Abstract: An aerial vehicle comprises an elongate envelope within which are at least one first compartment for holding a lighter than air gas and at least one second compartment for holding atmospheric air and said at least one second compartment having an inlet and an outlet and at least one pair of wings extending laterally from the envelope; said wings being planar units with a leading and trailing edge, the width of the wings from their leading edges to their trailing edges being substantially less than the length of the envelope with airfoil portions fitted between the leading and trailing edges of the wing: the top and bottom of the wings are mirror images of one another; in which forward motion of the vehicle is obtainable without trust through alternate diving and climbing motion.

Abstract: An aerial vehicle comprises an elongate envelope within which are at least one first compartment for holding a lighter than air gas and at least one second compartment for holding atmospheric air and said at least one second compartment having an inlet and an outlet and at least one pair of wings extending laterally from the envelope; said wings being planar units with a leading and trailing edge, the width of the wings from their leading edges to their trailing edges being substantially less than the length of the envelope with airfoil portions fitted between the leading and trailing edges of the wing: the top and bottom of the wings are mirror images of one another; in which forward motion of the vehicle is obtainable without trust through alternate diving and climbing motion.

Abstract: An aerial vehicle is described which comprises: a first compartment for holding a lighter than air gas; a second compartment for holding atmospheric air and having an inlet and an outlet; a solar panel for converting sunlight into electricity; a compressor for pumping atmospheric air through the inlet into the second compartment; control means for controlling the pitch and yaw of the vehicle; and a controller for controlling the buoyancy of the vehicle via the compressor and the outlet such that the vehicle is either lighter than the surrounding air and rising or heavier than the surrounding air and falling, and for controlling the control means such that the rising and falling motion includes a horizontal component. In another embodiment the solar panel is replaced by an engine and a fuel tank for storing fuel for the engine is also provided. The aerial vehicle can remain airborne for extended periods by using buoyancy propulsion.