Superconducting Technology Assessment - nitrd

In imaging and surveillance systems, most of the data collected tells us that nothing has changed and may be
discarded. Yet many systems are designed to ship all data to the ground for processing in a centralized location,
often introducing a substantial lag time before the useful information is ready. This scheme wastes substantial
bandwidth and transmission power, and reduces the value of the information. Instituting distributed, on-board
processing—especially if software defined and having a “send-everything” option—can deliver the actionable
knowledge contained in the data with better efficiency in terms of time, bandwidth, and power. Superconductive
digital electronics, once matured, should be up to this task.
Deep Space Applications
The cold background temperatures of deep space make the use of superconductive electronics for the entire
receive chain highly attractive. Superconductive antennas can set exceptionally low system noise temperatures.
Superconductive mixers are already the work horse of astrophysical receivers above 100 GHz. And the low noise
temperatures and extreme sensitivity possible in superconductive ADC and following digital filters allow weak
signals to be sensed.
One long-time dream for NASA is a mission to Pluto. Because a lander mission does not appear feasible, a flyby of
perhaps 30 minutes duration is the most likely scenario. With communication lag times of many hours between
Earth and Pluto, the space probe would require fully autonomous data gathering and analysis capabilities. Analysis
during flyby is critical for optimizing the quality of data collected. There is very little hope of providing the power
needed for CMOS-based data processing, but superconducting electronics could provide the processing capabilities
needed at a fraction of the power budget for CMOS.
NASA is actively pursuing a program for missions to the icy moons of Jupiter. Here, the problem for CMOS is both
cold and intense radiation. However, CMOS can be shielded and radiation-hardened, and radioisotope thermoelectric
generators provide both heat and electrical power. Nuclear propulsion is being developed as a key technology and
will provide more electrical power. Given these workarounds, superconducting electronics is not critical for achieving
mission goals; however, RSFQ could provide a boost in computing power and a higher-performance communications
system. This might serve to increase the science return of such missions.
For many years, NASA has been carrying out missions to Mars. Recently, it has committed to an ambitious program
of returning to the moon as a way-station for (potentially manned) travel to Mars. With all this activity, NASA has
come to realize the need for an interplanetary communications network to provide the bandwidth needed for
returning scientific data to Earth. The Mars Telecom Orbiter (MTO), expected to launch in 2009, is intended to
provide some of that bandwidth. Just as superconducting electronics is attractive for use in cellular phone
networks, so, too, it would be attractive in missions similar to the MTO. Additionally, the superconducting analog
of MTO could provide high-performance computing capability for in situ analysis of data.
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