|
Archives
Space Capsule Retruns Comet Dust To Earth
DUGWAY PROVING GROUNDS, UT (AP) - After a seven-year journey, a NASA space capsule
returned safely to Earth in January 2006 with the first dust ever fetched from
a comet, a cosmic bounty that scientists hope will yield clues to how the solar
system formed.
The capsule's blazing plunge through the atmosphere lit up parts of the western
sky as it capped a mission in which the Stardust spacecraft swooped past a
comet known as Wild 2.
"This is not the finish line. This is just the intermediate pit stop," said
project manager Tom Duxbury of the Jet Propulsion Laboratory in Pasadena, CA,
which managed the $212 million mission.
About a million comet and interstellar dust particles - most smaller than
the width of a human hair - are believed to be inside a sealed canister.
The particles, captured in 2004, are thought to be pristine leftovers from
the birth of the solar system about 4.5 billion years ago. Some samples could
be
even older than the sun.
The next stop for the capsule was the Johnson Space Center in Houston, where
scientists unlocked the canister. After a preliminary examination, they shipped
the particles to laboratories all over the world for further study to analyze
their composition.
"Inside this thing is our treasure," said principal mission scientists
Don Brownlee of the University of Washington.
Stardust's successful return was welcome news to the space agency, which
suffered a setback in 2004 when its Genesis space probe carrying solar wind
atoms crashed
into the same Utah salt flats and cracked open after its parachutes failed
to deploy.
After the Genesis mishap, engineers rechecked Stardust's systems. Duxbury
said its return home went "like clockwork".
The Stardust mothership released the shuttlecock-shaped capsule, which plunged
through the atmosphere at 29,000 mph.
The first parachute unfurled at 100,000 feet, followed by a larger chute,
which guided the capsule to a 10-mph landing at Dugway Proving Ground.
There was
a tense moment in mission control when engineers could not immediately
confirm the first parachute had opened.
Before coming to rest on its side, the capsule bounced three times but
didn't crack, said Joe Vellinga of Lockheed Martin, who helped lead the
recovery.
Scientists in white protective suits spent the day cleaning the capsule
and its canister of dust samples before the trip to Johnson Space Center.
The Stardust mothership remained in orbit around the sun and NASA is
considering sending it to another comet or asteroid to snap photos.
There won't be
another chance for a sample return, however, because the craft carried
only one capsule.
Stardust and Genesis were the first robotic retrievals of extraterrestrial
material since the unmanned Soviet Luna 24 in 1976, which brought
back lunar rocks and
soil.
The Stardust spacecraft was launched in 1999 and has traveled nearly
3 billion miles, including three loops around the sun.
In 2004, it survived a hazardous trip through the comet's coma,
a fuzzy halo of gas and dust, to snatch the cosmic dust with
a tennis
racket-sized
collector
mitt. Along the way, it also scooped up interstellar dust -
tiny particles thought to have been thrown out by stars that long
ago exploded and
died.
During the comet flyby, the spacecraft also beamed back 72
black-and-white pictures showing broad mesas, craters, pinnacles
and canyons
on the surface of Wild 2.
Six months ago, NASA sent the Deep Impact probe into the
path of another comet. The probe's high-speed collision
with comet
Tempel
1 set off
a celestial fireworks
display and bared the comet's primordial interior.
Scientists have been analyzing the voluminous debris hurled
from the comet and are trying to figure out the size
of the crater
caused by
the debris-shrouded
impact.
Archives
|