This proceedings, ""Engineering, Construction and Operations in Space II"", consists of the 165 papers presented at Space 90, the Second International Conference, in Albuquerque, New Mexico, April 22-26, 1990. The papers are divided into four sections. The first section presents the keynote addresses covering such topics as the legalities of extraterrestrial mining, NASA initiatives in technology, and advanced engineering design. Section two, Extraterrestrial Mission, includes discussions on all aspects of lunar engineering and construction from the use of lunar metals for rocket fuels to design criteria for lunar structures. Orbital Mission, the third section of the proceedings, explores such subjects as space station operations, space debris, lunar base site constraints, optimum structural design, and gravity effect on beam behaviour. The final section, Support Infrastructure, consists of papers on such topics as commercial spaceport considerations, limits of radiation exposure, cultural diversity and education.