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February Launch Planned For Mission To Collect Samples Of Comet Dust



FOR IMMEDIATE RELEASE

FROM: Vince Stricherz
University of Washington
206-543-2580
vinces@u.washington.edu
DATE: June 29, 1998

  February launch planned for UW mission to collect samples of comet dust

 It might sound like something from a
 popular science fiction movie, but a
 University of Washington astronomy
 professor's nearly two-decade dream of
 launching an unmanned spacecraft to collect
 interstellar dust from a comet is close to            
 coming true.                                          
                                                       
 Stardust will blast off from Cape
 Canaveral, Fla., in February. It will be             
 the fourth mission in NASA's Discovery               
 series, which captured public imagination a           
 year ago with Mars Pathfinder. It will be
 the first mission since Apollo to return
 samples of space material to Earth for
 analysis.

UW professor Donald Brownlee, the principal investigator for the project,
expects to find clues about the formation of the solar system and perhaps
the universe itself.

"We hope to understand how comets were formed and what they're made of," he
said. "We expect them to be the preserved building blocks of the outer
planets."

Brownlee began considering such a mission in1980. The idea was explored
seriously five years later when Halley's comet approached Earth, but it was
deemed unworkable then.

For Stardust's 7-year, 3.1-billion-mile journey, solar panels will power the
spacecraft to encounter Wild 2, a comet that altered course in 1974 after a
close encounter with Jupiter. Now instead of circling among the outer
planets in our solar system, Wild 2 (pronounced vihlt 2) travels among the
inner planets. It was discovered in 1978 during its first close approach to
Earth.

Wild 2's recent arrival to the planetary neighborhood makes the $200 million
Stardust mission possible. In 2004, the craft will pass about 75 miles from
the main body of the comet. That's close enough to trap small particles from
the comet's coma, the gas-and-dust envelope surrounding the nucleus. A
camera built for NASA's Voyager program will transmit the first-ever
close-up comet pictures back to Earth. Though the encounter will last about
12 hours, Brownlee says the really intense activity will be over in a matter
of minutes.

The collection system will extend from the spacecraft and trap particles as
they collide with it. To prevent damaging or altering the particles - each
smaller than a grain of sand and traveling as much as nine times the speed
of a bullet fired from a rifle - the collector uses a unique substance
called aerogel. Often called "frozen smoke," aerogel is a transparent blue
silica-based solid that is as much as 99.9 percent air. It is as smooth as
glass, something like plastic foam without the lumps. A block the size of a
person weighs less than a pound but can support the weight of a small car.

On the trip to Wild 2, the aerogel-equipped collection panel will be
deployed to trap interstellar particles traveling in space. During the
encounter with the comet, some 242 million miles from Earth, the opposite
side of the panel will gather bits of comet dust. Trapped particles will
leave a telltale trail through the aerogel that scientists will follow to
find the grains and extract them. Upon leaving the comet, the collection
panel will retract into its capsule.

Once the Stardust capsule parchutes into Utah's Great Salt Desert in 2006,
the particles it collects will go to Johnson Space Center in Houston and
then be parceled out to various research facilities, including the
University of Washington. Because comets are about equal parts ice and dust,
Brownlee believes the particles will be cryogenically preserved interstellar
dust left from the birth of the solar system some 4.6 billion years ago.
Such grains can be found only in the outer solar system, he believes,
because heat has destroyed them nearer the Sun.

Brownlee's previous work collecting cosmic dust particles led to their being
named Brownlee particles. Cosmic dust was brought back to Earth on Gemini
missions in the 1960s. Later, high-flying U2 planes and balloons gathered
particles from different levels in the atmosphere, and space dust even has
been collected from the ocean floor. "A comet mission is the logical
extension," Brownlee said.

The project is being carried out by a consortium that includes the Jet
Propulsion Laboratory and Lockheed Martin Astronautics. When it came to
picking a name, Brownlee said, it just seemed appropriate to select
"Stardust," the title Hoagy Carmichael put on a popular tune that since has
been recorded by numerous artists, including Willie Nelson and Ringo Starr.

"I liked it because most spacecraft missions had weird, bizarre names. They
were acronyms for something," he said. "This isn't an acronym for anything.
It's just a name that people know."

                           ###

For more information, contact Brownlee at
brownlee@bluemoon.astro.washington.edu or (206) 543-8575.

-----------------------------------------------------------------------------


FOR IMMEDIATE RELEASE

FROM: Vince Stricherz
University of Washington
206-543-2580
vinces@u.washington.edu
DATE: June 17, 1998

           "Send Your Name to a Comet" effort proves very popular

Hundreds of thousands of people will get a vicarious thrill tracking the
progress of the Stardust mission to comet Wild 2 in the next seven years,
knowing their names are inscribed on a microchip that is going along for the
ride.

In fact, NASA collected 130,000 names for one microchip already loaded on
the Stardust spacecraft, and more than 200,000 names have been placed on a
second. The names are etched electronically on a chip the size of a
fingernail, with writing so small that 80 letters will fit into the width of
a human hair and an electron microscope is needed to read them.

University of Washington Astronomy Professor Donald Brownlee, the father of
the Stardust mission, said plans are to place the chips in a museum when the
spacecraft returns to Earth in early 2006. He hopes they will go to the
Smithsonian Institution.

The drive to gather names for the mission has gotten new emphasis with the
recent release of the movie Deep Impact, a science-fiction thriller about a
comet colliding with Earth, and the imminent release of "Armageddon," about
an asteroid colliding with Earth. Paramount Studios and and the DreamWorks
SKG, which collaborated on "Deep Impact," are promoting the gathering of
names.

The only way to submit a name for inclusion on a chip is through Stardust's
web page, http://stardust.jpl.nasa.gov. Submitting a name automatically
grants permission for the name to be used in future exhibits and
publications by the Stardust collaboration, which includes the UW, NASA, the
Jet Propulsion Laboratory and Lockheed Martin Astronautics.

                                   ###



STARDUST MISSION TIMELINE

1929: Hoagy Carmichael writes the song "Stardust."
1974: Close encounter with Jupiter causes major orbital shift for comet Wild 2
1978: Wild 2 discovered by Swiss astrophysicist Paul Wild on Jan. 6 during
      its first close approach to Earth.
1995: NASA selects Stardust mission to retrieve samples from Wild 2.
1999: Launch of Stardust spacecraft scheduled for Feb. 6.
2000: March through May, interstellar dust collection.
2001: Jan. 15, Stardust passes near Earth to get a gravitational speed boost.
2002: July through December, interstellar dust collection.
2004: Jan. 2, encounter with Wild 2; spacecraft will fly through comet's
      coma, take pictures and collect dust samples.
2006: Jan. 15, spacecraft returns to earth; capsule containing comet samples
      dropped by parachute to the Utah Test Training Range; speed of 13 
kilometers
      (about 7 miles) per second is the fastest for any re-entry vehicle.



SOME STARDUST MISSION FACTS AND FIGURES

Principal investigator: Don Brownlee, University of Washington astronomy 
professor
Miles traveled: About 3.1 billion.
Distance from Earth during comet encounter: About 242 million.
Spacecraft: Weight 375 kilograms (about 825 pounds), about the size of an
   average office desk.
Capsule: About 30 inches across and 20 inches deep.
Thrusters: About 1 inch long and 0.5 inch wide, they look something like a
   pawn in a chess game (Manufactured by Primex Aerospace Co. of Redmond, 
Washington).
Camera: A spare from NASA's Voyager program, it has been retooled for this
   mission but contains the original optics; a new camera would cost a
   prohibitive $25 million to $30 million.
Transmitter: A dish-shaped antenna about 3.3 feet across will send images of
   Wild 2 back to Earth (Manufactured by The Boeing Co., Tukwila, Wash.).
Solar panels: They will collect energy from the sun to provide electrical
   power to the spacecraft.
Assembly: Conducted at the Lockheed Martin Astronautics in Denver;
   continually updated pictures of the work can be seen at the Stardust home
   page.
Launch vehicle: A Delta II rocket made by Lockheed Martin.
Collaborators: The project is being done for NASA by the University of
   Washington; the Jet Propulsion Laboratory in Pasadena, Calif., a division of
   the California Institute of Technology; and Lockheed Martin.



SOME FACTS ABOUT AEROGEL

Discovered: In the late 1930s, though scientists continue puzzling over its 
properties
Manufacturing process: Supercritical drying is used to extract the liquid
   from silica dioxide gel (similar in form to a gelatin dessert); normal.
   evaporation would cause the gel to collapse, but in this process the gel
   keeps its form.
Density: The lowest of any known solid; one form is 99.9 percent air and 0.1
   percent silica dioxide.
Strength: A block the size of a human being would weigh less than a pound
   but could support a car weighing 1,000 pounds.
Other uses: It is being considered as a non-flammable alternative to
   insulation and sound-proofing in walls and windows; it could be used as
   lightweight insulation in aircraft.



                                      ###