There are several technological barriers that lie ahead of humankind’s ability to send astronauts to Mars and eventually colonize the red planet.
One of those barriers is space radiation and the threat it poses to astronauts during spaceflight. While Earth’s magnetic field protects us from most radiation, astronauts may be at significant risk for radiation sickness and increased lifetime risk for cancer, central nervous system effects and degenerative diseases, according to NASA.
It’s a problem that has perplexed scientists since astronauts first landed on the moon, and it’s one that an LSU research lab is trying to solve.
The SpaRTAN Physics laboratory is focused on understanding the impact space radiation has on both the health of human spaceflight crews and the resilience of space vehicle hardware systems.
The laboratory team is directed by Jeff Chancellor, an LSU physicist, who oversees multiple research projects that are all aimed at better understanding space radiation and its effects. Chancellor has worked for or with NASA for 25 years.
Most of the research in the lab is computational, but Chancellor plans to test materials and radiation models at the only heavy ion accelerator in the United States, in Brookhaven, New York. One of the lab's most important projects focuses on more accurately simulating the space radiation environment.
“By using our approach, we can replicate all the ions and energies up until iron and nickel that’s measured, like inside the international space station,” Chancellor said. “It’s almost the same environment the astronauts are exposed to. We’ve developed a new model that NASA seems to be quite keen on. We’ve come pretty close to replicating it from a ground-based accelerator.”
Two LSU graduate students working in the lab, Jared Taylor and Nousha Afshari, recently went to SpaceX to present some of their research to the company’s radiation and medical team. SpaceX is an aerospace company founded in 2002, and became the first private company to send astronauts into orbit in 2020.
Beyond the protection of Earth’s magnetic field, astronauts can only be protected with material on the spacecraft. Taylor’s research focuses on designing radiation shielding for satellites and spacecraft.
“It’s trying to optimize, get the most shielding we can given the weight that we’re allowed,” Taylor said. “You can only send up so much material. They need that weight for other things so that longer-duration missions are more feasible.”
The trip to Mars is not a short one.
“Right now, the presumed minimum NASA mission is two and a half years--about six to eight months each way--and they’re talking about spending a year on the surface,” Chancellor said.
NASA has guidelines for how much radiation astronauts can be exposed to during their career. The two-and-a-half year time period would leave astronauts at or above that limit.
“If you’re trying to go to Mars, we need to get the dose down as low as we can,” Taylor said.
It isn’t just the technological and engineering aspects that present barriers. Scientists’ understanding of how radiation affects our cells and the models we use to predict those effects have not been updated in decades.
“We don’t understand it at all,” Chancellor said. “There’s never been a clinical outcome diagnosing humans attributed to space radiation. So I would argue we’re really struggling to figure out what’s going on. It’s a complex problem.”
Afshari used to work at a hospital where she worked with many throat cancer patients. She said she observed that many patients with similar health backgrounds and lifestyles, with similar size and location of cancer were affected differently from radiation therapy.
“They come back, and one of them, their quality of life has deteriorated so much and the other one is kind of fine and is going to have much later effects,” Afshari said. “I was curious about why we can't give patients better statistics. Why don’t we know who’s going to be affected more by radiation than other patients?”
Afshari’s research aims to develop better models of how radiation affects human cells, which could benefit both astronauts and cancer patients.
SpaceX’s CEO, Elon Musk, has said many times he believes SpaceX can send people to Mars sometime in the 2020s, but it’s unclear how realistic of a goal this is with the current technology.
“They’re expanding into heavier launch capability that NASA has not been able to accomplish for the last 20 years or so,” Chancellor said. “They’re the main contributor to space flight at this point.”
The chief medical officer at SpaceX is a friend of Chancellor’s and he invited him to speak about his lab’s research and its implications for space travel.
Chancellor sent Taylor and Afshari to give presentations. They also received a tour of the highly-guarded facility from an engineer who worked there for five years.
“I used to work as an engineer, and it’s just a different beast at SpaceX,” Afshari said. “It was very surreal.”
“We were pretty blown away by the tour that we got,” Taylor said. “One of the engineers was a fan or something because he said ‘Go Tigers’ as we walked by wearing LSU gear."
Chancellor said radiation has always been the most predominant risk for humans in space flight and our understanding of it hasn’t progressed much since the Apollo missions.
“I would say there is definitely a sense of urgency to figure it all out,” Chancellor said. “We’ve been talking about this approach and developing it for about 10 years now. We’re pretty confident that we’re going to show something different than what has been seen before.”