NASA Takes No Dirty Chances With Mars Rover
It’s cleaner than a hospital operating room and safer than a bank vault.
Welcome to NASA’s Mars waiting room, where a six-wheeled, 25-pound rover is being checked, double-checked and triple-checked by engineers and scientists covered from head to toe in tight, white jumpsuits for its Dec. 2 launch and July 4, 1997, landing on the Red Planet.
The rules are strict and clearly posted outside the first of four doors leading into this air-conditioned, nitrogen-cooled, methodically vacuumed and scrubbed sanctum of the Mars Pathfinder:
No perfume, after-shave, makeup, aerosol spray. No eating, drinking, smoking or chewing gum. No one with a cold, excessive coughing or sneezing, severe sunburn or flaking skin.
No more than five people allowed within 16 feet of the lander and rover, and they have to wear latex gloves in addition to their so-called bunny suits and face masks, and be grounded to prevent static electricity.
“Tourism is not permitted,” the sign adds.
Tourism here? You’ve got to be kidding.
Visitors must pass through Kennedy Space Center security checks and be escorted by NASA personnel to this gray metal building, locked and equipped with surveillance cameras. Even those with special badges and access codes must adhere to the schedule; anyone entering the building after hours triggers an alarm and, within minutes, encounters armed security officers.
The explanation for all this is simple: the National Aeronautics and Space Administration doesn’t want to contaminate Mars with Earthly germs.
If scientists are to ever determine once and for all that life exists or existed on Mars--that’s not a goal of this mission, by the way--you don’t want bacteria from Earth scattered all over the place.
“If one person sneezed, they could wipe out the whole spacecraft,” explained launch operations manager Curtis Cleven, who was arrested his first day here in August trying to get in. (He’d forgotten about the security.)
The worst is dirt.
“In general, if somebody coughs on the spacecraft that’s not nearly as bad as if somebody dropped a bunch of dirt on it,” microbiologist Bob Koukol said as he prepared to test yet again for cleanliness on the first morning of October.
“We’re looking for the most resistant bacteria forms that we can find,” said Koukol, who like Cleven normally works at the Jet Propulsion Laboratory in Pasadena. Spore-forming soil bacteria, for instance, could survive the flight to Mars “quite nicely,” he noted.
The maximum number of spores allowed on Mars Pathfinder is 300 per square meter of surface, Koukol said, but the spacecraft likely will have far fewer at launch.
Could stowaway spores cause an outbreak on Mars?
“The chance of a spacecraft carrying a life form that would live on the planet is less than one in 100,000,” Koukol said.
This will be the first spacecraft to land on Mars since NASA’s two Viking landers in 1976. The destination this time is an ancient flood plain with a wide variety of rocks, some 500 miles from where the first Viking lander plopped down. If all goes well, the rectangular, robotic rover will explore within 15 to 30 feet of the landing site and send back data on the composition of rocks and soil for at least a week, maybe even months.
Another security concern, at least on Earth, are the radioactive heaters inside the rover. The three plutonium-238 cells, each the size of a flashlight battery, are needed to keep the rover warm during the freezing Martian days and even icier Martian nights. Although the radioactivity level is low, safety precautions must be taken.
The Viking landers had even more stringent criteria for cleanliness: They were baked and sterilized before launch because of life-detection experiments on board.
There are no such experiments on Mars Pathfinder, part of NASA’s Discovery program for low-budget planetary research that limited spacecraft development to three years and $150 million. But, because of inflation, Mars Pathfinder will now cost $171 million, Cleven said.
Only part of Mars Pathfinder was baked before it arrived at Kennedy Space Center in August, namely, the aluminum frame of the rover and its steel-cleated wheels, the parachute, air bags, antennas and solar energy-generating panels. Since then, the spacecraft has been wiped frequently with alcohol to remove, but not kill, any lingering spores.
The inside of the rover must be as clean as the outside in case it crashes onto the Martian surface.
For planetary-protection engineer and chief cleaner Jack Barengoltz, it seems harder this time around.
With the Viking landers, “everyone who was doing it knew that they didn’t have to get rid of every last spore because we were going to cook them at the end,” Barengoltz said.
“In this case, there’s no cook at the end and so what we have is what we’ve got,” he said. “It won’t be sterile, but it’s going to be very, very clean.”
The precautions should ease once the heat shield is put around the cocooned lander and rover.
No changes have been made to the Mars Pathfinder mission as a result of the August announcement by NASA scientists of a Mars meteorite with supposed evidence of primitive life; there wasn’t enough lead time.
There also were no changes to the Mars Global Surveyor, to be launched Nov. 6 on a mapping expedition. It’s expected to orbit Mars for at least 50 years before crashing onto the surface of the planet.
Even though the Global Surveyor isn’t nearly as clean as Pathfinder, scientists aren’t too worried about polluting Mars when Global Surveyor finally comes crashing down.
“That meets our international agreements for protecting the surface from contamination,” said Global Surveyor project manager Glenn Cunningham. “After 50 years, everybody believes that they will have sampled the surface to see what microbes or things are there.”