Wellcome Trust.This is the author accepted manuscript. The final version is available from Elsevier via http://dx.doi.org/10.1016/j.tranpol.2015.05.00

SPS phase control studies

To properly point and form the satellite microwave power beam, the outputs of the power amplifiers in the transmitting array must be phased in a specific and coherent fashion. A retrodirective CW phase conjugating system using a spread spectrum uplink signal and a reference phase signal that is distributed via fiber optics, was selected as the control system for SPS. The design details are presented and applications of the system are discussed