Space Solar Power Concepts

Space Solar Power Concepts. Image credits, clockwise from upper left:

1. SPS-ALPHA concept by John C. Mankins, Artemis Innovation; graphic by Mark Elwood, SEI; sponsored by NASA NIAC.
2. Sun Tower [NASA].
3. DOE/NASA 1980s Reference Design. Artwork by Mark Maxwell.
4. SERT Sandwich Concept [NASA]
5. Integrated Symmetrical Concentrator. Artwork by Pat Rawlings, NASA.