Therefore its technique difficulty is big

The space shuttle is repeated to use, therefore its technique difficulty is big, the system design complications, zero parts more easy loss, from take-off, ascension, orbit circulate, again go into atmosphere until return to land process in, need to experience every variety extremely harsh environment, various weakness exposes to come out gradually in the use and shoot frequency every year from the plan also 24 times descend to 5 times in.
The United States develops and throw in to use five space shuttles, each development expenses is USD 2,000,000,000, altogether shoot 100 many, fly an expenses to be up to USD 500,000,000 each time, still need to carry on after returning in great quantities time-consuming hard to tackle of the check fix, this lets the United States the public finance of the aerospace bureau unbearable heavy burden.The United States once optimistically estimated in those early years, the space shuttle didn,t more than USD 6,000,000 shoot expenses each time.