STS-122 Space Shuttle mission (Atlantis) to the International Space Station carrying the ESA Columbus module has been cancelled and rescheduled for a January 2 launch. The postponement will give engineers time to evaluate false readings from the engine cutoff sensor system that measures liquid hydrogen in the external tank.
Of the four engine cutoff sensors, ECO sensor number three gave false readings during Sunday's launch attempt. The sensor system is one of several that protect the shuttle's main engines by triggering their shut down if fuel runs unexpectedly low.
Atlantis' scheduled launch on Thursday was delayed after two of the four engine cutoff, or ECO, sensors in the shuttle's external fuel tank gave false readings. A third sensor failed after the tank was drained of fuel.