Emerging Risk Assessment and Management Controversies in the Mars Sample Return, Rodrigue, Boulder Hazards Workshop, 2002

For a number of years, I have investigated the risk assessment and risk management controversy surrounding NASA's use of plutonium-238 dioxide radioisotope thermoelectric generators (RTGs) that are used to power spacecraft instruments for the Cassini-Huygens mission to Saturn and Titan and other missions to the outer solar system. Risk assessment done for NASA concluded that the risks involved were trivial, with extremely small probabilities of accidents releasing Pu into the earth's atmosphere and minor health effects in the event a worst-case accident did take place. Opponents claimed that NASA and the media were covering up the extent of the risk. They stated an accident could give every person on Earth lung cancer and directly cause the deaths of anywhere from 200,000 to 40 million people. Using e-mail, listservers, and newsgroups, a handful of people orchestrated a large political opposition movement to pressure Congress and the President to cancel the launch and later the Earth gravity-assist manoeuvre. They did not ultimately succeed in either of these goals, but they did succeed in making the use of RTGs controversial.

I am now following another emerging risk assessment and management controversy related to the space program: The Mars Sample Return Lander. This mission, if approved, could launch as early as October of 2011 and return to Earth in September of 2014.

This mission raises three distinct risk assessment and management controversies. The first of these is similar to the Cassini controversy: The mission will almost certainly involve the use of RTGs, because of the need for absolutely reliable power output for several months on Mars. Because of this, it can be expected that the same parties that orchestrated the anti- Cassini movement will begin to organize against the MSRL.

A second controversy has already erupted, complete with web page: http://www.icamsr.org. The concern of this oppositional strand is biocontamination of Earth by the Mars sample returned to Earth. The argument is that there is a non-zero probability of some kind of microbial life existing now on Mars which could be picked up by the MSRL and launched back to Earth. If the recovery of the spacecraft went awry, these organisms could conceivably be released into the Earth environment. Should that happen, there is again a very tiny but non-zero probability that the Martian organisms could adapt to Earth conditions and host organisms and generate a pandemic.

A third controversy is building within the scientific communities from which the principal investigators of the various investigations on the MSRL will be drawn, pitting geoscientists against bioscientists. The bioscientists, hopeful that some sort of Martian life would have survived the trip to Earth, would like to quarantine the samples as long as possible to give Martian life a chance to express itself in some measurable fashion. The geoscientists, while acknowledging the faint possibility of Martian life hitching a ride back to Earth and the appropriateness of a quarantine period, would like the samples speedily sterilized and distributed for their investigations.

Some of these controversies will pit conventional risk assessment expertise against lay activists who need not do professional risk assessment but need only question the legitimacy of expertise to generate opposition to the mission (the RTG and biocontamination controversies). Others will entail differences of opinion and priorities within the scientific community (notably the geoscience vs. bioscience division but also professional debates about the possibility of biocontamination and the efficacy of Biosafety Level 4 measures against it). I plan to follow these through the Internet, where the bulk of organizing can be predicted to take place.