Pakistan had won the 7th edition in Rawalpindi in 2006.

The bottleneck at U.S. launch pads in Florida has already led to costly delays in launching some of NASA’s scientific spacecraft and could force the agency to spend millions of dollars to avoid postponing long-awaited missions to Mars and Jupiter, say NASA officials.

Delays are costly mostly because they require NASA to keep paying the large team of contract workers who take care of a spacecraft and get it running after it’s in space.

Endeavour was supposed to blast off Saturday, but launch pad gear sprang a fuel leak. If repairs to the pad go well, the shuttle will try to launch Wednesday. But that’s also the launch date for NASA’s Lunar Reconnaissance Orbiter, an unmanned satellite to the moon.

NASA’s Leroy Cain said the shuttle has to launch before next Sunday. Otherwise, the angle of the sun means the craft would get too hot in space. He said the shuttle would not be able to launch again until July 11.

Cain said the moon mission also has to get into space by the same deadline, or it could not launch again until June 30. That’s because of the alignment between the Earth and the moon.

Rocket problems in 2008 forced Florida liftoffs to be put on hold for more than four months. That delayed the blast-off date of the moon mission by eight months, at a cost of more than $40 million, says manager Craig Tooley. He says he would try to offset the small cost of two days’ delay by replanning work to be done after launch.

Another mission, the Solar Dynamics Observatory, has been held back at least a year because NASA couldn’t find a hole for it in the launch schedule. Cost of that delay so far: $50 million, says NASA spokeswoman Rani Gran.

NASA is weighing whether to pay $20 million to expand the workforce of the private company that prepares rockets at the launch pad. That would help ensure an on-time departure for science missions to Mars and Jupiter.

NASA officials should do more to ensure delays don’t cause cost overruns, says Cristina Chaplain of the Government Accountability Office, a congressional investigative agency. “If delays are common,” she says, “let’s set aside the money.”