NASA has once again pushed back the launch of space shuttle Discovery. The first launch since last year's recurrence of the foam-shedding problem that caused the Columbia disaster now won't happen until July at the earliest, according to engineers.

The problem this time is with a fuel tank sensor. Fixing it will take three weeks, meaning the scheduled May launch window will come too soon. Programme engineer Wayne Hale said: "We wish it had worked out differently, but it's first and foremost that we fly safely."

The engine cut-off sensor coordinates timely shut down of the orbiter engines when the main fuel tank is empty. A fault could mean the shuttle fails to make it into orbit.

The three 2006 launches NASA had hoped for, which we reported at the start of this month, now seem unlikely.

NASA's new window to get Discovery off the ground runs from 1 to 19 July. ®

Related stories

• Shuttle pilot: flight risks still a mystery (26 June 2006)
• NASA probes underwater operations (30 March 2006)
• NASA deploys satellite swarm (23 March 2006)
• NASA relieved as probe makes orbit (13 March 2006)
• NASA finds a gusher on Saturn moon (9 March 2006)
• Ancient cosmic signal decoded (9 March 2006)
• Global warming may kill ground-based astronomy (9 March 2006)
• NASA plans three shuttle launches this year (1 March 2006)
• Fore-get space exploration (1 March 2006)
• Private enterprise needed in space: NASA (17 November 2005)
• Shuttle Endeavour ends two-year hibernation (7 October 2005)