Space Settlement Basics

DISCLAIMER: This web site is not a policy statement. It is intended to be an accessible introduction to the ideas developed in the Stanford/NASA Ames space settlement studies of the 1970s and follow on's to support the annual NASA Ames Student Space Settlement Contest.

Who?

You. Or at least people a lot like you. Space settlements will be a place for ordinary people.

Presently, with few exceptions, only highly trained and carefully selected astronauts go to space. Space settlement needs inexpensive, safe launch systems to deliver thousands, perhaps millions, of people to orbit. If this seems unrealistic, note that a hundred and fifty years ago nobody had ever flown in an airplane, but today nearly 500 million people fly each year.

Some special groups might find space settlement particularly attractive: The handicapped could keep a settlement at zero-g to make wheelchairs and walkers unnecessary. Penal colonies might be created in orbit as they should be fairly escape proof. People who wish to experiment with very different social and political forms could get away from restrictive norms.

Although some settlements may follow this model, it's reasonable to expect that the vast majority of space settlers will be ordinary people. Indeed, eventually most people in space settlements may be born there, and some day they may vastly exceed Earth's population.

What?

A space settlement is a home in orbit.

Pictures of space settlements.
Pictures of Kalpana One.
Lewis One space settlement design.

Where?

In orbit, not on a planet or moon. Why should we live in orbit rather than on a planet or moon? Because orbit is far superior to the Moon and Mars for early and long term settlement, and other planets and moons are too hot, too far away, and/or have no solid surface.

For an alternate view, see Robert Zubrin's powerful case for Mars exploration and settlement. Mars' biggest advantage is that all the materials necessary for life may be found on Mars, although it will take a long time before Mars settlers can build everything they need. While materials for free-space settlements must be imported from Earth, the Moon or Near Earth Objects (NEO's -- asteroids and comets), there are many advantages to free-space settlements including:

Mars and the Moon have one big advantage over most orbits: there's plenty of materials. However, this advantage is eliminated by simply building orbital settlements next to asteroids. Fortunately, there are tens of thousands of suitable asteroids in Near Earth orbits alone, and far more in the asteroid belt.

Early settlements can be expected to orbit the Earth where all the products of Earth's industrial might are available if transportation is sufficient for settlement in the first place. Later settlements can spread out across the solar system one step at a time eventually taking advantage of the water in Jupiter's moons or other icy bodies in the far reaches of the solar system. Eventually the solar system will become too crowded for some, and groups of settlements will head for nearby stars.

Interstellar travel seems impractical due to long travel times. But what if you lived in space settlements for fifty generations? Do you really care if your settlement is near our Sun or in transit to Alpha Proxima? So what if the trip takes a few generations? If energy and make up materials for the trip can be stored, a stable population can migrate to nearby stars. At the new star, local materials and energy can be used to build new settlements and resume population growth.

Why?

To survive and thrive.

Thrive

Why build space settlements? Why do weeds grow through cracks in sidewalks? Why did life crawl out of the oceans and colonize land? Because living things want to grow and expand, to thrive, not simply exist. We have the ability to live in space (see the bibliography), therefore we will -- but not this fiscal year

A key advantage of space settlements is the ability to build new land, rather than take it from someone else. This allows a thriving, expansive civilization without war or destruction of Earth's biosphere. The asteroids alone provide enough material to make new orbital land hundreds of times greater than the surface of the Earth, divided into millions of settlements. This land can easily support trillions of people.

Survive

Someday the Earth will become uninhabitable. Before then humanity must move off the planet or become extinct. One potential near term disaster is collision with a large comet or asteroid. We don't know where the next killer comet is and although we know where most of the potential killer asteroids are, some have not yet been found. Such a collision could kill billions of people. Large collisions have occurred in the past, destroying many species. Without intervention, future collisions are inevitable, although we don't know when. Note that in July 1994, the cometShoemaker-Levy 9 (1993e) hit Jupiter

If there were a major collision today, not only would billions of people die, but recovery would be difficult since everyone would be affected. If an extensive branch of our civilization is in space before the next collision, the unaffected space settlements can provide aid, much as we offer help when disaster strikes another part of the world.

Building space settlements will require a great deal of material. If NEOs are used, then any asteroids heading for Earth can simply be torn apart to supply materials for building settlements and saving Earth at the same time.

Power and Wealth

Those that settle space will control vast lands, enormous amounts of electrical power, and nearly unlimited materials. The societies that develop these resources will create wealth beyond our wildest imagination and wield power -- hopefully for good rather than for ill.

In the past, societies which have grown by colonization have gained wealth and power at the expense of those who were subjugated. Unlike previous settlement programs, space settlement will build new land, not steal it from the locals as there simply are no locals. Thus, the power and wealth born of space settlement will not come at the expense of others, but rather represent the fruits of great labors.

A Nice Place to Live

There will be little enthusiasm for moving into space unless people want to live there. In that vein, a few features of orbital real estate are worth mentioning:

How?

With great difficulty. Fortunately, although building space settlements will be very difficult, it's not impossible particularly if we start small and close to Earth. Studies suggesting that small settlements in Low Earth Orbit directly above the equator are practical mean that the first settlements can be much closer, much simpler, and much easier to build than previously believed. Nonetheless, building cities anywhere in space will require radiation protection, materials, energy, transportation, communications, and life support.

Space settlement feasibility was addressed in a series of summer studies at NASA Ames Research Center in the 1970's. These studies concluded that space settlement is feasible, but very difficult and expensive. Follow on work has made early settlement construction much easier by taking advantage of low radiation levels in ELEO (eliminating most or all shielding) and rotating at up to 4rpm to keep early settlements small. So small that space tourism offers an attractive route from where we are today to the first space settlements. Space tourism has already started. As of 2017 the Russians have flown seven space tourists, one of them twice, using the Russian portion of International Space Station (ISS) as a part time hotel.

The tallest poles in the space settlement development tent are launch, construction, and life support. Launch is expensive today because most vehicles are expendable. After a single flight they are thrown away. The keys to reusability are technology and launch rate. There are multiple efforts in progress to develop reusable rocket technology but today's flight rate, less than 100 per year, is completely insufficient. A single reusable vehicle that can fly twice a week can meet that demand. Somewhere above 10,000 flights per year is probably needed, and tourism -- at the right price -- can generate use that kind of flight rate. No other application, with the exception of space solar power, again at the right price, has the potential to require so many flights.

Space tourists will need hotels to stay in. A primitive space hotel is very similar to today's space stations, but does not need expensive scientific equipment. Should early space hotels be successful bigger and better hotels will be built. These hotels will need to provide life support, including recycling the air and water and perhaps even some agriculture. At some point the largest hotels will be the size of a small settlement (~100 m diameter). At that point building the first space settlement is not much more difficult than building yet another hotel.

Space solar power is the other source of high launch demand, although it cannot develop space hotels. Electrical power is a multi-hundred billion dollar per year business today. We know how to generate electricity in space using solar cells. For example, the ISS provides about 80 kilowatts continuously from an acre of solar arrays. By building much larger space energy systems, it is possible to generate a great deal of electrical power. This can be converted to microwaves or infra-red and beamed to Earth to provide electricity with absolutely no greenhouse gas emissions or toxic waste of any kind. If transportation to orbit is inexpensive following development of the tourist industry, much of Earth's power could be provided from space, simultaneously creating a large profitable business and dramatically reducing pollution.

When?

How long did it take to build New York? California? France? Even given ample funds the first settlement will take decades to construct. No one is building a space settlement today, and there are no immediate prospects for large amounts of money, so the first settlement will be awhile.

However, a few commercial firms are developing space stations which could double as space hotels. These may well be deployed in the next decade or perhaps even less. After that we are may need at least two or three decades of hotel development to get to the size of a small settlement. Construction of the first settlement could easily take most of a decade. Thus, somewhere in the neighborhood of 30-50 years from now people may be moving in to the first settlement. We cannot say when the first space settlement will be build but, with a little luck, the right unit of measurement is decades, not years or centuries. In the meantime, there's a lot to do. Better get started!

To the space settlement home page.

Author: Al Globus

DISCLAIMER: This web site is not a policy statement. It is intended to be an accessible introduction to the ideas developed in the Stanford/NASA Ames space settlement studies of the 1970s to support the annual NASA Ames Student Space Settlement Design Contest.