6. ALTERNATIVE OPTIONS FOR THE INITIAL DEMONSTRATOR This section is included to provide a brief overview of the range of other possible initial Powersat demonstrator options considered in this study. These options are not listed in any particular order. 6.1 Columbus Precursor Missions 6.1.1 Eureca-3 Eureca carries a multi-disciplinary payload complement ranging from astronomy to life science experiments. This means the Powersat technology demonstrator would have to be sensitive to possible conflicting payload requirements. However, it is reasonable to presume that at some stage during Eureca’s mission, a short period of time could be made available for the purpose of the Powersat demonstration. This time might be on the order of a few hours, but importantly, would require a large fraction of the available user power. A possible experiment could involve the spring-assisted deployment of an unfurlable or inflatable subsatellite equipped with an omnidirectional etched microstrip rectenna. (Figure 6.1-1) A laser experiment would use a “solid” subsatellite equipped with frequency-tuned solar cells and comer cubes as required. This subsatellite would be deployed at perhaps no more than a few centimetres per second, giving time for the experiment to acquire and lock onto the target. When the separation has reached a few metres, the experiment could then be conducted for as long as the subsatellite was in range. However, it is important to note that Eureca orbits in a sun-pointing mode. Therefore, the experiment will need to be completed in a short period of time (i.e. 5-10 minutes) before Eureca rotates significantly relative to the target
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