SPS construction artists concept

An artists rendering of a solar power satellite under construction. This idea was popular for a while in the mid/late 1970s during the energy crisis, and generally called for satellites generally compared in size to Manhattan island.

This image was apparently created by NASA in 1976.  The thinking at the time was that these structures could certainly be built within the 1990’s; I often wonder at what the people who were working on them would have thought at the time had they somehow found out that, nearly 40 years later, precisely zero effort would have been made to see SPS come to pass. A higher-rez version is available HERE.