• The initial demonstrator is not an end in itself, but the first step toward more advanced and costly activities later. Therefore, every effort should be encouraged to minimise the cost of the demonstrator and maintain a compressed schedule. Management innovation is critical in this regard. • The fundamental driver to an inexpensive/near-term demonstrator is, however, the combination of launch costs and launch opportunities. Launch systems that are historically susceptible to significant delays are incompatible with efforts to stay within low cost ceilings. • Many launch and platform options for the initial demonstrator were reviewed, ranging from sounding rockets and small launchers to Eureca and Spacelab. It was concluded that by far the best option for the initial demonstrator should be the use of the Ariane 4/ASAP microsatellite launch system. Shuttle launch options all fall within the start of the Space Station Freedom assembly sequence and, therefore, will be highly susceptible to significant delays. • The initial demonstrator reference concept is for microwave experimentation only, and uses five or six positions on a single ASAP ring, enabling an equivalent demonstrator mass of up to 200 kg. The concept hinges around the use of a small tether system needed to maintain an inflatable 12.5 m rectenna pointed at the transmission system remaining secured to ASAP. Travelling wave tubes are used for the microwave source, and power is supplied from a high-rate lithium battery. Depending on whether a fixed or inflatable reflector is used, it is estimated that around 500W can be transmitted between 0.25 and 1.5 km at 60% transmission efficiency. • The requirements for a microwave and laser demonstrator are very different. For microwaves, the most critical aspect is being able to control a
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