A new study funded by NASA shows that the long term effects of space travel could spell trouble for astronauts attempting to fly to Mars. It seems that astronauts undertaking the long voyage to Mars, could arrive at the Red Planet with brain damage.
For the new study, conducted by the University of California and published in the journal Science Advances, researchers bombarded mice with ionized oxygen and titanium nuclei for six weeks giving them a dose of particle radiation equivalent to what they would experience during a trip to Mars using todays propulsion technology and spacecraft shielding.
The results were unfortunately not promising. The mice all showed acute brain inflammation that changed the way their neurons fired, make them less efficient at transmitting electrochemical signals. This loss of efficiency hampered both their memory and problem solving skills, effects that were similar to those shown by brain cancer patients undergoing chemotherapy.
"This is not positive news for astronauts deployed on a two to three-year round trip to Mars," said Dr Charles Limoli, a professor of radiation oncology in UC Irvine School of Medicine.
"Performance decrements, memory deficits, and loss of awareness and focus during spaceflight may affect mission-critical activities, and exposure to these particles may have long-term adverse consequences to cognition throughout life."
The damage to the brain was particularly noticeable in the media prefrontal cortex and hippocampus, leading researchers to believe this would inhibit an astronauts ability to process complex problems and deal with unexpected events, both of which are very likely to occur when exploring a new planet for the very first time.
NASA is already aware that it will take a lot of shielding to keep the fragile human body safe on a trip to Mars. But the new study highlights just how difficult this could be especially considering the "very low" levels of cosmic radiation used for the study.
The simplest answer is to build more shielding around the craft, but this raises the cost of construction and increases the amount of fuel needed to make the trip.
Metals such as aluminum are not very good at protecting humans from radiation. Plastics are somewhat better, and some designs even suggest using water as a shielding substance. The research team, on the other hand, believes that there may be a medical answer to this problem.
"We are working on pharmacologic strategies involving compounds that scavenge free radicals and protect neurotransmission," said Limoli. "But these remain to be optimised and are under development."