WASHINGTON, Nov. 5 (Xinhua) -- The U.S. National Aeronautics and Space Administration (NASA) decided Friday to delay the launch of space shuttle Discovery until the end of the month.
Discovery's Friday launch try was scrubbed because of a hydrogen gas leak at the Ground Umbilical Carrier Plate, or GUCP, an attachment point between the external tank and a 17-inch pipe that carries gaseous hydrogen safely away from Discovery to the flare stack, where it is burned off.
Shuttle launch director Mike Leinbach characterized the leak as "significant," similar to what was seen on last year's two shuttle missions.
According to NASA, Discovery's next possible launch opportunity comes Nov. 30 at 4:05 a.m. EST (0905 GMT). The launch window for Discovery is Tuesday, Nov. 30 through Saturday, Dec. 5.
Leinbach said the delay will enable engineers to consider the problem and inspect the GUCP more closely.
Mission managers also will look closely at a crack in the external tank foam that developed as supercold liquid hydrogen and liquid oxygen were being drained from the tank.
The 15-story tall, orange external tank shrinks and expands as its temperature changes from the effects of the propellants. That change can cause the foam insulation on the outside of it to crack.
Mike Moses, chair of the Mission Management Team, said the crack did not develop until after the launch attempt was called off. However, he said the team will analyze the crack carefully.
Discovery was supposed to lift off Monday, but gas leaks, electrical problem with a backup controller, bad weather and hydrogen leak has forced five delays.
Discovery's 11-day mission is its final scheduled flight, and the fourth and final shuttle mission planned for 2010.
The six astronauts for the mission will deliver the Permanent Multipurpose Module (PMM) to the station. Two space walks, for maintenance work and component installation, are scheduled.
The PMM was converted from the multipurpose logistics module Leonardo and will provide additional storage for the station crew. Experiments in such fields as fluid physics, materials science, biology and biotechnology may be conducted inside the module.
The PMM also carries Robonaut 2, the first human-like robot in space, which will become a permanent resident of the station. In addition, the flight will deliver critical spare parts and an external platform that holds large equipment.