- MRI tests on travellers to International Space Station uncover effects on eyeballs and brain connections
- Mission to Mars may not be possible
- Humanity’s ability to get to and settle on another planet may also be a non-runner
By Eddie Wrenn
PUBLISHED: 05:57 EST, 13 March 2012 | UPDATED: 11:20 EST, 13 March 2012
Brain scans of NASA astronauts who have spent more than a month in space have revealed damage to their eyeballs and brain tissue.
The research may have long-term implications for long-term space journeys, hypothetically preventing us from spreading through-out the solar system and beyond.
Researchers used MRI scans to examine the eyes and brains of 27 astronauts, and found examples of brain damage caused by exposure to the micro-gravity of space.
This ranged from a flattening and bulging of the eyeball to damage to the connections between the brain and the pituitary gland – one of the key glands governing bodily functions.
With humans adapted over millions of years for living within the pressure of Earth’s atmosphere and gravity, it is unsurprising that space plays havoc with our systems.
In fact, with astronaut bodies trapped between conflicting gravity fields, lower gravity, and centrifugal forces, probably the most surprising fact is that our bodies can endure space at all.
The MRI scans took place on astronauts who on average had been exposed to zero or micro gravity for an average of 108 days, either on space shuttle missions or on-board the International Space Station.
The problems are similar to those caused by intracranial hypertension, a rare and dangerous condition where pressure inside the brain rises and presses against the skull and eye sockets.
The results, published in the journal Radiology, showed that:
- Nine of the 27 astronauts suffered an expansion of the cerebral spinal fluid space surrounding the optic nerve
- A flattening of the rear of the eyeball in six astronauts
- Bulging of the optic nerve in four astronauts
- Changes in the pituitary gland and its connection to the brain in three of the astronauts
While these findings are not likely to put a hold on any current planned space missions, there may be implications to long-term travel in space as humanity continues to broaden our horizons.
If humanity cannot survive years of living and travelling in space, our ability to spread through-out the solar system and beyond is at risk.
However it is likely that technological solutions will be found as we push the final frontier.
Study leader Larry A. Kramer, MD, professor of diagnostic and interventional imaging at The University of Texas Medical School at Houston, said: ‘Microgravity-induced intracranial hypertension represents a hypothetical risk factor and a potential limitation to long-duration space travel.
‘Consider the possible impact on proposed manned missions to Mars or even the concept of space tourism. Can risks be eventually mitigated? Can abnormalities detected be completely reversed?
‘The next step is confirming the findings, defining causation and working towards a solution based on solid evidence.’
The types of abnormalities spotted are observed in cases of intra-cranial hypertension where no cause can be found for increased pressure around the brain.
The pressure causes swelling of the juncture between the optic nerve and the eyeball which can result in visual impairment.
Bone mineral loss and muscle atrophy are some of the other known effects of zero gravity on astronauts.
William J. Tarver, MD, chief of flight medicine clinic at NASA/Johnson Space Center, said the agency has noted changes in vision in some ISS astronauts, but the origins were not yet fully understood.
He said: ‘NASA has placed this problem high on its list of human risks, has initiated a comprehensive program to study its mechanisms and implications, and will continue to closely monitor the situation.’
He added the findings are suspicious but not conclusive of intracranial hypertension.
No astronauts have been considered ineligible for space flight duties as a result of the findings
Read more: http://www.dailymail.co.uk/sciencetech/article-2114320/Can-humanity-cope-long-term-space-travel-Scans-reveal-damage-brains-eyes-astronauts.html#ixzz1oxWDfjjl