
Could a floating city in the clouds reduce the cost of launching spacecraft? - jlebrech
each city platform would work like a drone and it would be launched to just above its operating altitude and the drone would deploy from it&#x27;s rocket shell, then rendezvous with other platforms, it could then keep itself in the sky using solar arrays and propellers.<p>the second stage would be to add solar array only modules to the top and propeler only at the bottom with a living area sandwiched in between.<p>it could then be reached by traditional aircraft as a stop over for astronauts, and also create fuel for rocket launches.<p>rockets could then take just enough fuel to land on it and then be refueled from there, before launching again.
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informatimago
Unless you've got a big load of nonobtainium, on Earth, it would be very
costly or impractical or dangerous to keep a floating city in the clouds.

The easiest way to do it would be to have an enormous volume of lighter than
air gas, such as Helium (expensive and rarer by the minute), or Hydrogen
(dangerous and inconvenient (and the gazeous form needed for a floating city
isn't even the same as the liquid form needed for rockets!)).

Of course, you've got the alternative of using solar panels (very heavy), and
rotors, a lot of rotors (very heavy), and batteries, a lot of batteries (even
more heavier) to keep a city in the air even at night.

Alternatively, you could have a nuclear power plant on the ground microwaving
the energy to the city, but it should not go over the horizon.

In any case, a lot of cost, and you still have to pay to bring up to the city
all the material and consumible you need to push a rocket from there. The only
gain you have, is that you can use Oxygen from the atmosphere to lift the
material there. But stopping at a cloud city is a little silly, since you lose
any cinetic energy you had when you reached that altitude!

On the other hand, there are other planets where a cloud city would make much
sense: Venus or Jupiter for example. There, you have an altitude where the
pressure and temperature are similar to what we have on Earth surface, and
where we could place a clould city exploiting the resources around.

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brudgers
One place to begin analysis is the Tsiolkovsky Rocket Equation:

[https://www.nasa.gov/mission_pages/station/expeditions/exped...](https://www.nasa.gov/mission_pages/station/expeditions/expedition30/tryanny.html)

[https://en.wikipedia.org/wiki/Tsiolkovsky_rocket_equation](https://en.wikipedia.org/wiki/Tsiolkovsky_rocket_equation)

