[meteorite-list] Hayabusa On Course for Australia Landing Zone

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Wed, 9 Jun 2010 14:53:34 -0700 (PDT)
Message-ID: <201006092153.o59LrYdU027292_at_zagami.jpl.nasa.gov>

For JPL internal use only.

http://www.spaceflightnow.com/news/n1006/09hayabusa/

Hayabusa on course for Australia landing zone
BY STEPHEN CLARK
SPACEFLIGHT NOW
June 9, 2010

Five days before it will fall into the Australian outback, Japan's
returning Hayabusa asteroid mission finished targeting the landing site
Tuesday in a final ion engine burn.

Hayabusa's ion engine fired for two-and-a-half hours yesterday to
optimize its trajectory, ensuring the spacecraft releases a diminutive
return capsule exactly on course for landing in the Woomera test range
in South Australia.

The capsule is still expected to touch down under a parachute around
1400 GMT (10 a.m. EDT) Sunday. It will be just before midnight in
Australia.

The Japan Aerospace Exploration Agency says Hayabusa is now traveling
about 1.2 million miles from Earth, nearly five times the distance of
the moon.

A previous trajectory correction burn ended Saturday to bend Hayabusa's
future path from an imaginary point 200 kilometers, or 120 miles, above
Earth toward Australia.

Tuesday's maneuver was the last time Hayabusa's ion propulsion system
will be fired. The highly-efficient system, which consumes ionized xenon
gas, has amassed 40,000 hours of operating time on four engines since
the mission launched in May 2003.

The next milestone will be the release of the re-entry craft
approximately three hours before landing. The jettison was rescheduled
later in the flight due to concerns about the capsule's battery.

Hayabusa's $200 million mission was extended three years after a fuel
leak threatened the spacecraft at the end of its visit to asteroid
Itokawa, a potato-shaped rock about the size of a city block.
Controllers lost contact with the probe and were not able to recover the
craft in time to resume the trip home.

"We want to heat it up and prevent it from becoming cold, we changed the
separation time as late as possible to three hours before entry," said
Junichiro Kawaguchi, Hayabusa's project manager.

The 16-inch-wide capsule will be spring-ejected from the Hayabusa
mothership in a spinning motion for stability.

A carbon fiber heat shield will protect the craft during its 25,000 mph
re-entry. Temperatures around the capsule should reach about 4,900
degrees Fahrenheit, according to JAXA.

The unprotected Hayabusa mothership will plummet into the atmosphere and
burn up.

A NASA DC-8 tracking plane will fly under the capsule's re-entry
trajectory to document the fiery return.
Received on Wed 09 Jun 2010 05:53:34 PM PDT