Cosmic rays may damage astronauts’ brains

MIAMI, May 2, (Agencies): Flying people to deep space — like Mars or an asteroid — is high on NASA’s wish list, but research on mice suggested Friday that extended radiation exposure permanently harms the brain.

Central nervous system damage and cognitive impairments were observed in lab animals that were exposed to highly energetic charged particles — similar to the galactic cosmic rays that astronauts would encounter during long space flights — said researchers at the University of California, Irvine.

“This is not positive news for astronauts deployed on a two- to three-year round trip to Mars,” said lead author 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 longterm adverse consequences to cognition throughout life.” Currently, the world’s astronauts rotate in shifts that last about six months at the International Space Station.

In March, US astronaut Scott Kelly and Russian cosmonaut Mikhail Kornienko began the first year-long mission at the orbiting research outpost to test the impact of longer spaceflights on the body and mind.

NASA is aiming to send people to Mars in the 2030s, but skeptics say the technology is nowhere near ready, nor is it clear that such travel would be safe for people to undertake.

The latest research in the journal Science Advances subjected lab rodents to charged particle irradiation for six weeks at the NASA Space Radiation Laboratory at the Brookhaven National Laboratory.

This fully ionized oxygen and titanium led to brain inflammation, which disrupted the transmission of signals among neurons, said the study.

Transmit

The radiation impaired the brain’s communication network, interfering with the nerve cells’ ability to transmit signals.

“Like a bullet, charged particles hit dendritic branches and caused them to break off,” said the study.

“It’s well known that losing these dendritic branches is linked to cognitive decline in Alzheimer’s and other diseases.”

Tests on learning and memory also showed that irradiated mice did poorly and were prone to confusion, compared to normal mice.

“Radiation-exposed animals lacked curiosity (and were less active) in new situations and became more easily confused,” said the study.

“If the neuronal changes shown to occur in mice occur in astronauts, their response to unexpected situations, along with their ability to spatially reason and recall information may be impaired.”

Similar mental problems could take months to develop in humans, but any mission to Mars would likely take at least a year and a half, and possibly longer. Living on the ISS is not the same, because it circles the planet at a height that is still within the protective magnetosphere of the Earth.

Therefore, astronauts do not get bombarded with galactic cosmic rays that exist in deep space and are remnants of past explosions known as supernovae.

Limoli is part of NASA’s Human Research Program, which is probing how space radiation would affect deep space explorers.

He said spacecraft could include additional shielding in certain areas, but that these highly energetic particles will persist “and there is really no escaping them.”

In other news, SpaceX is just days away from shooting up a crew capsule to test a launch escape system designed to save astronauts’ lives.

Buster, the dummy, is already strapped in for Wednesday’s nearly mile-high ride from Cape Canaveral, Florida. He’ll be alone as the mock-up capsule is fired from a ground test stand and soars out over the Atlantic, then parachutes down.

Reliance

SpaceX is working to get astronauts launched from Cape Canaveral again, as is Boeing. NASA hired the two companies to ferry astronauts to the International Space Station to reduce its reliance on Russian rockets.

“It’s our first big test on the crew Dragon,” SpaceX’s Hans Koenigsmann, vice president for mission assurance, told reporters Friday.

The California-based SpaceX is aiming for a manned flight as early as 2017. It’s already hauling groceries and other supplies to the space station via Dragon capsules; souped-up crew Dragons will be big enough to carry four or five — and possibly as many as seven — astronauts.

NASA is insisting on a reliable launch abort system for crews — something its space shuttles lacked — in case of an emergency. That’s one of the hard lessons learned from the now retired, 30-year shuttle program, said Jon Cowart, a manager in NASA’s commercial crew program.

The 1986 Challenger accident occurred during liftoff, the 2003 Columbia disaster during re-entry. There was no way to escape, and each time, seven astronauts died.

NASA’s early Mercury and Apollo spacecraft had launch escape systems; the two-man Gemini capsules had ejection seats. The first four space shuttle flights also had ejection seats for the two-man crews, but those seats were removed as the crew numbers grew and the system was declared operational. The Russian Soyuz spacecraft have long had escape backup in case of a rocket explosion or fire at the pad. The system saved two cosmonauts’ lives in 1983.

Wednesday’s test is expected to last barely 1? minutes. “I can hold my breath the entire time probably,” Koenigsmann noted.

The eight rocket engines on the Dragon will fire in unison to propel the capsule off the makeshift stand, just as they would fire atop a rocket on the pad or in flight.