The Quarantine and Certification of Martian Samples: Opening Statement

National Research Council,
Space Studies Board

Public Briefing
May 29, 2001:
Opening Statement by John A. Wood,
Staff Scientist, Harvard-Smithsonian Center for Astrophysics and
Chair, Committee on Planetary and Lunar Exploration

Good afternoon and welcome. I am pleased to be here today with members of the authoring committee to publicly release this new National Research Council report, The Quarantine and Certification of Martian Samples.

The question of whether life exists or has existed on other planets is not a new one. For centuries, it has inspired the imaginations of astronomers, philosophers, authors, and members of the public. Nor is the question frivolous. Recent evidence of ancient water on the surface of Mars and an ocean on Jupiter’s moon Europa compels us to entertain the notion – however remote – that Earth is not the only planet in the solar system capable of sustaining life.



NASA, which sponsored our study, has already devoted significant resources to exploring the notion, and is dedicated to continuing its goal for at least the next two decades. A prime, and perhaps the only, means to provide a definitive answer to the life-on-Mars question is to retrieve surface samples of the Red Planet for detailed laboratory studies. According to NASA’s current Mars Exploration Program Plan, the first sample-return mission is scheduled to launch sometime early in the next decade and the samples could arrive on Earth a few years later.

A National Research Council report released in 1997 noted that although the probability is low that samples returned from Mars could contain dangerous organisms – be they pathogenically or ecologically dangerous – the probability cannot be shown to be zero. The report recommended that the samples should be delivered – appropriately contained — to a sample-receiving quarantine and research facility unlike any other in existence – one that is capable of protecting the scientific integrity of the extraterrestrial samples (that is, not contaminating them with terrestrial substances), while at the same time protecting Earth’s environment from exposure to potentially dangerous organisms from Mars.

The report suggested that the facility should be the most stringent type of containment facility available, of the type designated BSL-4 (biosafety laboratory, level 4). This is the same type of facility employed in the study of agents of highly infectious diseases, such as the Ebola virus. To ensure that all procedures run smoothly and flawlessly by the time the facility is needed, the report recommended that it be in operation at least two years prior to the launch of the first sample-return mission.

Subsequently, the Research Council’s Space Studies Board charged our committee to expound on the 1997 findings. We were asked to develop requirements for the characterization, biosafety certification, and properties of a quarantine facility suitable for housing martian samples. The central question posed to the group was, What are the criteria that must be satisfied before martian samples can be released from a quarantine facility? That question quickly led to three others:

• What are the optimal techniques for isolating and handling martian materials, determining their content of biota, if any, and carrying out basic geochemical characterization studies in the facility?
  
  
• How much capability for scientific analysis, beyond that required for biosafety certification, should be incorporated in the facility, and what principles should govern the utilization of this scientific capability?
  
  
• To what extent can valuable lessons be learned from the experience with the Apollo lunar samples and from recent developments in the biotechnology and biomedical communities?

In answer to the central question, what criteria must be satisfied before martian samples can be released from a quarantine facility, the committee recommended the following guidelines:

• If samples contain no organic matter and no other evidence of past or present biological activity, release of unsterilized portions to outside laboratories for further study is justified.
  
  
• If samples contain evidence of life or such evidence is questionable, which is the most likely case, subsamples that have been sterilized by heat or gamma radiation should be certified for prompt distribution to outside laboratories for biological and geochemical studies.
  
  
• If the samples are found to contain unmistakable evidence of life, they should be dedicated to biological studies. In that case, an elaborate plan for handling, curation, and study of the samples would need to be developed, and a facility much larger than the quarantine facility will need to be prepared. Samples should not be released from the quarantine facility until this research facility is ready to receive them.

The nature of the quarantine facility must be based on the BSL-4 standard of containment, which I mentioned earlier. Here are some pictures of BSL-4 laboratories at the U.S. Medical Research Army Institute of Infectious Diseases at Fort Detrick, Md. In one instance, researchers work on samples by sticking their arms through glove ports; in the other, workers are right in the room with the samples, but enclosed in a “space suit.” It is very awkward and difficult to get much done with these handicaps.

This fact, and the relatively small volumes that can be enclosed, led to one of the committee’s recommendations: only the simplest, most basic operations should be conducted there. Those operations should include unpacking the samples, preliminary examination, cataloguing, and storage. In addition, biohazard testing and life-detection studies that cannot be performed on sterilized samples must also be conducted within the facility. However, no further investigations that can be performed on sterilized samples outside the facility should be conducted there.

One difficult problem that has to be solved in designing the quarantine facility is how to simultaneously achieve biological containment and clean-room conditions in one facility. The Mars samples will have to be kept very clean. They must be uncontaminated by terrestrial microbes, which could confuse life-detection tests; and uncontaminated by terrestrial dust grains that could confuse sensitive geochemical tests. Biological containment is achieved by storing samples at air pressures lower than ambient air pressure, so that leakage moves air inward toward the sample and away from the external environment. Clean-room conditions, on the other hand, require chamber gas pressures to be greater than ambient pressure, so that gas leaks outward and possible contaminants cannot move toward the samples.

The report recommends that studies begin soon – prior to the design of the facility – to find a way to resolve these conflicting requirements. Other studies that need to be carried out as soon as possible should focus on the amount of damage varying amounts of sterilizing heat and gamma radiation have on the properties of organic and inorganic materials – properties that scientists will want to study in the sterilized samples they receive.

You’ll remember that this won’t be the first time extraterrestrial samples are brought to Earth and quarantined. Numerous samples – some quite large — were brought back from the moon during the Apollo missions 30 years ago. Our committee relived the construction and use of the Lunar Receiving Laboratory, or LRL, hoping to learn some lessons. In the LRL, an effort was made to keep the samples in a lunar vacuum at the same time they were being biologically contained. This slide shows the heart of the LRL before the first Apollo mission; the tank you see here was the vacuum chamber, behind a biological barrier. The vacuum chamber caused great difficulty in the preparation and use of the LRL, and it turned out to be unnecessary. The lesson here was to keep the Mars containment facility as simple as possible. For instance, it might seem desirable to maintain the samples at martian temperatures — which are below freezing — but this would add another layer of complication to the facility, which is already complicated enough by the requirement of combining biological containment with clean-room conditions. So our report recommends against trying to maintain martian temperatures, or placing any other requirement that unnecessarily complicates the quarantine facility.

The report recommends that the Mars sample quarantine facility should be affiliated with an ongoing containment facility with BSL-4 capability, such as the U.S. Army Medical Research Institute of Infectious Diseases; the Centers for Disease Control and Prevention in Atlanta; or the facility being built by the medical branch of the University of Texas at Galveston. Doing this will save both time and money, by providing institutional support, such as access to personnel, training, and security, and it may ease the problem of clearing an environmental impact statement, which can take years. The committee recommends, however, that management of the facility should remain under the control of NASA.

Experience with the planning, construction, staffing, and certification of BSL-4 facilities, and also the Lunar Receiving Laboratory, show that it will take at least seven years to prepare a facility to receive samples from Mars. Included in this time frame are developing protocols for the handling of samples, designing and building the facility, certifying the operability of all mechanical systems, testing, and cleaning. Because many questions still need to be resolved before design and construction can even begin, as I have mentioned, it is essential for work to commence as soon as possible in order for the facility to be ready in time for the first samples’ return. This is the strongest point our report tries to make.

This concludes my opening remarks. My colleagues and I will now take your questions. For those of you in the room, please step to a microphone. We’ll also be taking questions from those joining us via conference call. Please give your name and affiliation first. Thank you.

Photographs can be downloaded from <http://cfa-www.harvard.edu/~jwood/>