US Patent 10196123 Systems and methods including elevation control

A system for elevation control. The system comprises a substantially gastight envelope containing lifting gas wherein the envelope further comprises a plurality of envelope segments in fluid communication with one another. At least one tension cable connects at least two of the envelope segments. A control device including a motor adjusts the length of the tension cable to change the pressure within the envelope to thereby facilitate ascent and descent of the system. The control device causes the system to operate in ascent, descent, or vertically stationary modes.