Curiosity could jeopardize data by contanination

"If the Mars rover finds water, it could be H2 ... uh oh!"

If Curiosity locates H2O, a simmering NASA controversy will boil over. The rover's drill bits may be tainted with Earth microbes that could survive upon touching water.
by

Louis Sahagun

September 9th, 2012

Los Angeles Times

For all the hopes NASA has pinned on the rover it deposited on Mars last month, one wish has gone unspoken: Please don't find water.

Scientists don't believe they will. They chose the cold, dry equatorial landing site in Mars' Gale Crater for its geology, not its prospects for harboring water or ice, which exist elsewhere on the planet.

But if by chance the rover Curiosity does find H2O, a controversy that has simmered at NASA for nearly a year will burst into the open. Curiosity's drill bits may be contaminated with Earth microbes. If they are, and if those bits touch water, the organisms could survive.

The possible contamination of the drill bits occurred six months before the rover's launch last Nov. 26. The bits had been sterilized inside a box to be opened only after Curiosity landed on Mars.

But that changed after engineers grew concerned that a rough landing could damage the rover and the drill mechanism. They decided to open the box and mount one bit in the drill as a hedge to ensure success of one of the most promising scientific tools aboard Curiosity. The drill is to bore into rocks looking for clues that life could have existed on the planet. Even if a damaged mechanism couldn't load a drill bit, at least the rover would have one ready to go.

Under the agency's procedures, the box should not have been opened without knowledge of a NASA scientist who is responsible for guarding Mars against contamination from Earth. But Planetary Protection Officer Catharine Conley wasn't consulted.

"They shouldn't have done it without telling me," she said. "It is not responsible for us not to follow our own rules."
Those rules required sterilization of any part of Curiosity that will touch the surface of the planet, including the drill bits and all six of the rover's wheels. The precaution was taken to preserve the ability to explore water or ice — even if the chances of finding it were remote.

Conley, a microbiologist, said she learned about the unsealing of the box shortly before the launch. By then, it was too late to fix.

Other NASA officials said the decision to open the box of drill bits was a calculated risk.

"Water or ice near the surface in Gale Crater was not a significant probability," said David Lavery, program executive for solar system exploration at NASA headquarters. "We weighed that against the risks of not having a bit mounted in the drill prior to launch, and the specter of not being able to drill any holes at all on Mars."
"Of course, there is always a possibility that Mars will surprise us," Lavery said.

The box containing the bits was unsealed in a near-sterile environment, he said. Even so, the breach was enough to alter aspects of the mission and open a rift at NASA between engineers and planetary protection officials.

Curiosity was first proposed in 2004 under a mission category that would have allowed it to explore a region with ice and water. That category called for sterilizing portions of the spacecraft that would contact the surface of Mars to avoid contamination of moist areas where microbes — from Earth or from Mars — have the best chances of survival.

On Nov. 1, after learning that the drill bit box had been opened, Conley said she had the mission reclassified to one in which Curiosity could touch the surface of Mars "as long as there is no ice or water."
Conley's predecessor at NASA, John D. Rummel, a professor of biology at East Carolina University, said, partly in jest: "It will be a sad day for NASA if they do detect ice or water. That's because the Curiosity project will most likely be told, 'Gee, that's nice. Now turn around.' "

If water is found, Curiosity could still conduct tests from a distance with instruments including a laser and spectrometers.

About 250,000 bacterial spores throughout Curiosity are assumed to have survived the landing, officials said. Nearly all of them are believed to have perished within minutes of exposure to the harsh Martian conditions in Gale Crater — freezing temperatures, intense ultraviolet radiation and an atmosphere of mostly carbon dioxide.

But scientists have learned in recent years that some Earth life forms can live in space and in at least some of the conditions found on Mars. The European Space Agency discovered that lichens launched on a Russian Soyuz rocket in 2005 survived several days of full exposure to the vacuum of space and ultraviolet and cosmic radiation.

Just this year, Andrew Schuerger, a plant pathologist and expert on the survival of terrestrial microorganisms under Martian conditions, found a bacterium species capable of growing in conditions present on the surface of Mars, including air pressure of just seven millibars. Air pressure on Earth is 1,017 millibars at sea level.

NASA officials announced this week that one month into its two-year mission, Curiosity had made a scheduled pit stop while en route to Glenelg Intrigue, a tantalizing confluence of three types of terrain targeted for the first drilling experiment. The pause allows scientists to run tests on the mechanical joints of the rover's robotic arm and surface sampler, or scoop, and other instruments designed to help crack Mars' mysteries.

Sometime next month, NASA scientists are expected to select a rock at Glenelg Intrigue and bore into it with the drill, which will then transfer aspirin-size samples of powder from the rock into science instruments housed in the belly of the rover. Conley has no concerns that the experiment will contaminate the site because she believes any surviving organisms will die swiftly.

Fear of microbial contamination of the Martian environment long ago moved NASA and a United Nations space advisory committee to divide the planet's surface into areas based on the probability of encountering ice and water. The group also recommended sterilizing spacecraft destined for areas with ice and water.

Contaminating another planet is an ethical concern for scientists, as well as a practical one.

"We keep learning more and more about Mars and the amazing durability of life," said Bruce Betts, a spokesman for the Planetary Society in Pasadena. "So wouldn't it be tragic if some future expedition were to discover life on Mars only to discover later that it had actually discovered life from Earth?"


Colonization or contamination?

Contamination beyond microscopic

Contamination of other worlds is not limited to microbes...think of mankind himself.

"NASA Needs New Plan to Avoid Contaminating Other Worlds"

by

Ars Technica
 
April 19th, 2012

Wired

Over the past several decades, there’s been a stunning revolution in how we view the prospect of life on other planets. Starting with the Voyager missions in the 1970s, it became clear that the Solar System had a number of bodies that were geologically active. Evidence for oceans of liquid water and hints of Mars’ watery past soon followed. Meanwhile, back on Earth, we began to discover that life could survive in some extremely harsh conditions: high radioactivity, near-boiling water, even under blood red ice in Antarctica.

These findings raised two prospects, one exciting, one worrisome. The Solar System could be much more hospitable to life than we ever thought, but if we sent probes looking for it, there was the chance we could transfer an Earth-origin extremophile to the new world, ruining everything. To that end, NASA established some rough guidelines for how to treat the risk of contamination on its deep space probes. Recently, the National Academies of Science was tasked with evaluating the protocols. The organization found them a bit lacking, based on a risk target that is “apparently arbitrary.”

The existing standard for NASA missions to other worlds focuses on places like Mars and Jupiter’s moon Europa, where the evidence of liquid water is extensive. The new report would add Saturn’s Enceladus, which expels liquid water through visible geysers, and also Triton, the largest satellite of Neptune. This last body appears to be a Kuiper belt object captured by the planet (it orbits counter to Neptune’s rotation). The Voyager flyby identified extensive surface remodeling and possible surface eruptions, suggesting the presence of liquids. Although this may be liquid nitrogen, we don’t currently know enough about the moon to rule out the possibility of water.

If any of these worlds harbor either interesting prebiotic chemistry or even life, we’d obviously want to study it. And the surest possible way to eliminate that prospect is to introduce organisms from Earth as part of the process of accessing these environments. NASA has been considering how to avoid this since as far back as the Viking landers sent to Mars in the 1970s (which were baked at 111°C for a day and a half to kill anything off).

NASA’s current policy dates back a bit over a decade, to another report by the National Research Council (the arm of the Academies responsible for this one). That was based on an earlier standard suggested by the Committee on Space Research (COSPAR) of the International Council for Science. COSPAR had suggested creating a list of the probabilities that Earth-based life would survive various events associated with a space probe, such as radiation exposure, extreme cold and heat, etc. If the probabilities were multiplied and came out to less than a one-in-10,000 chance of contamination, the risk was considered acceptable.

That one-in-10,000 chance, the new report finds, doesn’t seem to have any solid basis. “Unfortunately, the historical literature does not record the rationale for COSPAR’s adoption of the 10-4 standard,” the authors report. “Nor, in, fact has the committee been able to come up with its own quantitative rationale for this number.” If the standard, as they say, is arbitrary, the process for evaluating the probability is seriously flawed. The process of multiplying probabilities together only works if those probabilities are independent, and there is no evidence that some of them are. For example, if cold resistant bacteria are more likely to be radiation resistant, it would throw the whole calculation off.

Given their dissatisfaction with the existing standards, the committee behind the new report has come up with a new one. They call for the use of a binary decision tree, in which a series of yes or no questions are considered: is there liquid water at the destination, is there some form of chemical energy to support life, etc. Strict attempts to control for contamination should only take place if the answers to most of these questions indicate there’s a risk that it will happen.

The report also points out that there are a number of areas that we can research right here on Earth that would help us understand the risks better. Any organism that could find a home in the environments on other worlds will be, by necessity, very cold tolerant. But we haven’t studied cold tolerant bacteria as well as we’ve looked at the ones that grow in hot environments. In particular, the report suggests that we look into whether the spores of cold tolerant organisms could survive some of the heat associated with decontamination and launch procedures, and whether they can form biofilms that aid their survival.

The authors also call for NASA to develop imaging technology that will actually let them scan spacecraft for microorganisms during assembly. This would help the launch team to make informed choices about decontamination, rather than relying on estimates or indirect measures.

Right now, it doesn’t look like NASA will have the budget to go anywhere near most of the locations considered to be at risk of the contamination for many years. But the ESA is considering a Europa mission, and the report might help inform the decisions made by that agency. And, eventually, NASA will undoubtedly find a way to send probes out to look for new life.

Cleanliness...

Cleanliness in space and materials and samples brought back is a critical aspect of space exploration. Being responsible travelers and explorers in space we don't want to contaminate alien environments. And we certainly don't want any contamination of the samples that are returned to Earth for analysis. If we are careless there, then the whole value of any mission would be worthless: Bad data and false conclusions including the time and costs of the mission. Thus great effort has been made to make our trips of humans, probes, tools, collection apparatus, etc. as contamination free as possible. Think back to Robert Wise's 1971 film "The Andromeda Strain" when the selected investigation crew had to endure hours of decontamination of their bodies to enter a safe area to scientifically discover the deadly alien biological anomaly that occurred on the surface and the attempts to isolate the only two survivors in an environment free of contamination. And as current and real as of the 9th of September when the Genesis probe will return to Earth loaded with solar dust; the containment of the samples will be placed in the highest contamination environment possible: "Genesis is the first NASA mission to develop a class 10 cleanroom (only 10 particles of contaminant per cubic meter)." And the situation works the other way: Squeaky clean items placed in space are desired and accidents do happen. On April 20, 1967 the Surveyor 3 spacecraft landed on the moon with a strain of Streptococcus mitis on board. The bacteria is common and harmless: Someone must have sneezed and there was a breech in the quest for a "zero contamination" assembly environment. The freeloader was discovered when in 1969 the Apollo 12 astronauts retrieved a sample of some circuit board insulation and brought it home for analysis. Now the bacteria was free-dried on the Moon's surface but rebounded back on Earth. Maybe no harm done on the Moon, but extra care must be exercised when visiting systems that would sustain any bacteria and allow reproduction. As a matter of fact, many scientists don't think a "zero contamination" system is possible. Consider also that contamination can be inorganic. And from an epistemological perspective, data received from contaminated materials is always suspect. The recent Genesis crash is a prime example. Certification of the purity of samples is nearly impossible.