Following on from this question: Can Cloud Nine be built?
Let us assume we have constructed a Cloud Nine tensegrity sphere with a 2 kilometer diameter out of a durable material for use in Earth's atmosphere. We have mastered making it go up and down. Now we need to stabilize and steer it.
How do we stabilize it? In other words how do we stop it from rotating and tumbling end over end like a beach ball? If we put weight at the bottom would it still wobble in high wind? To be useful it would have to be very stable.
The economic value of a Cloud Nine sphere is much higher if it is mobile rather than tethered to the ground (bonus question: is this even possible?). So how do we steer it in any direction we want to go in a practical way? In other words it needs to move under its own power without changing altitude. It doesn't have to be able to move fast, but it does have to be able to move against the various atmospheric forces, wind and weather that are pushing it around. Can this be done feasibly with current technology? For example, could this be done with solar power and propellers, maybe giant sails? Could we get some power out of electrostatic charge, maybe lightning strikes? What else is there using today's technology?
Finally, a sphere is only useful if it has lots of heavy stuff in it. People, buildings, and so forth. For example, imagine a hotel/tourist complex built at the center. Also, the weight of the sphere's shell could be quite substantial depending on the materials used and the desired thickness of the shell (we don't want the sphere destroyed by nature or attack). Please keep these two points in mind when answering. Thanks! And don't forget to include calculations of forces involved if possible. This question is tagged "hard science" and is basically an engineering/math question. Once we understand the physics and engineering of what's involved, we can work out whether it's economically viable using today's technology.
To be even more explicit: I'm just not sure how much power will be needed to push/pull the sphere around given its size and shape and whether you could even do it with current technology at a 2km or greater diameter. From Wikipedia: "Hindenburg was powered by four reversible 890 kW (1,190 hp) Daimler-Benz diesel engines which gave the airship a maximum speed of 135 km/h (84 mph)." The Hindenburg was 245m long, our sphere is 2000m wide (it may have to be much wider to lift a hotel, I don't know). If the sphere could go that fast by strapping lots of engines and propellers to it and the whole thing didn't use too much fuel then that's more than fast enough to be economical as a cruise ship/hotel. At Hindenburg speed it could cross the USA in 36 hours! So that's blazing fast. I was thinking, you know, could it float from city to city without taking a month and using an unrealistic amount of power? Consider a cruise ship in the Mediterranean for comparison. Except it flies.
I should also point out I have no idea how wide the sphere would have to be to lift a small "hotel city" / cruise ship equivalent. I've said 2km as a starting point. Maybe the diameter needs to be much greater.
EDIT #1: Let me clarify: if most of the weight is at the bottom, e.g. a hotel complex or something, considering the size of this 2km diameter (or wider) structure, could Earth weather provide a force strong enough so that there would be a wobble? Say a gust or hurricance or something pushed more on the top of the structure than the bottom. It would wobble until it settled right? That's why I tagged this hard science. I don't know how to do the calculations without much more research.
EDIT #2: When I say "steer" I mean can we move the sphere toward any point on the compass at a reasonable speed, regardless of what the weather is doing? So basically, can we move against the wind, and if so, with today's technology, how fast could we go, using propellors, maybe giant sails, and so forth? Again, not sure how to do the calculations, and that's how you should approach this question: by calculating.