wrong again
Yet again these folks overlook the Lunar resources model for powersat construction. Instead of using all exotic expensive lightweight composits & even more expensively hauling them up from the Earth's gravity well, ceramics, glass, solar array materials are available from the Lunar surface at less launch cost. Build 'em outa simple, robust materials. Of course cheap launch costs are still needed, but a >10x Earth launch cost reduction is easily achieved if it were a priority.