- Such an airship exists and there is a person aboard, with an oxygen mask.
- The person is thermally insulated to keep the heat inside.
- The jet streams are at an altitude around 9–12 km (30,000–39,000 ft) .
- Can a kite like the one in the picture be built to hold a person?
- Does the human body require pressurization as well as oxygen and insulation? ANSWER
- Is it possible using the jet stream systems to go around the world?
- Can the kite fly at speeds around 80-150 km/h related to the ground?
- Can it sustain a free fall from its cruising altitude around 9–12 km so that the pilot can land maybe using a parachute?
Launch Considering the altitude is up around 9–12 km then air would be thinner the size of it will have to be much larger to compensate. Use a cable and boat to lift the UltraKite into the Jet Stream. At preferred altitude cable then can be mechanically released from connected drag section of the kite. A drone or balloons could replace boat and then dropped. Maybe the person could ride in the drag section.
Long Term Altitude with Ultralights Gliders on Record.
The current 15460-meter glider height record was made with pressurized suits. But it is only 500 meters higher than Harris' previous record from 1986, which was done with just an oxygen mask. – Martin Argerami in a comment in Turbulent Jet Streams on Ultralights
As commented by @Jan Hudec: This is supposed to be a kite, but instead of being fixed to the ground as normal kite, it would have just a cabin with a braking parachute flying below the jet stream and the kite flying in the jet stream, so the whole thing would move at some speed between the slow speed of the wind at low altitude and the high speed of the jet stream.