The launch of the US space shuttle Endeavour has been delayed for a third time, until at least the 16th of this month, as engineers are trying to fix an electrical problem. The 14-day mission STS-134 is to be commanded by US astronaut Mark Kelly. The launch is supposed to be the US space program's second last shuttle flight to the International Space Station, followed by Atlantis next month. After that the 30-year-old shuttle program will end.