Superconductivity Activities in Space

One of the areas in which the U.S. does seem to have a clear technological lead is superconductivity for space applications. In both Europe and Japan there are research efforts related to high temperature superconductivity, but in all cases it appears to be basic or exploratory efforts rather than commercial development to create specific products for the space applications market. In all the site visits to the commercial laboratories and manufacturing units there were no indications that superconducting phase shifters, integrated phased array antenna systems, etc. were under development for space applications. The only work identified was that being carried out by NTT Laboratories and by Professor S. Tanaka at SRL. In contrast, in the United States a number of manufacturers of space systems such as Lockheed, TRW, and Ball Aerospace have active commercial development programs which are being carried out in conjunction with support from Sandia Laboratories, NASA Lewis Research Center, ARPA, and other defense-related agencies. Developers of high temperature superconductivity technology such as Dupont, Superconductivity Core Technologies (SCT), etc. are making good progress on YBCO and Thallium HTS strip products that potentially have a significant number of applications in space. Continued effective U.S. support of this key technology, which can provide some 3 dB or more performance gain in communications satellites of the future, would thus appear highly desirable.

Superconductivity Activities in Satellite Communications

At this time there is very limited European R&D activity in the area of superconductivity applications to space communications. The only explicit activity is a study by ESTEC under its Advanced Research Program.

Commercial aerospace organizations apparently have concluded that this is too far away from practical use in space communications programs to justify research in this area. Commercial users of space communications such as EUTELSAT and Inmarsat seem to have applied similar logic and are not actively pursuing R&D in this area.

In contrast, NASA (especially JPL), Ball Aerospace, TRW, Superconductivity Core Technologies (SCT), the University of Maryland Center for Commercial Development of Space in Satellite Communications, and Sandia Laboratories, among others, have active programs in this area.

In the United States several different types of applications are under active consideration or development. These include use of superconductivity strips as phase shifters in phased array antennas, as an integrated feature in an overall phased array antenna, as means of obtaining a higher sensitivity in deep space antenna design, as a way to obtain higher performance in passive radar sensors, and for a variety of space based systems where the natural space environment could eliminate the need for cooling in thallium or even YBCO superconducting strips.

Nowhere in Europe, not even at Matra-Marconi or ESA, did there appear to be comparable technology or parallel efforts being made in this field. Strategically, the United States would appear to have a lead in space applications of superconductivity. Since practical applications of this technology are likely to be five to ten years away, it seems highly unlikely that research efforts in this field would have been intentionally withheld. In part, the difference may be that in the United States a substantial part of the development of superconductivity research and development with respect to satellite communications is funded by the DoD and by the Strategic Defense Initiative, in addition to NASA and industry efforts. In Europe there may be efforts funded by military programs that this panel did not identify.

Published: July 1993; WTEC Hyper- Librarian