The cardiopulmonary system of astronauts in a microgravity setting will undergo significant alterations. When it comes to a risk associated with traveling to Mars, the biggest concern is prolonged exposure to microgravity – near zero gravity.
An astronaut’s ability to reach Mars safely and carry out their mission obligations once there could be predicted using a mathematical model created by space medical scientists from The Australian National University (ANU). The model might be used to evaluate how short- and long-duration space travel affects the body, and it could be a crucial component in assisting with the landing of people on Mars.
The model uses an algorithm based on astronaut data collected from past space expeditions, including the Apollo Missions, to simulate the risks of traveling to Mars.
Dr. Lex van Loon, a Research Fellow from the ANU Medical School, said, “However, there are multiple risks associated with traveling to Mars, the biggest concern is prolonged exposure to microgravity – near zero gravity – which, combined with exposure to damaging radiation from the Sun, could cause “fundamental” changes to the body.”
“We know it takes about six to seven months to travel to Mars, and this could cause the structure of your blood vessels or the strength of your heart to change due to the weightlessness experienced as a result of zero gravity space travel.”
“With the rise of commercial space flight agencies like Space X and Blue Origin, there’s more room for rich but not necessarily healthy people to go into space, so we want to use mathematical models to predict whether someone is fit to fly to Mars.”
Astrophysicist and emergency medicine registrar Dr. Emma Tucker said prolonged exposure to zero gravity could cause the heart to become lazy because it doesn’t have to work as hard to overcome gravity to pump blood around the body.
“When you’re on Earth, gravity pulls fluid to the bottom half of our body, which is why some people find their legs begin to swell up toward the end of the day. But when you go into space, that gravitational pull disappears, which means the fluid shifts to the top half of your body, triggering a response that fools the body into thinking there’s too much fluid.”
“As a result, you start going to the toilet a lot, getting rid of extra fluid, you don’t feel thirsty and don’t drink as much, which means you become dehydrated in space.”
“This is why you might see astronauts on the news faint when they step foot on Earth again. This is quite a common occurrence due to space travel, and the longer you’re in space, the more likely you are to collapse when you return to gravity.”
“The purpose of our model is to predict, with great accuracy, whether an astronaut can safely arrive on Mars without fainting. We believe it’s possible.”
Dr van Loon said, “Due to a communication delay in relaying messages between Mars and Earth, astronauts must be able to 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 at least 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. This is why we must be certain the astronaut is fit to fly and can adapt to Mars’ gravitational field. They must operate effectively and efficiently with minimal support during those crucial first few minutes.”
- van Loon, L.M., Steins, A., Schulte, KM. et al. Computational modeling of orthostatic intolerance for travel to Mars. npj Microgravity 8, 34 (2022). DOI: 10.1038/s41526-022-00219-2