When I was eight years old my family moved to Houston, Texas. As my father was a consultant rising the oil and gas industry’s consultancy ladder, it was inevitable that we would spend some time in a place other than London. Houston is a unique place, but was fascinating to a little girl; cowboys would ride into town with their covered wagons and every morning I would pledge allegiance to both the American and Texan flags.
However, there was one place which captured my imagination more than any other, the Johnson Space Centre. Home of mission control and the massive weightless environment pool (where they would place entire mock-ups of the space shuttle in order for the astronauts to train in a weightless environment) it was a place where my imagination could run riot. I could let it run as far as the edges of the universe.
I dreamed that one day I would explore the far reaches of the universe, that I’d be able be able to sit in a gleaming white space capsule whilst the earth appeared shimmering, beautiful and complete in the window. I would love to go into space; when the anniversary of the first moon landing was celebrated in 2009 I was genuinely moved as the precious few privileged men described walking on the moon.
Ever since watching the images of the landing capsules splashing down in the ocean and the astronauts being stretchered out, incapable of supporting their own bodies, I have wanted to know exactly what was happening to their bodies, what was changing in their physiology.
It is very complex, our physiology is, but there are some simple concepts which drastically change the body’s steady state of being.
What happens first is that the body quite simply loses its balance. Our vestibular and proprioceptive systems are responsible for keeping us balanced and upright, and stop us from falling over when walking down the street; our muscles have a multitude of receptors which monitor their precise pressure and length, whilst our inner ear works as our inner sprit level. These aren’t needed in space and settle in a new state, one that doesn’t keep you upright when back on earth!
There are also large changes in the cardiovascular system. Naturally on earth, due to gravity, blood is pulled downwards towards your feet meaning that more body fluids are found in your lower limbs. When gravity isn’t there, and the astronauts are floating their merry way around the weightless space capsule, blood and fluids redistribute more equally around the body. The redistribution shifts bloods and fluids headwards, and even affects the way the astronauts look, giving them bird legs and puffy faces.
The new space distribution of bodily fluids affect the sensors regulating fluids in the body, resulting in the kidneys eliminating seemingly excess fluids accumulated in the upper body. The decreased fluids throughout the body means that the heart doesn’t have to work as hard, when it is already working at a lower rate (it takes less energy to float around a spacecraft then happily strolling around on the earth). The heart becomes smaller and weaker. It undergoes cardiovascular deconditioning as the physiological needs in space are not as great as on Earth.
The weakened cardiovascular system, the lack of balance combined with the well-known bone degradation results in incredibly fit, courageous people being carried away in stretchers when arriving back at earth.
Today is the NASA’s Day of Remembrance. Remember those who have put themselves through this physiological ordeal to discover more about who we are and where we’re free, and paid the ultimate price.