Chris Hadfield will soon be the first Canadian commander of the International Space Station. The exuberant Canadian astronaut, who arrived at the high-flying laboratory Friday for a five-month stay, is also a willing guinea pig.
He and his crewmates will be poked and prodded for years to come as researchers and doctors explore just how far Earthlings can and should venture from the home planet.
Queasy stomachs, bone loss and muscle atrophy have long been associated with space travel, and there is new evidence that extended missions can raise pressure on the brain, impairing vision and multi-tasking skills.
Canadian astronaut Bob Thirsk’s eyesight deteriorated so badly on his six-month stay on the space station in 2009 that NASA sent up glasses so he could read emergency manuals, says Dr. Douglas Hamilton, now of the University of Calgary, who was Thirsk’s flight surgeon.
Thirsk’s eyesight recovered once he was back on the ground, but Hamilton says some space travellers have not been so lucky.
One astronaut was “literally walking into walls” weeks after his mission ended, while others have suffered permanent damage to their eyesight, says Hamilton, who has worked with NASA and its astronauts for years.
How limiting the problems could be to future space travel is an open question that space agencies and researchers are trying to answer on the space station, which is a test-bed for much longer expeditions to the moon and Mars.
Hadfield and his crewmates, U.S. astronaut Thomas Marshburn and Russian cosmonaut Roman Romanenko, rocketed into orbit Wednesday on a Soyuz rocket and have spent the past two days catching up with the International Space Station that speeds around Earth at 28,000 kilometres an hour.
By sidling up to the shiny station Friday, they will start to join the elite few who have spent months living in a weightless environment that does all kinds of curious things to the human body.
Hadfield is looking forward to flying from one end of the sprawling station to another, but it will take some practice to do it without banging into walls, cables and computers. And he’ll have to curb the Earthly habit of putting down of pencils and tools, that will simply float away.
When astronauts arrive at the station they often experience nausea – or “stomach awareness” as it’s called in NASA-lingo – but their stomachs tend to settle down after a couple of days.
They also grow. The 53-year-old Hadfield expects to soon be five centimetres taller, if only for the duration of his mission. Wrinkles will also disappear as fluids in his body shift upwards, making his face puffier and his legs skinnier.
Astronauts’ muscles weaken and calcium is stripped from their bones but improved exercise equipment and regimens – Hadfield plans to spend two hours a day in the gym – are designed to help slow the loss.
Hadfield and his crew will be running tests to gauge how much their hearts shrink and their blood vessels and blood pressure change.
“It’s a fascinating laboratory,” Richard Hughson of the University of Waterloo says of the station.
He designed some of the tests the crew will be running and says the cardiovascular system could probably cope with even longer missions if astronauts maintain rigorous and well-designed exercise regimes.
But the vision and brain changes some astronauts have experienced on the space station are seen as red flags.
Hamilton says many astronauts’ eyesight changes in orbit. Others have complained of cloudy thinking that make multi-tasking difficult – “the space stupids,” says Hamilton.
Bob Thirsk realized he had a problem when he started squinting at his space manuals.
“Bob was telling me that his near vision was gone and he couldn’t read,” says Hamilton, who got space shuttle commanders to take reading glasses up to Thirsk.
Thirsk now jokes about how he kept losing the glasses. “If I had a dollar for every time I lost a pen or lost my eyeglasses on the station, I’d be a rich man,” Thirsk said from Ottawa, where he is now vice-president of the Canadian Institutes of Health Research.
Some astronauts’ vision has changed permanently, says Hamilton, noting how some developed choroidal folds on the retina, which he likens to wrinkles on a carpet.
The vision changes could be a symptom of a much more serious problem known as intracranial hypertension, a condition in which pressure builds within the skull, Hamilton and his colleagues reported this spring.
They ran MRIs (magnetic resonance imaging) on the brains and eyes of 27 astronauts who had spent an average of 108 days in orbit. The MRIs revealed nine astronauts had expansion of the cerebral spinal fluid space surrounding the optic nerve, six had “flattening of the rear of the eyeball,” four had bulging of the optic nerve and three had changes in the pituitary gland that regulates important body functions, Hamilton and his colleagues at the University of Texas Medical School reported in the journal Radiology this spring.
The changes may also be tied to the way astronauts often lose their sense of smell and taste in space, says Hamilton.
To get a better read on what is happening, he says Hadfield and his crew will be doing ultrasounds on their eyes guided remotely by doctors on the ground and monitoring any change in vision.
And the space station is now equipped with plenty of adjustable eyeglasses, says Hamilton.