Martian Samples on Earth, Planetary Protection from Contamination Becomes Hot Issue

Now underway is a multi-nation, multi-billion-dollar Mars Sample Return program: a project for the 2030s that will involve hurling to Earth a select smorgasbord of soil, rock, and atmosphere from the Red Planet.

NASA and the European Space Agency are working together on the Mars Sample Return (MSR) campaign. The plan is for those gathered and contained Mars collectibles – roughly a pound of extraterrestrial goodies — to be plopped into the Utah Test and Training Range in west-central Utah.

But shooting back to Earth bits and pieces from Mars means figuring out how to deal with the potential for biological “hot property” — also called back contamination, or the introduction of possible biological matter from Mars into the Earth’s environment. That term can heat up oratory and public unease as people visualize creepy-crawlies from that distant world munching away at Earth’s biosphere. Then there’s also the issue of forward contamination, transporting microbes from Earth to the Red Planet.

While the chances of danger from bringing back a sample from Mars are seen as small, it’s not zero. The idea arguably has the makings of a real-time replay of Michael Crichton’s 1969 novel Andromeda Strain, transformed into a 1971 sci-fi film, which dramatized the idea of alien organisms infecting the Earth — in the story, an extraterrestrial pathogen hitched a ride to Earth on a satellite and caused a devastating mass outbreak.

Sample science and containment

Bringing back the goods from Mars is a longtime interest of John Rummel, a former and founding chair of the panel on planetary protection of the Committee on Space Research (COSPAR), an international confab of experts. He previously worked at NASA Headquarters (1986 to 1993 and 1998 to 2008) as the space agency’s senior scientist for astrobiology and as NASA’s Planetary Protection Officer.

“Recall that the Andromeda Strain was the story of extraterrestrial contamination due to a microbe collected by the US Army’s ‘Scoop’ project,” Rummel told SpaceRef. “NASA wasn’t involved!”

Moreover, the facility featured in Andromeda Strain was secret, located in the desert, Rummel added, “and with extreme failings in rodent control, to boot! Plus they didn’t screen their personnel for flicker vertigo or epilepsy. All bad ideas.”

Confusion and consternation

Rummel told SpaceRef his hope is that a very non-secret facility will ably deal with sample science and containment following a sample return mission, while leaving the rats behind!

“My chief concern at this point is not that there is something that will be returned from Mars that will be a danger to Earth’s environment,” Rummel said.

Rather, Rummel is concerned that limited forward contamination controls on Mars landers, the Mars Ascent Vehicle, and on the Earth Return Orbiter and Capture, Containment, and Retrieval System, “will lead to one or more successful, round-trip microbial (or viral) tourists that will be misidentified as Martians, and create confusion and consternation among the scientific analyses.”

In other words, he’s worried that spacecraft, contaminated with microbes from Earth, might then bring them back from Mars and potentially misidentify them as having Martian origins.

Enter China

The Chinese are scripting plans to have the sample return from Mars back before NASA, senses Dirk Schulze-Makuch, a professor at the Technical University Berlin, Germany, and an adjunct professor at Washington State University. However, Schulze-Makuch told SpaceRef, he doesn’t have any idea what planetary protection measures China is considering.

“In principle, there is probably not too much of a danger,” Schulze-Makuch told SpaceRef, “since Martian meteorites come to us all the time and microbes within the rocks could survive the space travel. But, of course, we have only one biosphere and you do not want to take any chances at all.”

Lip service

Mike Gold, an executive vice president at the space infrastructure company Redwire who’s also a former NASA associate administrator for Space Policy and Partnerships, recently spoke about planetary protection policies, flagging a few worries.

“My concerns relate to China and Russia who participate in a robust fashion at COSPAR, but my understanding is their actual follow-through of the regulations are wanting,” said Gold.

Speaking at this year’s Explore Mars Humans to Mars Summit on May 17 in Washington, DC, Gold told the audience he feared that those two countries are largely paying lip service to planetary protection. “The old joke in the planetary protection community,” he said, “is that when we discover alien life, it’s going to Russia, because the Russians are not following planetary protection.”

Global issue

Concerning China’s adherence to regulations, Gold said that there are differing opinions. In some hallway conversations, he said, Chinese officials will indicate that they are following planetary protection rules, but unlike other space exploration agencies, “they don’t follow the rules to have a public presentation at the United Nations or other appropriate international forum to brief on how they are abiding by planetary protection,” Gold said.

Planetary protection is a global issue, Gold added, “and if China or Russia violates it, we can all pay the price.” There’s need for public openness and transparency, he advised, if there are countries not following the rules.

“Again, it’s China, Russia that keep me up at night, relative to the scenario of bringing something back that could be dangerous,” said Gold.

Microbial metabolism

There has been only one mission to Mars that looked for any living microorganisms in the Martian soil and that was the twin Viking 1 and 2 Lander missions of the 1970s.

Researcher Barry DiGregorio tells SpaceRef that he supports, albeit the contentious view, that one of three biology experiments on each Viking lander picked up on indications of active microbial metabolism. He is director of the International Committee Against Mars Sample Return.

“Since then, no space agency has sent a follow-on life detection experiment to find out why one of the biology experiments in each lander got such positive results,” said DiGregorio. “This follow-on step was a necessary step to rule out the possibility that Mars might contain pathogenic organisms of the type that could cause a serious back contamination hazard to Earth’s biosphere,” he told SpaceRef.

In DiGregorio’s view, until any space agency — including the proposed Chinese MSR mission — has ruled out the chance that samples from Mars could infect our planet, “any studies of Martian samples should be restricted to the planet Mars itself, or in a exobiology lab in a space station like NASA’s Gateway orbiting the Moon, to test and characterize it for pathogens before samples are returned to Earth.”

Apollo – lessons learned?

Dagomar Degroot, an associate professor of environmental history at Georgetown University in Washington, DC has taken a close look back at the NASA Apollo program’s quarantine procedures. His latest work on the Apollo program’s quarantine and contamination mitigation practices was published in the June 2023 issue of Isis – A Journal of the History of Science Society.

Those measures were put in place as a precaution that returning lunar landing crews could harbor perilous micro-life from the Moon. The Apollo 11, 12, and 14 lunar landing crews were placed in quarantine, but lunar travelers from later missions were not required to be sequestered in isolation. Degroot’s research indicates that the containment protocol was regarded as a success, “but only because it was not needed,” he wrote in the study.

Asked about his views regarding the Mars Sample Return effort, Degroot told SpaceRef that “one of the great challenges of the Apolloquarantine protocol was to contain not only the samples astronauts returned from the Moon, but also the astronauts themselves — and the spacecraft in which they travelled.”

For now, sample return efforts from the Red Planet will only involve robots, Degroot said. “In the unlikely event that they introduce Martian microbes to Earth, that will make it easier for NASA and other space agencies to avoid contaminating our biosphere,” he said. After all, it’s easier to clean or decommission a contaminated robot than it is a living person. “Still, we should be wary,” he added.

Err on the side of caution

Degroot added that there will be a strong incentive for agencies to “prioritize easy access” to Martian samples “over preserving strict containment … and history shows that could compromise the security of a Mars Sample Return Receiving facility.”

The many containment breaches at the Lunar Receiving Laboratory in the 1960s, Degroot said, “should also remind us that banal problems — from faulty plumbing to human error — can undermine the security of even the most sophisticated facilities.”

Space agencies should communicate risks “transparently to policymakers and the public,” Degroot concluded, “and err on the side of caution, even if that slows the pace of exploration.”