The architecture of artificial gravity environments for long-duration space habitation.

Abstract

Gravity deprivation (weightlessness) leads to a multitude of problems for people during spaceflight. For reasons of health, comfort, and practicality, scientists have often proposed to provide artificial gravity by spinning the spacecraft. The spin-induced centripetal acceleration would act as an imperfect surrogate for natural gravity. Thus far, design studies for artificial-gravity spacecraft have emphasized the artifact rather than the environment. A great deal of engineering has gone into station dynamics, orbital mechanics, propulsion, power generation, 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. The effort has gone into transplanting elements originally designed for earth-normal or microgravity environments, rather than developing a new paradigm. This dissertation aims to advance the science of environmental design for artificial gravity. It consolidates current knowledge from engineering, life science, and architecture, and introduces new material through mathematical derivation and computer simulation. The history of artificial gravity shows an evolution of assumptions, goals, and strategies that provides a precedent for further design development. The debilitating effect of prolonged weightlessness argues in favor of artificial gravity, but the discomforting effect of rotation sets limits on radius and angular velocity. Rotation is the only viable means of providing artificial gravity, but motion within a rotating environment involves Coriolis accelerations and cross-coupled rotations that have a detrimental effect on comfort and habitability. As the radius of rotation is reduced, the apparent gravity becomes increasingly twisted, regardless of the rate of rotation or the intensity of the gravity. With this twisting effect, east and west (prograde and retrograde) emerge as gravitationally distinct directions, similar to up and down. This suggests that the basic architectural grammar of wall, floor, and ceiling should be augmented in artificial gravity to recognize a fundamental gravitational distinction between walls. The goal of environmental design in artificial gravity 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.