Flight International online news 12:00 GMT: Although March is the new notional target date for the next Space Shuttle mission, STS 121, it could be two weeks before NASA planners decide if that is realistic or not, NASA said on 18 August.
The decision will be based on further external tank foam shedding analysis. NASA also stressed the need to stop thinking about the number of flights and when they would fly, to avoid schedule pressure.
At the Paris air show NASA's administrator Michael Griffin talked of 18 to 23 remaining shuttle flights before the fleet’s retirement in 2010 but his 18 August comment suggests no one can know how few there will be.
“After each flight we’ll see what cards nature has played us,” says Griffin, signalling a flight by flight approach to planning.
NASA also announced a change to the sequence of Space Shuttle flights for the next three missions.
They will now be STS 121/Discovery, STS 115/Atlantis and then Discovery for STS 116.
Originally Atlantis was lined up for mission STS 121 but Atlantis is needed for STS 115. This is because, as it is a lighter orbiter than Discovery, it can lift the International Space Station’s second port truss, a task scheduled for mission STS 115.
If NASA had not swapped the missions Atlantis would have flown missions 121 and 115 back to back.
Space Shuttle Endeavour is not available because it is held up in its maintenance period due to Discovery’s and Atlantis’ return to flight activities. Endeavour is also as heavy as Discovery and cannot lift the truss.
ROB COPPINGER / LONDON
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Source: Flight International