There were long faces in the control room as NASA’s comeback mission after the Columbia disaster was put on hold. A technical glitch kept shuttle Discovery on the ground just hours before it was scheduled to lift off. If the problem cannot be solved by the end of the month the launch will have to be delayed until September. The spacecraft was supposed to take off on Wednesday evening from Cape Canaveral in Florida for a 12-day mission including three space walks and a stop-off at the International Space Station.The crew of seven were already inside the shuttle when take-off was aborted. NASA administrator Michael Griffin said: “We had an intermittent engine cut off sensor in the liquid hydrogen tank. It’s one of four. We require all four of them to work correctly before we launch.” NASA has until July the 31st. to launch Discovery. After that it will have to wait until September the 9th. when the International Space Station again comes into the right position for a rendezvous.