A couple of NASA engineers have written an interesting technical paper on a possible way of integrating components into a deep sapce mission capable spacecraft seen below.
NASA is working on developing the crew module - Orion, and the Space Launch System (SLS) rocket booster right now. But to get to the asteroids, Moon, Mars and other solar system places, you need a capability to survive and thrive in deep space that we do not have.
Orion by itself cannot do long term missions, it needs other components to go the distance in terms of months in deep space. The paper discusses all of these aspects and has some pretty good ideas.
Read the paper here: http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20120008183_2012008354.pdf
Sky Guy in VA