Mars astronauts could develop dementia on journey to Red Planet

Dangerous space radiation could mean astronauts develop dementia before ever setting foot on Mars

A lengthy Mars trip could spark dementia for astronauts Photo: GETTY

The technological challenge of getting to Mars may seem like a huge hurdle but it may be biology that holds humanity back from venturing to the Red Planet.

Astronauts could develop irreversible dementia on their journey because their brains are being bombarded with destructive space radiation, scientists fear.

The University of California found that exposure to highly energetic charged particles – much like those found in the galactic cosmic rays – can cause significant damage to the central nervous system, resulting in brain impairments.

“This is not positive news for astronauts deployed on a two to three year round trip to Mars,” said Charles Limoli, professor of radiation oncology in UCI’s 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.”

At its closest orbit Mars is around 34,000,000 miles from Earth and it takes between 150 and 300 days to reach the Red Planet depending on speed of launch. It means that simply travelling there and back could see astronauts being subjected to dangerous radiation levels for nearly two years.
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Female astronauts are known to be more susceptible to space radiation and generally spend 30 per cent less time in space.
To test the impact, rats were exposed to fully ionized oxygen and titanium to simulate space radiation, at Nasa’s Space Radiation Laboratory.
The researchers found that exposure to these particles resulted in brain inflammation, which disrupted the transmission of signals among neurons.
Imaging revealed that the brain’s communication had been damaged by reductions in the structure of nerve cells called dendrites and spines and alterations to synapses, which allow neurons to communicate with each other.

Nasa’s Curiosity rover has been on Mars since 2012

The rats also performed less well in tasks designed to test learning and memory.
While cognitive deficits in astronauts would take months to manifest, Prof Limoli said, the time required for a mission to Mars is sufficient for such deficits to develop.
People working for extended periods on the International Space Station do not face the same level of bombardment with galactic cosmic rays, as they are still within the protective magnetosphere of the Earth, the Van Allen belt.
The irradiated particles that compose these galactic cosmic rays are mainly remnants of past supernova events.
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Prof Limoli’s work is part of NASA’s Human Research Program which is looking at the impact of extended periods in space and how the problems could be mitigated.
He recommends building a spacecraft which would have increased shielding at areas where astronauts rest and sleep.
However, these highly energetic particles will traverse the ship nonetheless, he said, “and there is really no escaping them.”
“We are working on pharmacologic strategies involving compounds that scavenge free radicals and protect neurotransmission.
“But these remain to be optimized and are under development.”
Astronauts face a series of health problems related to spending long periods in space. Microgravity causes the heart to pumping as strongly causing muscle mass loss. Often astronauts pass out when they return to Earth.
Most struggle to sleep in space, only getting an average of six hours a night, which is bad for long term health.
Hearing and sight loss is also common. Of the 300 US astronauts examined since 1989, vision problems developed in 29 percent of those on two-week missions and a 60 per cent of those who spent several months on the International Space Station.
Astronauts are also at greater risk of kidney stones because of microgravity and the difficulty in staying dehydrated.
Space flight may also make astronauts infertile. Animal experiments have shown that both male and female reproductive organs are affected by microgravity.
Although most astronauts have already had their families by the time they go into space, Nasa is so concerned that it now offers egg and sperm freezing.
The Mars One mission is currently scheduled to land its first crew on the planet in 2025, but it has warned volunteers that conception may not be possible in reduced gravity and that a fetus born on Mars may not develop properly.
The first spacecraft ever to make the journey from Earth to Mars was NASA’s Mariner 4, which launched on November 28, 1964 and arrived at Mars July 14, 1965. It took just 21 photographs.
The research was published in the journal Science Advances.