ST. LOUIS, Mo.—More than just about anything, Robert Zubrin would like to see humans visit and then settle on Mars during his lifetime. The aerospace engineer has made a living of identifying technologies needed to get astronauts to the Red Planet and trying to build a public consensus that Mars is humanity’s next great leap.

Zubrin also likes to knock down hurdles and roadblocks that he sees standing between humans and Mars. Concerned about radiation? Don’t be, Zubrin says, because the in-flight dose won’t be appreciably greater than some US and Russian astronauts have accumulated during long-duration missions to the International Space Station. And what about the cost? If NASA were to buy services directly from industry and bypass the cost-plus method of contracting, humans could walk on Mars for tens of billions of dollars, he says.

Of late, Zubrin has been bothered by another potential difficulty between humans and the exploration and settlement of Mars—planetary protection. This is the prime-directive-style notion that humans should not contaminate other worlds with Earth-based microbes and, on the flip side, that humans should not introduce any potentially dangerous pathogens to Earth.

“Planetary protection is a massive problem for the exploration of Mars,” Zubrin said. “Really, it’s a racket.”

Canadian geese

This is not a problem that NASA or would-be explorers should take all that seriously with regard to Mars, Zubrin argued during a characteristically fiery talk in late May. He made his remarks at the International Development and Space Conference in St. Louis, which is held by the National Space Society and dedicated to the settlement of space.

Zubrin asserted that Mars almost certainly has no life to be infected by Earth and no extant life which might eventually infect Earth. Mars has no liquid water on the surface, where temperatures are well below freezing, and an ultraviolet light would kill any new life.

“It is true that if you were to go a few feet underground, soil would shield you,” he said. “But while microbes can then survive in a dormant state for a long period of time, there would still be cosmic rays. The microbes might survive for centuries, but not for billions of years.”

One aspect of planetary protection Zubrin highlighted concerned NASA’s on-again, off-again Mars sample return mission. Some plans for the mission have gone to great lengths to “protect” Earth from any Martian microbes that might somehow exist in the samples, including a rendezvous in lunar orbit so a crew aboard the Orion spacecraft could inspect them. This has added “billions” of dollars to the cost of sample return, Zubrin noted, and essentially serves no purpose because the Earth is already bombarded by rocks ejected from Mars. An estimated 500kg of Martian meteorites land on Earth every year.

“If we could get the red death from Mars, we’d already have it,” he said. “Instead, they’re completely destroying the sample-return mission. Heroic measures to quarantine a rock sample coming back from Mars make about as much sense as the customs people inspecting cars coming in from Canada, to make sure they don’t have Canadian geese in their trunk.”

An overly zealous Planetary Protection community could also effectively kill human exploration on Mars, he argued, because there is no way to sterilize a crew, especially if the unthinkable happens. “If you maintain this pretense, a human expedition to Mars is impossible,” he argued. “You cannot guarantee that a human mission to Mars won’t crash, in which case you’ll be scattering human microbes all over the surface.”

Musk, too

Others in the space community, too, have expressed similar concerns about overly deferential attitudes toward planetary protection. Most notably, SpaceX founder Elon Musk has said concerns about microbes buried deep in the Martian soil should not deter efforts by his company to both send robotic probes to Mars, as well as colony-transport ships.

Based upon these two conflicting attitudes—with NASA and some of its scientists on one side, saying every effort, regardless of expense, should be made for planetary protection, and those opposed to them, who are not as concerned—a day of reckoning may soon come.

Ars is aware of concerns in Congress about the prospect of private space companies sending missions to Mars and beyond, and legislation may end up preventing launches that do not comply with NASA’s current planetary protection rules. Whether we reach that point may not be academic for much longer, as SpaceX intends to send one or two Red Dragon spacecraft to Mars in 2020, and the company will need to obtain a launch license from the federal government for any such flight.