Sea Orbiter

Looks like they're actually going to take a shot at building this thing:



All the "sustainability" eco-snarking aside, it's a pretty damned cool idea. But if they can get it built for $43M, on that scale and fully functional, I'll eat my hat. You'd be hard-pressed to put up a building that size on solid land for that amount of money. My best-case guess is closer to $100M -- if the project is well-run and doesn't hit any major engineering snags, which it almost certainly will. Budget overruns and scheduling issues could easily bump it up towards a quarter of a billion.

Still, I'd love to see it become a reality, because building it will push outwards on the boundaries of engineering and materials science. That is exactly what we need to start doing if we're going to build practical and cheap interplanetary vessels.