GALVESTON - Distorted eyeballs. Decreased blood circulation. Increased feelings of isolation.
Perhaps unsurprisingly, the human body can experience a wide range of unique medical symptoms living in a space station 268 miles away from the surface of Earth and hurtling through space at 17,150 mph.
Now, a NASA astronaut is preparing to push the limits of human habitation of space. Next month, Scott Kelly and two Russian astronauts will begin a yearlong mission aboard the International Space Station.
Assuming that he does not have to abort his mission early, Kelly will become the first American astronaut to spend a year in zero-gravity. Three Russian astronauts have accomplished the feat. The record for the longest single space flight is held by Valeri Polyakov, who spent 437 days in space in 1994 and 1995, most of it aboard the Mir space station.
The goal of the mission is to study the effects of long-term space flights on the human body, said Dr. Tarah Castleberry, a professor of aerospace medicine at The University of Texas Medical Branch.
“A body is made for and adapted to gravity, but when you go into space you’re only at zero or very low gravity,” Castleberry said. The shift to zero-gravity can cause muscle and bone to deteriorate, and affects the body’s metabolic system.
Astronauts like Kelly are typically in top physical condition when they leave Earth, and over the 54 years that humans has been going to space, NASA has learned a lot about what a body does in orbit, and how to counteract some of those things.
“What we have learned over time is that many things happen to the human body in space,” Castleberry said. “But the human body adapts. It does these things naturally, and it does things it should do and that are normal.”
Information from Kelly’s mission will be used by NASA as it continues to plan for a manned mission to Mars. Being able to predict how a body will hold up over an extended period in space is an important hurdle to overcome.
“There are normal things that happen so that we can adjust to having no gravity,” Castelberry said. “The body does that. What we’re concerned about is that we know what happens to the body after two weeks, two months, six months. ... But there are some things that we’re concerned about if you have a longer stay.”
For instance, in weightless environments, liquids don’t flow through the body the same way they do on Earth’s surface. This lack of gravity can cause eyes to change shape, affecting vision. What’s unknown is how far that vision deterioration goes. Knowing that information is important, because sight problems would make exploring another planet difficult.
“We’re not sure if the body continues to have changes or does it reach a point of stasis where it’s not changing anymore,” Castleberry said.
The mission will also track Kelly’s behavioral health — including the effects the isolation of being in the space station has on his mental state. He will have to track his experiences in a journal.
“There’s no fresh air. There’s no wind. There’s no rain,” Castleberry said of the space station experience. “You can look down, and there’s Earth, but it can be pretty isolating.”
Much of the data collected about Scott Kelly will be compared to his twin brother and fellow astronaut, Mark Kelly.
Kelly and two Russian cosmonauts will launch from a site in Kazakhstan on March 27.