[meteorite-list] Hayabusa Probably Failed To Collect Asteroid Samples

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Wed Dec 7 12:17:31 2005
Message-ID: <200512071715.jB7HFu208524_at_zagami.jpl.nasa.gov>

http://www.newscientist.com/article.ns?id=dn8431

Asteroid sampling mission probably failed
Maggie McKee and AFP
New Scientist
07 December 2005

The Japanese spacecraft Hayabusa is likely to have failed in its
landmark mission to collect the first-ever samples from an asteroid,
mission officials said on Wednesday. It also faces trouble returning to
Earth.

The Japan Aerospace Exploration Agency (JAXA) had earlier said the
Hayabusa probe "most probably" succeeded in gathering material from the
Itokawa asteroid, 290 million kilometres from Earth, on 26 November. The
spacecraft was thought to have landed on the space rock for just one
second, firing two metal pellets to throw up material for collection in
a cone-shaped horn.

"But now we found that the possibility is very high that a metal bullet
to collect samples was not actually fired," a JAXA official said. "And
therefore the possibility is also very high that Hayabusa has failed to
collect samples". The official added that the agency still had a "slim"
hope that the probe may have caught some dust.

The reason for the confusion appears to stem from the fact that just
after the landing, the spacecraft put itself into "safe" mode - where
all unnecessary systems were shut down. This occurred after it suffered
a fuel thruster leak that caused it to move unexpectedly.

So ground controllers had to work for several days to recover control of
the spacecraft before they could download data from the touchdown. That
data now suggests the pellets were not fired.

Flat battery fear

Even if some dust managed to slip into the collection horn during the
touchdown on 26 November - or during an earlier, problem-plagued landing
on 20 November - the spacecraft's thruster problem means it may not be
able to leave the asteroid by mid-December.

If it misses that window, it must wait another three years before the
distance between Earth and the asteroid is ideal for the return trip.
But the spacecraft's battery may not last that long.

Nonetheless, mission officials remain hopeful of salvaging the mission.
"Hayabusa is now temporarily maintaining its proper position with an
emergency booster," the JAXA official said. "We won't give up our hope
as long as there is a possibility."

Hayabusa suffered a number of other problems, including the breakdown of
reaction wheels that controlled its stability and the loss of a robot
that was due to explore the asteroid.

It was launched in May 2003 with a budget of 12.7 billion yen ($100
million dollars) and was scheduled to return to Earth in June 2007. Once
near Earth, the capsule containing the asteroid samples was set to
detach from the probe and land in the Australian desert.

The asteroid was formed 4.6 billion years ago at the same time as the
solar system and represents a geological "fossil" from that time. Any
samples would also provide information about the composition and
structure of asteroids, which would be vital for any future plan to
deflect a celestial object on a collision course with Earth.
Received on Wed 07 Dec 2005 12:15:56 PM PST