Abstract: A structural system for lifting cells, constructed of modular, lightweight framing supporting thin, lightweight, single-ply or laminated, air-impermeable membranes, that maintain near constant-volume under low pressure for aerostatic lift in lighter-than-air aircraft; a system for controlling that aerostatic lift in a single or a plurality of such lifting cells, using electrically-powered vacuum pumps and valves; and a system for recovering electrical energy expended during ascent by using the inflow of air into the lifting cells during descent to generate electricity.