Tag Archives: science

O’Neill Cylinders and spatial planning

This post was originally posted on blogspot.com on October 18, 2012

In an earlier post I discussed the potential of Bernal spheres and Stanford tori for city states, in this posting I will discuss several ideas for the spatial planning of O’Neill cylinders.

The ideas I will discuss here are not developed for space colonization as such, but can nevertheless be very inspiring for Space settlers. Especially for the larger space habitats spatial planning is an important topic. In this post I will discuss three proposals: O’Neill’s own idea, Ebenezer Howard’s garden cities and the ideas of Frank Lloyd Wright. The purpose of this post is not to force a certain spatial plan on to Space colonies, but rather to provide a framework for developing better societies.

Since O’Neill cylinders provide a large plot of usable land, they allows for more sophisticated spatial planning then smaller habitats. The latter will typically be highly populated and most of their usable land will be used for housing and closely related activities. Consequently the smaller habitats will lack any significant amount of nature (forests for example), while many, if not most, people will appreciate nature.

Since the days of O’Neill, the consensus among space colonization advocates (and we follow this) is that industry, agriculture and living should be separated (the first two should not be located inside space habitats), this is an important difference with terrestrial spatial planning. Combined with the practically unlimited resources in space, we are free to design the interior of an O’Neill cylinder as we like.

In his book, The high frontier, O’Neill has given an example of spatial planning. In chapter 5 he describes the build cities at the ends of each stroke of land, referred to as “valleys”, and using the land areas it self for villages, forests and parks.

It would be interesting to look at a few spatial planning concepts from the past. In the 1930s the American architect Frank Lloyd Wright  designed his famous Broadacre City. In this proposal “true” cities would disappear, while people would spread out over the country (for this reason his plan was not very popular outside the USA). One feature of this scheme was that each family receives a 4,000 square meter plot of land [1]. Which was to be developed according to wishes of the receiving family. While there many really good aspects to his vision, there is some important critique about the Broadacre City idea, which can be found here. A serious drawback of the original design is that it heavily depends on automobiles for transportation. In a space based nation, in which people are spread over many different space habitats, cars are really cumbersome to handle. As O’Neill explained the main modes of transportation in and between space habitats are space ships, maglevs, bicycles and walking [2].

My personal favorite is, however, the garden city, a concept developed by Ebenezer Howard around 1900. In short this urban design is an attempt to reconcile the city and the countryside. In Howard’s plan a garden city should require 6000 acres of land (which is approximately 25 square kilometers or 2428.2 hectare), of which 1000 acres are used for the actual city and the other 5000 acres are destined for agriculture [3]. As I have already said, most space habitat advocates favor a physical separation of agricultural and living areas. At first sight Howard’s idea seems to be outdated, and it is to some degree. Nevertheless I believe that this garden city concept is good starting point for our own spatial plans. We should look for alternative destination for these agricultural lands, a portion can be reserved for allotment gardens, while another portion is reserved for sport associations (think about field hockey clubs, rugby clubs and so on). In Howard’s original designs there is a remarkable lack of recreation areas (to be fair Howard planned a park in the center of his city, but this is one is to small for serious sport practice.)

The actual city itself, would be an annulus around this central park and would be divided into six wards, each with 5,000 inhabitants. This would give a total city population of 30,000 thousand, in addition a further 2,000 would live in the rural area of the city. Howard also thought about what to do when the city population would grow, unlike the natural course of urban growth by which new buildings are attached to the existing settlement, he foresaw to build new garden cities a few miles away of the old one. In fact he suggested to build a central city, a garden city with 55,000 inhabitants, first  and later to build six (normal) garden cities around it. The central city would serve as a regional center. This particular configuration is not feasible for a standard O’Neill Cylinder (diameter 6.4 km and length 32 km), but is we would increase these dimension s with a factor 5 (which would give an areal increase of a factor 25) then it would become an interesting option. However such O’Neill cylinders XL will not be realized in early space colonization.

A different but related concept is Columbia, Maryland. Like the conglomeration of garden cities, the different villages of Columbia are not one single area but separated by green areas (called the Tivoli garden). The city’s 100,000 residents [4] are spread among nine villages, with a land area of 82.7 square kilometers (compare this with a valley of 107.23 square kilometers). If we would organize a valley in a similar fashion as Columbia, than we would get a city with population of between 130,000 and 143,000 [5]. In order to keep this city mostly car-free, they designers envisioned a minibus-network.

As I have said at the beginning of this post, the purpose of the mentioned examples is to inspire the spatial planners of O’Neill cylinders. And I hope they will not make the same mistakes as those made by terrestrial urban planners. Space colonization is a nice occasion to experiment with innovation on spatial planning. Of course the specific spatial plans will depend on the political choices made by the owners/governments of space habitats, different political ideologies require different spatial plans. The examples I selected here, reflect my personal believes about decentralized republicanism with its preference for small non-urban communities as the framework for active citizens participation in public affairs.

Notes

[1] A valley of a typical O’Neill cylinder is 3.35 by 32 kilometers, which is 107.2 million square meters. And using Wrights 4,000 square meters per family, we can calculate that a valley provides land for 26,800 families.

[2] I will discuss transportation in space colonies more deeply in another post.

[3] Using the standard dimensions of a O’Neill Cylinder (length 32 km, diameter 6.4 km), we can calculate that each valley can host 4.4 garden cities. This gives a total population of 141,000 people for each valley (4.4×32,000).

[4] Originally (in 1966) it was estimated that Columbia would have 110,000 residents in 1980.

[5] The lower estimate is based on Columbia’s current population, the higher one the estimate from note [4].

Planetary chauvinism

This post was originally posted on blogpot.com on July 31, 2012

In this post I will deal with the subject of planetary chauvinism and more specifically I will explain what planetary chauvinism is and why it is dangerous.

Essentially planetary chauvinism is the idea that human life should be based on the surface of a planet or planet-like object, such as the moon. In several earlier posts I have presented my objections against terraforming, lunar settlement programs and the colonization of Mars. All of these “space” colonization proposals are based on planetary chauvinism.

The origins of planetary chauvinist attitudes are simply based on psychology and ignorance. Many people believe that since humans have always lived on a planetary surface for ever we should do so in the future. Of course this is a logical fallacy, some practices we humans have done for centuries, slavery for instance, are now universally rejected or abolished. The other pillar of planetary chauvinism is ignorance, although many are familiar with space station like mir and the ISS, not very much people seem to know about the designs of space habitats capable of accommodating several thousands of people. Nor are there many people who realize that asteroids instead of planets or the moon are the true treasures of our solar system.

The question is why planetary chauvinism is dangerous. Many so-called “space programs”, regardless whether they are pursued by governments or private parties, are focused  on creating permanent bases on the moon or Mars. Although a lot of people seems to know about the dangers of low gravity on human health, the simple solution, rotating space habits in free space, is almost unknown outside the space advocacy movement. Not only is the low gravity of the moon and Mars a problem, but space habitats are actually cheaper than terraforming Mars, building domed cities on the moon. Why should we waste money on settling other planets, while with less money we can do the same job with free space habitats?

But the main danger of planetary chauvinism is that it will undermine the public support of any future space settlement program. Many ordinary people nowadays associate space colonization with settlements on Mars or on planets in other system. Since most people understand that these projects are costly and will take centuries to complete, they will tend to argue not to spend any money on those projects, regardless whether this is through taxation or private donations.

Planetary chauvinism with its narrow mind undermines the attempts to show the general public the real prospects of space development programs: the utilization of the resources from Near Earth Objects and the creation of space habitats. And by doing so planetary chauvinism is working against any serious space settlement program, therefore it is important to combat planetary chauvinism.

Breakthrough artificial egg cells

This post was originally posted on blogspot.com on November 24, 2012

The following article on BBC News describes a new technology to create egg cells, and although this technology currently only works for mice, I think this is an important development. In this post I will discuss why discoveries like this one are important for space colonization programs. In an earlier post I discussed some applications for artificial reproduction in space colonization.

My main point in that post was the need of a large gene pole. A low degree of genetic diversity will lead to inbreeding, which is usually associated with increased risk of genetic disorders. Unless we will apply strict genetic screening of immigrants, space populations will likely only exist for some generations. Even with genetic screening, we have the problem that most people are carriers of a few defect genes. The only way to solve the problem of a small gene pool, is to increase diversity. This can be done in two-way: massive immigration or import of human gametes.

Large scale immigration has multiple side issues: from a technical point of view we have to deal with the bottleneck to space, current rocket based space launch systems have limited capacity to send people to space. (We believe that all proposals for non-rocket space launch, are unlikely to developed soon, see also this post.) All best case scenarios predict that only a few hundred people can emigrate to space each year.

Another issue related to mass immigration is social-cultural and political. Space communities will most likely have very restrictive admission policies, and will select only those potential immigrants on whether they have certain desired qualifications and whether they do share the political ideology of a particular space colony. For example a more socialist oriented space colony is not likely to be willing to accept immigrants who are opposed to socialism.

The second solution for increasing genetic diversity is by importing human gametes. Human sperm can easily be collected on Earth, space governments could offer reasonable cash amounts to men in return of their sperm. Once collected, sperm is easily stored and transported, one launch could easily carry the sperm of several thousand males. The collection of human egg cells is much more difficult, eggs or ovary tissue can only be collected through surgery. It is clear that buying human eggs is much more expensive than human sperm, we have now also to pay for the surgery.

However this problem would be solved if we would be able to make egg cells from skin tissue, which can be collected in almost every reasonable hospital in the world. The procedure of collecting skin tissue is much less intrusive for women. Tissue cultures are just like sperm samples easy to store and transport into outer space.

Sperm donation and artificial egg cells will make it possible for Space communities to develop gene banks with high genetic diversity without the difficulties arising from (mass) immigration.

More:

Artificial sperm is also possible http://www.bbc.co.uk/news/health-14404183

Why rockets are necessary for Space Colonization

This post was originally posted on blogspot.com on May 11, 2012

In this posting I will argue why we should stick with chemical rockets for our program of space colonization.

Many proponents of space colonization are in favour of several types of non rocket space launch. Most commonly proposed are space elevators and projectile launchers, their advocates favor these because they believe that is launch methods will lower the costs of launching objects into orbit (and beyond). At this moment it costs us$10,000 to us$25,000  per kilogram to launch something into space (Wikipedia, see here) and its argued that the minimum energy required for space launch is much less than with rockets and so it would, in theory, to lower the costs of space launch (the Wikipedia article don’t show any explanation for this claim, so I am somewhat skeptical about it).

Although multiple launch schemes are proposed in the past, however no one, save for chemical rockets, has actually proven to be successful. Yes, there have been a multiple test of several proposed systems, but none of them has ever launched anything in space. Chemical rockets are proven technology, quite easy to build. This will lower our development costs, this is very important if we want to start with space colonization as soon as possible. Although the several proposals for non rocket space launch will work in theory, and they may lower launch costs, we cannot know when these methods are ready to use. Here we can compare this with the research on nuclear fusion power, which has started at same time as nuclear fission, but today there are still no commercial fusion power plants (at this moment they are not expected before the 2050s).

If, say, research will show that rail guns are the most efficient method of space launch, but it will take fifty years before this will be operational, then we should not go for it. Why? Because no one will invest in such project if there is no guarantee that it will work, while in the meantime it will not generate any revenue. Unlike in the case of fusion power research, which is funded by governments, we cannot afford to waste our time with developing speculative technology. Many space advocacy groups have lost their credibility because they were not able to come with realistic plans to get started with space development within the next ten to fifteen years. With realistic plans I mean plans that not rely on governmental funding and have clear ideas about generating revenue for repaying investors. In an upcoming post I will present a plan, which I believe will satisfy my criteria. Instead many “space advocacy” groups are wasting their time and their money with lobbying, not very successful if we look at the miserable state of the US space program. Also in an upcoming post I will argue why space tourism will not helpful for space colonization, this because many space advocates believe that space tourism will act as a catalyst for space development.

Since at this moment chemical rockets are the only proven method of space launch and we do not have the time for develop more speculative technologies, we should stick with chemical rockets. Even if could reduce launch costs, we have to take into account development cost and since we cannot predict the actual amount of time and money spent in research, we cannot afford to take this risk. Not that I am against research, but we should devote most of our funds and time for solving the real issues of space colonization, not for reinventing the wheel over and over again. This is actually what NASA is doing, while the Russians are using the same launch system for decades, with several improvements over time.

Rockets are maybe not the most efficient launch system, but at least they work.