Long mission tethered aerostat and method of accomplishing

A lift gas ballast device for a tetherable aerostat, comprising;

• (a) a tetherable aerostat;
• (b) a hollow flexible feed-tube embedded inside a tether having a first end connectable to said tetherable aerostat said hollow flexible feed-tube having a second end;
• (c) a self sealing gas double slip ring device secured to said second end of said hollow flexible feed-tube;
• (d) an earth based deployable lift gas ballast tank and connectable to said tetherable aerostat through said double slip ring and said hollow feed-tube;
• and
• (e) a ground based lift gas facility capable of hydrostatic connection with said tetherable aerostat to provide for the maintenance of the lift gas on the ground while the tetherable aerostat is deployed at altitude.

A tetherable lighter-than-air aircraft apparatus for replenishing lift gas comprising;

• (a) a tetherable aerostat, blimp, dirigible, balloon or airship;
• (b) a tether having a hollow flexible feed-tube with a first end connectable to said tetherable aerostat, blimp, dirigible, balloon or airship, said hollow flexible feed-tube having a second end;
• (c) a double slip ring device having a first rotatable slip ring at one end and a second rotatable slip ring at the other end interconnected by a coiled flexible tube, said second rotatable slip ring attached to said hollow flexible feed-tube and said first rotatable slip ring connectable to a lift gas ballast tank;
• and
• (d) a lift gas ballast tank capable of deployment on the surface of the earth in hydrostatic connection with said tetherable aerostat, blimp, dirigible, balloon or airship through said double slip ring and said hollow feed-tube.

A tetherable aerostat with a lift gas replenishment device comprising;

• (a) a tetherable aerostat;
• (b) a tether having a coaxial electrical cable and at least one coaxial optical fiber connectable to said tetherable aerostat;
• (c) a hollow flexible feed-tube disposed coaxial with said tether having a first end connectable to said tetherable aerostat, said hollow flexible feed-tube having a second end;
• (d) a rotatable and gas sealable double slip ring device having a first rotatable gas sealable slip ring at one end secured to said hollow flexible feed-tube and a second rotatable gas sealable slip ring at the other end, said second rotatable gas sealable slip ring connected to a lift gas ballast tank;
• and
• (e) a lift gas ballast tank disposable on the surface of the earth and connected to said tetherable aerostat through said double slip ring and said hollow feed-tube.