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 | The Space Shuttle Discovery sits on Launch Pad 39B at the Kennedy Space 
 Center. |   
 The launch of the Discovery space shuttle has been delayed for several 
 days because of technical problems. 
 No new launch date has been set, but Nasa managers say the most 
 optimistic possibility for the next attempt could be as early as Saturday. 
  
 The US space agency aborted Wednesday's launch shortly before lift-off 
 when a fuel sensor started to play up. 
  The orbiter was set to make the first flight since the loss of Columbia 
 and its crew of seven in February 2003. 
  All seven members of the crew died in the accident. 
  Discovery's astronauts had all been strapped into the shuttle and were 
 preparing for blast-off when the order came through to stand down. 
  Nasa's chief administrator Mike Griffin told 
 reporters he did not know whether the problem could be fixed at the launch 
 pad or would require the shuttle to be rolled back into its hangar 
 
 . 
  The latter would mean a lengthy delay to Discovery's mission to the 
 International Space Station. 
  The faulty sensor is one of four in the shuttle's external tank 
 responsible for making sure the spacecraft's engines shut down at the 
 proper point during the ascent. 
  The sensors ensure the engines are not suddenly starved of propellants 
 and are switched off in a controlled fashion. 
  Nasa said it appeared that one sensor was showing a low level on the 
 part of the tank containing the hydrogen propellant - even though the tank 
 had been fully topped up ready for launch. 
  The sensors "for some reason did not behave today and so we're going to 
 have to scrub this launch attempt," launch director Mike Leinbach informed 
 colleagues. 
  "So appreciate all we've been through together, but this one is not 
 going to result in a launch attempt today," he added. 
  The current launch window runs until the end of July, after which 
 Discovery would have to wait until September to get airborne. 
  The long wait results from the need to have the International Space 
 Station in the right position in orbit and Nasa's desire to launch during 
 daylight hours so it can photograph all aspects of the ascent. 
  Discovery's mission will be the first for a space shuttle in two and a 
 half years. 
   
 The agency says it has learnt the lessons of the Columbia accident.  
  (BBC)  |