SpaceX founder Elon Musk can’t wait to bring people — and probably, regrettably, brands — to Mars. But unless he starts taking space radiation seriously, Musk’s Martian bachelor pad will more closely resemble a barren litter box. A physicist tells Inverse the problem of radiation on Mars is more dire than scientists previously assumed.
According to a new study published in the journal Space Weather, levels of galactic cosmic rays (GCR) are much higher than what scientists typically see at this stage in the solar cycle. GCRs are high-energy protons and heavy ions from outside our solar system, which lose electrons as they beam through space at around the speed of light.
After analyzing data from CRaTER on NASA’s Lunar Reconnaissance Orbiter (LRO), scientists concluded the number of GCRs is ramping up to reach the highest levels recorded since Sputnik back in 1957. As such, aerospace companies need to think more critically about how to protect passengers.
The team attributes the unusually high levels of GCRs to the sun’s relative inactivity over the last 15 years. An active sun strengthens its magnetic field, which helps protect our entire solar system from galactic cosmic radiation. If that shield is weak, it could pose major health problems for astronauts traveling into deep space to Mars, asteroids, and beyond.
“Our sun’s activity has been very weak since about 2005 — anomalously so,” Nathan Schwadron, professor of physics at the University of New Hampshire and lead author of the study, tells Inverse. “It’s created an environment in our solar system where it does not do as good of a job as shielding cosmic rays coming in from beyond the solar system. With less shielding, we see higher levels of cosmic rays.”
There’s almost no research to inform us about the long-term effects of GCR exposure to the human body. The studies we currently have only provide information about astronauts who’ve spent a relatively short amount of time in space — a few months to a year at most — and even those reports are concerning.
“Beyond Low Earth Orbit, space radiation may place astronauts at significant risk for radiation sickness, and increased lifetime risk for cancer, central nervous system effects, and degenerative diseases,” NASA writes on its website. “Research studies of exposure in various doses and strengths of radiation provide strong evidence that cancer and degenerative diseases are to be expected from exposures to galactic cosmic rays (GCR) or solar particle events (SPE).”
GCRs won’t zap astronauts to their demise, like a ray gun from a sci-fi B-movie. But they could cause serious damage to astronauts’ cells, as they can pass through spacesuits with ease. This kind of radiation could also seriously mess with electronics onboard spacecraft, like SpaceX’s upcoming Mars rocket, the BFR.
Though NASA seems keenly aware of the risks space exploration GCRs pose, private space has been disconcertingly dismissive.
“There’s going to be some risk of radiation, but it’s not deadly,” Musk said back in 2016 at the International Astronautical Federation (IAC) in Guadalajara, Mexico. “There will be some slightly increased risk of cancer, but I think it’s relatively minor … the radiation thing is often brought up, but I think it’s not too big of a deal.”
For someone whose purported goal is to “make humans an interplanetary species,” Musk seems to take a cavalier attitude toward the overwhelming evidence that radiation will be the number one challenge for people who will travel to — and eventually live on — Mars.
“The space radiation environment will be a critical consideration for everything in the astronauts’ daily lives, both on the journeys between Earth and Mars and on the surface,” Ruthan Lewis, an architect and engineer with the human spaceflight program at NASA’s Goddard Space Flight Center, says in a statement published on NASA’s website. “You’re constantly being bombarded by some amount of radiation.”
Schwadron feels similarly concerned about the effect of GCRs on astronauts and is increasingly troubled by the private sector’s disinterest in them.
“I don’t think [the private aerospace sector] is taking the problem seriously,” he tells Inverse.
“We know that it’s not going to kill astronauts immediately, but in terms of long-term effects, we know next to nothing. And the only information we have comes from relatively short missions we did many, many years ago when the radiation environment was different.”
Since there’s so little research on space radiation’s potential effects on astronauts in long-duration missions, it’s hard to say what the solutions will be. But Schwadron says NASA and private aerospace must make future investigations a top priority.
Maybe Musk should consider shifting his priorities from “getting people to Mars” to “actually keeping people alive” there.
