PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
Contact: Mary Beth Murrill
FOR IMMEDIATE RELEASEAugust 21, 1997
SIGNATURES FROM EARTH BOARD SPACECRAFT TO SATURN
More than 616,400 signatures sent to NASA from citizens in
81 countries have been recorded on a high-tech data disk that
will be installed Friday on the Cassini spacecraft at NASA's
Kennedy Space Center in Florida, where the spacecraft is being
prepared for an Oct. 6 launch on a international scientific
mission to the planet Saturn.
The installation of the Cassini mission's "signature disk"
on the spacecraft marks the end of a 1-1/2-year volunteer-led
effort to sort, scan and record the hundreds of thousands of
signatures from postcards and letters sent to board the Saturn-
bound spacecraft from around the world.
"The signature disk idea began as a very small in-house
effort to let Cassini team members place their signatures
somewhere on the spacecraft they had helped build, then we
realized we could accommodate many more signatures and opened it
up to everyone," said Richard J. Spehalski, program manager of
the Cassini mission at NASA's Jet Propulsion Laboratory in
Pasadena, CA. "It has blossomed into a 'message in a bottle' to
Saturn from hundreds of thousands of people on Earth. We have
been overwhelmed by the response." Soon after the effort was
announced in November 1995, cards began arriving from around the
globe with as many as 35,000 signatures received during peak
"We received signatures from individuals young and old, from
whole families, hundreds of classes of students and whole
schools," said Charley Kohlhase, Cassini's science and mission
design manager, who oversaw the signature disk development. He
said at least one submission was received from a descendant of
the 17th century Italian-French astronomer, Jean-Dominique
Cassini, for whom the mission is named. Some even sent in paw
prints of their pets.
The two-story-tall spacecraft, scheduled for launch on an
Air Force Titan IV/Centaur launch vehicle on Oct. 6, is destined
to arrive at Saturn in July 2004, where it will orbit and study
Saturn, its rings, moons and magnetic environment in detail over
a four-year period. Cassini carries a scientific probe called
Huygens, provided by the European Space Agency. Huygens will be
released from the main Cassini spacecraft and parachute through
the atmosphere of Saturn's most intriguing moon, Titan, which is
thought to chemically resemble a very cold version of Earth's
environment before life began.
Cassini is an international mission conducted by NASA, the
European Space Agency and the Italian space agency. The Cassini
spacecraft carries 18 scientific instruments provided by
scientists from Europe and the U.S. The mission is similar in
scope to the Galileo mission , which sent a spacecraft to orbit
Jupiter and sent a probe to parachute into the atmosphere of the
"There are many different reasons for this outpouring of
signatures," said Kohlhase. "Each of our signatures is as unique
as our fingerprints. Some of us dream of venturing into the
cosmos. Sending our signatures can substitute for making the
Kohlhase said many of the submissions sent in were touching,
including one from a parent who sent the signatures of his
deceased 15-year-old daughter. Many signatures were received
along with poems, messages, original artwork and music, but only
the signatures were stored on the disk.
The disk includes the signatures of the two 17th century
astronomers for whom the Saturn orbiter and Titan probe are
named. Jean Dominique Cassini's signature was recorded from a
letter dated in 1690. Dutch scientist Christiaan Huygens'
signature was copied from a letter he sent to Cassini in 1684.
From November 1995 until January 1 this year, every signature
submission received by the Cassini office was electronically
scanned and recorded on data tapes by volunteers working at the
Planetary Society's headquarters in Pasadena, CA.
For the final product, Kohlhase chose the recently developed
digital versatile disk (DVD) format, which can hold up to 25
times more information than a conventional CD-ROM. The
collected signatures were recorded onto the DVD in May 1997 at
the Imation Co. in Menomonie, WI. Ten copies were made: one for
the spacecraft and the remainder for future display at museums
around the world.
The artwork covering the disk was designed by Kohlhase to
celebrate various elements of the Cassini mission, its scientific
targets, and the flags of those countries with the greatest
number of signatures sent to the program. (The largest number
was collected from the U.S., with a total of 542,020 from all 50
states.) Six Golden Eagle wing feathers are shown, symbolizing
both the quill pen and the ability to soar above the Earth.
JPL engineers and technicians who assembled the spacecraft
will place the disk into a shallow cavity between two pieces of
aluminum that will protect it from micrometeoroid impacts. The
package will be mounted to the side of the spacecraft beneath a
pallet carrying cameras and other science instruments that will
be used to study the Saturnian system. A specially designed,
multicolored patch of thermal blanket material will be installed
over the disk package.
Along with the spacecraft, the disk will reside in Saturn's
orbit centuries after the primary mission is completed in July
2008. The Cassini mission is managed for NASA's Office of Space
Science, Washington, D.C., by JPL, a division of the California
Institute of Technology.