Space shuttle launch cancelled due to technical fault

Read more: Irish American Endeavour Commander prepares for final shuttle launch

NASA officials have announced that the final launch of the Endeavour shuttle will be delayed until at least Sunday due to technical problems. Launch director, Mike Leinbach, cancelled the launch just as Mark Kelly and his crew was travelling by van out to their shuttle.

It was planned that Kelly's wife Congresswoman Gabrielle Giffords, who is recovering from a gunshot to the brain, along with his family and President Barack Obama were to be on hand for the launch.

Although the weather had been a concern, due to the blustery, stormy weather hanging over Cape Canaveral it was a technical problem that grounded the launch. The issue was with a thermostat on one of the fuel lines tied to Auxiliary Power Unit 1 heaters. This provides hydraulic power to steer the craft during ascent and descent.

Leinbach said "We will fly no orbiter before she's ready…Today she just wasn't ready to go…We need to keep those lines warm to keep things from freezing in orbit. We tried to let the line cool down by normal means to see if the heater would kick in by normal means. That did not work."

He said the soonest the shuttle could launch would be Monday afternoon but even that is tenuous. Leinbach said the three-day turn-around would be "an absolute minimum".

Thousands of disappointed fans have been crowding the coastal communities preparing for lift off. Police in the area were forecasting major traffic delays and schools in the area were to dismiss class early to watch the launch.

President Obama still plans to visit Cape Canaveral on Friday. He will tour an orbiter processing facility at NASA. This would have been the first time in NASA history that a serving president witnessed a launch.