It's maintaining a workable life-support system and a healthy crew for ten years in space which are the problems. The technology does not exist for this.
And that, of course, is the crux of the matter. We don't really know whether what we have available works or not without the testing we're doing now. I suspect it does, _if_ it can be made reliable enough. (Which, clearly, is a big "if.")
A word about the foam and tiles - it's the relative speeds that count. The 1200-2000 mph speed of the foam isn't that much different from the speed of the shuttle, so that even if it's hardened foam (not soft and squishy at all, the way we tend to picture "foam") the difference in speed may not be enough to make it a damaging projectile. A little slower to be sure, but enough to cause that kind of impact and damage? That's what the experts are trying to determine, as best thay can.
