Human Missions to Mars Must Search for Alien Life, New Report Finds

Human missions to Mars must search for extraterrestrial life, new report says

By Lee Billings edited by Claire Cameron

The best reason to send humans to Mars is not courage or glory, nor building colonies to guard against Earth-related existential risks. Rather, it is about answering a simple and unique question: is there or has there ever been life on Mars?

That’s the finding of a new report released Tuesday by the U.S. National Academies of Sciences, Engineering and Medicine, which lays out an ambitious, science-centered vision for human missions to the Red Planet, with the search for extraterrestrial life as its 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 that created the report. “And discovering existing or extinct life on Mars will be the discovery that defines the next century.”

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The report attempts to bridge the gap between NASA’s science and its human spaceflight program in pursuit of a common goal, said report co-chair Lindy Elkins-Tanton, a planetary scientist who directs the Space Science Laboratory at the University of California, Berkeley, as well as NASA’s Psyche mission. “Learning to blend these different disciplines is essential for our future as an interplanetary species,” she says.

The report outlines 10 additional science objectives beyond the primary search for life and ranks four potential crewed campaigns, each consisting of three sequential missions.

The top-ranked campaign suggests targeting a 100-kilometer-wide, geologically diverse and yet-to-be-selected “exploration zone” rich in near-surface glacial ice, where signs of past or present life might be found. This project would involve astronauts initially remaining on Mars for 30 sols (Martian days). This period would then be followed by an uncrewed cargo delivery and, finally, a crewed mission lasting 300 sols.

Other campaigns would be smaller but nonetheless bold. Two of these would involve building and operating drilling rigs on Mars, with one proposing drilling up to five kilometers deep to reach subterranean regions where potentially life-bearing liquid water could exist. The lowest-ranked campaign deviates from the others in that it would see astronauts carry out a series of shorter surface forays of 30 sols each to three separate sites across the planet.

All campaigns propose to leverage the “human-agent team” in the form of advanced robotics and software. And all include a “Mars surface laboratory” for immediate studies of samples, some of which would then be returned to Earth for further analysis.

Such “agents” can range from small autonomous devices to humanoid robots, says Jim Pawelczyk, a member of the report’s committee and a former NASA astronaut who is now a physiologist at Pennsylvania State University. “Their exact form will be determined by specific requirements, advances in hardware and artificial intelligence. This is why it is important to set scientific goals as early as possible; they will guide further technological development,” he says.

Yet despite the encyclopedic descriptions of each campaign contained in the 240-page report, it glosses over several crucial questions for planning future missions. For example, it does not identify specific exploration areas or establish protocols to maintain crew health and safety. It also does not propose a preferred approach for “planetary protection,” a term for protection against biological cross-contamination between Earth and Mars. (Current planetary protection guidelines would, in effect, prohibit crewed landings anywhere on Mars where liquid water is known to exist.)

These ambiguities are unlikely to be related solely to the report’s strict scientific focus, according to Jim Green, NASA’s former chief scientist and former head of the agency’s planetary science division, who was not involved in the work. NASA’s budget is a political football, subject to sweeping changes as presidents and congressional majorities change. The Trump administration, for example, has proposed abandoning a multibillion-dollar NASA-led effort to retrieve samples already collected by the agency’s Perseverance rover on Mars. “Because of the slowdown in the Mars robotic exploration program, we simply don’t know enough about Mars to select an exploration area as originally planned,” says Green.

The report also largely avoids the question of how any of its proposals would actually be implemented. It acknowledges NASA’s pre-existing “Moon to Mars strategy” — the agency’s shorthand for the Artemis program to return astronauts to the lunar surface as a precursor to human travel to the Red Planet — but it is agnostic about the timing of future Mars missions and the specific types of rockets and spacecraft required to carry them out.

“Our task, frankly gargantuan, was to decide what science should be done by humans – and done best by humans,” says Newman. “There will be so many discoveries and technological advances that will be needed for these missions; if we limit ourselves to how we can do things NOW, we weren’t designing the right campaigns for our future,” she adds, noting that the report doesn’t try to describe how to do it. All from a technological point of view.

What is clear, Elkins-Tanton says, is that the Moon remains NASA’s next astronautical target, and that putting boots on Mars remains a priority in the future. “We’re not going to Mars tomorrow,” she said.

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