A satellite payload designed and built by college students was successfully launched Saturday from Vandenberg Air Force Base, CA, onboard a NASA launch vehicle.
Now in orbit 1,200 kilometers (746 miles) above Earth, SURFSat-1 rode piggy-back on the upper stage launch vehicle for Radarsat, a Canadian satellite. SURFsat carries low-power radio transmitters which send in three microwave bands to NASA tracking stations. SURFSat-1 is used for deep space communication research and development, and also will be used to test a new set of Earth orbit tracking stations.
The student project was initiated at NASA's Jet Propulsion Laboratory in 1987 as part of the Summer Undergraduate Research Fellowship (SURF) program of the California Institute of Technology. The first objective was to design, build, launch and operate a low-cost, low-power vehicle to be used to test the performance of space communication in the new Ka-band, at frequencies of approximately 32 Gigahertz.
NASA's Deep Space Network is being upgraded to support higher frequency Ka-band transmissions from planetary spacecraft. This will permit the use of more channels compared to current X-band deep space links. One purpose of the SURFSat payload is to test how Earth's atmosphere affects Ka-band signals. Despite the new band's potential advantages for deep space communication, it is expected to be affected more by weather than X-band transmissions.
SURFSat-1 carries a pair of beacons, one in each of the two bands, which imitate a probe far out in deep space by transmitting at only a thousandths of a watt of power. As the satellite passes overhead, engineers can collect data allowing them to compare performance in each of the two bands over a wide range of elevation angles and weather conditions.
SURFSat-1 also carries an experiment to test ground stations supporting NASA's new Space Very Long Baseline Interferometry (VLBI) project. The stations will communicate with a spacecraft to be launched by Japan that will make radio astronomy studies of quasars and other objects at the edge of the universe.
When the project began in 1987, six Caltech students were chosen to begin SURFSat. Each summer, a new group of undergraduates took over. Through 1994, a total of 61 students, including those from other colleges, have participated. JPL provided a dedicated laboratory for the work and a test range and a lab at the Goldstone Deep Space Communications Complex. Three former SURF students are now full-time employees at JPL.
The original idea was to build a simple spacecraft appropriate to a student project and give students an opportunity to work with space technology. The solar-powered satellite consists of two aluminum boxes, about 30 by 30 by 40 centimeters (12 by by 16 inches) permanently bolted to the guidance section of a NASA Delta II second stage booster. Shortly after launch it was separated from the primary payload, Radarsat, and moved into a polar orbit.
Cost of the SURFSat project from beginning to end was $3 million.
The primary SURFSat-1 experiment was supported by the Deep Space Network Advanced Systems Program, sponsored by the NASA Office of Space Communications. Support for the second experiment was provided by the U.S. Space Very Long Baseline Interferometry Project at JPL, sponsored by NASA's Astrophysics Division. Support for the integration of the satellite with the Delta II launch vehicle was provided by personnel of the Orbital Launch Service Office at the NASA Goddard Space Flight Center, Greenbelt, MD, and McDonnell Douglas Aerospace.
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