December 9, 2025
4 min read
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Human Missions to Mars Must Search for Alien Life, New Report Finds
A major new study lays out plans for crewed missions to Mars, with the search for extraterrestrial life being a top priority
A. Martin UW Photography/Getty Images
The best reason to send humans to Mars isn’t for guts or glory—or the construction of colonies to safeguard against existential Earth-bound risks. Instead it’s to answer a single, simple question: Is or has there ever been life on Mars?
That’s the upshot of a new report published on Tuesday by the U.S. National Academies of Sciences, Engineering, and Medicine that presents an ambitious, science-centric vision for human missions to the Red Planet—with the search for alien life as their guiding star.
“When our astronauts set foot on Mars, it will be one of humanity’s greatest milestones,” says Dava Newman, an aerospace engineer and former director of the MIT Media Lab, who co-chaired the committee behind the report. “And finding extant or extinct life on Mars will be the discovery that defines the next century.”
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The report attempts to bridge the gaps between NASA’s science and its human spaceflight program in pursuit of a common goal, says report co-chair Lindy Elkins-Tanton—a planetary scientist who helms the University of California, Berkeley’s Space Sciences Laboratory, as well as NASA’s Psyche mission. “Learning how to blend these different disciplines is critical to our future as an interplanetary species,” she says.
The report lays out an additional 10 science objectives beyond the primary search for life and ranks four potential crewed campaigns, each composed of three sequential missions.
The highest-ranking campaign suggests targeting an as-yet-unselected, geologically diverse 100-kilometer-wide “exploration zone” rich with near-surface glacial ice, where signs of past or present life might be found. That project would involve astronauts initially staying on Mars for 30 sols (Martian days). This period would then be followed by an uncrewed cargo delivery and, finally, a 300-sol-long crewed mission.
The other campaigns would be slightly smaller in scope but audacious nonetheless. Two would involve building and operating drilling rigs on Mars, with one campaign proposing to drill as far down as five kilometers to reach subsurface regions where potentially life-bearing liquid water might exist. The lowest-ranked campaign deviates from the others in that it would see astronauts mount a series of shorter surface forays of 30 sols each at three separate sites across the planet.
All the campaigns propose leveraging “human-agent teaming” in the form of advanced robotics and software. And all include a “Mars surface laboratory” for immediate studies of samples—some of which would be later returned to Earth for deeper analysis.
Such “agents” might range from small autonomous devices to humanoid robots, says report committee member and former NASA astronaut Jim Pawelczyk, now a physiologist at Pennsylvania State University. “Their exact form will be determined by specific requirements, advances in hardware and artificial intelligence. That’s why it’s important to set the scientific objectives early; they drive subsequent technology development,” he says.
Yet, despite the 240-page report’s encyclopedic descriptions of each campaign, it glosses over several issues that are crucial to planning future missions. It doesn’t, for instance, identify specific exploration zones or lay out protocols for maintaining crew health and safety. Nor does it offer any preferred approach for “planetary protection,” the term for safeguarding against biological cross-contamination between Earth and Mars. (Present planetary protection guidelines would, in fact, prohibit crewed landings anywhere on Mars where liquid water is known to exist.)
These ambiguities are unlikely to be linked solely to the report’s strict focus on science, according to Jim Green, a former chief scientist at NASA and former leader of the agency’s planetary science division, who was not involved in the work. NASA’s budget is a political football, subject to radical shifts as presidents and congressional majorities change. The Trump administration, for instance, has proposed abandoning a NASA-led multibillion-dollar effort to retrieve samples that were already gathered by the agency’s Perseverance rover on Mars. “Due to the slowdown of the Mars robotic exploration program, we just don’t know enough about Mars to select one exploration zone as originally planned,” Green says.
The report also largely avoids the question of how any of its proposals would actually get done. It acknowledges NASA’s preexisting “Moon to Mars strategy”—agency shorthand for the Artemis program to return astronauts to the lunar surface as a precursor for human voyages to the Red Planet—but is agnostic about the timing for future Mars missions and the specific types of rocketry and spacecraft required to achieve them.
“Our frankly gargantuan task was to decide what science should be done by humans—and done best by humans,” Newman says. “There are going to be so many discoveries and advancements in technology that will be needed for these missions; if we constrained ourselves to the way we can do things now, we wouldn’t be designing the right campaigns for our future,” she adds, noting that the report doesn’t try to outline how to do everything from a technological standpoint.
What is clear, Elkins-Tanton says, is that the moon remains NASA’s next astronautical target, and putting boots on Mars remains firmly in the future. “We don’t just go to Mars tomorrow,” she says.
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