Martian rock samples returned to Earth via future spacecraft must be quarantined to protect our planet from hazardous organisms that could hitch a ride here, according to a new report from the National Academies' National Research Council (NRC).

The first Martian samples could reach Earth as early as 2014 and a maximum security quarantine facility would take seven years or more to design, build and test, so preparation for the facility should begin soon, NRC officials said.

"Building this type of quarantine facility is a project of enormous complexity," said John Wood, chair of the committee that wrote the report and staff scientist at the Harvard-Smithsonian Center for Astrophysics in Massachusetts. "We strongly recommend that this process get under way as soon as possible."

The facility will have to contain biological specimens to prevent contaminants from escaping and house "clean rooms" that prevent terrestrial organisms, dust and other foreign matter from getting into the Martian samples.

Those two focuses actually work at cross-purposes because containment facilities rely on low air pressure so leakages move air into the sample chamber while clean rooms are held at higher gas pressures to push Earth particles outward and protect the enclosed samples.

For that reason, extensive experimentation and testing is required to design this two-way protection system. That will have to precede any actual building.

Facility designers also have to figure out how to sterilize the environment in ways that have a minimal impact on the samples.

The report recommends that a continuing committee of biological and geochemical experts be assembled to oversee all aspects of planning, construction and operation of the quarantine facility.

The NRC named several agencies that should be involved in the quarantine facility and wants it located adjacent to an existing containment facility such as those operated by the Centers for Disease Control and Prevention in Atlanta, the U.S. Army Medical Research Institute for Infectious Diseases in Ft. Detrick, Maryland or a projected facility coming to the University of Texas Medical Branch at Galveston. NASA should be in charge though, the report recommends.

Because operations in a maximum security containment facility are highly constrained, the report recommends that scientists do minimal documentation and biohazard testing of incoming Martian samples.

Once samples are cleared for release, a broader range of examinations should be carried out elsewhere. Plans should be in place to promptly sterilize a portion of the samples after they are received so they can be safely transferred out of the facility for study in specialized university laboratories.

The plans relax a bit once samples are found to contain no organic, or possibly living matter.
In that case, they could be released without sterilization.

If the samples contain possible evidence of life, which is the most likely case, portions that have been sterilized by heat or gamma radiation could be certified for release and study elsewhere.

If the samples are found to contain unmistakable evidence of life, they should not be released at all until an expert panel of biologists is convened to assess the situation and possibly recommend building a special research facility just for their study.

The National Research Council is the principal operating arm of the National Academy of Sciences and the National Academy of Engineering. It is a private, nonprofit institution that provides independent advice on science and technology issues under a congressional charter.