| < A garden in outer space? > |
| The idea of extending our habitat into space became popular in the middle of the 20th century and produced monstrous propositions elaborated into stunning details as e.g. O'Neill's rotating cylinder (1976) with 8 kilometer diameter. These 'colonies in space' challenged the imagination of thousands of physicists and engineers, and of millions of amateurs (like me). However, all these concepts are technically highly demanding and would require huge investments of material and manpower, for their construction as well as for their maintainance (see my own humble proposal). |
| Another flaw of most of these propositions is their evident uselessness. They look like academic exercises - and most of them were. Some of them were proposed as 'islands of survival' in case of catastrophic destruction of the Earth. I doubt that any of them would sustain human life independent of the Earth for any significant time period. One potential use, recently resurrected to some actuality, could be to support the long-term travel to our neighbour planet Mars. |
| Why should we visit Mars? Very simple: because Mars exists, is within reachable distance, and because technical developments during the 44 years since our first visit to the moon should allow easier and more reliable solutions to many problems of manned spaceflight. Sir Edmund Hillary didn't have a better answer when asked why he climbed the Everest. Maybe we could add: It would be exciting to fly to Mars, an excitement for all scientists, engineers and pilots involved (and also for the rest of mankind, just watching). |
| Proposals for a flight to Mars operate with Hohmann transfer orbits, moving a spacecraft along an ellipse with the sun in one focus. Perfect timing provided, such a path should allow the propulsionless gliding from the orbit of Earth to the wider orbit of Mars, and back again. Since such travels only make sense if the spacecraft not only reaches the respective orbits, but also meets there the desired planet, space travellers have to stick to a rather tight time table. One such proposal foresees an orbit allowing 3 encounters with Earth and 4 encounters with Mars in 15 (Earth) years. |
| All you need is a short period of propulsion at the start - and patience thereafter. A lot of patience. And you will need kind of taxis and cargo vehicles attaching to and detaching from such a 'space cycler' when the desired destination is reached. The cycler itself will never stop. It will appear at the horizon, pass by, and dissappear again. And it will very rarely do so, once in a few years. It may be awaited with desire and greeted with joy - what a wonderful topic for a science fiction novel. |
| The most precious resource such a cycler could provide might be oxygen. As such a vehicle would always be exposed to the sun, simple photosynthetic organisms like blue algae and lichen, if present and active in sufficient quantity, could convert carbon dioxide exhaled by human passengers back into breathable air. I imagine a huge framework built from carbon fiber modules, with hundreds of large plastic bubbles inserted, pumped up with gas of variable composition and pressure (see the figure above). |
| The photosynthetic organisms might swim in outer chambers of these balloons, contained by a membrane that allows the passage of gases. The outermost bubbles could be maintained at conditions typical for the Martian surface, while towards the center of the construction conditions approach more and more those prevailing on Earth. The whole thing will be reminiscent of a beehive and could be assembled in space from simple modules. No high tech procedures would be necessary. A single person should be sufficient to do all necessary maintainance work. |
| On its monotonous cycle joining Earth and Mars this biosphere will appear like a green sparkling diamond providing a safe refuge with human living conditions. The same modules might be used to create housing on Moon or Mars. It would still be a far cry from an autark closed economic system, but give us a few more decades of research, and we can even put humans in a bottle and not just herbs, bacteria, mushrooms and shrimps. |
| MB 6/13 |
| next: A modular space colony back to: Reality Show? here a more realistic rotating cylinder
overview |
