After a prolonged wait of nine months, NASA astronauts Butch Wilmore and Sunita Williams finally returned to Earth from the International Space Station (ISS) on March 18. Both of them are currently undergoing a 45-day rehabilitation programme.
The two veteran NASA astronauts embarked on a one-week-long space venture last year. However, their stay got extended owing to unforeseen technical glitches including helium leaks and thruster malfunctions in the carrying Boeing's Starliner.
Why The Rehabilitation Programme Is Needed?
Upon returning to Earth after a spending a long period of nine months in space where gravitational pull is negligible, it was inevitable for the astronauts to encounter health implications.
To get rid of the inconveniences like puffy heads, chicken legs, taller space heights, and reduced bone density and to recalibrate their bodies for gravity, both Sunita and Butch are currently undergoing a 45-day rehabilitation programme.
About The 45-day Rehabilitation Programme
The extensive rehabilitation process initiated right from the landing day. As per media reports, the programme involves two-hour daily sessions seven days a week for 45 days. The reconditioning programme for the astronauts is being conducted by Astronaut Strength, Conditioning, and Rehabilitation (ASCR).
The programme is divided into three phases. While the first phase focuses on ambulation, flexibility, and muscle strengthening, the next phase includes proprioceptive exercise and cardiovascular training. The last and final phase, ehich is also the longest one, focuses on functional development.
What Is Microgravity?
According to NASA, 'Microgravity' is defined as a condition in which people or objects appear to be weightless.
Microgravity isften termed as 'zero gravity', which scientifically wrong and misleading. As the name suggests, the term 'micro' means 'very small'. So the feeling of weightlessness comes from the condition where gravity seems to be very small ocmpared to the Earth.
Due to the presence of microgravity, astronauts are always seen floating inside their spacecraft or the International Space Station. Moreover, the lack of gravity also facilitates easy movements of equipment weighing hundreds of pounds.
Microgravity's Impact On Human Body
From affecting fluid distribution, muscle loading to altering saignalling pathways- a prolonged stay in microgravity affects human body in several ways, according to NASA.
Basic physiological changes include alterations in blood pressure and the quantity of blood that is pumped by the heart with each beat. This can permanently affect the way organs and blood vessels behave.
"The heart does not need to work as hard against gravity to pump blood to the upper body. This causes blood volume to increase in the upper body. Since the heart is less efficient some blood remains in the heart after each contraction which slightly increases the pressure during the relaxation phase", NDTV reported citing a NASA report from 2015.
Apart from the impacts on cardiovascular health, microgravity can also affect the aerobic capacity, muscular strength, power, endurance, stamina, bone density, balance, agility, coordination, orthostatic tolerances, proprioception, neurovestibular function and flexibility of an astronaut.
