[meteorite-list] X-Ray Satellite Crashes Into Ocean

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Thu Apr 22 10:14:08 2004
Message-ID: <200304301506.IAA00538_at_zagami.jpl.nasa.gov>

http://www.newscientist.com/news/news.jsp?id=ns99993682

X-ray satellite crashes into ocean
Jenny Hogan
New Scientist
April 30, 2003
 
An Italian science satellite, which was descending in an uncontrolled
spiral towards the Earth, has crashed safely into the sea. People in 39
nations beneath its flight path had been warned that debris could crash in
their countries.

The risk of anyone being hit by fragments of the 1400 kilogram BeppoSAX
satellite was always fairly small - one in 2000, according to the Italian
Space Agency (ASI). But regular updates were issued by ASI to
countries under the satellite's equatorial orbit.

The flight path passed over some of the most heavily and densely
populated countries in the world, such as Indonesia and Singapore. Some
had issued public warnings, while others were considering closing their
airspace.

BeppoSAX was switched off in April 2002 and had been falling towards
Earth ever since in an uncontrolled descent. Since the switch-off, when
communication was lost, NASA had tracked the satellite's decaying orbit.

But only in its final hours - as the satellite entered the Earth's dense
atmosphere and broke up - could ASI predict where the debris was going
to land. The last observations on Tuesday indicate that the satellite
fragments splashed down in the Pacific at 2206 GMT, about 400
kilometres northwest of the Galapagos Islands.

White-hot chunks

BeppoSAX carried solar panels that were 18 metres wide but the
fragments that fell to Earth will have been much smaller. The satellite
was expected to break into around 40 pieces and much of its mass will
have burnt up as it sped through the atmosphere. In total, about 400 kg
was expected to survive to ground level.

There have been no confirmed sightings of the fall yet, but the
white-hot chunks of metal will have streaked across the sky like
fireworks.

"You would be lucky to see this, but very unlucky to be hit by
some," says Bill Ailor, director of the Centre for Orbital and
Re-entry Debris Studies. CORDS is a division of The Aerospace
Corporation in Los Angeles, California, which tracks objects in
near-Earth orbits.

Ailor points out that up to 200 large objects re-enter the
atmosphere every year. But there is only one recorded incidence of a
person being hit by falling space debris - and the lady was
unharmed. The BeppoSAX satellite attracted particular
interest, Ailor thinks, because it had a high-profile scientific
mission.

"But there is increasing concern
about the hazards of re-entering satellites," Ailor acknowledges. By
international agreement, space agencies are now designing spacecraft to
be safer in one of two ways. They must either break into fragments so
small that they will all burn-up, or control must be maintained during
descent so that they can be safely steered into the ocean.
 
Received on Wed 30 Apr 2003 11:06:21 AM PDT


Help support this free mailing list:



StumbleUpon
del.icio.us
reddit
Yahoo MyWeb