Introduction

The fate of the architect is the strangest of all.  How often he expends his whole soul, his whole heart and passion, to produce buildings into which he himself may never enter.

- Johann Wolfgang Von Goethe

Many have not taken the time to examine the project closely but have consigned it, with the usual indulgent smile, to the fate they reserve for other space-travel proposals.  My mirror project is in the best possible company, with the space station, the spaceship, the base established on the Moon, and even liquid-propelled rockets including the V-2.  This, at least, did not remain filed away among the "impracticable and crazy ideas" but showed the reality of its existence in a forceful manner by falling on various people's heads.

- Hermann Oberth

To the uninitiated, artificial-gravity rotating space stations may seem like little more than comic-strip fantasies, akin to the TV and movie-theater "space operas" of the past two decades, and not a worthy topic for serious research.

But in fact, the concepts of space stations in general, and artificial gravity in particular, are much older than many people realize.  By 1903, the year of the Wright brothers' famous flight, Konstantin Tsiolkovsky was already laying the theoretical foundations for liquid-fueled rockets, space stations, weightlessness, and artificial gravity.  Scientists and engineers have continued these studies ever since.

Proposals for space stations have been published in respected books and journals throughout the twentieth century, many of them based on artificial-gravity design concepts; not until the mid 1960's did zero-gravity concepts become prevalent.  That the U.S. Space Station currently under development will not include artificial gravity has as much to do with current budgetary and technological constraints as with long-term space station design goals.  Contemporary engineers and physicists such as Gerard K. O'Neill have written extensively about the possibility - and even the necessity - of developing large, permanent space manufacturing facilities and space colonies utilizing artificial gravity.  Continuing interest in manned missions to Mars necessitates an interest in artificial gravity as well, due to the length of the journey.

The powerful images from the movie 2001: A Space Odyssey, the book The High Frontier, and the space colonization studies of the '70s and '80s provide much of the impetus for this dissertation.  Descriptions of rotating cylindrical space colonies - four miles wide, twenty miles long, and supporting populations of millions of people - are within the natural domain of architectural endeavor.  So are the more modest space stations and Lunar bases that will precede them.  Science and technology have progressed to the point where visionary architecture is being conducted by physicists and aerospace engineers.

It was merely 54 years from the first airplane (1903) to the first artificial satellite (1957), and 12 more years to the first human footsteps on another celestial body (1969).  By comparison, it took 26 years to build the vaults of the cathedral of Chartres (1194-1220), and more than 300 years to finish the cathedral overall (1194-1513).  Much of what is considered to be great architecture took many years to complete.  We have grown impatient in modern times.  Space station research requires the sort of faith in the future exhibited by the master builders of bygone days.  It is not unreasonable to expect that the technology of a hundred years hence will be far beyond what we see today.

Although many proposals for artificial-gravity spacecraft have been published during the past century, the emphasis has been on artifact rather than environment.  A great deal of serious engineering has gone into station dynamics, orbital mechanics, propulsion, power generation, life support, structural capacity, and other aspects of satellite design; very little has been written about the appropriate environmental design to support intelligent life under such a novel condition.

As an antidote to the adverse effects of weightlessness, artificial gravity has great face validity, though it is not yet clear that it is the only antidote or even the best one; its real efficacy remains to be tested.  As a problem in mechanical dynamics, it appears solvable; many configurations have been proposed and analyzed in broad-brush detail, and no "show stoppers" have been found, though a complete solution (an implementation) has yet to be developed.  As a problem in habitat design, it is terra incognita.  Most studies have not progressed beyond specifications of raw volume - "x" number of modified space station modules or refurbished fuel tanks.  The studies that have taken a peek inside exhibit little accommodation to the peculiarities of artificial gravity.  The effort has gone into transplanting elements originally designed for Earth-normal or micro-gravity environments, rather than on developing a new paradigm.

This dissertation explores the architectural forms appropriate to artificial gravity.  Its focus is on the physical forces associated with life and motion in a rotating environment, and the formal (geometric) architectural response to those forces.  It is addressed to architects with an interest in aerospace, and to aerospace engineers with an interest in habitat design.  These two groups represent different professional cultures, with knowledge bases that have very little in common beyond the first year or two of university education.  It therefore seems beneficial to consolidate material in this dissertation that, although not new to science, may be unfamiliar to one profession or the other.

*  Chapter 1 presents a history of artificial gravity, and reviews a representative sample of the many technical studies and design concepts that have been developed over the past century.  The study of precedent is important to any design discipline.  The evolution of assumptions, goals, and strategies provides the basis for further development.

*  Chapter 2 reviews the relevant physiological research.  The debilitating effect of prolonged weightlessness argues in favor of artificial gravity, but the discomforting effect of rotation sets limits on the radius and speed.  There is still considerable uncertainty regarding the medical alternatives, as well as the comfort criteria for rotation.

*  Chapter 3 is a primer on the physics and dynamics that are essential to any substantive discussion of artificial gravity design.  Rotation is the only viable means of providing artificial gravity of indefinite duration.  Unfortunately, relative motion within a rotating environment involves Coriolis accelerations and cross-coupled rotations that have a detrimental effect on comfort and habitability.  Dynamic stability and structural stress also constrain the design.

*  Chapter 4 examines the laws of artificial gravity from the point of view of an inhabitant living and moving within the rotating system.  It visualizes the gravity environment in terms of the relative motions of free-falling objects and the apparent slopes of floors, ladders, and stairs.  Conformance to the comfort criteria for rotation does not guarantee an Earth-normal gravity environment, nor does it sanction the adoption of terrestrial design.

*  Chapter 5 explores the importance of gravity in the foundations of architectural theory.  A reexamination of fundamental principles suggests that the terrestrial architectural grammar of wall, floor, and ceiling should be augmented in artificial gravity to accommodate a gravitational distinction between east (prograde) and west (retrograde).  The goal is not to fool people into thinking they're on Earth, but rather, to help them orient themselves to the realities of their rotating environment.

The subject of artificial gravity was broached long ago, and is now a legitimate topic for discussion among theorists of space habitation.  Yet for all of the theorizing that has surrounded this topic over the past century, no one has ever actually experienced life in such an environment, free of the distortions caused by contact with the Earth's surface.  Any simulation one might perform here on Earth can only approximate what one would experience in space.  In designing the first such habitat, we must rely on predictive laws to extrapolate from our limited experience, with the understanding that our extrapolations may be imperfect.