Discovery crew hard at work
2006-07-12 06:55
Houston - Astronauts concentrated on
tasks like unloading supplies from the shuttle Discovery on
Tuesday a day after a spacewalk that Nasa said was a big step
toward completing the International Space Station.
They lugged cargo to the space station from the shuttle,
which arrived last week with more than 2 273kg of supplies and equipment for the station crew.
The shuttle Discovery will return to Earth next week with
more than two tons of trash and unneeded items from the space
station.
While the cargo transfer proceeded, astronauts Piers
Sellers and Michael Fossum readied their spacesuits for a
spacewalk on Wednesday.
It will be their third of the flight, and follows a
seven-hour spacewalk on Monday in which they repaired a space
station transporter that will be needed to complete the $100bn complex.
They struggled at times but finally fixed a cart that runs
on tracks outside the space station and will be used to haul
such things as large solar energy panels to be attached to the
facility on future shuttle missions.
The cart had been out of commission since December when its
power and data cable was inadvertently cut.
Nasa officials breathed a sigh of relief when Sellers put
the last bolts in place because failure would have been a big
blow to plans to complete the station before shuttles are
retired in 2010.
"If we didn't get this successfully changed, we couldn't
proceed with the next mission, which is right on our heels,"
flight director Rick LaBrode said. "It was a big deal."
Space station construction came to a halt when Nasa
grounded its three-shuttle fleet after the Columbia disaster in
2003.
Shuttles are the only spacecraft that can deliver the major
components of the station, which is sponsored by 16 nations.
Assuming Discovery completes this mission successfully,
Nasa plans to launch shuttle Atlantis on August 28 to carry up a
massive solar power array to provide more electricity for the
station as it grows in size.
Sellers and Fossum are set to test materials and techniques
for repair of heat shield damage on their Wednesday spacewalk.
On Monday's walk, Sellers' jet-powered backpack, which
would be used to get him back to the space station if he became
untethered from it, came loose twice.
Nasa engineers sent up questions in an e-mail message on
Tuesday that suggested he might have bumped the jet pack while
putting it on or while out in space.