Photos: The blended-wing design of Boeing's X-48B

A clear blue sky greeted the X-48B on its maiden voyage on July 20, when it flew for 31 minutes and reached a modest altitude of 7,500 feet. The flat fuselage blending into the wing, Boeing says, means more lift and less drag than with a more traditional tubular fuselage--which in turn will translate to reduced fuel consumption. The use of lighter-than-metal composite materials should also help cut back fuel use.

Don't look for a full-size version right away, however. Boeing has a long horizon for the R&D effort, envisioning the larger successors to the prototype serving as a multipurpose military platform--from cargo transport to bomber--in 15 to 20 years.