Commercial spaceflight: Progress and challenges in expanding human access to space

Commercial access to space travel for private individuals is a near-term reality. Compared to the few professional astronauts, cosmonauts, and taikonauts who have flown in space through government programs in the past six decades, the number of these new spaceflight participants (SFPs) will rapidly expand. The SFP cohort will have a much greater age range than traditional astronauts and may also have a much greater prevalence of medical problems. To date, regulation regarding medical screening, certification, or guidelines for suborbital and orbital SFPs has been relegated to the commercial space companies. However, many organizations, ranging from space advocacy groups to academic institutions to the Federal Aviation Administration (FAA), have offered input and recommendations for medical screening of SFPs for the industry's consideration. Simultaneously, governmental space agencies have made progress in defining appropriate preflight medical testing and medical standards and for those commercial providers that plan to provide access to the International Space Station (ISS). There is limited information available with regard to the effect of spaceflight-related stressors like acceleration, microgravity, and altered atmospheric pressure and breathing gas mixtures on individuals with medical conditions. To date, most research on humans exposed to challenging or extreme environments has focused on a healthy, young, and predominately male population. However, recent studies funded in part by the FAA and conducted by university programs have examined the effect of certain medical problems like cardiovascular disease, diabetes, and back problems in the acceleration environment. While the numbers are small, the early data from these studies examining the effects of acceleration are reassuring. There is still much for space medicine providers to learn from this new cohort of individuals that will soon be participating in commercial space activities. With appropriate training and treatment or stabilization of medical liabilities, most of those who desire to fly in space will be able to safely accomplish their dream.