[meteorite-list] The Rough Shape Of Asteroid Itokawa Revealed

Ron Baalke baalke at zagami.jpl.nasa.gov
Tue Apr 27 13:27:23 EDT 2004


The Rough Shape Of Asteroid "ITOKAWA" Revealed
April 27, 2004

Tokyo - A recent radar observation clarified the rough shape of an
asteroid called "ITOKAWA", where the MUSES-C (Hayabusa)
is heading for. A research group led by Dr. Steve Ostro of the
NASA Jet Propulsion Laboratory carried out observations by
transmitting radio waves to ITOKAWA from the radiotelescope at the 
Arecibo Observatory in Puerto Rico.

The radiotelescope is famous for having the largest diameter of 305 meters.
Their research is to observe time of wave reflection and frequency gaps over
a long time to study the shape and revolution of a faraway asteroid.

Hayabusa will carry out detailed observations for months after its
scheduled arrival at ITOKAWA in the summer of 2005. The onboard
high-performance camera will capture more precise images of the surface of
ITOKAWA, which looks like a potato in the image data retrieved by the
Arecibo Observatory?f s radiotelescope.

In addition, Hayabusa is expected to provide more detailed information on
the origin of the solar system through observations by spectroscopy of
several wave ranges including infrared rays and X-rays, and hopefully by
bringing back a fragment of ITOKAWA.

Hayabusa will conduct an "Earth Swing-by" in May 2004 to project itself
into the orbit of ITOKAWA.

HAYABUSA's mission: to bring back samples from an asteroid and
investigate the mysteries of the birth of the solar system.

HAYABUSA (MUSES-C) has been developed to investigate asteroids.
Asteroids are celestial bodies that are smaller than planets but are part of
the solar system. HAYABUSA was launched on May 9th, 2003, and has
been flying steadily towards an asteroid named "Itokawa," after the late Dr.
Hideo Itokawa, the father of Japan's space development program.
HAYABUSA is traveling through space using an ion engine. It will orbit the
asteroid, land on it, and bring back a sample from its surface.

Until now, the only extra-terrestrial celestial body from which we have
gathered samples is the Moon. But since the matter that comprises large
bodies such as the planets and the Moon has changed over time due to
thermal processes, these bodies cannot provide us with a pristine record of
the solar system. Asteroids, on the other hand, are believed to be small
enough to have preserved the state of the early solar system and are
sometimes referred to as celestial fossils. A soil sample from an asteroid
can give us clues about the raw materials that made up planets and
asteroids in their formative years, and about the state of the inside of a
solar nebula around the time of the birth of the planets. However small the
sample amount may be, its scientific significance is tremendous.

HAYABUSA's mission will play an important role in future space-probe

HAYABUSA employs a new technology - the ion engine. This engine first
ionizes the propellant gas, Xenon, then electrically accelerates and emits
the ions, to propel itself forward. As it is a highly efficient engine, it is
expected to be an important technological tool for our future exploration of
the Moon and the planets. HAYABUSA will demonstrate this technology.

Another innovation that HAYABUSA will demonstrate is the Autonomous
Navigation System, which enables the probe to approach a far-away
asteroid without human guidance. The system works by measuring the
distance to the asteroid with the Optical Navigation Camera, and using
Light Detection and Ranging.

HAYABUSA will not only gather samples but also observe the asteroid
with various scientific devices and measures. For that purpose, it is
equipped with a Telescope Wide-View Cameras and Light Detection and
Ranging, as well as with a Near Infrared Spectrometer.

It will also employ a hopping robot, which can move around on the
asteroid's surface. When HAYABUSA returns to Earth, a re-entry capsule
bearing a surface sample from the asteroid will separate from it and plunge
into the Earth's atmosphere. This is also a very important experiment in
space engineering.

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