How will NASA and ESA handle the Mars samples when they return them to Earth?

We have learned a lot about Mars in recent years. Multiple orbits and highly successful mobile missions have delivered a cascade of discoveries on the neighboring planet. But to take the next step by unveiling the secrets of Mars, we must send Martian samples to Earth.

ESA and NASA plan to send samples from Mars to labs here on Earth, where they will be subjected to a type of detailed analysis that can not be done with rovers on the surface of Mars. This effort is called the Mars Back Samples Campaign. Perhaps most surprisingly, perhaps the most difficult is not to bring the samples back to Earth, but to decide on the order of the scientific investigations in these samples.

"Mars Sample Return would be a huge advance for the science of Mars and the exploration of the solar system."

Sanjay Vijendran, coordinator of ESA's Mars Sample Return campaign.

The samples will be highly coveted by scientists around the world. They have the potential to reveal secrets and answer crucial questions in our quest to understand Mars.

"The return of samples to Mars would be a huge step forward for science on Mars and the exploration of the solar system," concludes Sanjay Vijendran, coordinator of the Mars Back Samples Campaign. 39; ESA. "The samples will fundamentally advance our understanding of Mars, the history of our solar system, and help us plan our future exploration missions."

In order for these samples to live up to their potential, they must be handled with care. But it all starts with the return of the samples to Earth.

ESA and NASA are working together to send these samples to Earth. NASA's rover 2020 will prepare samples and leave them in ships on the surface. Then, the Lander return samples will land on a platform near the Mars 2020 Rover landing site. An ESA mobile, called Sample Fetch Rover (SFR), will leave this platform and collect the samples.

SFR will transport them to the platform where they will be placed in a metal box on the Mars Ascent vehicle (MAV). The MAV will be the first vehicle to take off from the Martian surface and deliver the samples in Martian orbit.

Next is ESA's Earth Return Orbiter (ERT), where the samples will be placed in a sealed biological containment system and routed to the Earth's orbit. From there, the samples will be sent to the surface, with the aid of parachutes, to be recovered. Then the analysis starts.

NASA and ESA are thinking about how to process these samples, including rocks, gas and dust, for maximum scientific benefit.

The first consideration is to control the contamination. Any exposure to the Earth's atmosphere will alter the samples. Just like the samples from the Moon, Martian samples will be quarantined for protection.

"The sample tubes will contain Martian rocks, dust and the atmosphere."

Elliot Sefton-Nash, MSR scientist, ESA.

There are guidelines not only to protect samples from the Earth's environment, but also to protect the Earth from samples, just in case. In 1959, at the dawn of the space age, the international community created COSPAR, the Committee on Space Research. COSPAR has developed many guidelines to protect other worlds from terrestrial contamination, and vice versa.

COSPAR is currently updating its guidelines to prepare the March samples.

It all starts with a Sample Receiving Facility (SRF), where the samples will be quarantined. Even before the sample containers are opened, a scientific inquiry can begin. These Martian samples will be extremely valuable. Even Martian dust deposited on the surface of the sample containers will therefore be studied even before the containers are opened. Samples can also be studied with non-invasive X-rays before being opened.

Before samples are opened, the order of investigation and study will be predetermined.

"The sample tubes will contain Martian rocks, dust and the atmosphere," says Elliot Sefton-Nash, scientist from the MSR study at ESA's Scientific Assistance Office, "Even if the clock goes For example, gases trapped in the sample material could begin to mix with their environment, which could change the Martian chemical signatures that we want to measure. "

Scientists wish to take a multitude of measures. The trick is to find the best way to proceed because some of these measurements are time sensitive, others alter the samples. In addition, the samples, in accordance with the protocols of planetary protection, will eventually have to be sterilized, in case Martian hitchhikers would take them to Earth.

But the sterilization of samples is problematic. They must be sterilized using radiation, chemical processes or heat, and all of these methods can alter the samples. Therefore, any scientific investigation sensitive to these methods must be prioritized.

The group planning the sample processing is called the Scientific Planning Group for returning samples to Mars. The good news is that this group says that about three-quarters of scientific investigations can be done after sterilization.

But there are still many decisions to be made.

The order in which examinations are performed after sterilization is always important because some measurements will influence the results of others. For example, some measurements destroy samples for results, and not all measurements can be performed on all samples. According to ESA, the nature of the laboratory performing the work can be a decisive factor.

Precision carbon measurements in samples require strict control of carbon in the laboratory. An all-metal laboratory may be required to ensure the validity of the results. But an all-metal lab could contaminate samples for other measurements. Finding the right balance is a big puzzle.

Once the ESA Space19 + Council meets and finalizes its participation in the Mars Sample Return Mission, planning for sample handling can begin in earnest. It will be up to ESA, NASA and the scientific community to develop a plan that will provide as much scientific data as possible.