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Asteroid Sample-Return |
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The target is
asteroid 1998SF36, a small celestial body with largest dimension of about 500
m. Unlike other major celestial bodies such as Moon or Mars, minor bodies
such as asteroids are considered to conserve original material compositions
which did not undergo any substantial alterations since the time the solar
system was formed. Thus, if MUSES-C is able to collect and bring back even
just a few grams of material, we could significantly deepen the knowledge
about the origin and formation of our solar system. In Japanese
language the probe has been called “Hayabusa”, while the target asteroid has
been named “Itokawa”, in
honor of Dr. Hideo Itokawa, the father of the Japanese space program. Officials
information about this mission are available from JAXA
web pages. To realize this
mission, four main technology fields have been involved: · Propulsion using ion
engines · Autonomous navigation
using optical sensors and cameras · Sample collection
technology from a small celestial body ·
Technology for terrestrial atmospheric re-entry Space Robotics Lab
(led by Professor Kazuya
Yoshida) at Tohoku University has
been involved since the beginning in the working group for the design and
development of the sample collection technology, the 3rd topic in
the above listed fields. Involvement included numerical analysis as well as
experimental verifications of the different phases of the touch down maneuver
(descent, contact, ascent). The below picture
represents some of the strategies that can be used for sampling on a minor
celestial body. Hayabusa will employ the last one depicted, i.e. it
will use a bullet-like projectile to crush the surface and collect the
fragments that are generate by the high velocity impact (click here for more
information, in Japanese).
The small-sized
projector (gun) used to fire the projectile has been studied by the Shock Wave Research
Center at
The ascent after
the contact will be assured using four of gas-jet thrusters mounted on the
bottom surface of the probe. In order to avoid contamination from their
exhausted gasses, the thrusters will be fired after the sample collection
phase. Below are
animations related to Hayabusa touchdown phase (clicking on the
figures will start the movie).
· MUSES-C
hovering over the asteroid surface (MPEG, 2.3M) · The
sampling collection procedure in slow motion (MPEG, 1.9M) · Complete
sequence of touch-down (MPEG, 2.3M) · Example
of touch-down on smooth surface (MPEG, 2.8M) ·
Example
of touch-down on rough surface (MPEG, 2.8M) The previous animations
have been generated from the numerical simulations, using as data the best
estimated values known at the present time. The expected contact time will be
between 1 and 2 seconds, and only a few grams of material are expected to be
collected. We think that if Hayabusa will be able to make return them
to the earth, even though such a small amount, a significant progress in the
study of the origin of the solar system can be achieved.
The presentation
here is our outreach effort of research activities carried out with
responsibility of Space
Robotics Lab at Images and
animations in this page can be freely used. But please acknowledge to Dr. Yoshida when
used in news or publication medias. If you want an high definition version of
the animations (avi), please contact here. Space Robotics Lab at
Tohoku University Main
research topics (in English)
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