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From looking for life on Mars to powering future colonies, Los Alamos National Laboratory is developing instruments to help researchers better understand the planet and paving the way for future settlers.

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Confessions of a Martian Rock

By Nina Lanza

Staff Scientist at Los Alamos National Laboratory

Manganese on Martian rocks | Los Alamos National LaboratoryWhen LANL scientists found large amounts of manganese on a Martian rock called “Caribou,” they thought, “This has to be a mistake.” Then ChemCam discovered even more rocks filled with manganese oxides.



Confessions of a Martian Rock


By Nina Lanza


I look at rocks on Mars for a living—a lot of rocks. Because of this, I’ve gotten pretty good at knowing what to expect and what not to expect when analyzing the chemical make-up of a Martian rock. You expect to find lots of basalt, the building block of all planets.

Caribou Conundrum


Trace amounts of the element manganese typically exist in basalt. To get a rock with as much manganese as Caribou has, the manganese needs to be concentrated somehow. The rock has to be dissolved in liquid water that also has oxygen dissolved in it.


If conditions are right, the manganese liberated from the rock can then precipitate as manganese oxide minerals. On Earth, dissolved oxygen in groundwater comes from our atmosphere. We’ve known for some time now that Mars once had vast oceans, lakes and streams. If we could peer onto Mars millions of years ago, we’d see a very wet world. Yet we didn’t think Mars ever had enough oxygen to concentrate manganese—and that’s why we thought the data from Caribou must have been an error.

The Hunt Is On


So what do you do when you find a Martian rock with a chemistry you didn’t expect? You go look for more.


When NASA’s Curiosity rover arrived at the Kimberly region of Gale crater, we went to work, looking at the mineral-filled cracks in sandstones on the floor of what was once a deep lake. We used the ChemCam instrument, which sits atop Curiosity and was developed here at Los Alamos National Laboratory, to “zap” rocks on Mars and analyze their chemical make-up. (In less than four years since landing on Mars, ChemCam has analyzed roughly 1,500 rock and soil samples.)


When ChemCam fires its laser pulse, it vaporizes an area the size of a very small pinhead. The system’s telescope on the rover peers at the flash of glowing plasma created by the vaporized material and records the colors of light contained within it. This light allows us here on Earth to determine the elemental composition of the vaporized material.


And what did ChemCam discover? More rocks filled with manganese oxides. So Caribou was not a mistake — far from it.

Why Does Manganese Matter?


We never expected to find manganese oxides on Martian rocks because we didn’t think Mars ever had the right environmental conditions to create them. We can look to Earth’s geological record for an explanation. More than 3 billion years ago, Earth had lots of water but no widespread deposits of manganese oxides until after photosynthesizing microbes raised the oxygen levels in our atmosphere.


Although there was already plenty of other microbial life on Earth at this time, these new photosynthetic microbes used sunlight energy in a new way and created a new type of waste product in the process: oxygen.


By adding oxygen to the atmosphere, these tiny microbes transformed Earth’s environment. Suddenly, minerals never before formed on Earth started being deposited, including manganese oxides. This monumental environmental shift is recorded in the chemistry of rocks of that age all over the world. Earth has never been the same since. (Some hypothesize that more complex life forms, such as humans, might never have developed without this atmospheric change.)


So to summarize: In the Earth’s geological record, the appearance of high concentrations of manganese marks a major shift in our atmosphere’s composition, from relatively low oxygen abundances to the oxygen-rich atmosphere we see today. The presence of the same types of materials on Mars suggests that something similar happened there. If that’s the case, what formed that oxygen-rich environment?

How Did It Get There?


One way oxygen could have gotten into the Martian atmosphere is from the breakdown of water when Mars was losing its magnetic field.


Without a protective magnetic field to shield the surface from ionizing radiation, that radiation split water molecules into hydrogen and oxygen. Mars’ relatively low gravity couldn’t hold onto the very light hydrogen atoms, but the heavier oxygen atoms remained behind. Rocks absorbed much of this oxygen, leading to the rusty red dust that covers the surface today. While Mars’ famous red iron oxides require only a mildly oxidizing environment to form, manganese oxides require a strongly oxidizing environment. Finding manganese oxides suggests that past conditions were far more oxidizing than previously thought.

What’s Next?


NASA’s Opportunity rover, which has been exploring Mars since 2004, also recently discovered high-manganese deposits in its landing site thousands of miles from Curiosity, which supports the idea that the conditions needed to form these materials were present well beyond Gale crater.


Of course, it’s hard to confirm whether the ionizing-radiation scenario I’ve presented here for creating Martian atmospheric oxygen actually occurred. But it’s important to note that this idea represents a departure in our understanding of how planetary atmospheres might become oxygenated. So far, abundant atmospheric oxygen has been treated as a so-called biosignature, or a sign of existing life.


The next step in this work is for scientists to better understand the relationship between manganese minerals and life. On Earth, they are highly related—but they certainly don’t need to be.


So how can we tell whether the manganese on Mars might actually be made by microbes? The answer is lots and lots of laboratory experiments. If it’s possible to distinguish between manganese oxides produced by life and those produced in a non-biological setting, we can apply that knowledge directly to Martian manganese observations to better understand their origin.


In the meantime, we’ll keep our eyes trained on the Martian surface and see what other secrets it has to reveal.


Nina Lanza is a staff scientist at Los Alamos National Laboratory, which has built and operated more than 500 spacecraft instruments for national defense. That background gives the Laboratory the expertise to develop discovery-driven instruments like ChemCam and its souped-up successor, SuperCam, also developed by the Laboratory and scheduled for the Mars 2020 rover mission.


This was first published in Discover.

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The SuperCam Remote Sensing Instrument Suite for the Mars 2020 Rover: A Preview

By Roger Wiens, et al

Los Alamos National Laboratory Fellow and Principal Investigator for ChemCam

SuperCam figure in Spectroscopy Online | Los Alamos National LaboratoryThe SuperCam remote sensing instrument suite under development for NASA’s Mars 2020 rover builds on the successful architecture of the ChemCam instrument, adding remote Raman spectroscopy.



The SuperCam Remote Sensing Instrument Suite for the Mars 2020 Rover: A Preview


By Roger Wiens, Sylvestre Maurice, Fernando Rull Perez


The SuperCam remote sensing instrument suite under development for the National Aeronautics and Space Administration’s (NASA) Mars 2020 rover performs laser-induced breakdown spectroscopy (LIBS), remote Raman spectroscopy, visible and infrared (VISIR) reflectance spectroscopy, acoustic sensing, and high-resolution color imaging. The instrument builds on the successful architecture of the ChemCam instrument, which provides LIBS and panchromatic images on the Curiosity rover, adding remote Raman spectroscopy by frequency doubling the laser and using a gated intensified detector to obtain Raman signals at distances to 12 m. To the visible reflectance spectroscopy used by ChemCam, an acousto-optic tunable filter (AOTF)-based IR spectrometer is added to cover the 1.3–2.6 µm range that contains important mineral signatures. A complementary metal-oxide semiconductor (CMOS) detector provides color (Bayer filter) images at a pixel resolution of 19 µrad and an optical resolution of 30 µrad. Sounds are recorded via a Knowles Electret microphone, which is the same one that was included but not used on two earlier missions. The acoustic signals of the LIBS plasmas will provide information on the hardness of the targets, while other sounds (wind, rover sounds) will also be recorded. The laser, telescope, IR spectrometer, and camera reside on the rover’s mast and are provided by the Centre national d’etudes spatiales (CNES), while the LIBS, Raman, and VIS spectrometers and data processing unit are built by Los Alamos National Laboratory (LANL) and reside in the rover body. A calibration target assembly provided by the University of Valladolid, Spain, resides on the back of the rover. The overall mass of the instrument suite is 10.7 kg.


Over the past two decades the National Aeronautics and Space Administration (NASA) has sustained an evolving capability to explore the Red Planet (Mars). Starting from the small 11.5-kg Sojourner rover that landed in 1997, and continuing with the twin 175-kg Mars Exploration Rovers (MER) (1) the program reached a high point in 2012 with the landing of the 900-kg Curiosity rover (2). The next step in NASA’s “Journey to Mars” program is the deployment of a sample-collecting rover planned for launch in 2020. Currently known simply as the Mars 2020 rover, this vehicle will be nearly a twin of the Curiosity rover in size, but will support a new payload to complement its mission of caching samples for return by a future mission. This payload includes fine-scale mineralogy, organics, and chemistry instruments on the rover’s arm, a weather station, a stereo zoom imager, a ground-penetrating radar, and a device to generate oxygen as a technology demonstration in anticipation of astronauts and in situ rocket fuel production. The seventh instrument, SuperCam, is a highly evolved version of the successful remote-sensing composition instrument, ChemCam, on the Curiosity rover (3,4).


Although SuperCam resembles ChemCam in its basic architecture (Figure 1), a number of capabilities have been added, including remote Raman spectroscopy, infrared (IR) spectroscopy, color (versus ChemCam’s panchromatic) imaging, and acoustic sensing. These techniques respond to the Mars 2020 Science Definition Team Report (5), which encouraged co-bore-sighted measurements by multiple techniques, and required that mineralogical characterization be part of the rover’s remote-sensing capabilities.

Capabilities and Techniques


Figure 2 shows representations of SuperCam’s spectral and imaging techniques. Laser-induced breakdown spectroscopy (LIBS) uses a focused, pulsed laser beam to interrogate rocks and soils remotely with >10 MW/mm2, producing brief, luminous plasmas (for example, see reference 6). The optical emission from these plasmas is recorded; the atomic emission lines are calibrated, providing quantitative elemental abundances for major, minor, and trace elements. ChemCam has returned ~400,000 spectra to date on >12,000 observation points along the rover’s traverse, documenting the elemental compositions comprehensively (7). The LIBS technique can be used for depth profiles below the surface of the rock or soil. An added benefit is that the plasma shock wave removes dust, providing a clear view of the target for the other techniques (8).


The two mineral techniques are Raman spectroscopy and visible and infrared (VISIR) passive reflectance spectroscopy. VISIR spectroscopy has been used extensively from orbit around Mars with the CRISM and OMEGA instruments on the Mars Reconnaissance Orbiter and the Mars Express spacecraft (9,10). ChemCam also provides visible-range passive spectroscopy (11). However, the IR spectral range is far more diagnostic, particularly because of IR adsorption bands of clay minerals, which are of the greatest interest in the quest to understand Mars’ past habitability. The gap in the VISIR plot in Figure 2 is necessary so the laser can be used for the other techniques, while the gray band indicates the region that is strongly absorbed by atmospheric CO2.


Raman spectroscopy is overdue on Mars, as a Raman instrument was de-scoped from the payload of the MER that landed in 2004 (12). Raman spectroscopy works by indestructively stimulating the surface with coherent light. A small fraction of the returned light is modulated by the molecular vibrational modes, and these are observed with a sensitive detector, yielding information about the mineral and molecular structure.


Although nearly all terrestrial applications of Raman spectroscopy are performed at close range using continuous-wave lasers, and two such instruments are now being built for Mars (18,19), SuperCam implements a remote-sensing version (for example, see references 13 and 14). Remote Raman spectroscopy is achieved by the use of a pulsed laser, telescope, and a time-gated intensified detector to effectively remove ambient light and amplify the weak Raman signal coming from some meters away. The time gating has the added advantage of avoiding interfering fluorescence from mineral sources. As organic matter is scarce on Mars, fluorescence interference from organics, which is prompt and cannot be easily removed by time gating, is expected to be minimal.


Context imaging of the spectral targets has proven to be highly important in the past, and so an imager is a necessity on the SuperCam. The Remote Micro-Imager (RMI), as it is called, has been upgraded from ChemCam’s panchromatic version (15) to Bayer-filter color using a complementary metal-oxide semiconductor (CMOS) detector.


Finally, acoustic sensing was just added in 2016 based on the recognition that the intensity of the sound from the LIBS plasma shock wave can provide details of the physical characteristics (such as hardness) of the target (for example, see reference 16). It will also contribute to basic atmospheric science, and will record the unique signature of many artificial sounds.


Table I gives a list of the key functional features and capabilities. The elemental composition can be determined to 10% accuracy and precision within 7 m of the rover. The twin mineral capabilities of VISIR and Raman spectroscopy provide detections at or below the 5–10% abundance range for major mineral groups in the distance range to 12 m, which is the expected limit of the Raman spectrometer. The VISIR, with only the sunlight for illumination, can operate much farther. As demonstrated by ChemCam, atmospheric characterization can also be done with the available spectrometers. The acoustic sensing of LIBS can be done to a distance of 4 m. The microphone will also be useful in listening to rover-generated sounds and studying microbursts of wind. The Mars atmosphere, with a pressure of only ~0.7 kPa, and consisting of mostly CO2, is expected to transmit sound only poorly (especially above 10 kHz) and slowly (240 m/s).

Instrument Architecture


Figure 1 provides a schematic diagram of the SuperCam instrument architecture, and Figure 3 shows isometric views of the major units. The instrument follows the overall design of ChemCam in that it is built in two major sections. The mast unit consists of the laser, telescope, RMI imager, IR spectrometer, and electronics for these functions. For the LIBS, Raman, and the visible portion of the VISIR spectroscopy, an optical fiber transmits the light from the telescope on the mast to a unit in the body of the rover, where spectrometers for these functions reside. This split design significantly reduces the amount of mass and volume that are needed on the rover’s mast. The respective mast and body units weigh 5.9 and 4.8 kg. A set of calibration targets is mounted on the back of the rover, including 23 geological targets representing major igneous mineral groups, carbonates, sulfates, and a number of whole-rock compositions, and five targets specifically for trace-element calibration. Color targets for the imager were added to these and IR targets were added for the VISIR observations.


The separate units in Figure 1 also represent separate national contributions to the rover. The mast unit was contributed by and built in France, led by the Institut pour Recherche en Astrophysique et Planetologie (IRAP) in Toulouse, France, while the body unit was built by Los Alamos National Laboratory (LANL), where the instrument is being integrated. Jet Propulsion Laboratory, the developer and builder of the rover, provides the overall accommodation for the SuperCam instrument, including the optical and electrical cables. The calibration target is assembled and tested in Spain (the lead institution is the University of Valladolid), with contributions to the targets themselves from France, Denmark, Canada, and the United States.


The laser is integral to both the LIBS and Raman spectroscopic techniques. Its characteristics are given in Table II. Whereas ChemCam used an exotic Nd:KGW crystal (4), SuperCam returns to a more traditional Nd:YAG crystal that is thermally accommodated by being pumped by several diode bars that are optimized at three different temperatures. This provides an exceptional operating range of 40 °C. The LIBS technique uses the fundamental laser frequency, which is focused by the telescope to a tight spot on the target, providing the necessary high energy density to excite a plasma. For Raman spectroscopy the fundamental frequency is blocked; a frequency doubler is used to produce green light, the Raman bands of which can be detected by an intensified charge coupled device (CCD). This green beam enters a polarized prism that is part of a periscope that transfers the collimated beam around the telescope and aligns it on the target. The field of view of the focused telescope diverges slightly, matching the collimated 8-mm laser beam at 12 m. Beyond that the telescope field of view is under-filled by the laser-produced Raman footprint, and the signal decreases with distance. The energy of the laser beams can be reduced to limit saturation of the LIBS or Raman signals.


Table III lists some of the imaging and acoustic parameters. SuperCam achieves the same overall image resolution as ChemCam, but in color, by using a detector with four times the pixel density as ChemCam and employing a Bayer color filter. The microphone is the same model (Knowles Electret) as the ones that flew to Mars on the 1998 Mars Polar Lander (MPL) (17) and the 2007 Phoenix mission. However, neither mission had the fortune of recording sounds, as the MPL apparently crashed upon entry and the Phoenix microphone was never turned on for safety reasons. SuperCam thus expects to be the first scientific microphone to operate on the Red Planet. The Mars 2020 entry, descent, and landing (EDL) system also has cameras with microphones, but it is not known whether they will continue to operate once on the Martian surface. SuperCam’s microphone can record up to 3.5 min at a time, with its data packed in the same format as the RMI images. It can also record shorter durations, such as for individual LIBS plasmas.


Several functions are handled by microprocessor in the mast unit (Figure 1), including focusing the telescope, determining the proper exposure for the RMI imager, and implementing a high-dynamic-range (HDR) imaging mode. All of these functions must be handled autonomously. To aid in focusing, a seed distance to the target within ±5% is provided by the rover’s stereo navigation cameras. The focus stage is scanned across positions corresponding to this distance range (4). Two independent algorithms can determine the focus. One uses a continuous-wave (CW) laser to illuminate the target; a photodiode at the back of the telescope records the intensity as the focus stage is scanned. A second method uses RMI images captured as the stage is scanned, and finds the maximum contrast between adjacent pixels in a small field of view at the center of the image. A separate RMI autoexposure algorithm sums pixel intensities from successive images with different exposure durations until the intensity is in the optimum range. The HDR mode significantly extends the dynamic range of the CMOS device, which has a lower natural range than traditional CCDs. The merging of several images at different exposure durations accomplishes this task.


Table IV describes the SuperCam spectrometers’ characteristics. The body unit contains the three spectrometers used for LIBS (Figure 3). Two of these handle the visible and violet portion of the VISIR spectra, while the IR portion is recorded in the mast. The weaker signals comprising the Raman spectra, produced over a period of ~4 ns by the pulsed laser beam, are recorded with a transmission spectrometer in the body unit. Ambient-light reduction is accomplished by use of a time-gated intensifier, which can record exposures down to 40 ns, orders of magnitude shorter than an ungated CCD. In addition to time-gating, the unit intensifies the signal by ~10,000, boosting the signal from only a few photons to levels that are well above the CCD noise level.


The ultraviolet (UV) and violet spectrometers are relatively simple crossed Czerny-Turner reflection spectrometers of ChemCam heritage (3). The transmission spectrometer is designed for higher photon efficiency required for Raman spectroscopy, which can be achieved with transmission gratings. This spectrometer uses several tricks to increase the product of the spectral range and pixel resolution. Light entering this spectrometer passes through a prism containing an internal dichroic mirror, splitting the light and projecting it onto two gratings. These gratings transmit the light to separated traces on the face of the intensifier. One of these two gratings is actually a compound grating. These twin gratings are mounted at slight angles from one another, once again projecting two traces that are separated on the intensifier face. The three resulting traces are intensified and focused onto the CCD, which reads each trace separately. The result is ~6000 channels (spectral traces do not go all the way to the edges, avoiding edge distortion) compared to the 2048 channels read by the other body-unit spectrometers.


Light in the IR band is transmitted to its spectrometer via a periscope in the mast unit (Figure 1). The light is passed through a crystal modulated by an acousto-optic tunable filter (AOTF). A radio-frequency transducer is attached to its side. For each frequency of the piezo a single wavelength is selected and scattered by ±4°. A beam block is positioned at 0° to reject the main beam. Two HgCdTe (MCT) photodiodes register the intensity. The wavelengths are scanned with a resolution of 30 cm-1 and a sampling frequency of half of that. The unit is designed to achieve a signal-to-noise ratio of at least 60.


The detectors of all four spectrometers are cooled. For the body unit spectrometers, the CCDs are cooled below 0 °C by thermoelectric coolers (Figure 3). These coolers are necessary because the rover body is generally maintained in the range of 5–35 °C by a fluid cooling loop from the radiothermal isotope generator that provides electrical power to the rover. The mast unit is only heated electrically to maintain a temperature >-40 °C. In this environment, the IR spectrometer is already relatively cold, which is necessary to minimize noise in the IR range. The photodiodes are further cooled by small thermoelectric coolers to ensure that they operate between -100 °C and -50 °C at any time of the day.


The fields of view of each spectral technique are illustrated in Figure 4. The target is Stephen, observed by ChemCam on Curiosity. The dust removal distance from several rasters is highlighted by the yellow circle. Several LIBS pits are highlighted with arrows. Representative footprints are also shown for Raman and IR observations. The VIS portion of VISIR has the same footprint as the Raman. Figure 4 and Table IV show that the IR spectrometer observes a larger footprint than the other spectrometers, which gives it increased signal levels at all times of the day. As mentioned above, the effective Raman footprint is governed by the spectrometer field of view to a distance of 12 m, and by the collimated 8-mm diameter laser footprint beyond that. The LIBS analytical footprint is smaller than the spectrometer fields of view and is specified by the tightly-focused laser footprint, expected to be 300–500 µm, with the larger diameter corresponding to the 7-m maximum LIBS distance (4).

Status and Conclusions


As of early 2017 the SuperCam instrument has passed its critical design review. A high-fidelity engineering development unit is undergoing tests at Los Alamos to verify that requirements will be met. Parts are already being assembled for a qualification model, which will undergo full environmental tests including vibration, shock, and thermal performance. However, subsystems have already undergone many of these tests to provide greater confidence earlier in the program. In addition, some parts of the instrument have high heritage from the predecessor instrument. The flight model is scheduled to be integrated in 2018 and delivered to the rover later the same year. Launch of the Mars 2020 rover is scheduled for July of that year, with landing in February of 2021.


The SuperCam instrument is only possible because of the team’s previous experience with ChemCam. While the advantage of multiple co-boresighted techniques is very clear, the additional techniques will place a heavier burden on operations and data analysis. A relatively large international team is clearly a benefit in this regard. We are looking forward to the flood of data that SuperCam promises.

Acknowledgments


The SuperCam instrument is supported in the US by NASA’s Mars Exploration Program, in France by CNES, and in Spain by the regional government and private industry. In France, the hardware contribution to SuperCam is supported by the French space agency CNES, the Institut de recherche en astrophysique et planétologie (IRAP, Toulouse, France), the Laboratoire d’études spatiales et d’instrumentation en astrophysique (LESIA, Meudon, France), The Observatoire de Midi-Pyrénées (OMP, Toulouse, France), The Laboratoire d’astrophysique de Bordeaux (LAB, Bordeaux, France), The Laboratoire atmosphères, milieux, observations spatiales (LATMOS, Guyancourt, France), the Ecole Supérieure de l’Aéronautique et de l’Espace (ISAE-Supaero, Toulouse, France), and the Institut d’astrophysique spatiale (IAS, Orsay, France).

References



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  5. J.F. Mustard et al., http://mepag.jpl.nasa.gov/reports/MEP/Mars_2020_SDT_Report_Final.pdf (2013).

  6. D.A. Cremers and L.J. Radziemski, Handbook of Laser-Induced Breakdown Spectroscopy (John Wiley and Sons, 2006), pp. 302.

  7. S. Maurice et al., J. Anal. At. Spectrom. DOI: 10.1039/c5ja00417a (2016).

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  12. A. Wang et al., “Concepts and Approaches for Mars Exploration,” proceedings The Lunar and Planetary Institute, Houston, Texas, 2000, pp. 304–305.

  13. R.C. Wiens et al., Spectrochim. Acta A 61, 2324–2334 (2005).

  14. S.K. Sharma, Spectrochim. Acta A 68, 1008–1022 (2007).

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  17. J.-P. Williams, J. Geophys. Res. 106, 5033–5041 (2001).

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  19. L. Beegle et al., IEEE Aerospace Conference, March 2015, pp. 1–11, doi:10.1109/AERO.2015.7119105 (2015).


Roger C. Wiens is with Los Alamos National Laboratory in Los Alamos, New Mexico. Sylvestre Maurice is with the Institut de recherche en astrophysique et planétologie (IRAP) in Toulouse, France. Fernando Rull Perez is with the Centro de Astrobiologia, Unidad Associada CSIC-UVA, Cristalografia y Mineralogia Facultad de Ciencias in Spain


This was first published in Spectroscopy Online.

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Why Mars? The Allure (and Challenge) of Colonizing the Red Planet

By Roger Wiens

Los Alamos National Laboratory Fellow and Principal Investigator for ChemCam

Why Mars? | Huffington Post, Los Alamos National Laboratory

Mars is by far the most Earth-like body we know besides the Earth itself. Mars has nearly the same length of day; it has an atmosphere; it has dust storms, valleys, mountains, sunshine, wind, and water.

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Why Mars? The Allure (and Challenge) of Colonizing the Red Planet


by Roger Wiens


On May 30, Mars and Earth will get close. Really close. With a distance between them of only 46.8 million miles, it’s the nearest the two planets will be to each other in their respective orbits. While nearly 50 million miles might still seem far away (because it is), when you consider the average distance between the two planets is 140 million miles, this close approach of Mars makes the planet feel, well, like the neighbor it is. Not only does this give you a great opportunity to see the Red Planet in the night sky, it also gives us a chance to think about Mars and the possibilities it holds.


Over the last 20 years NASA has embarked on a steady program to explore Mars. Beginning with the little rover Sojourner, three generations of mobile robots have made the trek through space to the Red Planet. And now NASA is planning a 2020 mission to Mars to gather more data. These missions have been critically important on a scientific level, but they’ve also ignited the imaginations of children and adults alike about the possibility of humans someday living there. (Look no further than the blockbuster success of the movie The Martian for proof.) But all of this brings up an interesting question: Why Mars? After all, the solar system has plenty of other planets to choose from. What makes Mars so special?


A Home Away From Home... Maybe


Mars is by far the most Earth-like body we know besides the Earth itself. Mars has nearly the same length of day (24-hour, 40-minute day-night cycles); it has an atmosphere; it has dust storms, valleys, mountains, sunshine, wind, and water. When humans settle elsewhere in the solar system it will clearly be on Mars.


While it is substantially smaller than Earth and has only 38 percent of our gravity, our neighboring planet displays amazing diversity. It has a landmass equal to the seven continents of our own sphere. This smaller globe boasts the tallest mountain in the solar system, at a height of 17 miles, compared to Mt. Everest’s mere 5.5 miles above sea level. It also has a grand canyon, Valles Marineris, that stretches nearly the distance from San Francisco to New York. Within the last three years NASA’s Curiosity rover has driven over an ancient riverbed and found mudstones that were laid down in a fresh-water lake. We are still in an age of serendipitous discovery on Mars — we can’t predict what we will find next.


We do know that while Mars once had a habitable environment, its location farther from the Sun resulted in more catastrophic ice ages than Earth ever suffered. Worse than that, without a global magnetic field for protection, most of its atmosphere was slowly sputtered away by energetic particles from the Sun, so the pressure at Mars’ surface is only 1 percent that of the Earth, no longer enough to support lakes and oceans.


Given these realities, does human exploration of the Red Planet make sense? The answer is no, but we will do it anyway — and when we do, we’ll be armed with important information thanks to all of our robotic missions to Mars.


I have been fortunate to lead a joint French-American team using a laser-based sensor, ChemCam, which was developed at Los Alamos National Laboratory and is now aboard NASA’s Curiosity rover. When ChemCam fires its extremely powerful laser pulse at a Martian rock, it vaporizes an area the size of a pinhead. The system’s telescope peers at the flash of glowing plasma created by the vaporized material and records the colors of light contained within it. These spectral colors are then interpreted by a spectrometer, allowing us to determine the elemental composition of the vaporized material. ChemCam is designed to look for lighter elements such as carbon, nitrogen and oxygen, all of which are crucial for life — and all of which help tell us if we can someday safely inhabit the planet.


ChemCam was developed at Los Alamos because of our expertise in laser technology and spectroscopy, as well as our decades-long involvement in space. Now we’re working on SuperCam, an action-hero version for NASA’s 2020 mission to Mars that will allow us to conduct fine-scale mineralogy, chemistry, and organic detection and to create color images, with the added bonus of being able to dust off a surface via laser blasts.


All of this tells us that we can sufficiently explore Mars with rovers or by robotically bringing samples back to Earth. Isn’t that enough? I doubt it. As humans, we have the sense that we will not have really explored the planet until human boot prints sink into Martian sand.


A Pilgrimage of a Different Sort


But getting to Mars is no small task; and getting back to Earth is even harder — requiring the assembly of a relatively large rocket on the Martian surface to blast the astronauts back into orbit. It would be extremely costly, not to mention incredibly risky. Then there’s the added challenge of replenishing supplies for the Mars colonists if we decide to establish a permanent presence. The alignment of the planets only allows the transfer of people and goods every 27 months when Earth approaches its neighboring planet. That’s a long time to wait if people are in dire need of supplies. If only one mission is planned at each of these opportunities, how would Mars colonists deal with failed missions, which are a certainty given the challenges? Or suppose supply missions make it to Mars but land too far away to reach the original colonists?


Things could work if — but only if — everything goes right. The history of both recent space exploration and many human ventures through time tell us that one must plan for problems and failures — probably many of them. With this in mind, a sustained human presence on Mars is unlikely in the near future; but it could happen someday.


When I think of the men and women who will be the first to colonize Mars, I’m reminded of the pilgrims who set sail on the Mayflower in 1620 to settle in the New World. When they left their port in England, they had no idea what lie ahead — famine, disease, and death on an epic scale. (Nearly half of the pilgrims died the first winter, which was much harsher than winters in England; out of 100 colonists only four women survived to the Thanksgiving celebration the next autumn.) A similar uncertainty will face the first colonists to set foot on Mars, with one major difference: the first Martians will have abundantly more information. Because of missions like Curiosity, they’ll understand the temperatures, terrain, and resources of the planet — and have the equipment to protect them.


Regardless, the first human mission will require brave individuals. Fortunately, the human race has no shortage of people who look to the distant horizon and wonder, “What’s over there?” — and then quickly add, “Let’s find out.” It makes me proud to be an earthling.


Roger Wiens is a scientist at Los Alamos National Laboratory and principal investigator of ChemCam, a laser spectroscopy instrument that was developed at Los Alamos for NASA’s Curiosity rover. He is author of Red Rover: Inside the Story of Robotic Space Exploration, from Genesis to the Mars Rover Curiosity (Basic Books, 2013). Wiens was recently knighted (“chevalier”) by the French government for his work in forging strong ties between the French and American scientific communities.


This story first appeared in HuffPost.

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If these (Martian) rocks could talk

By Patrick J. Gasda

Staff Scientist at Los Alamos National Laboratory

ChemCam on the Mars rover Curiosity zaps rocks, then analyzes the spectrum of light emitted from the resulting hot plasmas to determine what elements are present.

Santa Fe New Mexican logo


Science on the Hill: If these (Martian) rocks could talk


By Patrick Gasda


Finding the element boron might not seem exciting, but if you find it on Mars and you’re interested in alien life, it’s a big deal. Like manganese, another element that NASA’s Curiosity rover discovered in surprising abundance on Mars, boron has a lot to say about the habitability of the Red Planet.


Understanding how these elements got there and the implications to our search for life on Mars is part of Curiosity’s mission. A rolling laboratory that has been creeping across Gale Crater for four and a half years, Curiosity bristles with drills, tools and instruments for studying the chemistry of rocks and soil. It’s all about answering a simple question: Could past or present conditions on Mars support life?


To help find out, Los Alamos National Laboratory, in collaboration with the French Space Agency CNES, developed an instrument called ChemCam. Although Los Alamos isn’t often associated with space exploration, the Lab has been building and operating instruments since the early 1960s to monitor the space radiation environment and on other missions, as well.


The lab also developed the nuclear battery, a radioisotope thermoelectric generator, that powers Curiosity. For ChemCam on the Mars rover, it was natural for Los Alamos to draw on its laser-induced breakdown spectroscopy technology developed for national security applications.


Riding high on the rover, ChemCam zaps rocks with a pinpoint infrared laser, then analyzes the light emitted by the resulting superheated plasma that’s hotter than the surface of the sun. Every element emits a unique spectrum, leading to ChemCam’s quick and sure identification of rocks and soil up to 23 feet away. ChemCam team members — or the rover itself—selects the targets, which are spotted through the rover’s mast-mounted cameras.


Early on, Curiosity’s other tools and instruments found clear evidence of ancient streambeds and lakes with all the key conditions required by life (but no life, yet). After that, the discoveries kept coming in. ChemCam revealed manganese oxides in Martian rocks. That was big news. On Earth, manganese oxides form only in an oxygen-rich atmosphere or in the presence of microbes, so Mars likely had an oxygen-rich atmosphere early in its history — the means by which the atmosphere could be enriched in oxygen without life on the planet is still being explored by Curiosity’s scientists


ChemCam also found boron. Most of us know boron through the mineral compound called borax that’s used in household products. You might even picture the 20 Mule Team Borax brand, which evokes scruffy miners hauling the powdery white stuff out of Death Valley, Calif.


It’s no coincidence that Death Valley and Mars have boron in common. Boron typically occurs in arid locations where water has evaporated. Mars researchers now know Gale Crater once held a lake, but as it evaporated and disappeared, boron, being very water soluble, flowed into a subsurface water system among gaps and cracks in the rock. Then that water dried up. The ChemCam LIBS findings, backed up by clear photos of bright veins of boron-bearing calcium sulfate, indicate that the temperature, alkalinity, and dissolved mineral content of the groundwater were suitable for life. Many terrestrial organisms would be happy living in these groundwater conditions.


There’s more to the story. The sediments that have filled Gale Crater over the eons establish a geologic calendar starting with the formation of the crater 3.8 billion years ago. First the crater filled with deposits from its lake, and then as the lake dried out, the crater filled to its brim with sands before eroding down to the level that we see today on Mars. These processes must have taken hundreds of millions of years to occur. That information helps loosely date the boron deposits and indicates the water, which would have retreated underground after the lake dried out, was active for a very long time, in a range from 3.8 billion to perhaps a little more than 3 billion years ago, extending the timescale of habitability of Mars much longer than previously thought.

Now that scientists know Mars had a hospitable environment for life, the next NASA mission to the Red Planet, in 2020, will blast off with more sophisticated instruments to look for signs of life itself. Just as ChemCam was vital in Curiosity’s discoveries, Los Alamos’s next instrument, SuperCam, which is already being tested at the Laboratory, will play a leading role in Mars 2020.


ChemCam only detects elements, but SuperCam will detect minerals as well as organic compounds — the very stuff of life — in rocks and dirt from a distance. And SuperCam’s new microphone will provide the first audible soundtrack from Mars, including a distinct “zap!” when the laser beam strikes a rock.


Until then, ChemCam is only half-way through its 1-million-shot design life, so the team looks forward to fresh data that continue deepening humanity’s knowledge of Earth’s little brother. For now, NASA’s rovers and Los Alamos’s robotic eyes and soon-to-come ears are the next best thing to being there.


Patrick Gasda is a postdoctoral researcher in the Space Science and Applications group at Los Alamos National Laboratory. As a member of the ChemCam team, he works with team leader Roger Wiens to study the geochemistry and astrobiology of Mars.


This story originally appeared in The Santa Fe New Mexican.

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LANL shoots for the moon in search for life on Europa

By Patrick J. Gasda

Staff Scientist at Los Alamos National Laboratory

OrganiCam: For a moon of JupiterTo help NASA with its interplanetary research, Los Alamos National Laboratory is designing a prototype instrument capable of withstanding the extreme conditions on Europa. It is proposed for an upcoming mission to Jupiter’s moon.

Santa Fe New Mexican logoLANL shoots for the moon in search for life on Europa


Extremely cold and bombarded by intense radiation, Jupiter’s moon Europa seems like one of the last places in the solar system to look for life. But Europa could hold organic material yet undiscovered and an ocean hiding deep below its thick, frozen crust.


To help NASA with its interplanetary research, Los Alamos National Laboratory is designing a prototype instrument capable of withstanding the extreme conditions on Europa. It is proposed for an upcoming mission to Jupiter’s moon. The goal is to deepen understanding of this tantalizing world and extend the search for life in the solar system.


Los Alamos scientists have plenty of history helping NASA explore another world for evidence of habitability and ultimately of life. In the early 2000s the first neutron spectrometer — developed by the laboratory — orbited Mars, discovering and mapping its vast water resources. More recently they designed ChemCam, a combination of lasers, spectrometers, a telescope, and a camera that piggybacked on the Mars Curiosity rover to study Martian rocks and helped find evidence for a habitable Mars in the past.


The Los Alamos team is now testing SuperCam, a souped-up version of ChemCam set to join the Mars 2020 mission with a camera, laser, spectrometers, and microphone to identify chemicals and minerals on the red planet.


ChemCam, SuperCam and OrganiCam leverage the lab’s work in radiation hardening of satellites, space-based detection and development of unique sensors such as those used for global security and nonproliferation.


The lab is collaborating with colleagues at the University of Hawaii and in France on OrganiCam, which uses a fluorescence-spectrometer similar in some ways to the one on SuperCam. Researchers are designing OrganiCam to identify possible organic materials on Europa. Once it arrives after its long journey, the instruments will get straight to work. Its pulsed laser will illuminate a large area and its super-fast camera will make a panorama in search of a nanosecond-brief fluorescence signal, glowing for a fraction of a second under the laser’s light.


OrganiCam’s spectrometer does two things: First, based on spots identified in panoramic fluorescence images, it detects the unique fluorescence signatures categorizing any organic materials present. If something glows with a nanosecond lifetime, it’s probably organic, and if it’s organic, it could be bacteria—life. Next, using Raman spectrometry, it identifies materials by their “fingerprint” spectra. Once glowing targets are identified by OrganiCam, the lander will stretch out its two-meter-long arm, scoop up samples and bring them inside for further analysis. Finally, the lander will send data up to an orbiter, which will relay the information to waiting scientists back on Earth.


So what makes researchers think life might exist in such an inhospitable environment? Since NASA began fly-by missions to Europa in the late 1970s and the Hubble Space Telescope saw possible water plumes in 2012, they’ve suspected the presence of hidden, subsurface liquid. NASA’s recent new analysis of information gathered by the Galileo spacecraft in 1997 adds to the evidence of an ocean.


Furthermore, tidal heating — an effect of Jupiter’s powerful gravity on Europa’s rocky interior and metallic core — is thought to warm the interior ocean and rocks. This heating may cause vents to form on Europa’s seafloor, similar to black smokers on the Earth’s seafloor, where this environment supports life and may be where life started. Scientists also plan to measure levels of carbon, hydrogen, nitrogen, oxygen, phosphorus and sulfur, the building blocks of life, up there on that frozen moon.


Simple, right? Not so fast — the challenges are many. For one thing, temperatures on Europa range from minus 300 degrees at night to minus 240 degrees during the day. By comparison, the warmest day on Europa is colder than the coldest night on Mars and colder than any spot imaginable on Earth.


As if the cold wouldn’t be hard enough on OrganiCam’s components, intense radiation slamming Europa from Jupiter’s huge magnetic field could darken the camera’s lenses, reducing the ability to collect usable data. High radiation could also cause OrganiCam’s electronics to fail. That’s where the lab’s expertise in designing, testing and building radiation-tolerant devices comes in. Lab scientists plan to evaluate the effects of that exposure on the instruments by exposing them to Europa-level radiation in the beam at the Los Alamos Neutron Science Center.


OrganiCam is expected to work for about 20 days. Its operational life is limited by its power source, but Europa’s harsh conditions will also quickly erode its performance. Though scientists may have to wait some years for results from OrganiCam, if all goes well, Europa may prove to be one of the best places in the solar system to look for life.


Patrick Gasda is a staff scientist in the Space Science and Applications group at Los Alamos National Laboratory. As a member of the OrganiCam team, he works with team leader Roger Wiens to study the geochemistry and astrobiology of Europa. The concept phase of OrganiCam is being funded by Laboratory Directed Research and Development funds and the Center for Space and Earth Science at Los Alamos National Laboratory.


This article originally appeared in The Santa Fe New Mexican.

Published Research

Oxidation of manganese in an ancient aquifer, Kimberley formation, Gale crater, Mars

By Nina Lanza, Roger Wiens, et al
Abstract

The Curiosity rover observed high Mn abundances (>25 wt % MnO) in fracture‐filling materials that crosscut sandstones in the Kimberley region of Gale crater, Mars. The correlation between Mn and trace metal abundances plus the lack of correlation between Mn and elements such as S, Cl, and C, reveals that these deposits are Mn oxides rather than evaporites or other salts. On Earth, environments that concentrate Mn and deposit Mn minerals require water and highly oxidizing conditions; hence, these findings suggest that similar processes occurred on Mars. Based on the strong association between Mn‐oxide deposition and evolving atmospheric dioxygen levels on Earth, the presence of these Mn phases on Mars suggests that there was more abundant molecular oxygen within the atmosphere and some groundwaters of ancient Mars than in the present day.

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High Manganese concentrations in rocks at Gale crater, Mars

By Nina Lanza, Roger Wiens, et al
Abstract

The surface of Mars has long been considered a relatively oxidizing environment, an idea supported by the abundance of ferric iron phases observed there. However, compared to iron, manganese is sensitive only to high redox potential oxidants, and when concentrated in rocks, it provides a more specific redox indicator of aqueous environments. Observations from the ChemCam instrument on the Curiosity rover indicate abundances of manganese in and on some rock targets that are 1–2 orders of magnitude higher than previously observed on Mars, suggesting the presence of an as‐yet unidentified manganese‐rich phase. These results show that the Martian surface has at some point in time hosted much more highly oxidizing conditions than has previously been recognized.

READ MORE

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Videos

ChemCam Update: Manganese Oxides on Mars
A recent discovery of manganese oxides in Martian rocks might tell us that the Red Planet was once more Earth-like than we believed. What does that mean?

Boron Discovered in Ancient Habitable Mars Groundwater
Boron was recently discovered in calcium-sulfate veins on Mars. This is the first Mars mission to detect boron on the planet.

Uncovering the Mysteries of Mars Habitability
The Lab-designed ChemCam instrument, atop NASA's rover, has discovered 25 different elements on Mars, providing important information about the planet.

Halos on Mars Could Mean a Longer Life-Friendly Past
A type of bedrock has been found in Gale crater on Mars, indicating that the Red Planet had liquid water longer than experts previously believed.

Zapping Rocks on Mars
ChemCam shoots lasers at Martian rocks and analyzes the data, which helps gives scientists a better understanding of Mars.

Life on Mars? Rock varnish might have an answer
Recent evidence from the red planet increasingly supports the possibility that life could have developed there.

Photos

    Mars rover depends on LANL technologies

    Black download iconMars rover depends on three LANL technologies.

    Roger Wiens and ChemCam Mast Unit

    Black download icon Roger Wiens removes the laser safety plug on the ChemCam Mast Unit, selected for Curiosity.

    This upclose look at SuperCam shows how much technical detail is needed for an interplanetary camera.

    Black download iconThis upclose look at SuperCam shows how much technical detail is needed for an interplanetary camera.

     

    Experts

    Roger Wiens | Los Alamos National Laboratory

    Roger Wiens

    Wiens is a scientist at Los Alamos National Laboratory and principal investigator of ChemCam, a laser spectroscopy instrument that was developed at Los Alamos for NASA’s Curiosity rover.

    Patrick Gasda | Los Alamos National Laboratory
    Nina Lanza | Los Alamos National Laboratory

    Nina Lanza

    Lanza is a Staff Scientist in the Space and Remote Sensing at Los Alamos National Laboratory. She is living her dream of working on a spaceship with lasers on Mars as part of the ChemCam instrument team.

    Patrick Gasda

    Gasda is a Staff Scientist in the Space Science and Applications group at Los Alamos National Laboratory. As a member of the OrganiCam team, he studies the geochemistry and astrobiology of Europa and Mars.

     

    Contact

    Charles Poling, (505) 257-8006, cpoling@lanl.gov
    Nick Njegomir, (505) 665 9394, 
    nickn@lanl.gov

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