Starting in-space settlement small and building from there

Giant in-space colonies like those depicted in these renderings by artist Don Davis

Bernal Interior. Interior including human powered flight. Art work: Rick Guidice. Credit: NASA Ames Research Center. NASA ID AC76-0628

AC75-1886f_md

– look fantastic and would clearly be places where many people would live if they existed today. The problem, of course, is that they do not exist and it’s difficult to convince people that it’s possible to ever build such gigantic habitats. But there are in fact ways to get from here to there.

When I fly into a big city and look out the window as the plane descends, I’m always amazed at just how enormous such places are. How could mere mortals create such a vast landscape of houses, buildings, skyscrapers, roads, bridges, harbors, and more? The answer, of course, is a city starts as a small settlement and over many decades the incremental efforts of thousands upon tens of thousands of people and their machines working in parallel day after day, year after year, create such massive metropolises.

Such a process can create cities in space as well. New Rome in orbit doesn’t have to be built in a day. We just need to get small “starter” settlements off the ground, so to speak.

That’s easy to say but what about the high cost of getting to space?

Fully reusable space transports like that being developed by SpaceX, Blue Origin, and other companies can bring down the  cost of getting to space by factors of 10-100. The cost of propellants is a less than a half percent of the cost of an orbital rocket launch. The rest of, say, the $60M cost of Falcon 9 goes for the vehicle, which currently is thrown away on each flight.

What about the detrimental effects of microgravity and radiation on human health?

Rotation of a habitat can provide artificial gravity and bulk materials such as water and structural metals can shield people in a habitat just as the atmosphere shields people on earth.

The toughest question is how to get started. When giant  habitats like those above were being designed in the 1970s, it was assumed that most of the material would be sent from the Moon. All of this would be paid for by huge investments from governments who would appreciate the construction of in-space solar power stations feeding energy via microwave to the earth.

Excavation activities on the Moon, space base solar power, and big government funding do not look likely to happen anytime soon, to say the least. Is there any other way to get space settlement underway?

Yes, it can still happen if the process can start small and pay its own way. Al Globus, who works as a contractor at NASA Ames Research Center in Mountain View, California, describes in a set of three documents listed below a plan for  small affordable space habitats in low earth equatorial orbit that will provide 1 g gravity and enjoy sufficient radiation protection for residents to live a healthy life. Space tourism will be a primary industry similar to the way many island economies on earth rely on tourism.

* Space Settlement the Easy Way, Al Globus and Stephen Covey, presentation at ISDC 2015, May 2015.
“This presentation shows how the results of the next two papers — “Space Settlement Population Rotation Tolerance” and “Orbital Space Settlement Radiation Shielding” — when combined suggest that small space settlements in equatorial LEO with little or no radiation shielding may be viable. Hopefully, this will be turned into a paper in the not-too-distant-future.”

Space Settlement Population Rotation Tolerance, Al Globus and Theodore Hall, preprint, June 2015.
“This paper reviews the literature to find that space settlement residents and visitors can tolerate at least four, and proabaly six, rotations per minute to achieve 1g of artificial gravity. This means settlements can be radically smaller, and thus easier to build, than previously believed. Combined with the next paper on radiation shielding, the first space settlements can be two orders of magnitude less massive and closer to Earth than previous designs making launch from Earth practical.”

* Orbital Space Settlement Radiation Shielding, Al Globus and Joe Strout, preprint, May 2015.
“The major result of this paper is that settlements in low (~500 km) Earth ***equatorial*** orbits may not require any radiation shielding at all based on a careful analysis of requirements and extensive simulation of radiation effects. This radically reduces system mass and has profound implications for space settlement as extraterrestrial mining and manufacturing are no longer on the critical path to the first settlements, although they will be essential in later stages. It also means the first settlements can evolve from space stations, hotels, and retirement communities in relatively small steps.”

Globus answered questions about space settlements in a recent on line forum: A NASA Expert Is Here To Answer Your Questions About Orbital Settlements – Gizmodo.

8 thoughts on “Starting in-space settlement small and building from there”

  1. Thanks, looks like his whole site on space settlement is down at the moment. I’ve now changed the links to files on my site.

  2. For an inflatable, non-tumbling, cylinder-shaped habitat 1 gee at 4 rpm, it calculates as follows:
    – Radius = 56
    – Length = 78.4
    – Surface area = 47,290 m2
    – For Kevlar at 0.292 kg/m2
    – Total = 13.8 tonnes

    So, a Falcon Heavy could launch a full-sized orbital hab with plenty of mass left over for equipment, starter supplies, and some starting structural materials. In LEO, however, there would need to be a way of rapidly detecting and repairing debris strikes.

    1. The Bigelow modules have quite good tolerance for debris strikes. I’ve heard that the Genesis modules are still very air tight. The multiple layers of vectran (a similar but stronger material than kevlar) act as quite an effective Whipple Shield.

      A station can also add more material over time. E.g. a NIAC study looked at compressing waste on a station into small sandbag like sacks that could be place around the exterior for debris and radiation shielding. That’s far more useful than dumping it into the atmosphere as is done now at the ISS.

      One complication is that a rotating habitat would need a non-rotating docking hub. There is some experience in the space industry with the mechanics of doing that since spin-stabilized satellites can have a de-spun component for the antenna.

      1. “a rotating hab would need a non-rotating docking hub”

        Or, the docking craft could rotate to match the hub. I think this later approach the easier.

        1. That’s true, particularly for the first gen system, though a small station rotating fast may offer some challenges for activities near the axis of rotation. I think a non-rotating hub would be useful eventually to make docking simpler and also to provide for a section where micro-g work could be done.

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