This is the concept design for the Nautilus-X, one of NASA's ideas for crewed deep space explorer. This craft would be launched from the International Space Station (or some other orbital platform) and could take six astronauts on long missions ranging anywhere from one to twenty-four months.
This is the work of two engineers, Mark Holderman and Edward Henderson, at NASA's Johnson Spaceflight Center, designed the craft to take us back to the Moon and then onto Mars, but building it wouldn't be cheap - the estimated price is a hefty $3.7 billion spread over more than five years of research and development, which is likely too much in the current economic climate.For a more detailed overview on the Nautilus X, check out this report, and for detailed technical specifications on the Nautilus-X check out SpaceRef.
Thanks to Klebert L. Hall for the tip!