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British scientists led by Nathaniel Szewczyk from Notthingham University believe that microscopic worms, which are biologically similar to humans, may hold important clues as to how we can adapt to long-term living in space environments, such as a colony on Mars.  

His team sent 4,000 microscopic worms, Caenorhabditis elegans, into space aboard the space shuttle Discovery, and were able to successfully remotely monitor 12 generations of them over a period of 6 months, whilst they were housed on the International Space Station.

This type of worm has long been used by scientists to further our understanding of human biology. They were the first multi-cellular organism to have its genetic structure completely mapped, and many of their genes perform the same function as found in humans, such as promoting muscle function.

According to Szewczyk, in a study recently published in the journal ‘Interface’, many of the biological changes that occur during space flight affect astronauts and worms in the same way.

"We have been able to show that worms can grow and reproduce in space for long enough to reach another planet and that we can remotely monitor their health. Worms allow us to detect changes in growth, development, reproduction and behaviour in response to environmental conditions such as toxins or in response to deep space missions," Szewczyk said.

This makes the worms an ideal and cost-effective way to study the possible effects of both long term and long distance human space exploration, which are known to have major challenges associated with them, including exposure to high levels of radiation, rapid loss of bone density and muscle weakness.

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Yet another problem with long term Space travel has been highlighted this week, following the release of results for a study by NASA researcher Lakshmi Putcha and her colleagues.

Need a medication here on Earth? No problem – simply visit your local chemists or look in your medicine cabinet at home where simple medications such as pain-killers or antibiotics, if stored correctly, have a shelf life of up to a couple of years and retain most of their potency in that time. However, astronauts in Space it would seem might not be quite so lucky.

Longer duration Space travel, such as to Mars, may require astronauts to spend up to 2 years on board a space craft, and so the need to take greater volumes of medication will be required. Little is currently know in relation to the potential effects that the Space environment can have on these – an environment subject to such factors as microgravity, radiation, flight vibration, as well as variations in temperature and humidity.

Consequently, a study was conducted involving flying four boxes of drugs, each containing 35 medications up to the International Space Station (ISS). In accordance with good scientific practice, four identical boxes were also kept under controlled conditions at NASA’s Johnson Space Centre in Houston, USA, to act as a control for comparison. The four boxes from the ISS were returned one by one, back to Earth after varying lengths of time, with one box returning after just 13 days and the last box returning after 28 months on the ISS.

The medications were analysed to see how they compared to the control kits and it was found that; less than third of the medications kept in Space met US requirements for levels of active ingredients; the longer the kits were in Space, the fewer the number of formulations that retained acceptable potency levels.

The authors conclude that "It is important to characterize space-specific degradation products and toxicity limits using ground-based analogue environments of space that include proton and heavy ion radiation, vibration and multiple gravity conditions.  This information can facilitate research for the development of space-hardy pharmaceuticals and packaging technologies."

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The dangers presented to astronauts by long term missions into Space have long been known, are numerous, and for the most part remain in the realms of theory and supposition due to a lack of real life situations and physical data.

What can be done by scientists is to create an artificial environment that simulates one or more of the conditions that may be faced by astronauts, and conduct appropriate experiments to evaluate the possible effects on the human physiology.

For example, scientists at the University of Alabama in Birmingham, USA have done exactly this in relation to the possible effects of cosmic radiation on the human heart, details published April 6 2011, in the journal Radiation Research.

Researchers analysed the effect of exposure to iron ion radiation on mice, a radiation commonly occurring in Space, to see if exposure promotes the development of arterial disease (atherosclerosis).

According to Prof. Dennis Kucik, associate professor in the department of pathology, UAB, “It's well known that prolonged exposure to radiation sources here on Earth, including those used in cancer treatment, excessive occupational exposure and atomic bombs, are associated with an increased risk for atherosclerosis. But cosmic radiation is very different from X-rays and other radiation found on Earth. The radiation risks of deep-space travel are difficult to predict, largely because so few people have been exposed."

Results from the research found that permanent damage to the aorta and carotid arteries in mice did take place, which suggests that deep Space missions, such as those to Mars, might present health risks for astronauts from radiation that could give rise to heart problems.   

For more details click HERE
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Galvanic Vestibular Stimulation system
Some interesting research is being conducted by Dr Steven Moore, associate professor of neurology at Mount Sinai School of Medicine in New York, USA.

His team has been developing a Galvanic Vestibular Stimulation system (GVS) that can safely induce the sensory and mobility disturbances that are often experienced by astronauts when returning to Earth’s gravity.  

The system developed uses large electrodes placed behind the ear to deliver small amounts of electricity (5 milliamp) to the vestibular nerve, which then sends the signal onto the brain and causes motor and sensory disturbances.

The human body is adapted to Earth and its gravitational force, with our brains receiving and interpreting the information sent from sensory organs, such as our eyes and our inner ear vestibular organs. When in the microgravity environment of Space, the pattern of information is changed with the gravity sensitive inner ear no longer functioning as it would on Earth. Many astronauts will suffer from Space Motion Sickness, disorientation and a loss of sense of direction early in the mission, before adapting to their new ‘weightless’ setting within a few days. When returning to Earth’s gravity once more though, they must readjust again and can experience problems standing up, walking and turning, and stabilizing their gaze. These disturbances can affect an astronaut’s vision and neurological functions, potentially affecting operational activities including the ability to safely land a spacecraft.

Thus, the development of a new tool that can safely simulate the vestibular disturbances experienced in Space can prove valuable.

"You can train for spaceflight tasks under normal conditions on Earth, but that will not give you an indication of what an astronaut will feel like," Dr. Moore said. "The GVS system will make mission simulations more realistic. This will be quite useful for astronaut training, especially for astronauts that have not flown before." 

Want to see a video showing the effects of the GVS? Click the link below;

http://www.nsbri.org/default/NSBRI%20News%20Pictures/Moore_Project/Moore_GVS.wmv
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Astronaut S Williams on ISS Treadmill
Reserachers from Marquette University, Milwaukee, USA, led by Prof Robert Fitts recently published results in the Journal of Physiology showing that astronauts suffer from a loss of muscle fibre mass, force and power when subject to the microgravity environment on board a spacecraft for any length of time.

The problem of muscle loss is a well known and researched area in space medicine, but this study is the first to include specific analysis of muscle cells on long-duration missions. Fitts and his team collected tiny samples of calf muscle tissue from nine US and Russian astronauts, 45 days before launch and again on the day of return from a six month mission onboard the International Space Station (ISS). Sample analyses results confirmed just how much muscles atrophy in zero gravity takes place, with according to Fitts, a decline of more than 40% in the capacity for physical work.

Crew members on board the ISS take part in a program of daily exercise, typically devoting up to 2 hours of their day for preparation and exercise time, either pedalling a stationary bike, jogging on a treadmill while held down by a harness, or using resistance devices. A once a day exercise session, however, no matter how intense, cannot compensate for the fact that whilst in Space their bodies are not having to work against the force of gravity.

From the day that we are born, here on Earth, we grow and function in a world where every movement we make requires our physiology to battle against gravity – and thus, our muscles develop and are maintained. Obviously, a lot depends on how active an individual is as to how well maintained those muscles are – are you a fitness god or a couch potato?

But the point is that astronauts on the ISS live in a virtually gravity free world. This has physiological effects and consequences which need to be addressed if a manned trip to Mars is ever to be a realistic option. 
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