Invertible aircraft

1. A rotorcraft, comprising:

a fuselage defining a vertical dimension with respect to the fuselage, the fuselage being characterized by a right-side-up orientation and an upside-down orientation with respect to gravity;

one or more rotors generally oriented for vertical thrust with respect to the fuselage;

one or more motors connected to the one or more rotors; and

a control system controlling the speed and direction with which the one or more motors drives the one or more rotors in rotor rotation;

wherein the one or more motors drive the one or more rotors in either of two directions of rotor rotation; and

wherein the control system controls the one or more motors to reverse the direction of rotor rotation with respect to the motors when the fuselage has switched between the right-side-up orientation and the upside-down orientation.

2. The rotorcraft of claim 1 , wherein the control system controls the reversal of rotor rotation based on the orientation of the fuselage with respect to gravity.

3. The rotorcraft of claim 1 , and further comprising an orientation sensor sensing the orientation of the fuselage with respect to gravity, wherein the control system controls the direction of rotor rotation based on a signal from the orientation sensor.

4. The rotorcraft of claim 1 , wherein the control system is programmed to coordinate the operation of the rotors to accomplish controlled flight, and wherein the control system adapts the control system's coordination of the rotors based on the primary direction of thrust with respect to the fuselage.

5. The rotorcraft of claim 1 , and further comprising a directional sensor sensing the external environment, wherein the control system adjusts a sensor signal from the directional sensor based on the primary direction of thrust with respect to the fuselage.

6. The rotorcraft of claim 5 , and further comprising a ground station depicting a video signal from the directional sensor, wherein the ground station displays the video signal in an orientation based on the orientation of the fuselage with respect to gravity.

7. The rotorcraft of claim 1 , wherein each rotor has a plurality of blades, and wherein each blade produces equal thrust in either direction of rotation for a given rotational speed.

8. The rotorcraft of claim 7 , wherein each blade extends out from a rotor hub along a longitudinal blade axis, and wherein each blade has 2-fold rotational symmetry around that blade's longitudinal axis.

9. The rotorcraft of claim 7 , wherein each rotor has a plurality of blades, and wherein at least one blade includes rigid sections at a leading edge and a trailing edge, and a flexible section intermediate the rigid sections, wherein the flexible section is adequately flexible to change in aerodynamic shape when the motors reverse the direction of rotor rotation.

10. The rotorcraft of claim 1 , and further comprising a surface-connection device affixing the rotorcraft to a surface such that it hangs from the surface without rotor activity to maintain its the rotorcraft's position.

11. An aerial vehicle, comprising:

a body characterized by a right-side-up orientation and an upside-down orientation with respect to gravity;

one or more thrusters providing thrust in a primary direction of thrust with respect to the body;

a control system controlling the primary direction of thrust with respect to the body in which the one or more thrusters provides thrust; and

an orientation sensor sensing the orientation of the body with respect to gravity;

wherein the control system reverses the direction of rotor rotation based on a signal from the orientation sensor that indicates the orientation of the body with respect to gravity has switched between the right-side-up orientation and the upside-down orientation.