NASA has had to delay the launch of one of its shuttles after a gas leak was discovered.

The Endeavour space shuttle was scheduled to launch on Saturday morning and travel to the International Space Station, but NASA had to delay the launch, after discovering a leak associated with the gaseous hydrogen venting system outside the shuttle’s external fuel tank.

Teams on Kennedy’s Launch Pad 39A are now in the process of changing out internal seals in the Ground Umbilical Carrier Plate, or GUCP, which is attached to the external tank. The vent line runs from the GUCP, away from the launch pad to a $quot;flare stack$quot; where excess hydrogen is safely burned off.

The leak is similar to what happened during the first launch attempt of space shuttle Discovery's STS-119 mission in March.

NASA managers will make a final decision by this afternoon about whether to launch the shuttle on Wednesday, June 17 or wait until later in the week.