An instrument called ROSINA,
with key components designed and built at the Lockheed Martin
Advanced Technology Center (ATC) in Palo Alto, will be launched
early next year on the European Space Agency’s (ESA) Rosetta
spacecraft. The goal of the ambitious international mission is to catch
up with, orbit, and land on Comet Wirtanen in an effort to answer
questions about the origin of our Solar System. "Rosetta has the most
instruments of any spacecraft — that makes it challenging and one of
the most exciting missions ever," said Dr. Claudia Alexander, U.S.
Project Scientist for the mission and NASA Jet Propulsion Laboratory
(JPL) scientist. "We’re going to see some big discoveries, just like
Galileo and Cassini."
Chosen among hundreds for its uniquely high volatile and organic
material content, Comet Wirtanen was discovered by Carl A. Wirtanen
on January 17, 1948 at the University of California, Santa Cruz Lick
Observatory. His wife Edith Wirtanen, who still devotes time to the
Visitors’ Services Department at Lick, succeeds him. "Carl would have
been very excited about the Rosetta mission," said Mrs. Wirtanen. "He
wanted to see what was inside the comet like everybody else. We
always teased him about discovering comets–that you’d get a medal
for each comet you discovered and at this rate, that he could use
them to tile the floor. He discovered about five of them. He had no idea
that it [Comet Wirtanen] would be this famous."
Comets are icy preserves of the material present during the formation
of the solar system, unhindered by the Sun’s scorching effects.
Ground-based studies show strong indications that complex organic
molecules, such as hydrogen, carbon, oxygen and nitrogen, sit
beneath the surface of comets. These elements make up nucleic and
amino acids, which are essential for creating life. Was life on Earth
spawned by a chance comet encounter? ATC helped develop ROSINA
with the University of Bern and other institutions to help scientists find
the answer.
The Rosetta Stone was used to decipher the meaning of a language
— the hieroglyphics of ancient Egypt — that previously eluded
anyone who dared to try. ESA’s spacecraft aims to be the Rosetta
Stone of the solar system — the decipherer of the many secrets
comets hold in their icy, dusty cores. Leading theories regarding their
physical and chemical composition, mass, surface and evolution differ
widely. Only with an instrument like the one designed with an
international team including the ATC can the various theories be
tested.
ROSINA — for Rosetta Orbiter Spectrometer for Ion and Neutral
Analysis — will perform composition analysis on the Rosetta mission.
A mass spectrometer uses electric and magnetic fields to map the
mass of an ion to its chemical composition.
ROSINA will analyze particles in the comet’s atmosphere by mass,
physical and chemical composition, temperature, and velocity. Such
data will yield important results about the formation, position and origin
of comets, the similarities between cometary material and the
interstellar material present during the birth of the solar system, and
help to determine relationships between comets and asteroids.
As the highest resolution mass spectrometer ever flown, ROSINA will
measure the isotopes Carbon 12 and Carbon 13, which differ by a
single neutron. Such elements are used in carbon dating, which
determines the age of an organism. "The Carbon 12 to Carbon 13 ratio
in a comet tells us about the material that was present in the dense
interstellar medium that formed our Sun. Only comets have this
information frozen within them," said Dr. Stephen Fuselier of Lockheed
Martin’s ATC and U.S. lead co-investigator for the ROSINA instrument.
"One of the mission’s most exciting pieces of information will come from
the ROSINA instrument," said Alexander. "ROSINA will perform carbon
dating on the comet’s nucleus. One of the things that we don’t know is
whether comets were part of our solar system in the beginning.
Figuring out the age of the surface of the comet will help us to figure
out what their role was to make the solar system come to being and
whether they bring in particles from outside the solar system."
ROSINA will also find out what generation star our Sun is. "ROSINA
will determine the metal content of the interstellar medium that formed
our Sun by using the Carbon 12 and 13, and carbon monoxide and
nitrogen ratios found inside comets," said Fuselier. "If it is very metal
rich, we know our Sun is not a second generation star because the Big
Bang only created hydrogen and helium. By determining the metalloids
inside the comet we can also deduce the size of the star that created
our Sun."
Rosetta’s ten-year mission begins with a launch in January 2003 from
Kourou, French Guiana. Flying first out to Mars and then back to
Earth, Rosetta will use the gravitational momentum from both planets to
slingshot it farther into space. It will then pass by asteroid Otawara in
July 2006 and complete another Earth gravity assist in November
2007. Rosetta will fly by asteroid Siwa in July 2008 and finally reach
comet Wirtanen in November 2011. The spacecraft will spend two
years mapping and examining the surface using remote sensing,
analyzing dust and vapors, and finally releasing a lander.
During its mission, Rosetta will fly by asteroids Otawara and Siwa on
its eight-year journey to comet Wirtanen. Otwara is the smallest
asteroid to be visited by a spacecraft; Siwa is the largest. Asteroids
are referred to as planetesimals — tiny seeds that were denied the
chance to accrete into anything larger. At times containing impact
marks nearly as big as the size of the asteroid itself, asteroid collisions
tell us about the turbulent nature of our solar system during its
formation. Analyzing their composition and mass can help determine
the likelihood of an asteroid-Earth collision.
Lockheed Martin Space Systems Company is one of the major
operating units of Lockheed Martin Corporation. Space Systems
designs, develops, tests, manufactures, and operates a variety of
advanced technology systems for military, civil and commercial
customers. Chief products include a full-range of space launch
systems, including heavy-lift capability, ground systems, remote
sensing and communications satellites for commercial and government
customers, advanced space observatories and interplanetary
spacecraft, fleet ballistic missiles and missile defense systems.
Headquartered in Bethesda, Md., Lockheed Martin is a global
enterprise principally engaged in the research, design, development,
manufacture, and integration of advanced-technology systems,
products, and services. The Corporation’s core businesses are systems
integration, space, aeronautics, and technology services. Employing
more than 125,000 people worldwide, Lockheed Martin had 2001 sales
surpassing $24 billion.
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NOTE TO EDITORS: Low- and high-resolution JPEG image files of
Rosetta and Comet Wirtanen are available: