Traveling to Mars will wreak havoc on the human body – But how much?

As humans prepare to venture deeper into outer space, including potential trips to Mars, we need understand and possibly mitigate the effects of microgravity and radiation on space travelers’ bodies. Due to a communication delay in relaying messages between Mars and Earth, astronauts must be both prepared and capable of carrying out their duties without receiving immediate assistance from support crews. This window of radio silence differs depending on the alignment of the Sun, Earth and Mars in its orbit, but could last for as much as 20 minutes. If an astronaut faints when they first step out of the spacecraft or if there’s a medical emergency, they’ll be nobody on Mars to help them.

Mathematical models have great value in supporting clinical decision making by better understanding the physiology, by predicting outcome, and can be used to safely test interventions. The purpose of our model is to predict whether an astronaut can withstand orthostatic stress on Mars without fainting. We here provide a first-layer reductionist approach assessing that it is safe to travel to Mars under the perspective of hemodynamic resilience to orthostatic stress.

What can and cannot be done by this mathematical model?

The primary objective of the here presented model is to predict if humans can withstand orthostatic stress on arrival on Mars after prolonged space travel. The model is suitable for short- and long-duration spaceflight, simulate re-entry to Earth’s and Mars’ gravity, and is validated using previous orthostatic stress experiments in astronauts.

The model presented here represents a healthy adult male astronaut and does not include any gender effects. As private aerospace companies offer more and more opportunities for people to go into space, the level of fitness of astronauts is dropping. They no longer train for years, making their strength and endurance less optimal. Furthermore, the model is limited in the sense that is only focusses on the cardiovascular system. If one really what to know the challenge of travelling to Mars on human health and well-being the model needs to be extended with modelling results of multiple organs and the influence of radiation.

What is next?

Space tourism is not ‘if’, it’s ‘when’. We will have people with imperfect health who want to go to space. They will need to be assessed by healthcare providers who specialise in rapid and accurate space diagnoses to make sure that are fit to fly.

Using this model, we are beginning to develop organ and organ system-level modelling and simulation tools that can assist healthcare providers better assess the fitness to fly of prospective space travellers. This will allow to predict the risk of travel for individuals and help healthcare providers give health-specific advice to passengers on commercial, tourist spacecraft. It will help ensure that people who want to fly to space can, with the lowest possible risk.