* 1941: Isaac Asimov published the science fiction short story "Reason," in which a space station transmits energy collected from the sun to various planets using microwave beams. "Reason" was published in the "Astounding Science Fiction" magazine. 
*1968: Peter Glaser introduces the concept of a "solar power satellite" system with square miles of solar collectors in high geosynchronous orbit for collection and conversion of sun's energy into a microwave beam to transmit usable energy to large receiving antennas (rectennas) on Earth for distribution.
* 1973: Peter Glaser is granted United States patent number 3,781,647 for his method of transmitting power over long distances using microwaves from a large (one square kilometer) antenna on the satellite to a much larger one on the ground, now known as a rectenna.
* 1978–1981: The United States Department of Energy and NASA examine the solar power satellite (SPS) concept extensively, publishing design and feasibility studies.
* 1987: Stationary High Altitude Relay Platform a Canadian experiment
* 1995–1997: NASA conducts a "Fresh Look" study of space solar power (SSP) concepts and technologies.
* 1998: The Space Solar Power Concept Definition Study (CDS) identifies credible, commercially viable SSP concepts, while pointing out technical and programmatic risks.
* 1998: Japan's space agency begins developing a space solar power system (SSPS), a program that continues to the present day.
* 1999: NASAs Space Solar Power Exploratory Research and Technology program (SERT, see below') begins.
* 2000: John Mankins of NASA testifies in the U.S. House of Representatives, saying "Large-scale SSP is a very complex integrated system of systems that requires numerous significant advances in current technology and capabilities. A technology roadmap has been developed that lays out potential paths for achieving all needed advances — albeit over several decades.