NSS Roadmap to Space Settlement Milestone 27: Utilization of Asteroids

After robotic identification of suitable asteroids, robotic and human crews following to establish mining bases and habitats for transient occupation, and eventually building permanent human settlements nearby.

construction of space settlement from asteroidThe eventual construction of rotating space settlements from minable asteroids. Image: Bryan Versteeg, spacehabs.com


Asteroids have huge mineral wealth if it can be accessed, including iron, nickel, platinum group metals, other non-volatile materials, and also volatiles like water ice. There are different classes of asteroids with varying amounts of these materials that would be useful both on Earth and in space. That potential value may be the primary driver for asteroid exploration and mining.

As is expected to be the case on the Moon and Mars, deposits of volatiles can be converted to rocket fuel and oxygen, thus enabling further space operations. The metals in asteroids can be refined and turned into construction materials for building large structures in space. Smelting and fabrication of parts from asteroids will require either the development of new techniques for doing this in microgravity, or the use of rotating structures to provide gravity so that existing methods can be used.

The practicality of returning asteroidal materials to Earth or other locations would depend on (1) transport costs, (2) value of the materials as delivered and (3) the extent to which those materials can be separated and purified to reduce the total mass before transport. Asteroid resources may greatly improve life on Earth. Economic return of materials to Earth is expected to involve the use of fuel obtained from asteroid mining.

In time, asteroids will see more permanent rotating habitats created nearby, probably made of asteroid derived materials, and using unprocessed asteroid materials for radiation shielding. These habitats will house either visiting crews or, if there is sufficient mining to be done, permanent occupants. With an appropriate asteroid, these mining stations may go through the same processes of growth as settlements on the Moon and Mars, and evolve into permanent settlements where people will raise their children and live out their lives, as on any far frontier. Proposals have also been made for hollowing out an asteroid and building a rotating space settlement inside it.

The eventual construction and location of rotating space settlements in the orbits of minable asteroids would reduce the materials transport costs of asteroid resources and derived materials for the construction of such settlements. This would create a synergism which should accelerate the asteroid mining industry.


  • Economic barriers (transport costs) to moving asteroidal products to space settlement construction sites and to the Earth and vicinity.
  • Lack of knowledge of methods for mining, refining, and fabricating asteroidal products such as building materials in microgravity.
  • Lack of detailed planning and design for use of the fabricated building materials to build large space structures.


This milestone will be considered achieved when asteroid mines and smelters are regularly sending ores or refined products to the Earth, Moon or Mars or are contributing substantial structural mass to rotating space settlements in any location.