laser propulsion at Avco Everett Research Laboratory as the special assistant to Arthur Kantrowitz, he moved to Arthur D. Little to work with Peter Glaser, the inventor of the solar power satellite (SPS). Chapman was actively involved in the NASA/DOE SPS Concept Development and Evaluation Program (CDEP) in the late 1970s and early 1980s and has since continued to make contributions to the literature on power from space. In the mid-1980s, Chapman shifted his focus to commercial space—building private companies that develop products and services for space-based, as well as Earth-oriented businesses. He served as president of the L5 Society (now the National Space Society) during the successful campaign to stop the US Senate from ratifying the Moon Treaty, which would have excluded any commercial activity on the Moon. Chapman was a member of the Citizens' Advisory Council on National Space Policy, which has advised several US Presidents on space-related issues. In particular, a position paper by the council was instrumental in convincing Ronald Reagan that it was technically feasible to intercept ballistic missiles in flight. Opponents thought the Strategic Defense Initiative (SDI) was a fantasy, dubbing it "Star Wars". In 1989, Chapman led a privately funded scientific expedition by sea from Cape Town, South Africa to Enderby Land, Antarctica, to gather information about mineral resources before the Madrid Protocol to the Antarctic Treaty made prospecting illegal on the continent. From 1989–1994, Chapman was the president of Echo Canyon Software in Boston which produced the first visual programming environment for Windows, before Microsoft introduced Visual Basic. In 1998, Chapman was Chief Scientist of Rotary Rocket of San Mateo, California. Rotary Rocket built and flew atmospheric tests of the Roton, a novel crewed, re-usable space launch vehicle. In 2004, Chapman presented two papers at the 55th International Astronautical Congress (Vancouver CANADA). The first, "Luces in the Sky with Diamonds," presented a design for a gossamer, iso-inertial SPS using thin films of artificial diamond in thermionic conversion devices. The second paper, "Power from Space and the Hydrogen Economy," discussed the implications of the recent discovery of vast deposits of methane hydrates under Arctic permafrost and on continental shelves, which may be sufficient to meet all world energy needs for many thousands of years. See the web address below for full text of this paper. Chapman was Chief Scientist of Transformational Space Corporation, "t/Space" of Reston, VA. Under a $6 million contract from