[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Stardust Mission
With all the attention that Comet Hale-Bopp is getting, the Stardust project
has put out this press release. As most members of this list probably
already know, the CI meteorites are suspected of originating from comets due
to their primitive makeup and high water content. Well, we will be launching
a spacecraft, Stardust, that will collect dust particles from Comet
Wild 2 and return them back to Earth. Analysis of these dust particles will
give us a great insight into what makes up a comet and will confirm
if certain types of meteorites, such as CI, really do come from comets.
I've started working on the Stardust project a couple of months ago,
and I'll keep you abreast on the progress of the mission.
Ron Baalke
----------------------------------------------------------------------
PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
http://www.jpl.nasa.gov
Contact: Jane Platt
FOR IMMEDIATE RELEASE April 3, 1997
NASA'S STARDUST TEAM STUDIES HALE-BOPP'S COMETARY COUSIN
Just as Comet Hale-Bopp continues its journey across the
nighttime sky, another currently visible comet, Wild 2, is
capturing the attention of NASA's Stardust Project for a vitally
important reason.
Stardust, a spacecraft with a planned 1999 launch, will
capture samples of comet dust from Wild 2 in 2004 for return to
Earth in 2006. This current appearance by Wild 2 (pronounced
"Vilt 2"), offers the Stardust team a prime opportunity to
prepare for the spacecraft's historic journey by gathering data
on the comet's brightness and the size and quantity of its gas
and dust particles.
The spacecraft is protected from oncoming cometary particles
with a front "Whipple Bumper," a shield named for renowned
astronomer Fred Whipple, with a composite structure that includes
metals and several curtains of the same material as bullet-proof
vests. However, the bumper does not offer unlimited protection
against a barrage of numerous, large particles.
"We want to study the dust envelope of Wild 2 so we'll know
how close we can fly without jeopardizing the spacecraft," said
Stardust Project Manager Dr. Kenneth Atkins. "These current
observations will help us significantly reduce the risk."
By observing Wild 2 in both visible and infrared light, the
Stardust team will be able to fine-tune models of the comet
environment and mission logistics. Final trajectory adjustments
may be made up to a few hours before encounter, using
observations made by Stardust en route to Wild 2. That encounter
will take place on January 2, 2004, about 98 days after the
comet's perihelion, or closest pass by the Sun. During Wild 2's
current visit, scientists will study the comet's activity at a
comparable post-perihelion point, gathering data crucial to the
success of the Stardust mission.
Wild-2 studies are being conducted at numerous
observatories, including Lowell Observatory, Flagstaff, AZ; the
Lunar and Planetary Laboratory, University of Arizona, Tucson;
the W.M. Keck Observatory and other major telescopes atop Mauna
Kea, HI; and the 200-inch Hale telescope at Palomar Observatory
near San Diego, CA. Amateur astronomers can see Comet Wild 2
with a relatively small telescope through August, with the best
viewing before the end of May. With an apparent magnitude of
9.6, Wild 2 is currently visible almost directly overhead about
one hour after sunset and is located in the constellation of
Cancer close to the Praesepe open star cluster.
Comet Wild 2, a short-period comet with a six-year orbit,
was discovered in 1978 by the Swiss astronomer Paul Wild, after
its close encounter with Jupiter in 1974. This may have been the
comet's first journey to the inner solar system in recent
centuries, which means it is in a more pristine state than other
comets which have been "around the block" more often. For this
and several other reasons, Wild 2 was chosen as the destination
comet for Stardust.
As Atkins explained, "Wild 2's orbit presents attractive
features for doing a sample return. The comet will be in the
right place at the right time so that when Stardust encounters
it, Wild 2 will have a relatively low flyby speed of 6 kilometers
per second (3.7 miles). This makes the task of catching the
comet dust as it whizzes by much easier. In addition, the
orbital geometry of Wild 2 enables us to save money by launching
Stardust on a Delta rocket and designing an efficient
trajectory."
To capture the comet dust without harming it, Stardust will
use aerogel, a spongy, silica-based solid with 99 percent empty
space. The tiny cometary particles will bury themselves in the
transparent aerogel, awaiting retrieval by scientists on Earth.
On its way to Wild 2, Stardust will loop twice around the Sun and
collect interstellar dust particles. By returning these space
and cometary materials to Earth, Stardust will mark the first
space sample return mission since the Apollo missions collected
moon rocks in the 1960s and 1970s.
Stardust co-investigator Ray Newburn said comets are
apparent leftovers from the formation of the solar system and may
unlock many cosmic secrets. As he put it, "Comets are a
different sort of beast. They've been in a cosmic deep-freeze
for most of the solar system's 5-billion-year history. Many
scientists believe comets added complex organic molecules to the
primordial soup of oceans that helped form life. Stardust should
give us some hard facts about Wild 2 and other comets, including
chemical composition and age."
Stardust is one of NASA's Discovery missions, which team the
agency with industry and universities to launch low-cost
spacecraft in a short time frame with highly-focused science
goals. Stardust's principal investigator is Dr. Don Brownlee of
the University of Washington, Seattle, WA.
The Stardust spacecraft and sample return capsule are being
built by Lockheed Martin Astronautics in Denver, CO. The mission
is managed by NASA's Jet Propulsion Laboratory for NASA's Office
of Space Science, Washington, DC. JPL is also developing the
aerogel and the spacecraft's navigational camera, also to be used
for scientific imaging. Stardust's cometary and interstellar
dust analyzer instrument is provided by Jochen Kissel through the
Max Planck Institute in Germany; the University of Chicago, IL,
is building a Whipple Shield dust impact counter.
Additional information is available on the Stardust home
page on the World Wide Web at:
http://pdc.jpl.nasa.gov/stardust/home.html.
#####