I is called a "Stall"
capsules.
It's called a Compartment.
Stable isotopes of elements are called stable because they do not radioactively decay.
cab
It depends of the compartment of course, some are more important than others, but a general compartment I believe might be termed a 'berth.'
The home of a horse is called a barn or a stable, and they sleep in a stall which is in the barn or stable.
it is called a stable
In some areas they are still called Stable boys or Lads even if they're women. In other areas they're called Stable hands or just a groom.
farm hand, stable boy, ranch hand
The Caboose
The compartment under a hot air balloon is called the gondola or basket. It is where passengers and the pilot stand during the flight.
The stable isotope produced by radioactive decay is called a daughter isotope.