The Human Body in Space

Feburary 16, 2026

Jawadul Islam

Queens High School of Sciences at York College

10th Grade

Outer space has always been a bizarre topic. Filled with so much unknown, scientists still try to explore its endless abyss. But for what reason does this ambiguity remain for this topic? It has been many years since we have been studying this void. There is a lot that we know about it, or at least, we think we do. But then why does it feel as though outer space remains as mysterious as it was previously known to be? Well, that is because the range of this void's mysterious force doesn’t remain limited to that which is within this outer world but can also impact the world that we live in, the world that seems familiar. But in fact, not only can outer space strangely affect the things around us, but it can also strangely affect our own bodies. Within this article, it will be discussed how our bodies can react and change strangely when entering this unknown world of space, particularly due to a phenomenon called microgravity.

(Image credit:BMIMI)

But first, one must understand what microgravity truly is. Microgravity is a situation where gravity's pull is very weak, leading to a feeling of near-weightlessness. This happens in space when objects are in free fall, such as when astronauts are orbiting Earth inside a spacecraft. Although gravity still exists, the feeling of weight is greatly reduced because both the object and its surroundings fall together at the same rate. This environment is different from zero gravity. Gravity is not absent, but it is significantly diminished. This leads to unique physical and biological effects on cells, fluids, and materials.

Microgravity has various effects on the human body. When astronauts are sent into space, the change of gravity disrupts aspects of cellular structures and functions. The factors coming from the new change in environment are capable of altering the cytoskeleton and cell adhesion mechanisms. When within microgravity, the cells often reorganize their internal frameworks. These changes in the internal framework are due to disruptions caused by microgravity. These disruptions damage the ability of the cell to respond to its surroundings, having the potential to destroy various tissues and bodily functions. For a deeper investigation, let's look at specific cell types that these disruptions of microgravity can affect. Microgravity can affect bone cells, leading to bone loss of astronauts. It is able to change muscle cell structures and functions and can affect retinal cells, causing vision changes reported by astronauts.

(Image credit:Frontiers) 

Microgravity also has various effects on more general bodily functions, more specifically the nervous and the immune systems. For the immune system, microgravity leads to alterations in gene expression within immune-related cells, particularly in blood vessel cells. It also affects T cells, but rather than gene expression and mutation, it affects the function/activation of the T cells. The weekend T cell activation makes astronauts more vulnerable to infections and reduces capabilities of body temperature regulation. For the nervous system, the main point of impact is the central nervous system. It goes through structural changes within microgravity, including fluid redistribution and brain shifts. These changes are connected to aspects such as balance and sensory issues, which are shown to be evident when astronauts return to Earth.

In conclusion, despite these changes and disruption due to microgravity, we have been able to alter the genetic structure and bodily system that can keep our lives moving. might seem interesting or might seem terrifying to some, they're still important to analyze. Due to the various other parts of space that are still left unknown, without a single idea of what secrets they might hide, it's important that we understand the effect that the environment of space, along with its factors, not only microgravity, might have on us and on our bodies. Only by doing this can we minimize risk and ensure that humans can continue to learn and thrive. Who knows what space exploration might hold for us in the future, but we will never find out if we don't try to understand space as it is, and specifically if we don't try to understand it for EVERYTHING that it is. So it's important that we continue to learn, continue to research, and pave the path for newer opportunities. Again, there's no telling what the future might hold, but to stay ready, you must remember to keep investigating, to keep learning, to keep yourself updated, and most importantly, to keep yourself curious.