Dr. Sagan's 2/9/1990 speech before the 5th Emerging Issues Forum at NCSU, broadcast live on NC Public TV. Introduction by Roy Park of Park Communications. Sagan spoke at the invitation of Jim Hunt, former NC Governor. Recorded by Dr. Woody Sugg on a home VCR.
While a student, I referenced Dr. Sagan's speech here in a 1990 radio interview with Gregg Maryniak and Chris Faranetta of the Space Studies Institute (SSI) and Dr. George A. (Jay) Keyworth II, former Reagan science adviser, on the subject of space solar power (SSP).
Princeton physicist Gerard K. O'Neill joined with sunsat inventor Dr. Peter Glaser and Raytheon engineer Bill Brown in the 1970s-1980s to work on solutions to projected massive 21st century energy requirements and biosphere preservation for a plan that would start up an ambitious off-Earth enterprise for America and partners.
NASA and the Department of Energy released a joint study "Satellite Power System Concept Development and Evaluation Program Assessment Report" in 1980. NASA and DoE found a technical case for SSP but no financial case assuming materials launched 100% from the ground.
SSP concepts have undergone technical improvements by independent teams. Propulsion and launch alternatives have multiplied as costs decline. PVs and robotics have improved. The discovery of water at the lunar poles aids the business case for sunsat manufacture using lunar materials, a rationale introduced by SSI, whose study in the mid-1980s found a 97% cost-savings by using the moon.
At the D3 Innovation Summit Pitch Challenge on March 2, 2016 in Washington, DC, a Naval Research Laboratory proposal on SSP won awards in 4 categories. Theirs was one of 6 winners out of 500 "breakout ideas" submitted in response to the challenge issued by DoS, DoD, and USAID.
The solar satellite idea originated with Peter Glaser of A.D. Little Corp. in 1968. The O'Neill-Glaser-Brown vision called for public/private partnerships under US leadership to expand industrial and economic activity on the High Frontier, including sunsat manufacture from lunar materials via lunar surface machines and free-space processing infrastructure. NEOs would be retrieved by the infrastructure for additional materials, meeting earthbound NEO defense requirements.
Over a 50-year period, SSP implementation would ease reliance on diminishing ground resources and fission for base load electricity in participating nations, extend the life of coal, oil & gas, provide clean energy to developing nations, and deliver instant secure power to forward military operations and disaster zones.
The activity over 5 decades would allay Dr. Sagan's concerns, here so eloquently expressed, over CO2 greenhouse warming and the problem of nuclear waste disposal.
These high flying assets would be the business backbone of space settlement. Dr. O'Neill's rotating habitats in free space, built also from lunar materials and powered by the sun, would facilitate the growth of industry and species to a potential several times the capacity on the ground. SSP workers, their families, and support personnel would live in normal 1g environments in sunlit cylindrical real estate in Lagrangian orbits known to be stable. These busy hubs, or "islands", would be part "mill towns" for the workers, part farms, part business, science, industrial & professional parks, part university, and part sports/recreation and tourism destinations. Travel and commerce between facilities and the Earth would be a relatively low energy-cost affair.
A political decision is needed. Darel Preble of the SSP Workshop at Georgia Tech proposes that Congress pass the Sunsat Act (http://www.sspi.gatech.edu/sunsat-how.pdf). Just as the Transcontinental Railroad Act and the Comsat Act opened the rail transportation and satellite communications industries, the Sunsat Act would create a public/private SunSat Corporation to oversee SSP development. A Presidential signature would permit permanent energy security for the US and partners. Preble projects that the $330 billion/year global comsat industry would be exceeded 100 times by the sunsat industry.
A Kubrick-Clarke-like generation could follow, many of the early spaceborn growing up in 1g communities 60 degrees east and west of the moon in wealth produced by lunar-made SSP.
A compendium of research and conference papers on the topics of solar power satellites, lunar machines, and manufacturing from in-space materials is housed at http://ssi.org, the website for the nonprofit Space Studies Institute founded in 1977 in Princeton by the late Gerard O'Neill.
"...I would put it (SSP) amongst any list of serious contenders for new energy technologies." - Dr. George Keyworth II, former Reagan science advisor, 1990 interview
"Our technology is capable of extraordinary new ventures in space, one of which Gerard O'Neill has described to you.... It is practical." - Carl Sagan, book blurb, The High Frontier (1989 edition) by G K O'Neill.