Bizarre Reason Astronaut Grew Two Inches Taller After 340 Days in Space

For most people, gaining a couple of inches in height is nothing short of a dream. However, for NASA astronaut Scott Kelly, this became a reality after spending nearly a year in space. Upon his return from the International Space Station (ISS) after a 340-day mission, Kelly was measured at two inches taller than his pre-flight height. While this might seem like something out of a sci-fi movie, the explanation behind it is rooted in the effects of microgravity on the human body. Let’s dive into the fascinating reasons behind this phenomenon and what it tells us about space travel and the human body.

The Role of Microgravity in Height Growth

On Earth, gravity constantly exerts force on our bodies, compressing our spines and keeping us at a fixed height. Our vertebral column is composed of individual bones called vertebrae, which are cushioned by discs filled with fluid. Gravity naturally compresses these discs, maintaining our typical height. However, in the microgravity environment of space, the force of gravity is significantly reduced, allowing the spine to decompress and stretch.

When astronauts spend extended periods in space, the spinal discs expand, increasing the distance between vertebrae. This expansion leads to an overall increase in height, sometimes by as much as two inches. Kelly’s case was no exception. His spine elongated due to the lack of gravitational compression, giving him a temporary height boost.

The Temporary Nature of Space-Induced Height Increase

While it might sound like a great perk of space travel, this height increase is only temporary. Once astronauts return to Earth, gravity begins to compress their spines again, and they gradually return to their original height. In Kelly’s case, within a few months of returning from space, he shrank back to his normal stature.

This temporary height gain is a well-documented phenomenon among astronauts. Even those who spend shorter missions in space, such as a few weeks or months, experience this effect. The longer the duration in microgravity, the more pronounced the height increase.

Other Effects of Space on the Human Body

Although growing taller in space may sound intriguing, it is just one of many physiological changes astronauts experience. Long-term exposure to microgravity can have significant effects on multiple bodily systems:

1. Bone Density Loss: The skeletal system weakens due to the lack of gravitational resistance, leading to bone density loss. This can increase the risk of fractures upon return to Earth.
2. Muscle Atrophy: Without the need to support their body weight, astronauts experience muscle weakening, requiring rigorous exercise regimens in space to mitigate the effects.
3. Fluid Redistribution: In microgravity, bodily fluids shift upwards, causing puffiness in the face and a decrease in leg volume.
4. Vision Changes: Some astronauts develop visual impairment due to increased pressure on the optic nerve, a condition known as Spaceflight-Associated Neuro-ocular Syndrome (SANS).
5. Radiation Exposure: Without Earth’s protective atmosphere, astronauts are exposed to higher levels of cosmic radiation, which increases the risk of cancer and other health issues.

The Kelly Twins Study: A Unique Opportunity

Scott Kelly’s extended mission in space presented NASA with a rare opportunity to study the long-term effects of space travel. Since he has an identical twin brother, Mark Kelly, who is also a former astronaut but remained on Earth, researchers were able to conduct a comparative study.

The study revealed that, beyond height changes, Scott’s body underwent numerous genetic and physiological shifts. Some of his DNA markers, gene expressions, and immune responses were altered by his time in space. Interestingly, while most of these changes returned to normal after a few months on Earth, some persisted longer, indicating potential long-term effects of space travel on the human body.

Implications for Future Space Missions

Understanding how the human body adapts to space is crucial as space agencies prepare for longer missions, including potential trips to Mars. A journey to Mars could take more than six months one way, with astronauts spending an extended period in microgravity before landing on a planet with a weaker gravitational pull than Earth. The insights gained from studies like Kelly’s help scientists develop countermeasures, such as specific exercises and medications, to minimize adverse health effects.

NASA and other space organizations are also investigating artificial gravity environments, which could help mitigate some of the negative impacts of prolonged weightlessness. Additionally, further research into the genetic changes induced by space travel could lead to medical advancements that benefit both astronauts and people on Earth.

The Fascination with Space and the Human Body

The case of Scott Kelly’s temporary height increase is just one of many intriguing aspects of human adaptation to space. From muscle atrophy to vision changes and even potential DNA modifications, the human body undergoes extraordinary transformations in the weightlessness of space. Each mission to the ISS or beyond provides invaluable data that brings us closer to understanding how we might one day live and thrive in space for extended periods.

So, while Kelly may have enjoyed a brief height boost, the broader implications of his journey are far more significant. As humanity prepares for deeper space exploration, every new discovery adds another piece to the puzzle of how we can survive—and even thrive—beyond our home planet.