NASA engineers are keeping close
tabs on a piece of Soviet-era space trash to decide whether to move the
International Space Station before the arrival of the shuttle Discovery on
Tuesday.
Discovery launched
toward the station with seven astronauts aboard on late Sunday, and is due
to dock at the orbiting lab tomorrow at 5:13 p.m. EDT (2113 GMT). But the
offending piece of space debris, a remnant from the Soviet navigation satellite
Cosmos 1275, will zip close by the station before the shuttle arrives.
"We haven't gotten data in our
office yet on how big it is," said NASA spokesperson Kylie Clem at the Johnson
Space Center in Houston.
Clem told SPACE.com that
flight controllers know the debris is expected to make its closest pass by the
space station at 3:14 a.m. EDT (0714 GMT) at a distance of about 2,600 feet (793 meters), Clem said.
If NASA engineers decide they need
to move the space station to dodge the space junk, they would fire the rocket
engines on the outpost's Russian-built Zvezda service module at about 9:54 p.m.
EDT (0154 March 17 GMT) for a short maneuver.
"We don't necessarily need to do the
burn until we get more data," station
commander Michael Fincke radioed down to Mission Control.
Discovery's STS-119 crew, commanded
by Lee Archambault, plan to inspect their
space shuttle's heat shield for damage in the first of a series of
in-flight surveys to ensure their spacecraft is healthy.
Space debris redux
The Cosmos 1275 debris is the latest
piece of wayward space trash to buzz the space station.
Last Thursday, Fincke and his two
crewmates had
to take shelter inside their Russian Soyuz TMA-13 spacecraft, which doubles
as a lifeboat, because of a close shave with a piece of a spent satellite
rocket motor.
Flight controllers learned of that
conjunction too late to plan an engine burn that would move the space station
clear of the debris, which was about 5 inches (13 cm) wide - larger than
initially reported - and travelling about 19,800 mph. The space station orbits
the Earth at about 17,500 mph.
As a safety precaution, Fincke and
flight engineers Yury Lonchakov of Russia and Sandra Magnus of NASA spent about
10 minutes inside the Soyuz. They were ready to shut the spacecraft's hatch and
evacuate the space station if the debris slammed into the space station and
breached its hull. NASA estimated they would have only had 10 minutes of air if
the impact occurred.
NASA typically moves the space
station if a piece of debris threatens to fly past the station within an
imaginary box around the orbiting laboratory. The box extends about 2,400 feet
(732 meters) above and below the space station, as well as 15 miles (24 km) to
either side of the outpost.
The amount of space trash has
increased in recent months after the Feb. 10 collision of a U.S. and a
different Russian satellite, which spewed two debris clouds after the two
spacecraft crashed into each other 490 miles (790 km) above Siberia. The new
debris has increased the damage risk to NASA's space shuttle and station
flights by about 6 percent, or 1-in-318, NASA officials have said.
Discovery is carrying a $298
million set of U.S. solar arrays and a new crewmember, Japanese astronaut
Koichi Wakata, to the space station. The new solar arrays and a final segment
of the station's backbone-like main truss will be installed during three
spacewalks planned for Discovery's flight.
Wakata will replace NASA astronaut
Sandra Magnus as a station flight engineer. He is Japan's first long-duration
astronaut and due to return to Earth later this summer.
Discovery is due to dock at the
space station on Tuesday at 5:13 p.m. EDT (2113 GMT).
SPACE.com is providing continuous
coverage of STS-119 with reporter Clara Moskowitz and senior editor Tariq Malik
in New York. Click here
for mission updates and SPACE.com's live NASA TV video feed.
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