Your Planetary Protection Officer
What on Earth does he do?
In an op-ed in yesterday's New York Times, evolutionary biologist Olivia Judson noted that NASA, at the behest of its "planetary protection officer," "is starting to prepare a high-security Martian containment facility." Who is NASA's planetary protection officer, and what does the job entail?
Since 1998, the space agency's planetary protection officer, or PPO, has been John D. Rummel, an astrobiologist and a commander in the U.S. Naval Reserve. This is actually his second tour of duty at NASA; once an aspiring astronaut, Rummel researched extraterrestrial life for NASA from 1986 to 1993, when he left to join the Marine Biological Laboratory in Woods Hole, Mass.
Rummel has two primary tasks: to ensure that outbound spacecraft aren't contaminated with biological material from Earth (forward contamination), and to protect the Earth from lifeforms that might be contained within samples retrieved from space (back contamination). These concerns trace back to the Treaty on Principles Governing the Activities of States in the Exploration and Use of Outer Space, Including the Moon and Other Bodies. This 1967 international agreement mandated that signatories avoid "harmful contamination" when surveying the cosmos. That meant not only protecting the Earth from extraterrestrial microbes that could cause disease, but also protecting other planets and cosmic objects from organisms native to our world.
Planetary protection wasn't an issue during NASA's lunar missions in the late 1960s and early 1970s, because scientists agreed that the moon was hostile to all life. But the same couldn't be said of Mars, so the agency established its Planetary Protection Office in 1976, to deal with contamination issues raised by the Viking mission.
The standards for planetary protection are issued by the U.N. Committee on Space Research. Rummel currently chairs COSPAR's Panel on Planetary Protection, whose latest policy guidelines were adopted in 2002. For example, any future missions to Europa, an icy moon of Jupiter, must be designed to reduce the odds of forward contamination to less than 1 in 10,000.
The job of the PPO and his staff, then, is to figure out how, exactly, NASA can conform to those standards. The primary method of preventing forward contamination is to construct the spacecraft in a clean room, akin to the assembly facilities where semiconductors are made, and then sterilize the vehicle before it's launched. The Viking landers, for example, were encased in a special "bioshield," then baked at 100 degrees Celsius; the bioshield wasn't jettisoned until after the spacecraft had cleared the Earth. Because of the sensitivity of contemporary equipment, however, the baking method is no longer appropriate for the most advanced spacecraft. NASA is currently researching a chemical sterilization process that uses hydrogen peroxide, among other methods.
Rummel's other big challenge is designing and building a suitable containment facility for the analysis of Martian samples. Sometime next decade, NASA hopes to complete a mission that can return up to a kilogram of Martian rock to the Earth. Though there's only a tiny chance that such a sample will contain an organism, let alone one that might cause a nightmarish scenario out of The Andromeda Strain, NASA doesn't want to take any chances with the future of the human race. Rummel and his cohorts have already published a voluminous draft protocol for handling these samples in a safe manner and are hard at work designing an appropriately fortified laboratory.