Public Release: 

SRI International Will Operate Radio Telescope To Test Mars Global Surveyor Spacecraft Signals

SRI International

A Team from SRI, Stanford University, NASA and JPL Will Send and Receive Signals from 150-Foot Parabolic Reflector Antenna Located in the Stanford Hills

MENLO PARK, Calif. (November 22, 1996) -- On early Sunday, Monday and Tuesday mornings of next week (November 24, 25 and 26), SRI International will operate a radio telescope and its 150-foot parabolic reflector antenna (called the "dish") to test UHF communication signals to and from the Mars Global Surveyor spacecraft that was launched on November 7. The tests will be conducted in collaboration with the Stanford University School of Engineering STAR Lab, the Jet Propulsion Laboratory (JPL) and NASA spacecraft experimenters.

The team will listen for signals from the Mars orbiter part of the spacecraft and will send signals to simulate the operation of the Mars lander apparatus so that the UHF communication link to be employed at Mars can be checked out before the spacecraft leaves Earth's vicinity. It will be impossible to receive these signals from Earth when the spacecraft is near Mars because of the great distance.

Stanford University personnel will analyze and interpret the received signals, which will be reported on a World Wide Web page in real time (http://nova.stanford.edu/projects/relay). JPL representatives will access data directly from the spacecraft via a network connection through JPL, and other personnel will control the data transmissions sent from the dish. SRI will provide the tracking and transmitter operations.

"We are very excited about the experiments to be conducted next week," said Michael D. Cousins, Program Manager with SRI's Geoscience & Engineering Center. "The program is an excellent opportunity for exercising our capabilities for high sensitivity radio signal acquisition and an occasion to newly apply our UHF transmitter in a unique and useful way."

The dish, which weighs 300,000 pounds and is located in the hills behind Stanford University near Interstate 280, concentrates radio signals from space and focuses them on an antenna. The radio signals are then converted by the antenna into electric signals, which are in turn strengthened by a receiver and recorded by computer.

The dish was constructed for the U.S. Department of Defense in the early 1960s and has been used since then for radio propagation and phenomenology research. It was used for about ten years in conjunction with the Pioneer spacecraft program to study solar wind plasma and has also been used for radioastronomy applications, diagnosis of signals from disabled spacecraft, transmission to spacecraft and spacecraft telemetry reception. The dish, which was renovated recently, has been used for radioastronomy research and training. SRI also uses the dish to instruct and inspire local high school students through a volunteer program.

SRI International, celebrating its fiftieth anniversary this year, is one of the largest research, technology development and consulting firms in the world. SRI's Geoscience & Engineering Center specializes in the analysis of earth and space environments and their affects on people and systems.

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