WHO
  WHAT
  WHERE
  HOW
  WHY
  WHEN
  COST

What?

A space settlement is a home in orbit.

• Rather than live on the outside of a planet, settlers will live on the inside of gigantic spacecraft. Typical space settlement designs are roughly one half to a few kilometers across. A few designs are much larger.
• Settlements must be air tight to hold a breathable atmosphere, and must rotate to provide psuedo-gravity. Thus, people stand on the inside of the hull.
• Enormous amounts of matter, probably lunar soil at first, must cover the settlements to protect inhabitants from radiation. On Earth our atmosphere does this job, but space settlements need about five tons of matter covering every square meter of a colony's hull to protect space settlers from cosmic rays and solar flares.
• Each settlement must be an independent biosphere. All oxygen, water, wastes, and other materials must be recycled endlessly.