Imagine if a pharmaceutical company began giving an experimental drug to people without any clinical trials. The company had conducted only limited studies of the drug on cell cultures and animals. Those tests had revealed dire effects of the drug. Would the drug company’s actions be considered legal or ethical? If you substitute ‘NASA’ for ‘pharmaceutical company’ and ‘deep-space travel’ for ‘experimental drug,’ you have precisely the situation with regard to future human deep-space missions.
In fact, it is certain that a formal clinical trial of human deep-space exploration under established regulations would have been legally prohibited, given the known damaging effects of radiation and microgravity on cells, tissues, animals, and humans revealed by scientific studies. The known effects on humans would have made such a clinical trial legally indefensible.
Even as the Artemis program aims for long-term occupation of the moon, and Elon Musk and the Trump administration push for a Mars mission, human exploration of deep space could be deemed ethically indefensible because of the established hazards of radiation, weightlessness, disease, toxic chemicals, and psychological trauma. NASA itself has recognized such severe, unsolved “Red Risks” of deep-space travel; and researchers have conceded that they cannot reliably estimate the medical risk of deep-space exploration missions. Deep space beyond Earth orbit is particularly hazardous because astronauts are not shielded from the most intense interplanetary radiation by the Earth’s magnetosphere. And on deep-space missions beyond Earth orbit, rescue or resupply may be weeks or months away.
In trying to understand the effects of deep space, scientists are trapped in a cosmic catch-22. They cannot be sure that humans can survive in deep space until humans are sent on deep-space missions. But they cannot ethically send humans on deep-space missions until they know that astronauts can survive.
What’s more, the profoundly traumatic medical and psychological impacts of long-term lunar and Mars missions could be deemed inhumane under rules governing imprisonment of convicts, treatment of prisoners of war, or other such humanitarian situations.
It’s possible to envision what a Mars mission would be like, given the known effects of deep space and the debilitating impacts on astronauts of missions on the International Space Station. Mars-bound astronauts would be confined for nine months in a windowless craft the size of a small motor home. They would be speeding through a pitch-black, airless, frigid outer space with no possibility of rescue or resupply. They would eat only dehydrated, space-radiation-degraded food. Personal hygiene would be minimal. They could not take baths, and there would no laundry, so they could not wash their clothes. So, the craft would grow more and more fetid with the exudations from their bodies.
Weightlessness would require them to exercise hours a day in an ultimately losing effort to maintain their muscles and bones. Their eyesight would become blurry, and they might even go blind. Amid long periods of crushing boredom, alarms would signal the malfunction of some critical system that provided air, water, or heat. They would have to repair it, or perhaps die.
They could only contact loved ones through a link that would impose long delays. There would be no clinic, with only one trained medical caregiver, little diagnostic equipment, and a limited supply of pharmaceuticals. They would be bombarded by intense deep-space radiation that could kill them immediately, or ultimately give them cancer.
After the nine months, their craft would descend on a roaring pillar of flame to land on a desolate, lethally cold, airless, radiation-blasted surface covered with toxic dust. Upon landing, they would have to instantly transition from weightlessness to gravity, their muscles and bones weakened. Nearly crippled, nearly blind, traumatized, and depressed, they would have to immediately begin to perform complex tasks crucial for their survival.
After a month on the planet surface enclosed either in the lander or in a spacesuit, they would be launched once more for a nine-month voyage back to Earth. Even with the promise of home, on this return voyage they would continue to suffer whatever medical and psychological problems arose on their outbound voyage and their stay on the Martian surface.
However, this scenario is optimistic. The crew may well have succumbed to any number of medical or spacecraft catastrophes. After all, deep-space travel is a “serial killer,” as are lunar and Mars missions. That is, they are like the serial circuits of old-time Christmas tree lights, in which the loss of one defective bulb extinguished the entire string of lights. Similarly, in deep space a single medical catastrophe amid untold possibilities could end in astronauts’ death or disability. Any organ—heart, lungs, immune system, brain, or eyes—could fail. And the severe limits on medical capabilities in deep space would prevent treatment.
Likewise, in deep space, the loss of any spacecraft system—oxygen supply, temperature control, food, water, or radiation protection—would mean catastrophic failure, ending in death. For example, the loss of both the Space Shuttles Challenger and Columbia were due to the failure of single components of the massively complex spacecraft systems. The Challenger exploded because of a burn-through of a solid-fuel rocket booster, and the Columbia disintegrated because a piece of foam insulation damaged a carbon-fiber tile on the wing.
While astronauts do give informed consent to undertaking space missions, they may not really be “informed,” given that deep-space travel, including extended lunar and Mars missions, has never been carried out and cannot be simulated. Thus, it presents hazards that have never been experienced by astronauts and cannot be anticipated. So the analyses of the hazards of deep-space travel can be no more than limited, educated guesses—not an ethical basis for requiring consent. And, astronauts may well be under coercion in some sense, with their own ambition and dedication compelling them to risk their lives on missions that are hazardous, even lethal.
Given all these issues, a key ethical question is: At what point does exploration become exploitation, in which the advocates of human deep-space travel become willing to sacrifice the lives of astronauts for scientific, political, and economic gain?
Dennis Meredith is the author of “Earthbound: The Obstacles to Human Space Exploration and the Promise of Artificial Intelligence.”
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