Superconductors Will Get First Space Testing : Science: The new devices, if they prove hardy enough, could greatly reduce the weight and cost of orbiting electronic equipment.
A scientific satellite to be launched next year will carry electronic circuits made from high-temperature superconductors for the first tests of the materials in space, researchers said Monday at a meeting of the American Assn. for the Advancement of Science.
Scientists hope that the superconductors, whose existence was first reported in January, 1987, could reduce the weight of many electronic devices and, thus, the cost of putting them in orbit, but it is first necessary to see how well they survive in the hostile environment of Earth orbit.
In a daylong seminar here on the high-temperature superconductors, which carry electricity without any loss because of resistance, scientists also said that they are much more enthusiastic now about the commercial development of the materials than they were a year ago, and that the first commercial uses could appear within three to five years. The superconductors could also have a previously unsuspected impact on the microwave electronics industry, they said.
Surprisingly, researchers agreed, Japan has not taken the lead in developing the superconductors that had been expected. Japanese and American investment in the new technology has been about the same, roughly $250 million a year, and well ahead of other countries’ spending. But in the United States, two-thirds of the funds have come from the government, while in Japan two-thirds have come from industry.
While most Japanese companies are working on only one particular type of superconductor material because they think it is the most promising, they could have a major advantage if it proves to be most effective.
But if another type of material proves better, said Edward J. Mead of E. I. du Pont de Nemours & Co., “they could all go marching off the edge of the cliff together, like a bunch of lemmings.”
The new high-temperature superconductors were discovered at an IBM Corp. research laboratory in Zurich, Switzerland, a feat for which the inventors won the 1988 Nobel Prize in Physics. Previous superconductors, which were either metals or alloys, had lost all resistance to the flow of electricity only at temperatures near absolute zero, roughly minus 460 degrees Fahrenheit.
But the new materials, ceramics containing copper oxides and certain other metals, were superconducting at around minus 400 degrees and, within a year, researchers led by physicist PauW. Chu of the University of Houston and others, had raised the minimum temperature for superconductivity to minus 285 degrees Fahrenheit.
The significance of this achievement was that it made possible cooling with inexpensive liquid nitrogen rather than the much more expensive liquid helium used with previous superconductors. Researchers predicted a vast array of new applications for the materials, including magnetically levitated trains, long-distance transmission of electricity and exceptionally fast supercomputers.
But researchers encountered major difficulties. The superconductors could carry only limited amounts of electricity and, because they are brittle ceramics, cannot readily be fabricated into wires. By a year ago, the superconductivity community had become very discouraged about the prospects for commercializing the technology.
They are regaining their enthusiasm, however. “We’ve entered a period of consolidation and the progress has been really tremendous,” Chu said Monday. One of the most important developments, he said, was the ability to achieve high current-carrying capacity in thin films of the ceramic superconductors.
These thin films can be used to produce electronic devices, such as the superconducting quantum interference devices, or SQUIDS, recently perfected by IBM. SQUIDS are very sensitive detectors of electromagnetic radiation, and Chu predicted that the new SQUIDS could be marketed in as little as three years.
The new SQUIDS could have major applications in prospecting for petroleum and metal ores, Chu said. Researchers inject an electrical charge into the ground and look for telltale minute residual electrical currents. SQUIDS are now used for such purposes, but the requirement for liquid-helium cooling makes them too cumbersome for routine use.
No cooling at all might be needed for superconducting electronic devices used in satellites as long as they were shielded from direct sunlight. Four companies, including Du Pont, are producing superconducting electronic devices, such as capacitors and filters, that will be carried on a Naval Research Laboratory satellite to be launched sometime in 1991, he said.
Another potential new application for the materials is the production of microwave communications and radar devices.
Although the commercial market for superconducting microwave components would be only about $5 million by 1995, Mead said, that technology could be particularly valuable to the military. Conventional microwave radars divert a significant amount of energy into what are known as side lobes--emissions at a 90-degree angle to the main radar beam. “It is these lobes that an enemy locks on for detection and jamming,” Mead said. The use of superconductors reduces the side lobes substantially.
But all the panelists agreed that it will be well into the next decade before high-temperature superconductors are used for large magnets, electricity transmission and similar applications.
“This is a marathon, not a sprint,” Mead said.
