Shame to see they have problems but a good call in halting missions to sort it out, they can't afford another Challenger stlye cock-up. The engines on the shuttle are an amazing piece of work, they produce over 1,000,000 pounds of thrust each and are about the same size as a medium size (CFM,V2500) jet engine. Fuel consumption is rather high though, the three engines manage to burn about 240,000 litres a minute. Liquid oxygen and hydrogen are quite light but it's still about 720 tons of fuel for the 8.5 minute burn.