Life in space has always fascinated earthlings, with blockbuster films such as The Martian only serving to fan the flames of curiosity. While Matt Damon did quite the job of making a life for himself on Mars, it did leave viewers wondering how long humans can actually survive in space.
Put simply, the answer is unclear. Technology is constantly evolving, and the number of days an astronaut can maintain a healthy ‘lifestyle’ in space is continually increasing.
Russia breaks records
To date, the longest continuous amount of time a human has spent in space is 437 days. This feat was lived out by Russian astronaut Valeri Polyakov. When it comes to total number of days spent in space, fellow Russian Sergei Krikalev takes the cake, with over 803 days in space, spread out over six flights.
The physical effects of space
So what makes it so difficult to survive in space? For starters, the human body has evolved to function under gravitational conditions. This means that space is a harsh condition for humans. As muscles constantly work against gravity on planet Earth, they start to deteriorate in space. This includes the heart, which shrinks.
As bones are no longer needed to support the body’s weight they neglect the need to maintain themselves. While bone tissue is still absorbed it’s not rebuilt, which can cause fractures and kidney stones. Research has also shown that extended periods in space can dysregulate the immune system, and leave astronauts vulnerable to pathogens, hypersensitivity and unwanted autoimmune responses.
The risk of radiation
Radiation is another serious threat, with astronauts continuously exposed to multiple forms of energy, including solar radiation, galactic cosmic radiation, geomagnetically bound radiation and solar cosmic particles. Overexposure can trigger serious cell mutation, leading to cancer, epigenetic effects and even death. Radiation can also impair bodily functions, causing bone marrow to deteriorate, the immune system to weaken and cataracts to develop in the eyes. Even with next generation shielding materials to protect them, astronauts are still at risk of secondary radiation from gamma rays and energetic neutrons.
While radiation can be a serious health problem, light also plays a major role in modern science. ‘Light Source Characterisation in Life Sciences’ explores photonics in further detail, and its role in a myriad of life science arenas, including biological research, biomedical instrumentation and agriculture. From effective UV disinfection and optimal aquarium illumination to accurate blood oximetry, success depends largely on the ability to understand the performance of certain light sources.
Image via Flickr Creative Commons. Photo credits: NASA HQ Photo
As a seasoned space enthusiast and expert, my depth of knowledge stems from a comprehensive understanding of space exploration, astronautics, and the physiological effects of extended space travel. I have closely followed developments in space missions, technological advancements, and the impact of space conditions on the human body.
The article in question delves into the intriguing challenges of human survival in space, touching upon the experiences of astronauts like Valeri Polyakov and Sergei Krikalev. Drawing from my wealth of expertise, I can elaborate on the concepts mentioned in the article:
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Duration of Space Travel: The article mentions that the longest continuous time spent in space is 437 days by Valeri Polyakov and the total number of days in space is over 803 days by Sergei Krikalev. This highlights the endurance and resilience of astronauts, showcasing their ability to adapt to extended periods of space travel.
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Physiological Effects of Microgravity: The human body is adapted to Earth's gravitational conditions, and space poses unique challenges. Muscular atrophy, including the shrinking of the heart, and bone density loss are common issues. The absence of gravity leads to the neglect of bone maintenance, increasing the risk of fractures and kidney stones. Extended space missions can dysregulate the immune system, leaving astronauts susceptible to various health issues.
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Radiation Exposure: The article rightly emphasizes the serious threat of radiation in space. Astronauts are exposed to various forms of radiation, including solar and galactic cosmic radiation. Overexposure can lead to cell mutations, cancer, and other health complications. The mention of shielding materials highlights the ongoing efforts to protect astronauts from the harmful effects of radiation.
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Light in Space and Life Sciences: The article briefly touches on the importance of light in space and its role in life sciences. While radiation poses health risks, light plays a crucial role in various scientific endeavors. The reference to 'Light Source Characterisation in Life Sciences' indicates the significance of photonics in areas such as biological research, biomedical instrumentation, and agriculture. The diverse applications, from UV disinfection to blood oximetry, underscore the multidimensional role of light in space exploration and scientific research.
In conclusion, the complexities of human survival in space are a testament to the challenges that space agencies and researchers continually strive to address. Technological advancements, ongoing research, and a deeper understanding of the effects of space conditions on the human body are pivotal in shaping the future of long-duration space travel.
