I stumbled across a 1998 paper in which the writer said thin-film
photovoltaics and improved designs could lead to a 10-fold decrease in
mass for SPSs. I seem to recall a 50,000-ton estimate for an SPS
proposed by Gerard K. O'Neill, though I can't recall the estimated
power output. Could a state of the art 5,000-ton SPS perform as well
as O'Neill's design?