SCOTT KELLY RETURNS 2 INCHES TALLER
NASA astronaut is back in the USA where he’ll face the poking and prodding of scientists who will compare the space traveler with his twin who stayed on Earth
NASA astronaut Scott Kelly returned to the USA on Thursday after spending nearly a year in space. Now that Kelly is home, his journey is just beginning. Kelly’s year in space was part of a NASA twin study involving his brother, Mark. While Scott was in space, Mark remained earthbound, which will allow scientists to study the effects of space travel on the human body in preparation for a crewed mission to Mars.
Specifically, researchers will look at the effects of space radiation, as well as the effect of visual impairment associated with long-duration space flight, according to Graham Scott, chief scientist at the National Space Biomedical Research Institute and deputy project scientist for the NASA and NSBRI Twin Study.
What can a year in space do to the human body?
VISION
One of the primary things researchers will focus on is the effect of long-term space on Kelly’s vision, according to Scott.
“We will be looking at the eyes to see how much visual acuity has been lost,” he said during a phone interview Thursday.
Scott said the majority of astronauts who return from time in space have mild vision loss, but researchers aren’t completely sure why vision is affected while in space.
BONES AND MUSCLES
For almost a year, Scott Kelly did not have to use his legs to walk but instead floated to different areas of the space station. In the past, astronauts would leave space with brittle bones and weak muscles, according to Scott.
Lack of use also causes muscles to become weak and shrink.
Researchers have helped mitigate the impact on bones and muscles by implementing exten- sive workout routines that astronauts carry out while in space. Scott said that onboard the International Space Station, astronauts tie themselves down to a treadmill, strap into a bike and use a resistance device to work out for two to 2.5 hours a day.
When bones break down, they release calcium, which can lead to kidney stone formation and bone fractures.
LONG-TERM EFFECTS OF RADIATION
Radiation is the biggest issue astronauts will face when they journey to Mars, Scott said.
On the International Space Station, astronauts get 20 times the amount of radiation people on Earth are exposed to, according to Scott.
“If you go on a journey to Mars and get into deep space, there is several hundred times, maybe 300 times the radiation,” he said.
He said researchers are extremely interested in the effect radiation has on the heart, blood vessels, bones, central nervous system and the brain — as well as the cancer risk.
Kelly’s medical study with NASA will continue long after this year, including yearly physical checkups.
THE HEART CAN SHRINK
While in space, the cardiovascular system does not have to work as hard as it does on Earth.
“Just like the bones and muscles, the heart is designed to work in one gravity here on Earth, so when you put the heart in space, it operates differently and changes shape,” Scott said.
He noted that one of the transitional effects of returning to Earth is that astronauts can feel faint, so they are placed on custom beds.
BODY
One obvious change for Kelly was that he came back 2 inches taller than his brother because a lack of gravity causes spinal disks to expand.
When astronauts return to Earth, they must readjust to gravity and can have issues with balance and simple tasks such as standing up, walking or operating a vehicle.
Scott said astronauts go through a physical reconditioning program and typically function normally within one to three weeks unless they’ve suffered significant bone or muscle loss, which could take months or years to recover from.