Nasa has again delayed the launch of the space shuttle Atlantis to finish repairs to its fuel tank which was damaged in a hailstorm in February.
The US space agency had hoped the shuttle, which is due to take equipment to the International Space Station, would be ready for a May launch.
But Nasa officials said 8 June was now the earliest possible date.
Huge hail stones hit Atlantis, causing hundreds of dents and minor surface damage to some 26 heat shields.
The insulating foam and the heat shield on the shuttles have been of critical concern to Nasa since the destruction of Atlantis' sister ship Columbia and the deaths of its crew in February 2003.
Columbia was struck on launch by a large piece of insulation foam that punctured a hole in its left wing and left it open to the destructive superheated gases of re-entry.
Lot of work
Nasa has redesigned the tank to try to minimise foam loss, and has now carried out three successful flights.
Nasa managers had been studying whether to replace the tank for the Atlantis mission, but are now confident the existing one can be repaired and are pleased with the progress of repairs.
"We don't see any showstoppers in front of us... but there is still a lot of work to be done," said Bill Gerstenmaier, Nasa's associate administrator for space operations.
Atlantis' mission is due to take it to the International Space Station, where astronauts will fit a new backbone segment to the orbiting platform and install a new set of solar wings.
The delay in launching Atlantis puts back the flights of other shuttle missions that Nasa hopes to launch this year.
It also means a prolonged stay for US astronaut Sunita Williams at the space station.
Ms Williams was originally due to have returned to earth with the Endeavour mission in June.
But with Atlantis flying to the station in June, Endeavour's flight has been postponed until August.
When she returns, Ms Williams will have stayed in space for eight months - breaking the US record for the longest continuous stay in space.
She told reporters via satellite that the delay had not affected her routine.
"It doesn't really matter. I have lots to do up here," she said.
The space station is currently half-built, and Nasa must fly at least 13 more missions to finish constructing it before it retires its fleet of shuttles in 2010.