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Spysat Debris Delays New Satellite’s Launch

February 28, 2008

This
story was updated at 3:34 p.m. EST.

The planned
Friday launch of a new U.S. spy satellite has been delayed by space debris from
last week’s destruction of its disabled predecessor, the mission’s launch
provider said Wednesday.

Initially
slated for a Feb. 29 liftoff from Vandenberg Air Force Base in California, the
National Reconnaissance Office’s classified NROL-28 reconnaissance spacecraft
will stand down for at least two weeks to avoid the orbiting remains of the destroyed
USA-193 satellite
, the United Launch Alliance said in a mission update.

“This is a
precautionary measure to avoid possible debris from the satellite that was
intercepted on Feb. 20,” a spokesperson for ULA, which is overseeing the new
satellite’s launch atop an Atlas 5 rocket, said in a Wednesday mission hotline
update.

The U.S.
Navy cruiser USS Lake Erie launched
an SM-3 missile
from the Pacific Ocean on Feb. 20 to destroy the defunct
USA-193, a school bus-sized classified reconnaissance satellite that failed
shortly after its December 2006 launch. The satellite’s demise was a safety
measure to prevent its half-ton load of toxic hydrazine rocket fuel from
endangering people on Earth, Pentagon officials said.

As of
Monday, the military was tracking less than 3,000 pieces of
debris
, all smaller than a football in size, from 5,015 pounds (2,275
kg) satellite’s destruction, Pentagon officials said. Left unattended, at least
half of the satellite was expected to survive reentry to rain down on Earth
next month.

“From the
debris analysis, we have a high degree of confidence the satellite’s fuel tank
was destroyed and the hydrazine has been dissipated,” said U.S. Marine
Corps Gen. James Cartwright, vice chairman of the Joint Chiefs of Staff, in
Feb. 25 statement.

The
satellite, which was also known as NROL-21, was destroyed about 153 miles (247 km) above Earth by a kinetic hit with a missile
launched from a point northwest of Hawaii at 10:26 p.m. EST (0326 Feb. 21
GMT).

Military
officials said Monday that the majority of the destroyed satellite’s debris has already
reentered the Earth’s atmosphere or will do so in the next few weeks. There
have been no reports of any debris fragments surviving their fiery atmospheric
reentry to impact the ground, they added.

Eager
skywatchers, however, did report
sightings
of what appeared to be the dead satellite’s remains in orbit.

Last week,
NASA space operations chief Bill Gerstenmaier said the civilian agency did not believe
that debris from USA-193 would hinder the planned March 11 launch of the
shuttle Endeavour to the International Space Station (ISS).

“We
don’t think it’ll be a problem, but we’ll continue to analyze it to make sure
that it’s not a problem or a concern to us,” Gerstenmaier
said on Feb. 20
, just after the space shuttle Atlantis landed earlier that
day.

The agency
activated a backup shuttle runway in California in addition to its primary
landing site at the Kennedy Space Center in Cape Canaveral, Fla., in
order to land Atlantis and its seven-astronaut crew as soon as possible and give
the U.S. military a clear shot at the ailing spy satellite. The shuttle
ultimately touched down in Florida after clear weather made its backup landing
strip unnecessary.

While the
U.S. Navy had modified three SM-3 missiles to make the satellite shot, the
spacecraft was successfully destroyed on the first attempt.

As of
Monday, the space surveillance systems of the U.S. Strategic Command were
continuing to monitor the remaining satellite debris to track any future risk
to ground or orbital object, military officials said.


Source: imaginova



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