Russell Hoyle

Office of Public Affairs, University Communications

University of California, Berkeley

2120 Oxford St. 3rd. fl. MC #4204

Berkeley, CA 94720-4204

Phone: (510) 643-9464 Fax: (510) 642-7289

Robert Sanders

(510) 643-6998



BERKELEY, NOVEMBER 30 — 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

“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

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.


Janet Luhmann can be reached at (510) 642-2545 or at Greg Delory is at (510) 643-1991; Dave Curtis is
at (510) 642-5998.

For more detail on the Mars microphone, see UC Berkeley’s Web site at

The sounds of Mars can be heard on the Planetary Society’s Web site — — during Planetfest ’99, being held Dec. 3-5 in

For more information on the Mars Polar Lander, try