Why are space shuttle launches delayed so frequently?
From a distance, a space shuttle looks pretty sturdy. It's enormous and solid, and it can withstand extreme temperatures when it enters the Earth's atmosphere. But in some ways, a space shuttle is delicate. NASA describes it as the "most complex machine ever built." A fully loaded shuttle weighs around 1,300,000 pounds (589,670 kilograms) and includes lots of complex circuitry and moving parts,… » Full Story on HowStuffWorks
