This
story was updated at 12:20 p.m. EDT.
The space
shuttle Discovery dodged a mysterious piece of orbital trash Thursday as its astronaut
crew prepared for a planned landing in Florida.
Shuttle
commander Rick Sturckow and pilot Kevin Ford fired Discovery's engines at 12:02
p.m. EDT (1605 GMT) for 14 seconds to move the spacecraft clear of the space
junk and continue on with their landing attempt today.
The
"mystery orbital debris," as Mission Control called it, apparently came free
from the shuttle or the International Space Station while both vehicles were
linked during a spacewalk on Saturday. NASA engineers do not know what the
object is or its size, but it has been creeping ever closer to Discovery since
the shuttle fired its engines to leave the station's orbital neighborhood
Tuesday.
At 12:55
p.m. EDT (1655 GMT), the debris was expected to fly within a safety perimeter
box that extends out 25 miles (40 km) around Discovery and 2 miles (3 km) above
and below the shuttle.
"Based on
the latest tracking data, the object will move in and out of that box over the
course of 11 consecutive orbits," said NASA commentator Pat Ryan. "The two
objects [are] in essentially the same orbit, but with different velocities."
Discovery's
debris-dodging maneuver will not impact NASA's plan to try and land
the shuttle at the Kennedy Space Center in Florida today, Mission Control
said. The shuttle is due to touch down at 7:05 p.m. EDT (2305 GMT), but could
also try for an 8:42 p.m. EDT (0042 Sept. 11 GMT) opportunity depending on
weather conditions.
Thunderstorms
near the shuttle runway could keep Discovery and its seven-astronaut crew in orbit
an extra day. NASA could also activate a backup runway in California as early
as Friday in order to bring the shuttle home. The shuttle blasted
off late Aug. 28.
Space
debris has dogged Discovery's mission to the International Space Station.
A piece of
Chinese satellite debris was due to pass by the space station twice early
Wednesday, but never came anywhere near the orbiting laboratory. Last week, a
massive chunk of a 3-year-old European rocket buzzed the orbital outpost and
linked shuttle, zipping past about 1.3 miles (3 km) ahead of the station, but
it too posed zero risk of impact, Mission Control said.
Discovery
is returning to Earth to wrap up a 13-day cargo run to the space station. The
astronauts performed three spacewalks, replaced one member of the station's
crew and delivered tons of supplies, science gear and a treadmill named after TV
comedian Stephen Colbert.
The shuttle
is bringing home NASA astronaut Tim Kopra, who is ending a nearly two-month
mission to the space station. He was replaced by astronaut Nicole Stott during
Discovery's flight.
Discovery
is also returning
Buzz Lightyear, a 12-inch Disney toy, to Earth to wrap up his own 15-month
space mission. Buzz launched to the station in May 2008 as part of an educational
campaign and will receive a hero's welcome at Walt Disney World in Florida -
including a tickertape parade - after returning to Earth.
SPACE.com
is providing complete coverage of Discovery's STS-128 mission to the
International Space Station with Managing Editor Tariq Malik and Staff Writer Clara
Moskowitz in New York. Click here
for shuttle mission updates and a link to NASA TV.
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