As I understand it, the ISS is very valuable. It is not that spectacular to the public as a manned planetary or moon mission is, but it has its points. I know that a lot of good scientific work was done on MIR, and the ISS is for sure better then mir ever was. <br />Of course the money spent on ISS, shuttle, klipper and the like is a huge ammount, but it comes back. It does not pay back like a bank investment, but it pays back in other values. If we (as mankind) can achieve just one single breakthrough (e.g. in the devellopment of medication or other things related to chrystal grow in zergo-G) with the work on ISS it was worth it. All experiments done on the ISS or the shuttle (or before on MIR) have been just the tip of a spearhead of a spear of thousends of scientists in labs arround the world. Its a shame that our industrialized countries do not spend much more in that field. Think about Russia and how much they do in space science with the little budget they have as a country. Russia has an economic power like Spain I think. Its a huge country, but it is a much smaller economy then e.g. Germany. But they do what they can, and it will sooner or later pay off. With more and better educated people, with a better overall state of air and space industry. <br />I remember very well how deeply dissapointed the science comunity in my homecountry was, when the austroMIR project was cut in half. They planned two MIR missions, but scrubbed the austroMIR2 due to budget restrictions. It really was a shame. And all the scientists that worked on the program said that we lost a real bargain with that.<br />I think the ISS is well worth the effort, and it needs the unique capabilities the shuttle has. And when its completed, the klipper will be a superb contribution to it.