The U.S. and Endeavour orbiter flags wave in the breeze in front of the space shuttle Endeavour Friday afternoon June 12, 2009 at the Kennedy Space Center in Cape Canaveral, Florida.[Xinhua/AFP Photo]

The U.S. National Aeronautics and Space Agency (NASA) on Saturday cancelled the planned launch of space shuttle Endeavour because of a hydrogen leak, a spokesman said.

The launch has been delayed by at least four days, reports said.

The leak was near the ground umbilical carrier plate, which is attached to the external tank, NASA said in a statement.

The spacecraft's external fuel was immediately pumped out after the fault was discovered.

The technical problem, detected when the spacecraft was being fueled, was similar to the one that occurred during the first launch attempt of the space shuttle Discovery in March, reports said.

Endeavour had been scheduled to lift off from the Kennedy Space Center in Florida at 7:17 a.m. EDT (1117 GMT) for a 16-day mission to deliver the last part of a Japanese laboratory to the International Space Station.

Reports said the launch is likely to be postponed to next Wednesday, but that will coincide with the planned launch of an unmanned rocket carrying a spacecraft for a moon exploration mission.

Decisions on the time arrangement of the two launches have yet to be made, Mike Moses, shuttle manager of Kennedy Space Center, said.

The Endeavour's 16-day mission will feature five spacewalks and complete construction of the Japan Aerospace Exploration Agency's Kibo laboratory. Astronauts will attach a platform to the outside of the Japanese module that will allow experiments to be exposed to space.

The STS-127 crew members are mission commander Mark Polansky, pilot Doug Hurley and mission specialists Dave Wolf, Christopher Cassidy, Tom Marshburn, Tim Kopra and Canadian Space Agency astronaut Julie Payette. Kopra will join the space station crew and replace Japanese astronaut Koichi Wakata. Wakata will return to Earth on Endeavour to conclude a three-month stay at the station.

(Xinhua News Agency June 14, 2009)