http://spaceflightnow.com/2014/12/03/hayabusa-2-launches-on-audacious-asteroid-adventure/
Hayabusa 2 launches on audacious asteroid adventure
by Stephen Clark
Spaceflight Now
December 3, 2014
A Japanese H-2A launcher blasted off from an idyllic island spaceport
Tuesday, dispatching a daring six-year expedition to bring a piece of
an asteroid back to Earth.
The Hayabusa 2 mission's roundtrip voyage began at 0422 GMT Wednesday
(11:22 p.m. EST Tuesday) with a thunderous ascent from Tanegashima Space
Center in southern Japan.
The 1,300-pound spacecraft rode a hydrogen-fueled H-2A rocket through
clouds hanging over the seaside spaceport, leaving a twisting column of
exhaust in its wake before disappearing hundreds of miles over the Pacific
Ocean.
The rocket's upper stage engine fired two times to accelerate Hayabusa
2 on a speedy departure fast enough to break free of the pull of Earth's
gravity.
The robotic explorer, packed with four stowaway landers to be deployed
to the asteroid's surface, separated from the H-2A rocket at 0609 GMT
(1:09 a.m. EST). Applause could be heard in a live webcast of the launch
provided by the Japan Aerospace Exploration Agency, which manages the
Hayabusa 2 mission.
The launch marked the opening chapter in the most ambitious mission to
an asteroid ever attempted. The roundtrip journey will take six years
to complete, and Hayabusa 2 promises to expand scientists' understanding
of how asteroids may have seeded Earth with water and organic molecules,
the building blocks of life.
Hayabusa 2 is heading for asteroid 1999 JU3, a carbon-rich world just
900 meters - about 3,000 feet - across with a tenuous gravity field 60,000
times weaker than Earth's.
The mission follows up on the achievements of Japan's Hayabusa 1 probe,
which made the first roundtrip flight to an asteroid from 2003 to 2010.
The first Hayabusa mission encountered several crippling problems, including
a fuel leak, failures in its pointing system, and a glitch with the craft's
sample collection system.
Despite the challenges, the spacecraft returned to Earth in 2010 - a few
years late and carrying a fraction of the asteroid specimens intended.
But Japanese scientists found microscopic samples from asteroid Itokawa
- Hayabusa 1's research subject - inside the probe's landing vehicle.
The success vaulted Japan into the big leagues of solar system exploration.
Many scientific milestones have been achieved from asteroid observations
and samples from the asteroid Itokawa, said Tetsuo Tanaka, associate
director general of JAXA's Lunar and Planetary Exploration Program Group.
Going to a far-off asteroid and returning with samples from it for the
first time, these are tremendous technological challenges and our success
in meeting them has brought worldwise admiration.
For the Hayabusa 2 project, Japan's development of its own deep space
exploration technology aims to lead the world in that technical field,
Tanaka said. The Hayabusa 2 project sets new challenges for Japan's unique
technologies. How we face those challenges and how we use (the) project
results will surely bring new impacts to the world.
Artist's concept of the Hayabusa 2 spacecraft at asteroid 1999 JU3. Credit:
JAXA
But Hayabusa's troubles meant it was prudent for engineers to make changes
on Hayabusa 2.
We changed a lot of parts on Hayabusa 2, said Hitoshi Kuninaka, JAXA's
Hayabusa 2 program manager. We installed four reaction wheels, and Hayabusa
1 had only three. The sampling system also has some improvements. Our
operations software was upgraded for better proximity operations around
the asteroid.
Hayabusa 2's electrically-powered ion engines were upgraded to produce
more thrust, and engineers installed a Ka-band antenna to beam data back
to Earth at four times the rate possible on the first Hayabusa mission.
Many scientific milestones have been schieved from asteroid oobservations
and samples from the asteroid itokawa. going to a far off asteroid and
returning with samples from it for the first time. these are tremendous
technological challenges and our success in meeting them has brought worldwise
admiration.
Japan has gained unique exploration experience through projects like Yayabusa,
Kaguya and Kkaros.
For the Hayabusa 2 project, Japan's development of its own deep space
exploration technology aims to lead the world in that technical field.
he Hayabusa 2 project sets new challenges for Japan's unique technologies.
Wow we face those challenges and how we use project results will surely
bring new impacts to the world.
The spacecraft will arrive at the asteroid in June 2018 after swinging
by Earth late next year to get a boost to the mission's destination, which
circles the sun between the orbits of Earth and Mars.
The probe will initially park itself 20 kilometers, or about 12 miles,
from the asteroid for a comprehensive survey with a set of spectrometers,
cameras, and other sensors
