THE ADVANTAGES OF SPACE LIVING OVER PLANETARY LIVING

BY MIKE COMBS

Much of Star Trek deals with colonies on Earth type planets in other solar systems. But do we have any assurances that Earth-like worlds are as common in the Milky Way galaxy as they are in Hollywood, California? The future scenario that Gene Roddenberry presented seems clear enough. We would build cities on the Moon, colonies on Mars, habitations wherever there was solid ground underfoot and gravity to keep you from drifting away. We occasionally see orbiting star bases, sure, but these are only way stations, refueling depots, laboratories. The crew can look forward to going home on completion of their tour of duty. Even if "home" is not Earth, then it is surely a planet, or at least a moon. These lines of thought are no different from what serious futurologists predicted and went completely unchallenged until the work of Professor Gerard K. O'Neill.

In 1969 O'Neill asked some of Princeton University's finest science and engineering students the following question: Is the surface of the Earth really the best place for an expanding industrial society? After some initial research was done, it seemed that the best place for our technological civilization is not on Earth or even on a planetary surface. A space habitat, orbiting in free space, would seem to have many advantages over any planetary home.

A space habitat will most likely be in the form of a sphere pressurized with air and spinning to simulate gravity. Sunlight is brought in with mirrors and windows. The interior can be landscaped to look very much like Earth. Hauling up the materials to construct this miniworld from Earth's deep "gravity well" would make the project too expensive to even consider, so we will use lunar materials that will require only one twentieth of the energy for their retrieval. The moon will provide oxygen, silicon, aluminum, and titanium. The asteroids can supply carbon, hydrogen, and nitrogen.

When the calculations were finished, it seemed evident that planets actually represent the hard way to go about doing things. A planet uses a tremendous amount of mass to create a gravity field and hold down an atmosphere, while a simple rotating, pressurized structure can achieve much the same effect. A good illustration of this principle is the fact that the asteroid belt alone contains sufficient resources to create, in the form of space habitats, three thousand times the land area of the Earth. However, if all of the asteroids were lumped together into a planet, that planet would be tinier than our moon. Besides this incredible economy of mass, are there other advantages of space living over planet living?

There has been much talk about becoming a solar society, but thus far it has been "talk" only. There is a good reason why we cannot shift over to a full scale solar economy and it is because solar energy is inconstant here on the surface of the Earth. Solar power is blocked by the shadow of the Earth at night, is interrupted by cloudy weather, and even on a "clear" day is filtered by miles of atmosphere. Consequently, we have obtained energy by constant, although indirect, means (I.E., fossil fuels).

In space, outside the shadow of the Earth, solar energy is constant and reliable. The builders of an aluminum smelting plant in space can confidently count on using solar energy to power their facilities without worrying about energy shortages, the rising cost of fuel, or environmental impact. Any time we go down to a planet, we will be faced with limitations on the amount of solar energy that we can use. Planets with atmospheres, in particular, not only further limit the use of solar power, but also have weather that must be given consideration when building large structures.

Although Star Trek's artificial gravity remains a fiction, a space inhabitant need not do without gravity as long as a habitat can be rotated. In space, one can have gravitational freedom. Any G force, from zero, to a fraction, to full, to in excess of a G can be produced by the appropriate rotational speed or lack thereof. Planets, on the other hand, have gravities that can't simply be turned off. Gravity places limits on the efficiencies obtainable for transportation. There is reason to believe that certain materials can be made in zero G that either cannot be made, or can be made only in small amounts, in a gravity field. Gravity also limits the size of structures that we can build on a planet. In space there is no reason why artifacts many cubic kilometers in volume cannot be built.

When we talk about a planet we are talking about a large but nonetheless finite environment. When we talk instead about living in space we have moved into the realm of the infinite. The resources of the Solar system are beyond human comprehension and the resources of the universe are as close to infinite as we need concern ourselves with. Using these materials to construct space colonies, we can provide all of the land area that any foreseeable population growth could require. With industry moved into space, our civilization could evolve toward what we see in Star Trek: a society enjoying all of the benefits of hightech living without the disadvantages of pollution and destruction of the natural environment.

When we speak of bringing in extraterrestrial materials or energies we are discussing the creation of new wealth, not merely the redistribution of wealth already here. Isaac Asimov, the famed science writer, has observed that energy derived from space would not be geography bound. There would no longer be energy rich or energy poor areas. The same can be said of space resources. A shipment of asteroidal steel can be sent to one part of the planet as easily as another.

If these ideas are correct, then by the 23rd century there could conceivably be more people living in space than on Earth. The surface of our world, free of the major, voracious, polluting industries could be restored to a more natural, parklike form. Earth's main industry would then be tourism. The "Star Trek scenario" of searching through innumerable solar systems for a place to live where you don't have to carry your air in a bottle may become unnecessary in a universe where you can manufacture your own miniworld to your own specifications.

One of the most profound points of the space colonization concept is that now any star system can be inhabited. Nothing would delight a space colonist more than, upon arriving at another solar system, discovering rings of asteroids but no planets. What use would he/she have for steep gravity wells? The assumption that other intelligences in the universe might use similar techniques to colonize space vastly increases the odds that we will find them. On the more practical side, man's options are also vastly increased. If we use the technology that we have wisely, we can utilize all of the energy and natural resources that we and our children could ever need. Once man is out into space there will be no more limits to growth. With the seed of man spread throughout the galaxy the human species would, in effect, become immortal.

And if we ever did encounter an Earth type planet in our journeys it would indeed be an interesting place to study. Or, perhaps, to set up a tourist stop.

Tasks:

1. Study the vocabulary of the text. Exchange the lists of vocabulary items with your group mates and share the ideas of the text.

2. Comment on the following:

A space habitat

use lunar materials

advantages of space living over planet living

solar energy

finite environment

the benefits of high-tech

"Star Trek scenario"

space colonization

3. Give the main ideas of the text that contribute our understanding of space exploration.

4. What are the controversial points of the text?

5. Discuss in groups the benefits of space exploration.

TEXT 6

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BASIC CONSIDERATIONS IN SPACECRAFT DESIGN	\|	SPACE AND HUMAN SURVIVAL

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