The Effects of Space Travel on the Human Body

To mark International Day of Human Space Flight, UCL Physics & Astronomy Digital Student Ambassador Nishta explores how the extreme forces of space affect the human body from lift-off to touchdown.

Nearly all of us have been on an airplane and experienced a take-off. Recall that force that pushes you backward into your seat as the plane lifts off the ground and the tingly feeling in your stomach as you go airborne. 

Now imagine the same but with nearly 100 times the force and accelerating vertically, I’m getting a headache just thinking about it. This is where the effects of space travel on humans begin.

If you’ve somehow managed to fight past the headaches, nausea, and uneasiness from the rocket launch and reach outer space, space radiation is waiting to have a go at your health.

While we're snugly nestled within Earth's protective atmosphere and magnetic field, astronauts are exposed to a variety of radiation, including particles trapped in our planet's magnetic field, solar flares from the Sun, and galactic cosmic rays.

While studying about space weather through my course on space plasmas and magnetospheric physics, I’ve learned about how spacecrafts are shielded against these particles and rays. Spacecrafts carry delicate cameras and sensors on board, all of which need to be shielded from radiation. Further, the sleeping quarters of the crew need to be protected even more heavily. Shielding for these purposes is usually done using polyethylene, which is hydrogen rich and can withstand most impacts in space.

However, this shielding isn’t absolute and radiation exposure could cause increased risks of cancer, heart disease, and other degenerative ailments. VIGIL, ESA’s planned mission to closely study the sun, hopes to explore how we can protect ourselves and space explorers from solar radiation. My professor, Dr. Daniel Verscharen is the Science Lead for the Plasma Analyser (PLA) instrument (being designed by UCL/MSSL) on board ESA’s Vigil mission.

Sounding a bit scarier now? Astronauts also deal with living in confined spaces for prolonged periods. They have no access to nature or sunlight, have different day/night cycles, and are isolated for months. Further, due to being so far away from Earth, communications to mission control would take way too long to travel to them in an emergency. For example, a spacecraft orbiting around Mars would receive a signal from Earth 20 minutes after it has been sent, meaning astronauts need to be equipped to handle any situation on their own. And as if the psychological effects on the body weren’t enough, astronauts also deal with physical degradation.

Imagine a world where gravity plays by different rules—a realm where bones lose mineral density at an alarming rate, muscles waste away, and bodily fluids collect in the face and cause permanent bloating. In this weightless realm, astronauts face a myriad of challenges, from bone loss and muscle atrophy to vision problems and shrinking bones.

Has this been a very gloomy read? I’d hate to leave y’all without a note of optimism for space travel, so fear not, our astronauts are not without their defences. Researchers tirelessly work to develop countermeasures to combat the perils of space travel. From specialized exercise routines to experimental drugs combating bone loss, every tool in our arsenal is wielded in the name of astronaut health and well-being. More information on shielding can be found in these slides made available by NASA.
 
And besides, despite the myriad challenges posed by space, there's an undeniable sense of awe and wonder that accompanies each journey beyond our atmosphere. This is probably why we continue to venture out into the literal unknown for science, pushing the boundaries of human exploration and paving the way for a future among the cosmos.

Author: Nishta Varma