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The concepts for Mars return mission samples, like this one, have been around for decades, but there is now a new surge to return samples of the red planet. (credit: NASA / JPL-Caltech) |
by Van R. Kane and Pat Nealon
Monday, August 19th, 2019
In November 2018, Thomas Zurbuchen, NASA's Associate Administrator for Science, announced the selection of Jezero Crater as the landing site for the March 2020 rover. March 2020, which will likely be renamed next year in some something a little more eye-catching, will be launched in July 2020 and will land on March 18, 2021. It will then circulate around Jezero, with the help of a very sophisticated sampling system to collect pieces of Mars. and seal them in pencil-sized tubes. But it's not just another mission on Mars. March 2020 represents the most concrete step in achieving a goal that has been a priority for US planetary scientists for nearly 50 years: returning samples from Mars. The launch and landing of March 2020 will be not only an important technical achievement, but also a major psychological advance. After decades of false starts and even inversions, the goal of returning the sample to Mars – or MSR, as it has long been called in planetary circles – has now taken his flight.
| The launch and landing of March 2020 will be not only an important technical achievement, but also a major psychological advance. After decades of false starts and even inversions, the goal of returning Mars samples has now taken off. |
Mars has already hosted a small flotilla of orbiters, landers and rovers. Another lander, three rovers and two orbiters are expected to arrive in two years time. Yet, returning long samples of the surface was the ultimate goal of Martian studies. The instruments that humanity has sent into this world are marvels of sophistication and miniaturization. However, they can not begin to match the sophistication and diversity of instruments used by scientists on Earth.
As an example of the limitations of the instruments we can send to Mars, let's take a recent scientific article that announced that organic molecules had been found in material analyzed by one of Curiosity's mobile chemistry instruments. Fragments of detected carbon-containing molecules suggested that they could come from much more complex organic molecules known as kerogens. These complex organic molecules, if they were the source of the fragments, can come from meteorites, interplanetary dust, Martian geology or biology. There is simply no room, mass or power available on a landing gear or a mobile to answer definitively the question of what were the parent molecules or how they were formed. We are left with tantalizing and ultimately frustrating clues. If the Curiosity samples were in Earth's laboratories, scientists could both research the identity of these parent molecules and how they were created.
Likewise, an international science team recently claimed to have discovered the oldest known terrestrial fossils on Earth in Western Australia, dating back about 3.4 billion years. Their methods illustrate the need to send back samples to explore the question of life, ancient or contemporary, on Mars. The probable microfossils are only 10 micrometers in diameter and are found in the spaces between the sand grains of an old beach transformed into sedimentary rock. Using extremely sensitive X-ray absorption spectroscopy, made possible by the energy generated by a synchrotron, a combination impossible to pack on board a mobile, scientists have discovered residual chemicals expected fossilized biological remains. Tiny deposits of pyrite, the gold of the mad, found on the microfossils could be the product of sulfur-based metabolisms that these creatures could have used to extract energy in a world without oxygenated atmosphere. Analyzes at these tiny scales go beyond what can make the instruments of a spaceship. But they could be performed in land-based laboratories on samples returned from Mars.
NASA and the European Space Agency (ESA) have developed an ambitious plan with three launches and multiple gears, as well as a land sampling center. (credit: Caltech / JPL) |
The beginnings of Mars Sample Return
Acknowledging these needs, the first proposals for robotic retrieval of a sample of Mars date back to the early 1970s. While NASA was working on the Viking missions on Mars, Martin Marietta conducted a study on the appointments and the schedule. robotic mooring in orbit on Mars, which was later considered one of the most difficult aspects of the return of robotic samples. Among the other major challenges was the design of a vehicle capable of surviving the coldness of Mars and successfully emerging from the surface to reach orbit. The two 1976 Viking missions proved that NASA could land a spacecraft on Mars. Viking could have been the basis of a sample return mission if it had been approved.
But by the mid-1970s, the American global scientific community considered the return of the Mars sample as a long-term goal.[1], not in the short term. Scientists did not know the surface of Mars well enough to identify the most attractive site to sample. The scientific community has advocated one or more precursor missions to better characterize the Martian surface. Scientists speculated on when they would know enough to confidently pursue a return of samples mission. This debate continued throughout the 1970s and 1980s.
| It was useless to spend billions of dollars to bring back an identical rock to several Martian meteorites already fallen on Earth. They needed a series of missions that would select a high quality sample. |
But the Viking experiment had created a problem: although Viking had many scientific goals, the one that attracted the most attention was the detection of life on Mars; When Viking failed, political and public support for the continuation of Mars missions evaporated. The US global scientific community continued to approve the return of the March sample, but it did not find support for all Mars missions throughout the 1980s, not to mention incredibly expensive.
In the 1990s, NASA finally resumed the exploration of Mars after a long interruption. Unfortunately, the Mars Observer spacecraft failed to reach the orbit of Mars in 1993, delaying its exploration again. Then, in 1996, a science team claimed to have discovered evidence of fossil life in a Mars meteorite found in Antarctica. Although this claim has not been widely adopted by the scientific community, it has nevertheless sparked a new interest from the White House for the Red Planet.
By the end of the 1990s, the return of samples to Mars was enjoying increasing support within the scientific community and companies began to conduct engineering studies. It seemed like NASA would start working on a real mission back to Mars in the early 2000s. But in 1999, NASA lost the Mars Climate Orbiter and Mars Polar Lander satellites, which led to the development of the Mars satellite. agency to reevaluate its strategy on Mars. As part of NASA's new NASA exploration strategy, the agency halted the effort to return samples, concluding that the scientific community was not yet sure enough about Mars to know where get the best sample. It was useless to spend billions of dollars to bring back an identical rock to several Martian meteorites already fallen on Earth. They needed a series of missions that would select a high quality sample.
The Mars Exploration Program
NASA, as part of its new Mars Exploration Program,[2] has quickly launched such missions: the rovers Spirit and Opportunity landed in 2004 and Mars reconnaissance orbiter, arrived at Mars in 2006. The European orbiter Mars Express began its studies in 2004. The Mars Science Laboratory, later named Curiosity, was originally scheduled for launch in 2009 which has been postponed to 2011, with significant costs. While Sprit and Opportunity were designed to track water, Curiosity was designed to track carbon, and Mars Reconnaissance Orbiter was intended to create a global database on how water and other conditions needed for creation and to the maintenance of life were integrated, collectively exploring the past or present habitability of Mars. It could be argued that missions in orbit and orbit on Mars over the past two decades are essentially part of Mars' retest effort, or at least the first necessary step in a return strategy of Mars. sample.
What these missions revealed on Mars resulted in a drastic change in targets for the return of the sample. According to the first concepts, the LG had taken samples in the immediate vicinity of the LG, assuming that all the material returned from Mars would be valuable. This strategy would have been similar to China's plans to return samples of the moon. The future Chinese mission Chang'e-5 aims to understand how the youngest mare was formed and a sample collected directly at the landing site anywhere in a vast region will answer this question. Similarly, a hoped-for US return mission to explore the history of the Moon's mantle and crater depends on the impact of dispersal of rock fragments of key geological units on the surface, so that it can constitute a collection of samples near the lander. A Mars return mission to China, whose launch is scheduled for 2028, should apparently also take samples of the immediate landing site.
However, Western scientists have turned away from this approach for Mars. This was partly due to the discovery that more than 100 known Mars samples were already on Earth, expelled from the Martian surface by impacts and delivered to our world in the form of meteorites. Second, scientists have realized that the samples that best record the earliest history of Mars – dating back to a lost time on Earth, much more geologically active – are found in local regions. They are also fragile materials, such as sediments, that would not survive the impacts to be delivered naturally to the Earth. Plans for a return of Martian samples eventually included a specially designed mobile mission to collect and cache a variety of samples from an ancient and geologically diverse site.
The Martian gambit
This brings us to the current decade. In 2011, the National Research Council produced Vision and travels for global science during the 2013-2022 decade, otherwise known as the 10-year study of planetary sciences. The decennial survey recommended that a mission to cache samples on Mars be the highest priority of a high-class mission (a mission costing more than one billion dollars at the time). The Mars community has not recommended any other mission, putting all its chips on the table. This decision was potentially controversial because the return of samples would not cover all areas of pressing scientific investigations on Mars, leaving some researchers from the Martian community without a mission to advance knowledge in their respective fields. It was also possible that NASA – and the decision-makers who controlled the agency's budget – could do not finance the early stages of sample restitution due to concerns about cost. The ten-year committee concluded that after more than forty years waiting for samples of the red planet, placing any other mission on the list of priorities – thus leaving the decision makers the opportunity to choose a mission at lower cost and to launch the potty road again – no longer was practical. The Mars community had systematically reviewed its list of scientific questions and the most important problems remaining required that carefully selected samples of Mars be brought back to Earth. The return of samples is the mission that, according to the Martian community, offers the greatest potential for progression of Martian science.
| The ten-year committee concluded that after more than forty years waiting for samples of the red planet, placing any other mission on the priority list, thus offering decision-makers the opportunity to choose a mission at lower cost and toss the pot back from the samples on the road. again – it was more convenient. |
One of the benefits of returning samples to Mars is that samples can be shared around the world, taking advantage of non-US scientific capabilities. It also makes the return of samples attractive for international participation, which is considered by many to be necessary for political support for such an expensive mission. At the time, NASA was in discussion with the European Space Agency (ESA) to participate in its ExoMars program. NASA and ESA would build each rover for Mars, and the NASA rover would focus on collecting samples for a possible return to Earth. ESA would build an orbiter on which NASA would provide instruments and NASA would launch all spacecraft. The program was an ambitious and expensive undertaking. The 10-year study in 2011 favored NASA's participation in ExoMars, but recommended a $ 3.5 billion to $ 2.5 billion investment in the astrobiological exploration apparatus of Mars (MAX-C) . NASA's mission planners have been striving for efficiency and effectiveness, while NASA management has negotiated with ESA to encourage Europeans to bear more of the costs. After a prolonged effort in which the agencies were able to reach the recommended cost levels for NASA, the US Bureau of Management and Budget (OMB), concerned about the cost overruns of Curiosity and the James Webb Space Telescope, wishing not commit the government to the subsequent missions needed to recover the samples, ordered NASA to withdraw from the program, damaging NASA's relationship with ESA.
NASA officials did not want to lose the manpower and capabilities developed over the decades needed to explore Mars, especially with respect to entry, descent and the Landing, and quickly began looking for another mission on Mars. John Grunsfeld, then deputy administrator in charge of science, initially proposed a medium-sized orbiter or robot ($ 700 million) for Mars, but he immediately faced resistance from the scientific community, saying that neither of them missions did not follow the recommendations of the decennial survey. He created a working group at NASA to determine the way forward for NASA's Mars program. The group discovered that NASA could take several paths on Mars to achieve its goals, but that all required a mission leading to a possible return of the sample.[3] In essence, the group said: "Follow the recommendations of the decennial survey".
March 2020
It was reported that the successful landing of Curiosity in the summer of 2012 had prompted President Barack Obama to ask what other exciting missions NASA was planning to plan for Mars. This high-level political interest, combined with the task force report, led to the approval of the March 2020 mission at the end of the same year. March 2020 would be based on the Curiosity entry descent and landing system and the successful design of the mobile.
Informed sources told us that for many years to 2016, OMB officials objected to the inclusion of the sample caching system as of March 2020. The latter would probably not could not do it without the slightest indifference to the mission of the Obama administration. OMB is inspired by elected senior management and, without active and ongoing support for key initiatives, OMB budget reviewers are regaining basic skepticism about costly programs and long-term commitments. If the March 2020 project had overshot the budget at that time, the OMB would have possibly removed it by forcing the removal of the caching equipment from the samples, which would have effect of neutralizing the spaceship. March 2020 has kept its budget during this period.
What the OMB apparently could have done at that time would have been to avoid spending almost all the money needed to develop the technology needed to retrieve March samples – another key recommendation of the decennial survey of 2011. Funding for the development of the March sample return technology could have started in 2013, but it was virtually non-existent for four years. We were told that it was forbidden for NASA officials to publicly mention the return of samples from Mars or to initiate discussions with potential foreign partners about such a mission. . The opposition of the OMB was apparently based on its general opposition to all the expensive space missions and its skepticism that NASA could control the costs of such a mission.
On the way to bring back pieces of Mars
The situation was different after the change of administrations starting in 2017. New members of the executive have apparently lobbied the OMB officials to stop opposing new missions on March, and in the summer of 2017, NASA was finally able to indicate that it had begun working on a "targeted and fast" sample return design architecture from Mars . With NASA approval, the Jet Propulsion Laboratory began developing the technology needed to capture a cartridge sample the size of a soccer ball in orbit around Mars. In the fall of 2017, two companies also began testing a technology for rocket engines in order to lift a cartridge sample out of Mars.
| After decades of reviewing and planning the return of a sample of March, it seems that the decisive momentum is finally in place for the program. |
In April 2018, NASA announced the signing of a "Statement of Common Intent" with the European Space Agency to develop a sample return plan for Mars. ESA signed contracts for the research robot study that would retrieve the samples from Mars and a robotic arm that would load them into the return capsule. ESA is also studying the return vehicle to capture the capsule in orbit. With ESA building the rover fetch, the arm and possibly the spaceship back, NASA will not have to build these expensive elements of the mission. But the agency will certainly have plenty of hands to develop the complex and expensive vehicle of the March ascent.
To return the March 2020 samples, NASA and ESA must formally approve their portions of missions to follow the 2020 rover. ESA's approval comes from its ministerial meeting to be held next November. In the meantime, the managers of this agency have launched a call for proposals for an orbiter return samples. This would allow ESA to embark quickly on development if its ministers approve participation in the returns program.
The NASA and ESA projects call for a careful choreography of launches and operations to return samples to Earth as early as 2031. (Credit: Caltech / JPL) |
On the US side of the Atlantic, Congress has given NASA $ 50 million this year for preparatory work. The administration has proposed $ 109 million over the next fiscal year for future missions to Mars, the bulk of which will be used to prepare a sample report. (The House of Representatives bill supports this funding and a launch date of 2026. The Senate still has not acted.) Within NASA, the March program has received approval to officially develop the budget potential contributions to enable NASA to make a decision. program next year.
After decades of reviewing and planning the return of a sample of March, it seems that the decisive momentum is finally in place for the program. The first mission of the series, the 2020 rover, should be launched next summer. All good preparations are underway on both sides of the Atlantic. Critical decisions will come this fall for ESA and possibly for NASA with the publication of the President's 2021 budget, which could provide a new official start-up authority and a new budget – or not.
If America has a new president the following year, its administration will have to confirm its support. Nevertheless, this seems like a good time to hope. From here, the Mars 2020 rover will cross the Jezero Crater by collecting carefully selected samples of Mars. This could really change the psychology regarding the return of samples to Mars. With actual samples deposited on Mars, there will be more and more calls – and possibly political support – to bring them back to Earth for analysis. These samples may not answer with certainty if life once existed on Mars, but they will allow humanity to answer this question more than ever for millennia, since humans have looked at the red planet and wondered if there was anything alive on it. .
For more information on NASA and ESA Mars' developing sample return program, we recommend this presentation as of June 2019.
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Endnotes
- National Research Council. OOpportunities and choices in space science, 1974. Washington, D.C .: The National Academies Press, 1975.
- NASA Press Release, "NASA presents Mars Exploration Program for the next two decades," October 26, 2000.
- March Program Planning Group, "Summary of Final Report", September 25, 2012.
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