You gotta have control power sufficient to deal with the instability, plus
some for maneuvering. The M2-F2 ($6M Man) didn't have it. Fly-by-wire would
have done nothing for it; it was just a bad design. The M2-F3 (big center
vertical fin) flew much better due to adequate open-loop roll damping and
directional stability.

That crew return vehicle concept (X-38??) that was/is in the works was
basicallly a lifting body design. But that one used a steerable parachute
for final approach and landing. Not a bad trade, actually, when you
consider the weight cost of something like a deployable control/lift device.
This way, the shape can be optimized for controlled re-entry and initial
descent.

Pete

"Doc Font" wrote in message
...
So is it feasable at this time considering the advancements in computer
controls? Like the F-117 or F-16 are unstable without their computer
systems but they work because the computer constantly adjusts the
flight. Could they build an easy to fly lifting body now?