Roger C. Wiens

Capabilities of LIBS for analysis of geological samples at stand-off distances in a Mars atmosphere

The use of LIBS for stand-off elemental analysis of geological and other samples in a simulated Mars atmosphere is being evaluated. Analytical capabilities, matrix effects, and other factors effecting analysis are being determined. Through funding from NASAs Mars Instrument Development Program (MIDP), we have been evaluating the use of LIBS for future use on landers and rovers to Mars. Of particular interest is the use of LIBS for stand-off measurements of geological samples up to 20 meters from the instrument. Very preliminary work on such remote LIBS measurements based on large laboratory type equipment was carried out about a decade ago. Recent work has characterized the capabilities using more compact instrumentation and some measurements have been conducted with LIBS on a NASA rover testbed.

SOLAR-WIND KRYPTON AND SOLID/GAS FRACTIONATION IN THE EARLY SOLAR NEBULA

Krypton is the best candidate for determining limits on solid/gas fractionation in the early sun because of the smoothness of the odd-mass abundance curve in its mass region, which permits relatively precise interpolations of its abundance assuming no fractionation. Here we calculate the solar-system Kr abundance from solar-wind noble-gas ratios, determined previously by low-temperature oxidations of lunar ilmenite grains, normalized to Si by spacecraft solar-wind measurements. The estimated ^(83)Kr abundance of 4.1 ± 1.5 per 10^6 Si atoms is within uncertainty of estimates assuming no fractionation, determined from CI-chondrite abundances of surrounding elements. This is significant because it is the first such constraint on solid/gas fractionation, though the large uncertainty only confines it to somewhat less than a factor of two.

The Suess-Urey mission (return of solar matter to Earth).

The Suess-Urey (S-U) mission has been proposed as a NASA Discovery mission to return samples of matter from the Sun to the Earth for isotopic and chemical analyses in terrestrial laboratories to provide a major improvement in our knowledge of the average chemical and isotopic composition of the solar system. The S-U spacecraft and sample return capsule will be placed in a halo orbit around the L1 Sun-Earth libration point for two years to collect solar wind ions which implant into large passive collectors made of ultra-pure materials. Constant Spacecraft-Sun-Earth geometries enable simple spin stabilized attitude control, simple passive thermal control, and a fixed medium gain antenna. Low data requirements and the safety of a Sun-pointed spinner, result in extremely low mission operations costs.

The NASA Mars 2020 Rover Mission and the Search for Extraterrestrial Life

Abstract The NASA Mars 2020 rover mission will explore an astrobiologically relevant martian site to investigate regional geology, evaluate past habitability, seek signs of ancient life, and assemble a returnable cache of samples. The spacecraft is based on successful heritage design of the Mars Science Laboratory Curiosity rover, but includes a new scientific payload and other advanced capabilities. The Mars 2020 science payload features the first two Raman spectrometers on Mars, the first microfocus X-ray fluorescence instrument, the first ground-penetrating radar, an infrared spectrometer, an upgraded microscopic and stereo context cameras and weather station, and a demonstration unit for oxygen production on Mars. The instrument suite combines visible and multispectral imaging with coordinated measurements of chemistry and mineralogy, from the submillimeter to the regional scale. Using the data acquired by the science instruments as a guide, the team will collect core samples of rock and regolith selected to represent the geologic diversity of the landing site and maximize the potential for future Earth-based analyses to answer fundamental questions in astrobiology and planetary science. These samples will be drilled, hermetically sealed, and cached on the martian surface for possible retrieval and return to Earth by future missions. The Mars 2020 spacecraft is designed and built according to an unprecedented set of biological, organic, and inorganic cleanliness requirements to maximize the scientific value of this sample suite. Here, we present the scientific vision for the Mars 2020 mission, provide an overview of the analytic capabilities of the science payload, and discuss how Mars 2020 seeks to further our understanding of habitability, biosignatures, and possibility of life beyond Earth.

Two Years of Operations of the ChemCam Instrument onboard the Curiosity Rover at FIMOC, the French Operations Center for Mars Instruments

Following the successful landing of the Curiosity rover in Gale Crater, on August 5, 2012, science Operations started at Jet Propulsion Laboratory (JPL) right after turning on the instruments minutes after landing. During the first 90 days of the mission, all operations took place at JPL. On November 8th, 2012, ChemCam engineers were officially the first team to operate the instrument remotely from FIMOC, the CNES Operations Center located in Toulouse, France. The instruments have been operated remotely since that day alternating weekly with the Los Alamos National Laboratory Operations Center for ChemCam. This paper will give an overview of how ChemCam teams interact remotely with JPL in a unique way to operate instruments on Mars: monitoring the instrument health, analyzing received data products, preparing the daily Rover activity plans, and generate instrument sequences to be delivered to JPL. It will also present the instrument status after nearly two years on Mars, and how FIMOC operations can benefit future space missions to Mars.

Standoff Biofinder: powerful search for life instrument for planetary exploration

The “Standoff Biofinder” is a powerful “search for life” instrument that is able to detect biomolecules from a collection of rocks and minerals in a large area with detection time less than a second using a non-contact, non-destructive approach. Biological materials show strong, short-lived fluorescence signals when excited with ultraviolet-visible (UVVis) wavelengths. The Standoff Biofinder takes advantage of the short lifetimes of bio-fluorescent materials to obtain real-time images showing the locations of biological materials among luminescent minerals in a geological context. The Standoff Biofinder uses an expanded and diffused nanosecond pulsed laser to illuminate a large geological region and a gated detector to record time-resolved fluorescence images. The instrument works in daylight as well as nighttime conditions and bio-detection capability is not affected by the background light. The instrument is able to detect both live and dead biological materials, and is a useful tool for detecting the presence of both extant and extinct life on a planetary surface. The Standoff Biofinder instrument will be suitable for locating fluorescent polyaromatic hydrocarbons, amino acids, proteins, bacteria, biominerals, photosynthetic pigments, and diagenetic products of microbial life on dry landscapes and Ocean Worlds of the outer Solar System (e.g., Enceladus, Europa, and Titan). An important feature of the Standoff Biofinder instrument is its capability to detect biomolecules which are inside ice, without sample collection.

Development of laser-induced breakdown spectroscopy for planetary surface exploration

Recently, LIBS (laser-induced breakdown spectroscopy) has been proposed as a new method for planetary exploration with Mars specifically targeted. There are many reasons for this including the ability for rapid analysis, stand-off analysis (e.g. up to 20 meters), and the ability to readily combine LIBS with other spectroscopic methods that provide data complementary to a LIBS analysis. In comparison with past and current elemental analysis methods used for planetary landers and rovers, these capabilities of LIBS should greatly increase the scientific return from future missions. We are conducting laboratory and field tests of compact LIBS instrumentation to evaluate the method for Mars missions. Selected geological samples are being analyzed and analytical figures-of-merit are being determined for soils and water ice/soil mixtures. Measurements are being conducted at 4 meters distance with the sample maintained in 7 Torr CO2 (Mars atmosphere) or at 50 mTorr pressure to simulate an airless body (e.g. asteroid). In addition, we are conducting engineering studies and are designing a compact and lightweight prototype LIBS system.Recently, LIBS (laser-induced breakdown spectroscopy) has been proposed as a new method for planetary exploration with Mars specifically targeted. There are many reasons for this including the ability for rapid analysis, stand-off analysis (e.g. up to 20 meters), and the ability to readily combine LIBS with other spectroscopic methods that provide data complementary to a LIBS analysis. In comparison with past and current elemental analysis methods used for planetary landers and rovers, these capabilities of LIBS should greatly increase the scientific return from future missions. We are conducting laboratory and field tests of compact LIBS instrumentation to evaluate the method for Mars missions. Selected geological samples are being analyzed and analytical figures-of-merit are being determined for soils and water ice/soil mixtures. Measurements are being conducted at 4 meters distance with the sample maintained in 7 Torr CO2 (Mars atmosphere) or at 50 mTorr pressure to simulate an airless body (e.g. aster...

Three-color resonance ionization spectroscopy of Zr in Si

It has been proposed that the composition of the solar wind could be measured directly by transporting ultrapure collectors into space, exposing them to the solar wind, and returning them to earth for analysis. In a study to help assess the applicability of present and future postionization secondary neutral mass spectrometers for measuring solar wind implanted samples, measurements of Zr in Si were performed. A three-color resonant ionization scheme proved to be efficient while producing a background count rate limited by secondary ion signal (5×10^(−4) counts/laser pulse). This lowered the detection limit for these measurements to below 500 ppt for 450,000 averages. Unexpectedly, the Zr concentration in the Si was measured to be over 4 ppb, well above the detection limit of the analysis. This high concentration is thought to result from contamination during sample preparation, since a series of tests were performed that rule out memory effects during the analysis.