DOI: https://doi.org/10.58248/RR89
Overview
On 18 March 2026, astronauts crewing NASA’s Artemis mission to the moon entered a 14 day quarantine. This aimed to limit their chances of catching illnesses that could delay the launch scheduled for 1 April 2026.
However, the astronauts face several health risks as part of the mission; the first to the Moon since 1972. These include physiological and psychological challenges due to factors such as microgravity, radiation exposure, and isolation. These and other risks will also be faced by astronauts in potential future missions to Mars, and to people that may participate in space tourism.
Astronaut health is therefore an important area of research in supporting human spaceflight. Understanding the associated risks and developing countermeasures is essential for mission success and crew safety.
The integration of robotics, artificial intelligence (AI), and advanced monitoring technologies is increasingly central to ensuring crew safety and efficient medical support during missions, where real-time Earth-based intervention may be limited.
As such, space health research is multidisciplinary, drawing on medicine, psychology, engineering and data science.
There is significant research investment in the UK and in several other countries. An article in Nature noted that China’s investments in space medicine would consolidate its “position in this field”.
As international and commercial space activities expand, understanding the medical, operational and regulatory implications of human spaceflight is increasingly important for national space strategies and long-term planning.
Background
Upcoming missions, such as NASA’s Artemis and potential crewed missions to Mars, will expose crews to higher radiation levels, partial-gravity environments and more challenging medical scenarios.
Early space missions, such as Mercury (1961) and Apollo (1968), provided the first insights into how microgravity affects human physiology, revealing issues like fluid redistribution and bone loss. Early research programmes such as Skylab and Mir provided foundational data on long-duration spaceflight. The International Space Station (ISS) provides further data on the effects of space on the human body.
The UK contributes to space health research through collaborations with the European Space Agency (ESA), academic institutions, industry partners, and UK Research and Innovation (UKRI)-funded projects. It also participates in Earth-based space simulations such as those conducted at Antarctic research stations.
Research programmes such as NASA’s Human Research Program and the European Space Agency Space Medicine Team have generated datasets on cardiovascular adaptation, musculoskeletal changes and psychological resilience. NASA’s Twins Study highlighted genetic and epigenetic changes during spaceflight. ESA research has expanded on the implications for circadian rhythms and behavioural health.
Private companies including SpaceX and Blue Origin are accelerating the pace of human spaceflight, introducing new challenges for health standards, liability and alignment of national space objectives. NASA is working with SpaceX to develop the Starship Human Landing System to carry astronauts from the lunar orbit to the Moon’s surface and back for Artemis III and Artemis IV.
Health risks and implications
Astronauts face several health risks during space missions. Learning how these interact helps scientists develop better ways to keep astronauts healthy, including through exercise, nutrition, medicines and mental health support.
Some of these health impacts are short term in nature and resolve relatively quickly upon return to Earth. However, some are likely to be long-term
| Risk | Implications |
| Radiation exposure | Radiation exposure from cosmic rays and solar particles can damage DNA and increase cancer risk. It may also affect the brain and nerves, possibly changing thinking or mood. Shielding remains limited, especially for deep-space missions. |
| Muscle and bone loss | Microgravity reduces mechanical loading on the body, leading to muscle atrophy and bone loss, which can result in osteoporosis-like symptoms. |
| Cardiovascular deconditioning | In microgravity, the heart and blood vessels adapt, which can make exercise and recovery harder. These changes may have implications when astronauts return to Earth. |
| Psychological effects | Isolation, high-stress environments, sensory monotony and communication delays can cause a range of psychological issues. Stress in space can affect hormones, making it harder to think clearly and manage emotions. |
| Circadian rhythm disruption | Sleep disturbances and fatigue are common due to altered light-dark cycles and operational demands. Astronauts on the ISS experience 16 sunrises per day. |
| Vision impairment | Microgravity leads to fluid shifts in the body, affecting vision and intracranial pressure. Spaceflight-associated neuro-ocular syndrome affects visual acuity due to intracranial pressure changes. |
| Immune system changes | Infection risks can increase. Latent viruses may reactivate. Gut bacteria may shift, affecting digestion and immunity. |
| Nutrition issues | Maintaining freshness, taste, and nutritional value of food is important for morale and health. |
Emerging health challenges
As missions change and extend beyond low Earth orbit, new health risks will emerge.
For example, Mars missions could entail prolonged exposure to radiation, isolation and limited medical support. They may also involve exposure to Martian dust, which due to its small grain size could cause lung irritation, absorb into the bloodstream and lead to disease. Extended communication delays will require crews to manage more medical issues autonomously, increasing the importance of onboard diagnostic tools and decision-support systems.
AI may help to monitor astronauts’ health, spot problems early, and manage care when missions are far from Earth. Robotics may assist with surgical procedures or complex tasks in environments where human dexterity is impaired, or a qualified experienced surgeon is required. On-board drug manufacturing, bioreactors and 3D-printed pharmaceuticals may support long-duration missions where resupply is not possible.
Commercial spaceflight and space tourism may lead to a wider range of health issues being experienced given the likely greater diversity of those participating in these activities.
UK research landscape
The UK is actively involved in space health research through the UK Space Agency, ESA, and UKRI-funded projects.
The UK Space Agency funds research into astronaut health challenges such as muscle loss, psychological isolation, spinal health during long missions and how the human body responds to microgravity.
The European Space Agency (ESA) conducts research to investigate the effects of microgravity and other space environment factors on the human body. It leads experiments on sleep, immune function, metabolism and biological responses to microgravity using model organisms and advanced imaging platforms.
This research supports Europe’s contributions to NASA’s Artemis programme and the planned Gateway (the first space station around the Moon), helping to develop solutions such as telemedicine capabilities and life-support systems for long-duration missions.
ESA’s Space Medicine Team studies cardiovascular adaptation, bone and muscle loss, circadian disruption and psychological resilience. The European Astronaut Centre provides medical support and operational training for astronauts.
ESA’s Concordia Station in Antarctica simulates isolation and extreme conditions. It uses the extreme Antarctic environment to study the physiological and psychological challenges of long-duration human spaceflight to the Moon and Mars. Researchers specifically monitor how isolation, confinement and low oxygen levels affect small crews to develop medical countermeasures and life-support technologies for future deep-space exploration
UKRI funded projects contribute to space research and innovation by supporting science that aids understanding of space environments and human spaceflight. These complement broader UK research into space systems and physiological adaptation.
Policy and regulatory issues
Funding
The UK Government has committed £2.8 billion from 2025/26 to 2034/35 to support ESA programmes “with further commitments set to be made in 2028 at the next ESC Council of Ministers”. An evaluation conducted by RAND Europe, commissioned by the UK Space Agency, found that “every £1 public investment in ESA programmes leads to £7.49 directly benefiting the UK economy”.
The Space Academic Network stated that space missions and research require long-term commitments, suggesting 10‑year funding cycles with 15‑year outlooks. It said shorter cycles risk capability loss and disrupt collaboration between agencies.
Policy
A Space Regulatory Review was conducted in 2024. It made 17 recommendations that would “deliver the greatest impact for the sector” and the economy. These included greater coordination across regulators and government departments, clear government policy and work to develop international partnerships.
The House of Lords UK Engagement with Space Committee report, The Space Economy: Act Now or Lose Out, November 2025, found that “the UK space sector lacks the strategic direction necessary for success”. It made several recommendations including that the government provided “a coherent strategic direction with clear delivery plans” and “ensure that structures of government are adequate to deliver cross-governmental space policy”.
Ethics
Ethical considerations, such as informed consent for high-risk missions, remain an important area of discussion among policymakers and researchers. Issues such as risk communication, data privacy and management of medical decision-making during emergencies are emerging areas.
The growth of commercial spaceflight introduces additional factors, including health standards for non-professional participants and liability arrangements, which are currently being explored through international and industry-led initiatives.
Acknowledgements
POST is grateful to Dr Laura Steel, Research Fellow in Visual Neuroscience, Sussex University, for her help in producing this briefing.