A Common-Factor Approach for Multivariate Data Cleaning with an Application to Mars Phoenix Mission Data

Data quality is fundamentally important to ensure the reliability of data for stakeholders to make decisions. In real world applications, such as scientific exploration of extreme environments, it is unrealistic to require raw data collected to be perfect. As data miners, when it is infeasible to physically know the why and the how in order to clean up the data, we propose to seek the intrinsic structure of the signal to identify the common factors of multivariate data. Using our new data driven learning method, the common-factor data cleaning approach, we address an interdisciplinary challenge on multivariate data cleaning when complex external impacts appear to interfere with multiple data measurements. Existing data analyses typically process one signal measurement at a time without considering the associations among all signals. We analyze all signal measurements simultaneously to find the hidden common factors that drive all measurements to vary together, but not as a result of the true data measurements. We use common factors to reduce the variations in the data without changing the base mean level of the data to avoid altering the physical meaning.Comment: 12 pages, 10 figures, 1 tabl

Lunar and Planetary Science 37

Includes preface, table of contents, program, abstracts and indexes for the 37th LPSC. This conference included special sessions on: the Bosumtwi Meteorite Impact Crater Drilling Project; the Deep Impact Mission; and the Hayabusa Asteroid Mission.sponsors Lunar and Planetary Institute, NASA Johnson Space Centerprogram committee, Stephen J. Mackwell, co-chair, Eileen K. Stansbery, co-chair ... [and others] ; compiled by Lunar and Planetary Institute.PARTIAL CONTENTS: Constraints on the Huygens Landing Site Topography from the Surface Science Package Acoustic Properties Instrument / M.C. Towner, J. R.C. Garry, H. Svedhem, A. Hagermann, B.C. Clark, R.D. Lorenz, M R. Leese, B. Hathi, and J.C. Zarnecki--Do Hadean Zircons Retain a Record of the Late Heavy Bombardment on Earth? / D. Trail, S.J. Mojzsis, T.M. Harrison, and H.F. Levison--Principal Component Analysis of Geochemical Data at Gusev Crater / E. Tréguier, C. d'Uston, and R. Gellert--Brown and Clear Olivine in Chassignite NWA 2737: Water and Deformation / A.H. Treiman, M. McCanta, M.D. Dyar, C.M. Pieters, T. Hiroi, M.D. Lane, and J.L. Bishop--Two Likely Meteorite-dropping Bolides Recorded by a New High-Res All-Sky CCD Camera / J.M. Trigo-Rodríguez, A.J. Castro-Tirado, M. Jelínek, S. Vitek, J. Llorca, and J. Fabregat

The characterisation of the organic material in Ontong Java Plateau tuff as an analogue for the search for fossil life on Earth and Mars

PhD ThesisDistinctive microtubules in glassy volcaniclastic shards can be observed within tuff from the Ontong Java Plateau (OJP_13), which have been suggested to be putative ichnofossils and could serve as analogues for the types of samples that may be encountered on Mars. Argon cluster ion beam etching and ultraviolet/ozone cleaning were evaluated as methods for decontaminating geological samples prior to analysis. Xray photoelectron spectroscopy (XPS) and gas chromatography/mass spectrometry (GC/MS) were conducted on a sample of OJP_13 tuff. The comparative efficiency of conventional pyrolysis gas chromatography/mass spectrometry (py-GC/MS) and pyGC/MS with tetramethylammonium hydroxide, also called thermal hydrolysis and methylation-GC/MS (THM-GC/MS) to detect and identify the organic material in OJP_13 samples was assessed. Measurements of the carbon and nitrogen chemistry in OJP_13 were made using XPS, and this was compared to the data that was obtained by THMGC/MS. The XPS analysis demonstrated that organic material was concentrated in the perimeter of the glass shards. Time of flight secondary ion mass spectrometry imaging demonstrated that the organic material was associated with micro-fractures in the surrounding matrix and in the devitrified glass textures in the perimeter of the shard. The analysis was conducted on OJP samples from different strata and basalts from other regions, which did not contain the tubular features. This demonstrated that nitrogenous organic material was not specific to the OJP_13 sample that contained the microtubules but appeared to occur throughout the OJP tuff. THM-GC/MS and XPS analyses were conducted on artificially decomposed plant biopolymers. The composition of the organic material in OJP tuff was similar to that of decomposed chitin. It was proposed that a component of the organic material in OJP could be the remnants of a chitinous organism. The presence of chitin implied that fungi could have produced the microtubular textures. Additionally, during this investigation, it was observed that carbonaceous films on the surfaces of minerals are thermally stable and are therefore undetectable by py-GC/MS. These films may be responsible for the non-biological synthesis of complex organic compoundsThe Leverhulme Trade Charities Trus

Visible and Near Infrared imaging spectroscopy and the exploration of small scale hydrothermally altered and hydrated environments on Earth and Mars

The use of Visible and Near Infrared (VNIR) imaging spectroscopy is a cornerstone of planetary exploration. This work shall present an investigation into the limitations of scale, both spectral and spatial, in the utility of VNIR images for identifying small scale hydrothermal and potential hydrated environments on Mars, and regions of the Earth that can serve as martian analogues. Such settings represent possible habitable environments; important locations for astrobiological research. The ESA/Roscosmos ExoMars rover PanCam captures spectrally coarse but spatially high resolution VNIR images. This instrument is still in development and the first field trial of an emulator fitted with the final set of geological filters is presented here. Efficient image analysis techniques are explored and the ability to accurately characterise a hydrothermally altered region using PanCam data products is established. The CRISM orbital instrument has been returning hyperspectral VNIR images with an 18 m2 pixel resolution since 2006. The extraction of sub-pixel information from CRISM pixels using Spectral Mixture Analysis (SMA) algorithms is explored. Using synthetic datasets a full SMA pipeline consisting of publically available Matlab algorithms and optimised for investigation of mineralogically complex hydrothermal suites is developed for the first time. This is validated using data from Námafjall in Iceland, the region used to field trial the PanCam prototype. The pipeline is applied to CRISM images covering four regions on Mars identified as having potentially undergone hydrothermal alteration in their past. A second novel use of SMA to extract a unique spectral signature for the potentially hydrated Recurring Slope Lineae features on Mars is presented. The specific methodology presented shows promise and future improvements are suggested. The importance of combining different scales of data and recognising their limitations is discussed based on the results presented and ways in which to take the results presented in this thesis forward are given

Mars Sedimentology and Stratigraphy

This conference seeks to stimulate the exchange of ideas among the community of scientists with common interests in sedimentary processes and the stratigraphic record of sedimentary rocks on Mars. Topical sessions will include weathering processes, provenance, and diagenesis of sediments; transport and depositional processes (fluvial, eolian, lacustrine, evaporitic, volcaniclastic, and impact), both past and present; characterization and origin of vast exposures of layered bedrock; controls on stratigraphic stacking patterns and stratal geometry; and the evolution of sedimentary basins, including patterns of deformation.sponsors, California Institute of Technology ... [and others]conveners, John Grotzinger, David Beaty ; scientific organizing committee, Gilles Dromart ... [and others].PARTIAL CONTENTS: Sediment Prediction Through Basin Analysis: An Example from Acidalia Planitia--Geologic Analysis of Various Hydrated Formations Exposed on the Plateaus Surrounding Valles Marineris, Mars--Fluvial Sediment Accomodation and Mesoscale Architecture, Some Neglected Perspectives--Wind-eroded Floor Deposits in Noachian Degraded Craters on Mars--Geobiology and Sedimentology of the Hypersaline Great Salt Lake, Northern Utah, USA: Analogues for Assessing Watery Environments on Mars

Development of a hybrid sounding rocket motor.

Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, Durban, 2013.This work describes the development of a hybrid rocket propulsion system for a reusable sounding rocket, as part of the first phase of the UKZN Phoenix Hybrid Sounding Rocket Programme. The programme objective is to produce a series of low-to-medium altitude sounding rockets to cater for the needs of the African scientific community and local universities, starting with the 10 km apogee Phoenix-1A vehicle. In particular, this dissertation details the development of the Hybrid Rocket Performance Code (HRPC) together with the design, manufacture and testing of Phoenix-1A’s propulsion system. The Phoenix-1A hybrid propulsion system, generally referred to as the hybrid rocket motor (HRM), utilises SASOL 0907 paraffin wax and nitrous oxide as the solid fuel and liquid oxidiser, respectively. The HRPC software tool is based upon a one-dimensional, unsteady flow mathematical model, and is capable of analysing the combustion of a number of propellant combinations to predict overall hybrid rocket motor performance. The code is based on a two-phase (liquid oxidiser and solid fuel) numerical solution and was programmed in MATLAB. HRPC links with the NASA-CEA equilibrium chemistry programme to determine the thermodynamic properties of the combustion products necessary for solving the governing ordinary differential equations, which are derived from first principle gas dynamics. The combustion modelling is coupled to a nitrous oxide tank pressurization and blowdown model obtained from literature to provide a realistic decay in motor performance with burn time. HRPC has been validated against experimental data obtained during hot-fire testing of a laboratory-scale hybrid rocket motor, in addition to predictions made by reported performance modelling data. Development of the Phoenix-1A propulsion system consisted of the manufacture of the solid fuel grain and incorporated finite element and computational fluid dynamics analyses of various components of the system. A novel casting method for the fabrication of the system’s cylindrical single-port paraffin fuel grain is described. Detailed finite element analyses were performed on the combustion chamber casing, injector bulkhead and nozzle retainer to verify structural integrity under worst case loading conditions. In addition, thermal and pressure loading distributions on the motor’s nozzle and its subsequent response were estimated by conducting fluid-structure interaction analyses. A targeted total impulse of 75 kNs for the Phoenix-1A motor was obtained through iterative implementation of the HRPC application. This yielded an optimised propulsion system configuration and motor thrust curve

Detection and Analysis of Martian Low-Temperature Geochemistry

The history of Mars is encoded in the geochemistry of ancient sedimentary Martian rocks and secondary phases. Recent landed missions have provided unparalleled datasets with which to investigate this geochemistry. Accordingly, this thesis is concerned primarily with the in-situ analysis of low-temperature Martian geochemical processes by landed missions, and the attendant Earth-based studies which enrich those in-situ investigations. There are five main studies reported here. The first is an analysis of a Mars-analog environment on Earth. Datasets similar to those that will be produced by the upcoming Mars-2020 rover are used to evaluate the ability of the rover to reconstruct a known paleoenvironment, to identify reference datasets that require further development, and to suggest operational modes that most efficiently use the rover’s resources. The second study is an in-situ noble gas analysis using the SAM instrument on the Curiosity rover to investigate a jarosite-containing sample using a two-step heating analysis for K-Ar dating. The jarosite likely formed at 2.12±0.36 Ga while plagioclase in the sample formed at 4.07 ± 0.63 Ga, indicating that liquid water interactions continued in Gale crater well past the end of the Hesperian period. The following chapter details another noble gas analysis, focusing on cosmogenic dating of surface exposure. In contrast to <100 Ma exposure ages observed at the floor of Gale crater, exposure ages exceeding 1 Ga are detected on the flanks of Mount Sharp. These ages indicate Mount Sharp formed during the Hesperian and has been largely unchanged in the intervening 3.1 Ga. The next study is a reevaluation of the data used to identify the presence of perchlorate in Gale crater. These data suggest that perchlorate is indeed present, but that it must be Amazonian in age, suggesting that rare surface wetting events have caused leaching of this soluble ion into the bedrock. The final study reports the development of a technique for measuring the isotopes in perchlorate using Orbitrap mass spectrometry on Earth, allowing investigation of the formation processes that impact the chlorine isotope ratio of this molecule on both Earth and Mars

The Second Conference on Lunar Bases and Space Activities of the 21st Century, volume 1

These papers comprise a peer-review selection of presentations by authors from NASA, LPI industry, and academia at the Second Conference (April 1988) on Lunar Bases and Space Activities of the 21st Century, sponsored by the NASA Office of Exploration and the Lunar Planetary Institute. These papers go into more technical depth than did those published from the first NASA-sponsored symposium on the topic, held in 1984. Session topics covered by this volume include (1) design and operation of transportation systems to, in orbit around, and on the Moon, (2) lunar base site selection, (3) design, architecture, construction, and operation of lunar bases and human habitats, and (4) lunar-based scientific research and experimentation in astronomy, exobiology, and lunar geology

Fortieth Lunar and Planetary Science Conference

Special sessions on Lunar Missions, Messenger at Mercury, and Icy Satellites of Jupiter and Saturn were held. This CD-ROM contains the contents, program, abstracts, and author indexes for the 40th Lunar and Planetary Science Conference.sponsored by Lunar and Planetary Institute, NASA Johnson Space Centerconference co-chairs, Stephen J. Mackwell, Eileen StansberyPARTIAL CONTENTS: Equilibrated Aggregates in Cometary IDPs: Insights into the Crystallization Process in Protoplanetary Disks / L.P. Keller and S. Messenger--The Impact Crater Jebel Waqf as Suwwan in Jordan: Effects of Target Heterogeneity and Impact Obliquity on Central Uplift Formation / T. Kenkmann, W.U. Reimold, M. Khirfan, E. Salameh, K. Konsul, T. Lehmann, and H. Khoury--The Dispersal of Pyroclasts from Apollinaris Patera, Mars / L. Kerber, J.W. Head, J.B. Madeleine, F. Forget, and L. Wilson--The Age of the Medusae Fossae Formation: Reassessment Using Lava Flow Cast and Mold Contacts / L. Kerber and J.W. Head III--Possible Liquid-like Water Produced Seepage Features on Mars / A. Kereszturi, A. Horváth, A. Sik, A. Kuti, Sz. Bérczi, T. Gánti, T. Pócs, and E. Szathmáry