Tag: planetary protection

Sample Return in the Time of Coronavirus

 

Sample return from Mars. Artist rendering of a Mars sample return mission. The mission would use robotic systems and a Mars ascent rocket to collect and send samples of Martian rocks, soils and atmosphere to Earth for detailed chemical and physical analysis.  No rocket has ever taken off from Mars and this NASA and European Space Agency (ESA) project is in early planning stages. Still, blue-ribbon science panels have recommended efforts to begin preparing the public for an eventual Mars sample return. ( Wickman Spacecraft & Propulsion)

For space scientists of all stripes, few goals are as crucial as bringing pieces of Mars, of asteroids, of other planets and moons back to Earth for the kind of intensive study only possible here.  Space missions can, and have, told us many truths about the solar system,  but having a piece of Mars or Europa or an asteroid to study in a lab on Earth is considered the gold standard for learning about the actual composition of other bodies, their histories and whether they could — or once did — harbor life.

In keeping with this ambition, the last National Research Council Decadal Survey listed a Mars “sample return” as the top science priority for large Flagship missions.  And the Perseverance rover that NASA is scheduled to send to Mars next month will — among many other tasks — identify compelling rock samples, collect and cache them so a subsequent mission can pick them up and fly them to Earth.

Two asteroid sample return missions are also in progress, the NASA’s OSIRIS-REx mission to Bennu and the Japan Aerospace Exploration Agency (JAXA’s)  Hayabusa2 mission to the Ryugu.  Both spacecraft are at or have already left their intended targets now and are expected to return with rock samples later this decade, with Hayabusa2 scheduled to complete its round trip later this year.

An illustration of the coronavirus. (Centers of Disease Control)

So sample return is in our future.  And in the case of Mars the samples will not with 100 percent certainty be lifeless — a major difference from the samples brought back from the moon during the Apollo missions and the samples coming from asteroids.

This possibility of a spacecraft bringing back something biological — as in the 1969 book “The Andromeda Strain” — has always been viewed as a very low probability but high risk hazard, and much thinking has already gone into how to bring samples back safely.… Read more

Planetary Protection and the Moons of Mars

Mars with its two moons, Phobos and Deimos. Phobos orbits a mere 3,700 mile3s (6,000 km) above the surface, while Deimos is almost 15,000 miles (24,000 kilometers) away from the planet. In comparison, there is an almost 384,000 kilometers mean distance between the surface of the Earth and our elliptically orbiting moon. With the moons so close to Mars, debris from meteorite impacts on the planet can easily land on the moons. (NASA/JPL-Caltech/University of Arizona)

Sometime in the early to mid-2020s, the capsule of the Japanese Martian Moons eXploration (MMX) mission is scheduled to arrive at the moons of Mars – Phobos and Deimos.

These are small and desolate places, but one goal of the mission is large: to collect samples from the moons and bring them back to Earth.

If it succeeds, the return would likely be the first ever from Mars or its moons — since planned sample return efforts from the planet itself will be considerably more challenging and so will take longer to plan and carry out.

The Mars moon mission has the potential to bring back significant information about their host planet, the early days of our solar system, and the origins and make-up of the moons themselves.

It also has the potential, theoretically at least, to bring back Martian life, or signatures of past Martian microbial life. And similarly, it has the potential to bring Earth life to one of the moons.

Hidenori Genda, an ELSI planetary scientist with a long-lasting interest in the effects of giant planetary impacts, such as the one that formed our moon. His work has also focused on atmospheres, oceans, and life beyond Earth. (Nerissa Escanlar)

Under the general protocols of what is called “planetary protection,” this is a paramount issue and is why the Japan Aerospace Exploration Agency (JAXA) was obliged to assess the likelihood of any such biological transfers with MMX.

To make that assessment, the agency turned to a panel of experts that included planetary scientist, principal investigator, and associate professor Hidenori Genda of Tokyo’s Earth-Life Science Institute.

The panel’s report to JAXA and the journal Life Sciences in Space Research concluded that microbial biology (if it ever existed) on early Mars could have been kicked up by incoming meteorites, and subsequently traveled the relatively short distance through space to land on Phobos and Deimos.

However, the panel’s conclusions were unambiguous: the severe radiation these microbes would encounter on the way would make sure anything once living was now dead.… Read more

Planetary Protection is a "Wicked" Problem

The Viking landers were baked for 30 hours after assembly, a dry heat sterilization that is considered the gold standard for planetary protection.  Before the baking, the landers were given a preliminary cleaning to reduce the number of potential microbial spores.  The levels achieved with that preliminary cleaning are similar to what is now required for a mission to Mars unless the destination is an area known to be suitable for Martian life.  In that case, a sterilizing equivalent to the Viking baking is required.  (NASA)

The only time that a formally designated NASA “life detection” mission was flown to another planet or moon was when the two Viking landers headed to Mars forty years ago.

The odds of finding some kind of Martian life seemed so promising at the time that there was little dispute about how much energy, money and care should be allocated to making sure the capsule would not be carrying any Earth life to the planet.  And so after the two landers had been assembled, they were baked at more than 250 °F for three days to sterilize any parts that would come into contact with Mars.

Although the two landers successfully touched down on the Martian surface and did some impressive science, the life detection portion of the mission was something of a fiasco — with conflict, controversy and ultimately quite a bit of confusion.

Clearly, scientists did not yet know enough about how to search for life beyond Earth and the confounding results pretty much eliminated life-detection from NASA’s missions for decades.

But scientific and technological advances of the last ten years have put life detection squarely back on the agenda — in terms of future searches for fossil biosignatures on Mars and for potential life surviving in the oceans of Europa and Enceladus.  What’s more, both NASA and private space companies talk seriously of sending humans to Mars in the not-too-distant future.

With so many missions being planned, developed and proposed for solar system planets and moons, the issue of planetary protection has also gained a higher profile.  It seems to have become more contentious and to some seems far less straight-forward as it used to be.

A broad consensus appears to remain that bringing Earth life to another planet or moon, especially if it is potentially habitable, is a real possibility that is both scientifically and ethically fraught. But there are rumblings about just how much time, money and attention needs to be brought to satisfying the requirements of “planetary protection.”… Read more

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