Choosing the location

One other factor that can strongly influence the size and the costs of the project is the location of the settlement. Although both the Lagrangian points and the geosynchronous equatorial orbit are stable enough to allow the building of settlements, the distance factor alone is enough to make the L o w E ar th O r b it (L E O ) a better candidate.

Placing the settlement in the LEO has several advantages, as well as quite a few disadvantages. The good news is that, as we have already discussed, the Equatorial Low Earth Orbit virtually eliminates the need for radiation protection, reducing weight by 90%, cutting production costs by a large margin and making the settlement overall easier to build. Furthermore, the short transit time between the colony and Earth means that materials and even people can be quickly delivered, making the space settlement safer in case of emergency. On the opposite side, placing the settlement too low in orbit can result in severe orbital decay which might pose serious dangers to the population on board. Additionally, being so close to Earth can diminish the spaceoutpost role of the colony by being too far away from any other astronomical objects.

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By setting the two forces above equal, we get

Which is approximately equal to 7 .8 k m / s for a circular orbit of 400 km above Earth.