I wonder how much you really save. It would pay for itself better the more they are used and I hope the satellites are designed for up to 25-30 years. It should not be too hard, look at pioneer ten! In order to justify such a system NASA would be compelled to use it. Similar to how some people claim the shuttle was a justification for ISS.

its a good to build up such an infrastructure. I do not consider my self one to go off on wildeyed speclative dreams that have little hope of happening. . . but none the less this has got me thinking "manned mars mission". It would be just the thing.

-Justin Kelly