I remember seeing pictures of the first time astronomers were going to see pictures from the Hubble telescope. They were expecting beautiful images but got blurry pictures instead. They were in shock. Their faces just showed dumbfounded expressions. It took three years, I think, before they could fix it. And that was when you could fix it because you could use the space shuttle which we no longer have. There is a video that shows the process of building, launching and landing the Mars rovers. You see the stress they are under during the different stages. <a href="http://m.youtube.com/watch?v=zu059sefT94" rel="nofollow"></a>