http://planetary.org/html/news/opinions/hazardous.html

When I read the opinion piece by Robert Zubrin ("Contamination From Mars: No Threat," The Planetary Report, July/August 2000), I didn't know how to react. As a biologist working on planetary protection and Mars sample return at the SETI Institute, I wondered how an engineer and Mars enthusiast like Zubrin could make such irresponsible and inaccurate statements. Obviously, Zubrin is entitled to his opinion, even if it's based largely on misuse of facts. But what about the readers of The Planetary Report? Don't they deserve more than op-ed humor?

The real business of planetary protection should not be taken as lightly as Zubrin suggests. What if readers accept the article at face value and believe the inaccuracies and misrepresentations he so carelessly throws about? What if they swallow the argument that "back contamination mavens need to back off" because "their warnings have no rational basis and are being used to urge crimes against science"? Therein would be the crime against science. To launch a mission without planetary protection measures would doom it to failure (or to borrow from Zubrin, it would be just plain nuts). More than just science and technology are involved. Rather than try to dissect Zubrin's arguments one by one, let me clarify several important matters-about policies, procedures, public concerns, and ethical issues.

Significantly, Zubrin's perspective fails to consider the extensive policy and procedural requirements behind back contamination controls for Mars missions. The Outer Space Treaty of 1967 specifically states that all space exploration must be done in a way that avoids harmful contamination to celestial bodies or adverse changes in the environment of the Earth from the introduction of extraterrestrial materials. Like it or not, NASA can't leave home without planetary protection measures. Based on recommendations of the Space Studies Board of the National Research Council (NRC), these measures include strict sample containment, special handling under quarantine, rigorous testing to determine if Martian materials are biohazardous, and yes, even sterilization under certain situations. The NRC is hardly an alarmist group-but its report specifically urges that NASA "adopt a prudent approach, erring on the side of caution and safety." Somehow I'd rather listen to the NRC than an errant rocket scientist when it comes to protecting my home planet and the science on board.

If the NRC's cautious opinion isn't convincing enough, repeated research surveys of the general public and expert biologists alike have indicated strong support for a conservative approach to sample return. In fact, more than 4,300 Planetary Society members from countries around the world responded to the first survey back in 1994. An overwhelming majority indicated that "all materials brought to Earth from Mars should be considered hazardous until proven otherwise."

In addition, like all responsible government agencies, NASA must follow the National Environmental Policy Act. Thus, for a sample return mission, NASA is required to prepare an Environmental Impact Statement and make it available for public review and comment well before launch. The public expects and demands nothing less. Gone are the days when experts could make decisions behind closed doors with assurances like "Trust me-I'm a rocket scientist." Considering everything that has been written about Mars and its potential for life, how could NASA possibly adopt a position like Zubrin's? No back contamination controls? No way! And don't forget the rest of the government. Once the Martian samples reach terra firma, agencies like the United States Department of Agriculture, Environmental Protection Agency, Centers for Disease Control, and others with jurisdiction over environmental, health, and safety areas will likely be involved. Once again, NASA can't ignore back contamination concerns, however small the risks.

Zubrin is correct when he recounts a NASA planning meeting in which someone seriously proposed that Martian samples be sterilized before being brought to Earth. What he doesn't mention are the many discussions at numerous other NASA workshops and meetings where experts have debated alternative mission plans, both with and without sterilization. There's not a scientist around who wouldn't rather return pristine samples as opposed to cooked ones-but still, scientists realize that they have to consider many alternatives (even unpalatable ones) before selecting the final mission configuration. What's more, every engineer recognizes this as standard procedure. On one point we can agree with Zubrin: it would be a terrible scientific loss to sterilize the samples-nevertheless, it might be better than no samples at all. (Yes, NASA must also consider the null alternative, which in this case means no sample return-period.)

Finally, consider the ethical implications of discovering Martian life-especially if detected on Earth in returned samples. What are the ethically acceptable levels of risk posed by the importation and handling of potential extraterrestrial organisms on Earth? Who will be involved in making decisions about these risks? Should scientific exploration proceed in the face of potentially novel life-forms and scientific uncertainty? Are current handling procedures adequate to safeguard Earth and its inhabitants? The concerns and questions about Mars sample return are actually quite similar to those encountered during the 1970s and '80s by ethicists debating the implications of genetic engineering. Now, as then, these questions require serious consideration, not flippant suggestions to "back off."

I can understand Zubrin's impatience about back contamination controls. He's confident in our impressive technological prowess; he's raring to go and doesn't want anything to slow down or stop our exploration of Mars-especially not burdensome regulations based on very small risks and scientific uncertainty. Yet when he suggests that there's no need for back contamination controls on Mars sample return missions, he's advocating an irresponsible way to cut corners. If he were an architect, would he suggest designing buildings without smoke detectors or fire extinguishers?

While I share Zubrin's enthusiasm for Mars exploration and hope that someday we find life on Mars, I'm one biologist who's glad to know that our government is doing the right thing. NASA, its scientists, and its engineers are taking a comprehensive view of what is required for a successful mission. Back contamination controls are most definitely part of the plan-for lots of good reasons-despite what Zubrin suggests.