The role of superconductivity in the space program :

Abstract

This report describes the results of a study designed to assess the role which superconductivity might play in the U.S. Space Program. The study was performed by members of the staff of the Boulder Laboratories of the National Bureau of Standards.Six technical subject areas were considered; high field magnets, magnetometers, digital electronics, high-frequency detectors, instruments related to gravitational studies and ultra high-Q cavities.The study identifies a number of applications of superconductivity which are of potential interest to NASA. Wherever possible, the devices are related to specific types of space missions.Keywords: Computers; digital electronics; gravitational studies; high-Q cavities; infrared detectors; magnetometers; magnets; microwave detectors; space; superconductivity. IMPORTANT NOTICECertain companies and commercial equipment are identified in this report. This identification does not imply endorsement by the National Bureau of Standards nor does it imply that the equipment identified is necessarily the best available for the purpose. properly applied to magnet structural components, could make impressive reductions in the specific weight of large magnets.It is suggested that mater-Lais programs, directed toward magnet weight reduction, be stimulated by NASA in order to provide a base for optimization of the specific weight of superconducting magnet systems.The reduction of specific weights could provide longer term benefits to the space program.Many of the more ambitious programs for space colonization and travel involve superconducting magnets (e.g., fusion reactors or MHD generators for energy production, the mass-driver system, plasma or MHD propulsion engines, etc.). Low-Frequency Superconducting SensorsThe primary device in this class is the SQUID (Superconducting QUantum Interference The suggestions for experiments on gravitational theories are many, and it is difficult to select any one for special encouragement. It might be best to let the individual researchers develop their proposals to a higher level before any major commitments are made.Obviously these researchers will need minor funding for this work. High-Q CavitiesThere are many applications for superconducting high-Q cavities, but for space applications the most prominent is the use of such cavities as stabilizing elements in clocks and oscillators.The best Q for a superconducting cavity achieved to date is 5 x 10^, and the best stability is 3 x 10^.Since it is generally possible to find the center of a reso--18 nance line to one part per million, it is reasonable to expect that a stability of 2 x 10 will be achieved using present technology. This might be accomplished within ten years. On the other hand, large increases in Q values will require major advances in superconducting technology. The likelihood of it happening within the next ten years cannot be reasonably assessed.One intriguing potential space application of these oscillators is their use for ranging.The possibility that gravitational radiation migh...