Is it worth it?
The question was raised in a story of yours the other day (re. prof. Steven Weinberg). That is, has the space station actually facilitated any science worth the expense.
£2.3bn a year (and that's just NASA's contribution) sounds like an enormous amount of money to spend on something that doesn't actually give much of a return (certainly not $2.3bns-worth). If you multiply this by the number of years the ISS has been running then just think of what else you could do with that kind of budget!
As an aside, I also question why the US (and others) are so interested in going to the moon again. It's a long way away, it's incredibly expensive to send people there and get them back safely, it's not particularly interesting (what more can be learned that has not already been learned from previous trips there), it may be full of mineral wealth but realistically how useful and practical is it to make use of this. Same goes for any less-friendly applications that no-doubt some people have in mind. Basically, it doesn't make any sense at all! Which makes me think there's something I've missed.
The other bazaar thing is that by NASA's own estimates, it will take years and years to plan and build the kit for such a mission. How come, when they managed to do it relatively easily (well, ok, not easily, but you know what I mean) almost 40 years go?