how the lack of gravity can scramble your brain

We’ve been going to space for 60 years now, and despite crewed launches becoming routine by now, trying to leave our home world is still expensive, difficult, and dangerous. Even if we forget the radiation, cramped quarters, and the deadly vacuum outside the spaceship ready to kill you at a moment’s notice, astronauts’ constant freefall does some serious damage over the course of an extended stay in orbit. The heart shrinks. Muscles atrophy. Fluids redistribute, upsetting balance, coordination, and even one’s sense of taste. Bones start to be reabsorbed by the body for nutrients. Urges for bodily functions become harder to detect, and even something as simple as going to the bathroom becomes a hassle.

And now, according to a new study by NASA-backed scientists found that because microgravity changes the very structure of the brain, reducing the number of connections between different areas and cortexes by changing how it floats in an astronaut’s skull, it can have adverse mental effects as well. While sensory and motor skills being compromised probably isn’t a surprise as fluids in our inner ear now can’t read our balance and orientation, and the brain has to kick in to actively compensate for typical automatic processing, a reduced ability to read others’ emotions was unexpected. Why is not known, but test subjects’ responses seem to indicate mild boredom and depression as potential culprits.

Now, it has to be noted that the participants were not sent to space. Instead, they were subject to 60 days in bed, with their heads slightly below the rest of their bodies to simulate the change in fluid distribution seen in astronauts. It’s possible that the excitement and novelty of being in space would’ve helped at first, but astronauts usually have their days packed with a lot of work and experiments, as well as mandatory exercise, so drudgery, stress, and overwork are pretty constant fixtures of astronaut life. Depression and isolation are not unknown among those who spent prolonged periods of time in space, and the study’s findings correlate well with the limited clinical data on actual spacefarers.

Even more concerning was the fact that after getting back upright, some subjects’ cognitive performance failed to improve rapidly, highlighting the need for proper and thorough medical care and therapy to adjust back to normal on Earth. While many of us may give little thought to sending crews for three year long missions to Mars, and plenty of astronauts may volunteer to go without a second thought, medical experts and clinical psychologists worry that what we’ve collected in our current experiments says this would be a terrible idea that could go very, very wrong hundreds of millions of miles from help. But that doesn’t mean travel to other worlds is out of the question for humans.

The answer would be bigger, faster, more comfortable ships with artificial gravity. They would be arguably the most expensive and sophisticated things we’ve ever built, but they would be worth every penny. By making space hotels with creature comforts similar to an actual hotel on Earth not just possible, but downright viable, and giving explorers the ability to function without having to bear the full damage of microgravity, and with the added bonus of personal space and proper rest and recreation, space travel could become lucrative, productive, and accessible. We even have all the designs and materials for creating such craft. All we need is financing and logistical backing from space agencies and aerospace pioneers.

We’ve made great strides in science and technology by sending humans to space, and we owe a lot to the hundreds of dedicated explorers who put their bodies and lives on the line to help advance our species. But if we want to keep reaching outward into space, and go further, for longer, with larger crews, we owe it to those we send to take their comfort and health into proper consideration, and listen to the researchers studying long term effects of cosmic radiation and microgravity on the human body. Missions to Mars should look like those in sci-fi movies, not just because they would be cool, but because we want our astronauts to survive and function well on a hostile alien moon or planet.

See: Basner, M., et al, (2021) Continuous and intermittent artificial gravity as a countermeasure to the cognitive effects of 60 days of head-down tilt bed rest, Frontiers of Physiology, DOI: 10.3389/fphys.2021.643854