* Astronomy

Nasa has started the countdown to Monday's space shuttle launch that will ferry equipment to the International Space Station.
The shuttle is due to launch from Florida's Kennedy Space Centre at daybreak - around 06:21 local time (11:21 BST) on a 13-day mission.
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A stuck or leaky valve discovered Saturday night during launch  preparations could delay the scheduled April 5 liftoff of space shuttle Discovery.
NASA engineers said they found the leak in a valve while working on the shuttle's engines.
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NASA is targeting Monday, April 5, for the launch of the next space shuttle from the agency's Kennedy Space Centre in Florida. Shuttle Discovery's seven crew members had planned to lift off on March 18 to begin the STS-131 mission to the International Space Station. However, cold weather in Florida has delayed Discovery's move to the Vehicle Assembly Building to complete the shuttle's processing, which has delayed the rollout to the launch pad.
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Space shuttle Discovery's external fuel tank and two solid rocket boosters were attached on January 26 in the Vehicle Assembly Building at NASAs Kennedy Space Centre, Florida.  Technicians completed the task in preparation for mission STS-131, scheduled to launch March 18.