[meteorite-list] Hayabusa Capsule Plunges to Earth After Historic Visit to Asteroid

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Sun, 13 Jun 2010 20:58:53 -0700 (PDT)
Message-ID: <201006140358.o5E3wrOj001130_at_zagami.jpl.nasa.gov>

http://www.spaceflightnow.com/news/n1006/13hayabusaentry/

Capsule plunges to Earth after historic visit to asteroid
BY STEPHEN CLARK
SPACEFLIGHT NOW
June 13, 2010

Cutting across the night sky at more than 27,000 mph, a small Japanese
capsule returned to Earth from the surface of an asteroid Sunday and
landed in the remote Australian outback.

The 16-inch-wide capsule plunged into the atmosphere over Australia at
1351 GMT (9:51 a.m. EDT) on the second-fastest re-entry of a manmade
spacecraft ever attempted.

Streaming video from Australia showed a luminous fireball appear in the
sky near the correct position, indicating the Hayabusa craft was on
track toward a touchdown in the Woomera Prohibited Area in South
Australia around 1411 GMT (10:11 a.m. EDT), or 11:41 p.m. local time.

A fleet of all-terrain vehicles and helicopters were standing by at
Woomera, a military installation in the Australian outback. More than 50
representatives of the Japan Aerospace Exploration Agency joined several
dozen Australian workers to recover the Hayabusa capsule.

The recovery teams detected the capsule's beacon signal and a helicopter
located the downed craft in the expected landing zone at 1456 GMT (10:56
a.m. EDT).

Officials plan to retrieve the capsule by Monday afternoon, Australian
time.

The capsule was programmed to dive into the atmosphere at an angle of
approximately 10 degrees, braving temperatures of nearly 5,000 degrees
Fahrenheit during the moment of peak heating.

A carbon fiber heat shield was designed to protect the craft from the
destructive heat.

The capsule was supposed to jettison a portion of its heat shield and
backshell once it reached a point 6 miles above Earth, permitting its
parachute to unfurl and slow the craft to a more gentle velocity.

Hayabusa's main spacecraft also plummeted back to Earth just a few miles
behind the capsule, but it burned up during re-entry as expected.

The Hayabusa mothership spring-ejected the drum-shaped return capsule at
1051 GMT (6:51 a.m. EDT) as the craft traveled more than 25,000 miles
above the planet. Hayabusa put the capsule in a slow spinning motion
before separation to keep the uncontrolled container stable and
thermally condition its battery.

Japanese officials last communicated with the Hayabusa probe at 1328 GMT
(9:28 a.m. EDT) as it passed out of range of ground stations. A rush of
applause, smiles and handshakes went through the control room around the
same time.

Sunday's fiery return to Earth wrapped up a mission lasting seven years
and traversing more than a billion miles across the solar system.

Hayabusa launched in May 2003 and reached asteroid Itokawa in September
2005 for three months of research and daring close approaches to the
potato-shaped object. The visit ended with a series of attempts to
collect samples from the asteroid, but the spacecraft inadvertently
landed on the surface for 30 minutes.

Telemetry analysis after two touchdowns on Itokawa showed Hayabusa
likely did not fire a projectile into the asteroid's gravely surface,
but Japanese scientists are hopeful light amounts of dust could have
moved into the funnel leading to the sample container.

Officials won't know for sure until the capsule is flown back to Japan
and moved into a special curation facility at the Sagamihara campus on
the outskirts of Tokyo. That could occur as early as Tuesday or Wednesday.

"That is the ideal scenario," said Junichiro Kawaguchi, Hayabusa's
project manager. "In an off-nominal scenario, recovery itself may take
several days or more, so accordingly the return to Japan may be delayed."

Researchers will take their time examining and opening the container.

"Opening the capsule will take place within a few weeks of arrival
here," Kawaguchi said in an interview from Sagamihara. "We must take the
utmost care to open the capsule. It takes a lot of time to study the
samples because they will probably be in fine particles."

Scientists must also distinguish between contamination from Earth and
particles from the asteroid, and that could take several months.

Hayabusa missed an opportunity to come home in June 2007, but the probe
finally fired its ion propulsion system to begin the journey back to Earth.

The spacecraft was stymied by a major fuel leak, the failure of
two-thirds of its attitude control system, the loss of three of its four
ion engines, and trouble with its primary battery.

The problems put the mission in doubt many times, and Kawaguchi remained
publicly pessimistic about Hayabusa's chances until the final days
before re-entry.

"We have been quite lucky in succeeding and continuing this mission,"
Kawaguchi said last week. "I personally am very proud of the teams,
comprised of the engineers and the scientists who continue to do these
activities."

"We've just been lucky."
Received on Sun 13 Jun 2010 11:58:53 PM PDT