Geriatric Space Travel©

Abstract

The world community continues to move towards exploring the solar system, with exploration of our immediate solar system aimed at establishing intra-planetary colonies, first perhaps on our nearest Earth neighbour Mars. Long haul and intergenerational space flight, with intra-and perhaps extra-planetary colonisation, at the current level of technology, will probably create the need for geriatric space travel.Humans are uniquely adapted to a live, survive and thrive in Earth gravity (1g) of approximately 9.8m 2 . When humans move beyond this gravity and the Earth's protective gravitational field, human growth, development and physiology is impacted. This brings to the forefront two main areas of consideration: multi-morbidity and increasingly complex care needs of an active geriatric crew, whose skills, academia and practical knowledge may be required for longer, and more enduring working lives, and the physiological hostility of altered gravity environments.Whilst aging on Earth is a complex topic; altered gravity environments will bring even greater challenges. Bodily systems known to be affected by altered gravity environments include the immune, cardio-vascular and muscular-skeletal systems. Gross affects on these systems have been catalogued over the years; the most notable being rapid onset of osteopenia and osteoporosis, even after relatively short exposure to altered gravity environments of two weeks. Newer areas of study of the effects of altered gravity have broadened to include infection susceptibility and disruptions to the gastrointestinal-pulmonary and gastrointestinalskin axes. Nutritional changes caused by gastrointestinal microbiome imbalances can affect both the uptake of nutrients as well as medications, with possible impacts on cellular operations and perhaps cognition.In the altered gravity environment those individuals genetically predisposed to certain diseases may be at risk of accelerated onset of cognitive decline, immunological and physiological changes. This paper explores some of the known physiological stresses caused by altered gravity environments, highlighting the possibly of disease and aging insults that may be experienced by the geriatric astronaut.