​When we think of human spaceflight, it’s easy to focus on rockets, spacecraft and mission timelines. Less visible, but just as critical, is the quiet disruption of the body’s natural rhythms. On board the International Space Station, astronauts witness multiple sunrises and sunsets every day, challenging circadian systems that have evolved under a single 24-hour light–dark cycle. Sleep, hormonal regulation, cognition and overall wellbeing all depend on rhythm. The below article written by Dr Maria Helena Itaqui Lopes, originally published in the journal Zero Hora and website GZH, explores rhythm from a clinical and musical perspective, and reminds us that the language of the body matters deeply, whether on Earth or in orbit.

​One day, while studying the biography of Herbert von Karajan, the legendary conductor regarded as one of the greatest in the history of conducting and often referred to as the “conductor of conductors”, I was struck by his reflections on rhythm. He stated that “if no one teaches students the basic disciplines of rhythm, things become impossible”. Although this statement, coming from a musician, may at first seem to relate exclusively to music, in reality rhythm goes far beyond this. It encompasses a sense of balance in physical movement, mental processes, learning, self-care, daily activities and vital energy.

​Our bodies function rhythmically. We need only recall cardiac rhythm, breathing, sleep, digestive function and circadian rhythms, among many others. Of the biological rhythms that regulate bodily function, the circadian rhythm stands out as a central example, as it organises hormonal release in a time-dependent manner. The secretion of cortisol, melatonin, growth hormone and insulin follows patterns that influence metabolism, immune response, cognitive performance and tissue repair. In preventive medicine, recognising these rhythms allows functional variations to be interpreted, the timing of assessments to be guided, and interventions to be individualised.

​Still within the scope of preventive medicine, the starting point for a health review is not defined by age-related calendars nor by the presence of symptoms, but rather by the early recognition of functional changes, taking family history and genetics into account. Beginning an assessment at this stage means respecting an individual’s biological timing, interpreting subtle functional signals and anticipating risks before disease becomes established. In this way, the clinical review becomes a strategy of continuous, personalised care, aimed at preserving autonomy and health over time.

​These notions of the body’s own language interact with our daily activities. Returning to music, we know that a large proportion of Baroque works were written at a tempo of 75 to 80 beats per minute, measured by a metronome (a device used by musicians to regulate tempo by setting beats per minute), which corresponds closely to the average resting heart rate considered normal. It could be said that this synergy is pleasing to most people.

​A medical consultation also has its own rhythm, which is sometimes forgotten or even never learned. A consultation has a beginning, a development, a moment of climax and a conclusion. Expressing empathy either too early or at an inappropriate moment disrupts this balance, and the doctor–patient relationship becomes misaligned. Entering the correct frequency to properly understand a patient is a skill that requires a basic sense of rhythm. An andante tempo (a musical term referring to tempos between 72 and 84 beats per minute) closely resembles our heart rate and therefore feels comfortable to us. In other words, at the start of a consultation or during a visit to a patient in a hospital bed, the encounter should follow a rhythm that conveys safety and support from the doctor. This is a skill that should be better recognised and valued by professionals. From the patient’s perspective, the choice of when to undertake a clinical review should be carefully considered and planned for the new year that is beginning.

​Another, rather striking, story related to rhythm concerns three conductors who died while conducting the third act of Wagner’s opera Tristan and Isolde. The pauses in this passage are intermittent and irregular, creating tension that can affect both mind and body. Karajan, aware of this and seeking to protect himself, would dissipate this intense tension by using breathing movements to distance himself from the musical strain.
In life, as in music, it is essential to find the right rhythm for each challenge, especially when it comes to caring for one’s own health.

When humans eventually set foot on Mars, they’ll face a medical challenge that rarely needs to be thought about on Earth - TIME. A radio signal between Earth and Mars can take 4 to 24 minutes to travel one way. That means if an astronaut sends a question to Mission Control, it could be more than 40 minutes before they receive a reply, which in an emergency situation is far too long to wait.
To close this gap, NASA and Google are working together on something called the Crew Medical Officer Digital Assistant (CMO-DA), an artificial intelligence system for space medicine designed to support astronauts when Earth is too far away to give immediate help. Think of it as a “medical copilot” that will not replace doctors, but instead will help the crew diagnose and manage problems step-by-step using knowledge adapted specifically to space medicine.

Unlike a standard chatbot, the CMO-DA can work with multiple kinds of input. Astronauts might type or speak questions, upload vital signs, or share images from a portable ultrasound. The system then offers possible causes, highlights urgent warning signs, and suggests treatments that match the very limited supplies they have available to them. The big difference from Earth-based systems is that it’s trained with information that reflects spaceflight medical challenges, such as fluid shifts in low gravity, the increased risk of kidney stones, or how certain drugs behave differently in space.
To test its usefulness, NASA and Google have been running the assistant through structured scenarios. These use the same exam style that medical students face, called Objective Structured Clinical Examinations, where candidates are judged on how well they manage a case. The early results look promising, with the AI decision support tool giving safe, reliable advice, and it helps astronauts approach a situation more clearly under stress.

This project is part of NASA’s broader plan for Earth-Independent Medical Operations. For deep-space missions, it has long been recognised that crews need a much higher degree of autonomy, since communication with Earth may be delayed or even cut off entirely—for example, when Mars is hidden behind the Sun. A tool like the CMO-DA gives astronauts a way to stabilise and treat a patient without waiting for ground communication.
It’s important to remember that the system is meant as support and not as an authority. Ultimately, the astronauts in-situ remain the decision-makers. The assistant provides structured checklists, reminders, and treatment suggestions. It can also document everything that was done and prepare a clear report so that, once communication is restored, doctors on Earth can follow-up what happened and advise on next steps.

The future will bring new features, with researchers aiming to link the assistant to onboard sensors, wearables, and imaging devices, and to test it in Mars analogue missions on Earth. The goal is a complete medical system—crew, tools, and smart software working together to make medical autonomy on Mars a reality.
This technology, however, isn’t just for astronauts. It could also benefit people in remote communities on Earth, where medical access and connectivity are limited. In that way, a tool built for Mars missions medical support might improve healthcare for millions here at home.
NASA and Google’s project shows how AI in aerospace medicine is shifting from science fiction into practical support for space medicine—with potential benefits reaching well beyond Mars.

Microbes are generally associated with infection, and the usual response to their mere presence is to eradicate them as quickly as possible. For example, the “no-rinse soap” used during space travel mainly consist of antimicrobials, i.e. chemicals that kill microbes, with the aim to remove bacteria on the skin.
It is correct that microbes can cause disease, but it is microbes that created an environment and an atmosphere on Earth that allow plants and animals to exist. Microbes are literally everywhere, and we ourselves depend upon microbes to keep our external facing surfaces healthy and to help with the breakdown of food in our gut and production of substances that our body needs. The microbes form actual communities with thousands of species in and on us, for example the gut, respiratory and skin microbiomes, and these communities collaborate with our immune systems.

​To give an idea of their importance, data suggest that it is the pollution from antimicrobials that is the primary responsible for climate change because their impact is very broad and reduces the microbial diversity and changes the microbial balance. Similarly, studies indicate that antibiotics have long-term impact on our health, and they have been shown to increase the frequency of cancer, diabetes, asthma as well as functional impairments in children’s development, immune function, and cognition. Poor gut health, which usually means an unbalanced and low diversity microbiome, has also been associated with mental health problems including depression and anxiety as our gut microbiome is responsible for producing substances needed for normal brain function.
On the International Space Station skin issues and problems with wound healing have been reported. Microgravity and radiation have generally been assumed to be responsible for this and the fact, that “no-rinse-soap” is a cocktail of antimicrobials, has received practically no attention. Antimicrobials are traditionally used for treating wounds, but the US FDA reported in 2016 and again in 2022 that they are ineffective in treating wounds, and studies have demonstrated that antimicrobials directly impair healing and that a healthy wound microbiome is required for healing to take place. These novel conclusions banning antimicrobials in skin care and wound healing are further supported by the positive findings with a new technology, MPPT (micropore particle technology), which acts by regulating the wound microbiome without killing anything. MPPT has been able to achieve 100% wound closure rates, including in complicated wounds and in people with impaired immune function. This observation shows that approaches that support the collaboration between the microbes and the immune system can be much more effective than the traditional, old blanket-bombing approach of eradicating all microbes, which renders the skin debilitated and less resilient.

These observations are relevant to space travel, in terms of both the environment onboard and clothing, food and methods of ”washing”. Our bodies have evolved on Earth, where microbes were and are present, and our evolution has benefited from this as the microbes assist in protecting our surfaces and in delivering nutrients and critical compounds needed for our health. This dependence persists, even if we decide to leave Earth for shorter or longer periods of time. It is therefore a necessity, particularly for deep space travel, which does not permit us returning to Earth periodically to update our microbiome, to develop environments and procedures onboard that can sustain our microbial requirements.
These considerations are based on an article recently published in Frontiers in Public Health, which focuses on the role of antimicrobials in causing climate change from severely damaging the Earth’s microbiome. The impact of antimicrobials on the Earth microbiome and the microbiome inside a space station are comparable as they are both closed systems. It is consequently important to consider the essentiality of the microbial environment, when planning human life outside the Earth’s environment.

Bone plays an important role as a structure that supports the body and stores calcium. It retains fracture resistance by remodelling through a balance of bone resorption and formation.
Bones are usually dense and strong enough to support your weight and absorb most kinds of impact. As you age, bones naturally lose some of their density and their ability to regrow/remodel themselves.

​In a microgravity environment, because of reduced loading stimuli, there is increased bone resorption and no change in or possibly decreased bone formation, leading to bone mass loss at a rate of about ten times that of osteoporosis. Life in the microgravity environment of space brings many changes. Loss of bone mass is particularly noticeable because it affects an astronaut’s ability to move and walk upon return to Earth’s gravity.
Human spaceflight was once a fantasy only to be found in between the pages of a novel or on movie screens, however, now it is almost a tangible reality. Humans are going to spend more time in space. The human body is intrinsically adapted to Earth’s gravity, so exposure to conditions of reduced gravity, or microgravity can cause complications in many normal bodily functions. Microgravity decreases the effort required for movement.The length of space missions—and consequently the amount of time astronauts spend in orbit—has increased since humans began exploring space. Space travellers are exposed to numerous stressors while in space.
The reduced mechanical loading of weight-bearing bones caused by microgravity (μg) leads to bone loss in humans, especially in long-term space missions. As previously mentioned, this bone loss results from increased bone resorption and either unchanged or decreased bone formation, as observed in various human studies conducted both in space and during bed rest. Microgravity causes calcium to be released from bones, which suppresses parathyroid hormone (PTH) and lowers circulating levels of 1,25-dihydroxyvitamin D, although concentrations of 25-dihydroxyvitamin D remain adequate. This process reduces calcium absorption in the body.

The decrease in bone formation is associated with impaired osteoblast function and increased osteocyte apoptosis. Physical exercise using devices such as treadmills and resistive exercise equipment can help reduce the negative impact of microgravity on bones and muscles. Weight training and aerobic exercise are designed to simulate the mechanical loads normally exerted by gravity on Earth.
Proper nutrition and the use of supplements—such as vitamin D and calcium—are important to support bone health during and after a space mission. Rehabilitation programs include structured physical exercise, physical therapy, and nutritional monitoring to ensure optimal recovery. Together, these countermeasures aim to preserve musculoskeletal health in space and promote a successful transition back to Earth's gravity. Continued research is essential to refine these strategies for longer missions, such as those to the Moon or Mars.​

The webinar, organised by InnovaSpace Director Prof Thais Russomano, was presented by 4 students from the Remote Medicine iBSc program, National Heart & Lung Institute, Imperial College London, and in association with the MVA (Moon Village Association). The focus of the event was on one of the most critical aspects of future lunar habitation: human health.
Join the student panel as they explore the unique environment of the Moon, the history of its human exploration from NASA Apollo Mission first steps to future Artemis plans, its potential impact on human physical health and mental well-being, Moon research and Earth-based space analogues, and research limitations and gaps in the knowledge.
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Congratulations to the presenters - Manvi Bhatt, Nareh Ghazarians, Diya Raj Yajaman, & Elvyn Vijayanathan - and good luck with your future careers. 

​I became involved in Space research whilst my husband was completing his PhD in the early 90s, acting as ‘flight nurse’ for several parabolic flight human research studies. I went on to co-develop the Evetts/Russomano (ER) technique for basic life support in space, while continuing to work as a renal specialist nurse in the UK.

​In 2011, I became the sole flight nurse for the European Astronaut Centre in Cologne, Germany. I enjoyed two successful years working closely with the flight surgeons within the Operational Space Medicine Unit (OSMU), as it was called then. I was part of a team responsible for the day-to-day management and administration necessary for maintaining ESA (European Space Agency) Astronaut health. One of my key responsibilities was to track and retrieve data from medical events related to ‘pre’, ‘in’ and ‘post’ space flight activities.  
 
The role also involved working as the interface between OSMU, NASA, the ESA flight clinic and occasionally the Russian Space Agency, coordinating somewhat complex planning to ensure all flight medical examinations were completed within a rigid timescale from an Astronaut’s initial mission assignment, 18 months before they flew, to two years post-mission. The examinations took place at the locations of all 3 agencies to accommodate an Astronauts packed international training schedule. Astronauts who weren’t assigned to a mission, also required coordination of annual medicals locally.

​I particularly enjoyed good relationships with the NASA flight nurses who I had the pleasure to meet when visiting the Johnson Space Center in Houston. It was a great opportunity to meet all those I had been communicating with by phone and email, to cement our good working relationships.
 
I represented OSMU at weekly events such as the astronaut training coordination meetings, where planning and updates on training schedules and upcoming flight assignments would be discussed. Each team involved in preparing an Astronaut for flight was granted a certain number of hours of the astronaut’s time from a packed pre-mission schedule, to complete the necessary training and preparatory requirements. Arduous negotiations were required with other departments and the agency central mission organisation authority, should a team think they needed extra time to complete their activities.
 
As the Flight Nurse I was responsible to lead weekly clinical meetings to update the flight surgeons on any new information and issues relating to an astronaut’s health and the work underpinning their welfare.

This post does not attempt to address the many changes the human body experiences in space, such as volume modifications in body compartments, fluid shifts, structural configuration in receptor* morphology and, as a consequence, possible variations in pharmacology response, etc.

Rather, this post presents some of the technical challenges that an anaesthesiologist may encounter in space.
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Confined space.
On Earth gravity keeps everyone’s feet on the ground. Different pieces of equipment can be repositioned depending on the procedure, machinery can be brought in as needed (XRay scans in orthopaedics, for instance), electric cables can be switched to other convenient wall sockets etc. In a fixed volume space capsule, you don’t have all these possibilities. Everything is measured for maximum volume efficiency. Taking into consideration that anything can and will float if not properly anchored, we can imagine what an “anaesthesia dance” could happen!

What equipment?
On Earth an anaesthesia workstation is always present in the OR. Depending on its complexity its volume can vary between a medium size fridge to a large double-doored one, just put on its side. You don’t have this amount of deposit in a space cabin, but let’s suppose for one moment that you do - you then need an Anaesthesia Gas Scavenging System (AGSS), which removes the anaesthesia gases that have leaked out or at the end of the procedure. On Earth, these gases are expelled into the atmosphere (there is a lot to talk about this and the greenhouse effects too) and the air currents around any medical facility carry them away. In space you don’t have this. Any gas must be expelled using energy, an active process. Otherwise, the whole cabin will become a big anaesthesia machine with all crew members affected. And, speaking of energy, an anaesthesia workstation is also powered by electricity, which is a limited resource in space, depending on the surface of the solar (or light in general) panels. This energy must be stored and used for other life maintenance systems as well, of which a critical example is the Sabatier reactor that provides oxygen. 

Regional anaesthesia
The simplicity and portability of the necessary equipment makes this type of anesthesia attractive. For peripheral neural blocks all you need is a simple ultrasound machine and dedicated needles. The potential drawbacks are that the technique/s need to be taught on Earth but their “transposition” to space is a bit problematic. If the spinal/epidural anaesthesia is relatively simple to learn, the USG (ultrasound guided) blocks are more challenging. Furthermore, the bodily fluid shift due to the lack of gravity causes many tissues to change their tridimensional appearance, leading to increased difficulty in performing the block.

The cardiovascular responses that accompany spinal/epidural anaesthesia on Earth, in terms of heart rate and blood pressure, are different in space. There may be a lack of reactivity so a certain reduction in blood pressure, for example, might not be compensated.
We need to remember that the hostile environment in space, especially radiation, affects not only the human body, but also many sensitive electronic components of medical equipment, leading to possible dysfunction. Monitors can potentially de-calibrate and all the information you receive may become inaccurate.

Fluids
Preparing and administering a fluid on Earth is routine, however, the lack of gravitation in space poses other challenges: air and fluids do not mix. It is called “lack of buoyancy”. Unless we use special equipment to separate fluids from air nothing can be delivered to the patient. This statement is true also for the anaesthesia vaporiser (a special closed recipient that contains the anaesthesia substance); not only can you not simply fill it the way it would be done on Earth, but even if you could, the anaesthesia liquid that becomes vapour cannot separate from the fluid from which it originates. It just cannot exit the vaporiser. Below is a small example of how liquids behave in space and what happens when a liquid exits a recipient:

​The same is true for another type of anaesthesia, called TIVA = Total Intra Venous Anaesthesia. This technique uses a dedicated syringe pump that pushes different anaesthesia substances through an intra venous line. It’s a useful technique both in terms of volume and energy expenditure, but again we face the same problems: how to fill the syringe without air bubbles and how to protect the electronics of the syringe pump (in fact a computer in all respects) from the deleterious influences of space radiation!

As you can see, space medicine is a very important topic and many people dream of its future use. Yet, we still have a long way to go! With the advent of intermediary space “stops” and the continuous development of new technologies, every challenge will be solved, sooner or later.

​5G is the fifth generation of wireless communication technology, promising faster data transfer speeds, lower latency (round trip latency >10 milliseconds), increased network capacity (1 million devices per sq km), 99.999% network reliability and battery life of up to 10 years for IoT devices. There is considerable hype in the media that deployment of 5G will revolutionize healthcare by enabling new medical applications and improving existing ones. Using Edge computing, 5G Data can be processed closer to where it is generated. IoMT (Internet of Medical Things) devices generate huge amounts of data. Cloud computing can provide the necessary infrastructure to process and analyze this data. Faster transmission of data will enable more efficient storage in the cloud. Accessing more bandwidth and computing resources, and providing infrastructure to enable scalability will now be less problematic.

​No doubt clarity of images transmitted will be better and the immersive experience in video conferencing will be an all-time high. Mammograms, CT, MRI, and ultrasound images generate large amounts of data. High-speed transfer and processing will save a few minutes. Onboard cameras, camera-based Headgear, and ‘Body Cams’ for paramedics can transmit patient data to hospitals in real-time using ultra-fast and low-latency 5G connected ambulances, with medical equipment, patient monitoring applications and telemetry devices that ensure excellent pre-hospital management. 5G can facilitate real-time control of medical robots, enabling precise and safe interventions in performing complex procedures. 5G enables faster and more efficient data transfer, facilitating clinical trials and drug development, as these require the collection of large amounts of data from multiple sources.

This article addresses the notion of buoyancy and why drinking beer in space (the ISS usually orbits in the thermosphere), or any carbonated drink for that matter, does not produce the known tingling sensation we can feel in our noses here on Earth.

So let’s first briefly consider what is buoyancy?
In simple terms, whenever an object is put into a fluid there are several forces that act upon it. The liquid exerts a force from the bottom upwards that tries to push that object up. Then there is the liquid force itself, let’s call it weight, that pushes an object downwards. However, because the liquid pressure increases the deeper you go down into the fluid, there will always be an upwards force bigger than the downward force.
This can be explained by looking at the formula for hydrostatic pressure:

In this formula, p is the density of the liquid, g is the gravitational force (9.81 m/s2) and h is the height of the fluid column measured from the surface. Keeping all the other parameters of the formula constant, the "h" at the bottom of a submerged object will be higher than the one at its top.
But we also have here another component: the "g". Well, there is practically no "g" in space, unless we artificially produce it. So, in this case, all the objects inserted or included into a fluid will just stay there.
Of course, there are many other factors that play a role here, for example the superficial tension of the fluids etc., however, for the sake of simplicity I am considering here only the buoyancy. So, nothing happens with the CO2 bubbles inside the fluid because they are no lighter than the fluid that surrounds them, perhaps looking something like in this photo:

This not mixing between the fluid and gases within creates a hard enough life for anyone who would like to enjoy a beer in space (hypothetically, at least as alcohol consumption is not permitted on the ISS), but let's also not forget the cabin temperature of roughly 20 degrees Celsius, which is way too high to enjoy an ice cold beer. If you want to cool it a bit forget leaving it outside too - just take a look at what the temperatures are "outside", unless of course you want to lick your beer like an ice-cream!

My name is Lucas, I am a doctor in the UK working in anaesthetics (or Anaesthesiology for any American readers) and intensive care medicine. I have had an interest in space medicine for over 10 years now, inspired by none other than Prof Thais Russomano who has mentored me over the years and still does. My Master’s dissertation (back in 2009) focused on CPR (cardiopulmonary resuscitation) methods in microgravity, with my continued research interest surrounding critical care in space. I am careful to say that I am a doctor with an interest in space medicine and physiology, as opposed to a ‘Space Doctor’ – as there are many individuals out there who have committed many more years than I have to this field and are vastly more experienced than I am! A club I aspire to join one day.

The idea of this blog, or series of blogs, is to look at some of the latest research in space physiology and space medicine, then consider how this will play out clinically. With a particular focus on critical care and potentially worst-case scenarios when in space (or microgravity environment). Something all doctors will have done in their careers; we are equipped with the skills to critically appraise papers and then ask if they are clinically relevant, or how will it change current practice.

​Over the last 60 (ish) years of human space flight, there is lots of evidence to show that there are many risks when the human body has prolonged exposure to microgravity, which can affect most body systems – eyes, brain, neuro-vestibular, psychological, heart, muscle, bone, kidneys, immune system, vasculature, clotting and even some that we haven’t fully figured out yet. But then what needs to be done is to tease out how clinically relevant are these from the research, how could that potentially play out if you were the doctor in space, then how to mitigate that risk and potentially treat it.