NEWS RELEASE, 11/30/99
NASA moves into era of talking pictures, thanks to microphone built at UC Berkeley and mounted on Mars Polar Lander
By Robert Sanders, Public Affairs
BERKELEY--- Scientists at the University of California, Berkeley, together with The Planetary Society, are boosting the National Aeronautics and Space Administration out of the silent movie era into the realm of talkies.
They've built the first microphone to fly aboard a NASA spacecraft - the Mars Polar Lander - so it can send back audio as well as video after the spacecraft lands Dec. 3 on Mars.
Within the first 24 hours after the lander nestles down on rolling plains near the Martian south pole, project scientist Janet Luhmann expects to hear the first sounds from the surface of another planet.
"I'll take anything," she admitted, but most likely the first sounds will be that of the camera scanning the surface or the lander robot arm unfolding. During quieter times, scientists may hear the whistling of the wind or the rush of turbulent dust devils, or perhaps the snap, crackle and pop of electrical discharges in the dust clouds.
NASA even wants to listen to some of its equipment in operation, to make sure it is running smoothly. This represents a marked change in attitude for NASA, since it was reluctant to include the microphone on the mission to Mars.
"We were not a highly supported endeavor," Luhmann said. "Basically, we were told to be invisible."
Luhmann proposed the idea to NASA in the early 1990s, but was turned down. Later, while working at UCLA and then at UC Berkeley, she and a like-minded colleague, David Juergens of the Jet Propulsion Laboratory in Pasadena, conducted further tests and proposed that a microphone fly aboard the Mars Polar Lander as part of the science payload.
The opportunity finally came after the idea was carried to NASA by the late Carl Sagan, founder of The Planetary Society, a Pasadena-based public interest space organization, and the society's director, Louis Friedman. It seems Sagan had tried to convince NASA to put a listening device on the Viking Landers in the mid-1970s. Faced with such an eloquent and famous lobbyist, Luhmann said, the agency agreed, as long as The Planetary Society supported all the costs and found someone already selected for the Mars Polar Lander science payload to piggyback the instrument.
Luckily, Russian scientists agreed to fit the microphone and analysis software - barely two ounces, a mere two inches on a side, and a half-inch thick- inside their lander experiment, the Light Detection and Ranging system. Built by the Space Research Institute of the Russian Academy of Science under the sponsorship of the Russian Space Agency, LIDAR sends out light pulses to locate and characterize ice and dust hazes around the Lander for atmospheric and meteorological studies.
"It's such an obvious thing to do on Mars, or on any planet with a sufficiently hospitable surface and a real atmosphere," Luhmann said. "It's time to do it, the technology is up to it."
The Planetary Society engaged the Space Sciences Laboratory to build the Mars Microphone within the size and weight constraints. Roughly $50,000, an extremely low cost for space flight-qualified instrumentation, paid for a $15 hearing aid microphone and state-of-the-art electronics to process, compress and store the sound data.
Because the microphone is a very small part of the mission, however, NASA has allotted data transmission for only 10 seconds of telephone-quality sound each day for the first week of lander operations. That allowance may be adjusted as the mission proceeds, depending on the results and the value of the microphone to the other lander operations.
To make the most of this limitation, the instrument is set to save and send back only the loudest noises occurring during its periods of operation. The sounds will be muffled because of the much lower atmospheric pressure, but most should be recognizable. If necessary, the microphone can amplify sounds up to 64 times.
In addition, throughout its periods of operation the instrument is set to record a sound spectrum to give scientists back on Earth information on the range of frequencies and volume of sounds on the Martian surface.
Luhmann noted that microphones were sent on a few other missions beyond Earth. A Soviet Venus probe recorded sounds as it entered the Venusian atmosphere in 1978, but she could find no evidence of sounds recorded after it landed. The Galileo probe supposedly carried a microphone to record lightning in Jupiter's atmosphere, but reports of returned data are similarly absent. More recently, the European Space Agency put a microphone aboard the Huygens probe - part of the Cassini spacecraft - that will land on Saturn's moon, Titan, in 2004.
But the Mars Polar Lander will send back the first sound ever recorded from the surface of a planet.
"This is really a test, but I hope we have shown NASA how popular the idea is," Luhmann said. "Hopefully microphones will become a part of many Mars landers."
Under Luhmann's direction, the Mars Microphone was designed and built by Space Sciences Laboratory engineers David Curtis and Henry Primbsch, with consultation from Department of Physics professor Forrest Mozer. Lab space physicist and postdoctoral research fellow Greg Delory tested the instrument and developed the mission operations scenario. On Dec. 3, Delory will be at the Mars Polar Lander science operations facility at UCLA when the first sounds arrive.
Sensory, Inc., of Sunnyvale, Calif., a company co-founded by Mozer, donated a RSC-164 speech recognition microcontroller to serve as the heart and brains of the instrument. The microcontroller has been used to add speech recognition to numerous consumer products including cordless phones, alarm clocks, electrical switches and even toys, like KOBY, The Interactive Bear.
For more detail on the Mars microphone, see UC Berkeley's Web site at http://plasma2.ssl.berkeley.edu/marsmic/.
The sounds of Mars can be heard on the Planetary Society's Web site- http://www.planetary.org/ - during Planetfest '99, being held Dec. 3-5 in Pasadena
For more information on the Mars Polar Lander, try http://mars.jpl.nasa.gov/msp98/index.html.
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