The concrete-floored room looks, at
first glance, like little more than a garage. There is a red tool
chest, its drawers labeled: "Hacksaws." "Allen wrenches." There are
stepladders and vise grips. There is also, at one end of the room, a
half-built spaceship, and everyone is wearing toe-to-fingertip
protective suits.
"Don't. Touch. Anything."
Bruce Jakosky says the words politely but tautly, like a
protective father - which, effectively, he is. Jakosky is the
principal investigator behind NASA's next mission to Mars, putting
him in the vanguard of an arcane niche of science: planetary
protection - the science of exploring space without messing it up.
As NASA pursues the search for life in the solar system, the
cleanliness of robotic explorers is crucial to avoid contaminating
other worlds. Contaminants from Earth could inadvertently kill life
forms on other planets just as we discover that they exist.
The decontamination of spacecraft, an obscure arm of space
science, has grown in importance as NASA turned its attention to
places such as Mars, Titan and Europa that have environments that
are potentially conducive to life.
Jakosky's immediate concern is a $671 million probe named the
Mars Atmosphere and Volatile EvolutioN orbiter, or MAVEN, which
Lockheed Martin Space Systems is building south of Denver.
The craft is scheduled to launch in late 2013. Its mission is to
delve into Mars' transition from a wet and warm planet to one that
is dry and cold - vital research for determining whether Mars ever
harbored life.
The spacecraft needs to be scrubbed so that when it impacts Mars,
it is carrying no more than 500,000 spores of microbial life, so few
they could fit on the head of a pin. The goal is simple, said
Jakosky, a University of Colorado at Boulder professor: "Don't
contaminate Mars or jeopardize your science." The trick is in the
execution.
Many of the achievements that marked the onset of the Space Age
meant sending astronauts into space. Today, scientists have entered
a gilded age of robotic space exploration.
The rover Curiosity that landed on Mars this summer is just one
in a suite of machines that have been sent to study new corners of
space. Other missions will send probes to intercept an asteroid and
visit a distant moon that could contain three times as much water as
Earth. It is an era fraught with anxiety for those who have the
curious task of keeping space free of contamination.
"This business is not for the faint of heart," Jakosky says.
Planetary protection must operate on three levels at once.
First, spacecraft must not bring a potentially harmful level of
microbes from Earth to another planet or celestial body. Scientists
also must be careful not to mess up their own work - signs of
extraterrestrial life could be "discovered" but could actually be
false-positives born on a launch pad at Cape Canaveral.
"Taking life from Florida to Mars might give you the wrong
impression about Mars," said John D. Rummel, NASA's former planetary
protection officer, now a professor of biology at East Carolina
University.
Most pressingly, when robots or astronauts return with samples
from space, scientists must take care not to expose the Earth to
alien contaminants. No one knows what would happen - probably
nothing, but considering how the Earth struggles with its own
