Artificial gravity as a countermeasure for mitigating physiological deconditioning during long-duration space missions

Abstract

In spite of the experience gained in human space flight since Yuri Gagarin’s historical flight in 1961, there has yet to be identified a completely effective countermeasure for mitigating the effects of weightlessness on humans. Were astronauts to embark upon a journey to Mars today, the 6-month exposure to weightlessness en route would leave them considerably debilitated, even with the implementation of the suite of piece-meal countermeasures currently employed. Continuous or intermittent exposure to simulated gravitational states on board the spacecraft while traveling to and from Mars, also known as artificial gravity, has the potential for enhancing adaptation to Mars gravity and re-adaptation to Earth gravity. Many physiological functions are adversely affected by the weightless environment of spaceflight because they are calibrated for normal, Earth’s gravity. Hence, the concept of artificial gravity is to provide a broad-spectrum replacement for the gravitational forces that naturally occur on the Earth’s surface, thereby avoiding the physiological deconditioning that takes place in weightlessness. Because researchers have long been concerned by the adverse sensorimotor effects that occur in weightlessness as well as in rotating environments, additional study of the complex interactions among sensorimotor and other physiological systems in rotating environments must be undertaken both on Earth and in space before artificial gravity can be implemented.

International roadmap for artificial gravity research

“…The parameters that are most effective for mitigating physiological deconditioning in microgravity (rotation rate, radius of the centrifuge, and duration and frequency of AG exposure) need to be determined early in the exploration mission planning process to inform optimal decisions on the vehicle capabilities. 1 In addition, potential side effects of intermittent or continuous rotation need to be understood and addressed. These side effects, which include motion sickness, disorientation, and falls, are caused by the Coriolis and cross-coupled angular accelerations generated by head and body motion in a rotating environment.…”

Sleep in space as a new medical frontier: the challenge of preserving normal sleep in the abnormal environment of space missions

“…There is no limit to human potential nor to what one would wish for or hope to conquer. Certainly this attitude drives the thought and imagination of those who are closely involved in the technical challenges of space travel [3] . Space agencies such as the National Aeronautics and Space Administration (NASA) of the United States, the Russian Federal Space Agency (FKA or RKA), the European Space Agency (ESA), the China National Space Administration (CNSA), the Japan Aerospace Exploration Agency (JAXA), and Indian Space Research Organization (ISRO) are in the forefront of aerospace research, whatever their local political agendas may be.…”

Ergonomic Challenges for Astronauts during Space Travel and the Need for Space Medicine

“…Human beings have not evolved to live in space and our bodies are unable to rapidly adapt to the extreme conditions faced by astronauts. Many of the deleterious effects of space travel described above may simply be as a consequence of having to live in microgravity and the solution would seemingly be equally obvious, namely the development of systems to simulate gravity, so called 'artificial gravity' [AG] [125,126]. The notion of giant spinning wheels portrayed in science fiction, at least today are perhaps impractical to construct and the potential positive attributes for astronaut health remain theoretical and unproven.…”