The central premise of the blockbuster film “Project Hail Mary” is a long-shot mission with a familiar goal: Save humanity from extinction. While the details of the threat facing humanity are new to this story, moviegoers are used to bingeing on popcorn while watching a heroic quest to save the Earth from certain doom. And like so many popular movies of this genre, from “Armageddon” to “Interstellar,” the hero’s journey involves a seemingly impossible mission into space.

The film’s release is well timed for the new era of space exploration. NASA’s Artemis II mission, scheduled to launch in early April, will send four astronauts around the Moon on a path that will take them deeper into space than any humans have ever traveled.

The flyby mission is primarily about testing equipment for a lunar landing in 2028. But the broader plan was outlined in detail in March 2026 by NASA officials: to establish a permanent base on the Moon.

NASA is not alone in its lunar ambitions. Private space companies SpaceX and Blue Origin are developing next-generation spacecraft, rovers and drones to facilitate the American Moon base. And other nations, notably China, are working toward their own lunar outposts.

These nations and corporations see the Moon as a stepping stone toward more ambitious goals: a major human migration into deep space, including Mars.

Given the moment, it’s worth reflecting on what those investing billions in human space exploration, whether tax dollars or private funds, are trying to accomplish. As a biologist, I recognize the limitations of humans as space explorers. As I explain in my book, “Becoming Martian: How Living in Space Will Change Our Bodies and Minds,” while biologists have learned a lot about how the conditions of space affect the human body and mind, sending people on longer missions deeper into space will expose people to unknown health risks.

Boldly going

Plans to send people to the Moon and beyond are accelerating. NASA’s new administrator, Jared Isaacman, has argued that beating China to the Moon is a matter of national security, calling the Moon “the ultimate high ground.” He has also promoted the economic benefits of establishing a space economy that includes mining and manufacturing on the Moon.

Subcommittees in both the House and Senate have passed bills to codify these initiatives into law – making the goal of creating a permanent base on the Moon official U.S. policy. They appear to have bipartisan support, and votes in both houses of Congress are expected soon.

The United States and China are targeting landing humans on Mars in the 2030s, with the intention of building infrastructure that enables long-term habitation.

In March 2026, NASA also announced that the agency intends to test nuclear propulsion during an uncrewed flight to Mars in 2028. Nuclear-powered rockets have the potential to substantially reduce the time it takes to reach Mars, which would make crewed flight to the red planet more feasible.

Humans or robots?

But why do people need to go to Mars? As with the Moon, the purported motivations for both the U.S. and China establishing a human presence on Mars are scientific, economic and geopolitical. Yet these are distinct objectives that are often conflated.

In terms of science, NASA has had dramatic success with its Mars rovers, including the discovery last year of a potential biosignature that could be the best evidence yet that the planet was once home to microbial life.

Robotic missions also have a lower price tag and a higher acceptable risk margin than human missions. While Isaacman remains publicly committed to the Artemis program and its human spaceflight goals, the agency’s plan also includes a suite of robotic missions to the Moon’s surface it hopes to develop in partnership with companies, universities and international partners.

Likewise, some economic objectives, such as establishing mining and manufacturing facilities, could be accomplished using AI-equipped robots, such as those Tesla is developing. Robots are a long way from being able to accomplish the full range of tasks that a human can do, but prioritizing robotic activities could lower the exposure that people have to the hazards of space.

If having people on the Moon and Mars is indeed necessary to achieve these objectives, let’s be clear about the risks that the people undertaking these missions will be assuming.

Space and the human body

While scientists have learned a lot about how space affects the body during the six decades of human spaceflight, there are still significant blind spots. Among them are the effects of deep-space radiation.

The 24 Apollo astronauts who traveled to the Moon are the only people who have ever been past the Van Allen radiation belts, an area of space surrounding our planet formed by Earth’s magnetic field.

By trapping radiation from the Sun and from deep space, our planet’s magnetic field is part of what makes Earth habitable for us and other life forms. The Moon and Mars lack magnetic fields, so radiation levels on their surfaces are substantial. NASA researchers are now conducting experiments on rodents using simulated galactic cosmic rays, which are largely blocked by Earth’s magnetic fields. Preliminary results suggest that this type of radiation may impair cognitive abilities, but the actual effects on people are unknown.

Similarly, while medical researchers know that floating in a zero-g environment causes muscle atrophy and bone density loss during long stays on the International Space Station, they know relatively little about how partial gravity affects muscles and bones. The Moon has one-sixth the gravity of Earth, and Mars has a little over one-third.

Pilots on Earth can simulate partial gravity for up to 30 seconds at a time during parabolic flights, but only the 12 Apollo astronauts who walked on the Moon have ever experienced it for longer than that. The longest they stayed was about three days. Scientists can only speculate about whether prolonged exposure to the partial gravity of the Moon or Mars would have consequential health effects.

Human interest

Sending robots to space avoids having to deal with risks to human health. But there are downsides. Not only do robotic space missions have fewer capabilities than crewed missions, they often fail to capture interest and imagination and demonstrate national prestige in the same way that human missions can.

The four members of the Artemis crew will captivate people worldwide watching their daring mission around the Moon, much like moviegoers root for Ryan Gosling’s character in “Project Hail Mary” as he boldly seeks to save humanity from certain doom on the big screen.

That human interest is the common link that ties together public and private space ambitions worldwide. While robotic missions are more practical and cost effective, they simply don’t inspire the masses the way a human crew can. Beyond achieving any economic, political or scientific goals, space exploration is ultimately about people doing difficult things.

I am the author of the book Becoming Martian published by MIT Press