StrategyPage has a great series up on the X-45C and X-47B unmanned arial vehicles:
The U.S. Navy has invested over a billion dollars, so far, in developing combat UAVs (Unmanned Aerial Vehicles) that can operate from aircraft carriers, and replace some of the manned aircraft on carriers. Final design and construction of the full size X45C combat UAV has begun, and these will make their first flights in 2007, or earlier. The smaller X45A has now spent two years doing flight tests and serving as a test bed for the flight control software. The X45A is intended just for development. The navy is sharing, with the air force, the development effort for flight control software development, and other new technology. However, the navy is developing carrier landing software alone. This will be one of the most technically difficult aspects of the project.
The X-47 is plan ‘B’ in case the X-45 doesn’t work out.
The Navy and Air Force are supposed to work out a compromise solution and settle on one design. Dont be surprised if they don’t and both the X-45 and the X-47 (or even another design) goes into production.
See the Strategy Page post for more info and bigger (and more) pics. (BTW: The pic in this post of an X-47 UAV landing on a carrier is an “artists concept”, not an actual photo.)