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NASA NTRSDate not supplied

Astrobee: Five years of Completed, Current, and Future Research on the International Space Station using Free Flying Robots.

After five years on the International Space Station (ISS), the Astrobee Research Facility, has completed over 160 Test Sessions logging over 1200 hours of operations. Managed by the NASA ISS Program OZ office and supported by NASA Ames Research Center (ARC) in California, the Astrobee Team currently maintains two identical free-flying Astrobee robots and a Docking Station for research on the ISS. As a technology demonstration platform, the Astrobee Robots are available for Guest Scientists to use for a spectrum of research capabilities. Using ambient air on the ISS, propelled by battery-operated fans, Astrobee is designed to autonomously operate throughout most of the USOS (US Orbital Segment), with the objective of minimizing the need for astronaut support. Astrobee carries a suite of six cameras, a two degree-of-freedom (DOF) arm with a gripper that can grasp ISS handrails and other objects, and three payload bays that provide power and data for guest science hardware. Astrobee can autonomously execute hours-long flight plans or be tele-operated from the ground. While the Astrobee Team continues to improve mapping and autonomous flight capabilities, one of the main goals of Astrobee Robots is to provide research opportunities for Guest Scientists. The Astrobee Robot Software (ARS) makes extensive use of the open-source Robot Operating System (ROS). The ARS can be used interchangeably with an Astrobee Simulator or as Astrobee’s onboard software. ARS features include autonomous docking and perching, real-time teleoperations from the ground, plan based autonomous tasks, multi Astrobee communication, among other capabilities. Through simulation software and ground testing laboratories, the Astrobee Team is available to support Guest Scientists during development and testing and lead real-time ISS operations. The Astrobee Team and Guest Scientists have completed research including Astrobatics maneuvers, RFID and sound sensing capabilities, Gecko materials studies, student Robotics Programming Challenges, and Free Flyer formation flight investigations. Current science with the Astrobee Robots is investigating new docking capabilities through software only research as well as testing new docking hardware installed on the Astrobees. The Astrobee Team and other researchers at NASA Ames continue to explore robotics applications for future NASA missions such as Gateway and potential experiments involving human-robot interactions. Continued advanced mapping resolution capabilities, and high-resolution panoramic imagery also remains areas of research. Exciting in development research involves docking for rendezvous proximity operation (CLINGERS), multi resolution 3D scanning (MRS), space debris removal in microgravity (REACCH). This presentation will mainly focus on completed research over the past year and current science being performed on the Astrobees. This presentation will also focus on how a Guest Scientist/Researcher progresses from conception to running their science on the Astrobees on the ISS, as well as discuss the Astrobee Facility resources available for supporting ground testing and real-time ISS operations.

Astrobee↗
NASA NTRS2024

South Africa Ecological Conservation: Identifying and Mapping Riparian Areas in South Africa with Earth Observations

Riparian zones are thin strips of wetland that occur along the edges of rivers, lakes, and other water bodies. They provide many ecosystem and societal benefits such as stream bank stabilization, flood control, and habitat stability, making these zones very important areas to preserve and protect. Recognizing the need to accurately map these ecosystems in a cost-effective way, we partnered with the South African National Biodiversity Institute (SANBI) and the Biodiversity Survey of the Cape(BioSCape) to develop a GI methodology using Esri's ArcGIS Pro and data from Landsat 9 Operational Land Imager-2, Sentinel-2 Multispectral Instrument, and the Shuttle Radar Topography Mission to identify potential riparian zones (PRZ) and observed riparian vegetation(ORV) in the Southern Cape and the North West Province of South Africa to estimate the actual riparian vegetation (ARV) within those areas. Potential riparian ecosystems were calculated by utilizing a Topographic Wetness Index (TWI) and a water feature layer, while observed riparian vegetation were calculated by overlaying a Normalized Difference Vegetation Index (NDVI) and TWI. Actual Riparian Vegetation is determined by the overlap of ORV with PRZ and is done with conditional statements; ORV within PRZ is ARV. This method significantly improved a current riparian land cover classification since it combined high resolution optical imagery and topographic data. We anticipate such maps will be used by conservationists and practitioners interested in riparian monitoring and management.

Remote Sensing↗
NASA NTRS1980

Coordinates of features on the Galilean satellites

Control nets of the four Galilean satellites, established photogrammetrically from pictures taken by the two Voyager spacecraft during their flybys of Jupiter in 1979, are discussed. Coordinates of 504 points on Io, 112 points on Europa, 1547 points on Ganymede, and 439 points on Callisto are listed. Selected points are identified on maps of the satellites. Measurements of these points were made on 234 pictures of Io, 115 pictures of Europa, 282 pictures of Ganymede, and 200 pictures of Callisto. The systems of longitude were defined by craters on Europa, Ganymede, and Callisto. Preliminary solutions are found for the directions of the axes of rotation of the Galilean satellites. Mean radii are determined as 1815 + or - 5 km for Io, 1569 + or - 10 km for Europa, 2631 + or - km for Ganymede, and 2400 + or - 10 km for Callisto.

Merton, E. D.↗
NASA NTRS2016

Global Variations in Regolith Properties on Asteroid Vesta from Dawn's Low-Altitude Mapping Orbit

We investigate the depth, variability, and history of regolith on asteroid Vesta using data from the Dawn spacecraft. High-resolution (15-20 m pixel(sup -1)) Framing Cameraimages are used to assess the presence of morphologic indicators of a shallow regolith,including the presence of blocks in crater ejecta, spur-and-gully-type features in crater walls,and the retention of small (less than 300 m) impact craters. Such features reveal that the broad,regional heterogeneities observed on Vesta in terms of albedo and surface composition extend to the physical properties of the upper approx. 1 km of the surface. Regions of thin regolithare found within the Rheasilvia basin and at equatorial latitudes from approx. 0-90 deg. E and approx.260-360 deg. E. Craters in these areas that appear to excavate material from beneath the regolithhave more diogenitic (Rheasilvia, 090 deg. E) and cumulate eucrite (260-360 deg. E) compositions.A region of especially thick regolith, where depths generally exceed 1 km, is found from approx.100-240 deg. E and corresponds to heavily cratered, low-albedo surface with a basaltic eucritecomposition enriched in carbonaceous chondrite material. The presence of a thick regolithin this area supports the idea that this is an ancient terrain that has accumulated a larger component of exogenic debris. We find evidence for the gardening of crater ejecta towardmore howarditic compositions, consistent with regolith mixing being the dominant form of "weathering" on Vesta.

asteroid↗
NASA NTRS1975

A global magnetic anomaly map

A subset of Pogo satellite magnetometer data has been formed that is suitable for analysis of crustal magnetic anomalies. Through the use of a thirteenth-order field model fit to these data, magnetic residuals have been calculated over the world to latitude limits of plus or minus 50 deg. These residuals, averaged over 1-degree latitude-longitude blocks, represent a detailed global magnetic anomaly map derived solely from satellite data. The occurrence of these anomalies on all individual satellite passes independent of local time and their decay as altitude increases imply a definite internal origin. Their wavelength structure and their correlation with known tectonic features further suggest that these anomalies are primarily of geologic origin and have their sources in the lithosphere.

Regan, R. D.↗
NASA NTRS1975

Application of satellite remote-sensing data to land selection and management

A pilot project conducted to demonstrate the utility and economy of satellite data in preparing thematic maps of a wilderness area emphasizing those resources of greatest interest to the potential owner is described. Vegetation maps delineating potential commercial timber and maps of suggested mineral prospecting areas of seven scattered regions were prepared by interpretation of LANDSAT images, coupled with a limited amount of ground truth. Images acquired both in winter and summer seasons were registered to township maps and used in making interpretations of the areal extent of commercial timber potentials. The amount of snow cover visible through the forest canopies was found to be a useful indicator of timber potentials. Identification was made of characteristic topographic features which are typical of flood plain deposits or of the well developed trellis drainage patterns which can indicate the strike of structural grain of underlying Cretaceous sedimentary rocks. The presence of igneous and mixed igneous and metamorphic rocks were indicated by combinations of spectral differences and anomalous interruptions of local radial drainage patterns.

Stringer, W. J.↗
NASA NTRS1982

Unveiling Venus with VOIR

The goals and intended capabilities of the Venus Orbiting Imaging Radar (VOIR), scheduled for launch in the mid-1980's, are reviewed. Current Pioneer Venus Orbiter data is considered of unsufficient resolution for actual planetary mapping of the geologic terrain of Venus, while the VOIR possesses an SAR which is able to provide a 600 m line pair resolution. The data would yield information of small-scale roughness and the rms slope of surface features, would serve as an efficient altimeter, and help track the planet's gravity field to within 1/5000 cm/sec resolution. Estimations of wind velocity and turbulence would be made available, and a Langmuir probe, a quadrupole mass analyzer, and an ion analyzer will detect ions, electrons, elemental compositions, concentrations, and densities, as well as velocities.

James, W.↗
NASA NTRS1984

Euro-african MAGSAT Anomaly-tectonic Observations

Preliminary satellite (MAGSAT) scalar magnetic anomaly data are compiled and differentially reduced to radial polarization by equivalent point source inversion for comparison with tectonic data of Africa, Europe and adjacent marine areas. A number of associations are evident to constrain analyses of the tectonic features and history of the region. The Precambrian shields of Africa and Europe exhibit varied magnetic signatures. All shields are not magnetic highs and, in fact, the Baltic shield is a marked minimum. The reduced-to-the-pole magnetic map shows a marked tendency for northeasterly striking anomalies in the eastern Atlantic and adjacent Africa, which is coincident to the track of several hot spots for the past 100 million years. However, there is little consistency in the sign of the magnetic anomalies and the track of the hot spots. Comparison of the radially polarized anomalies of Africa and Europe with other reduced-to-the-pole magnetic satellite anomaly maps of the Western Hemisphere support the reconstruction of the continents prior to the origin of the present-day Atlantic Ocean in the Mesozoic Era.

Hinze, W. J.↗
NASA NTRS1985

Euro-African MAGSAT anomaly-tectonic observations

Preliminary satellite (MAGSAT) scalar magnetic anomaly data are compiled and differentially reduced to radial polarization by equivalent point source inversion for comparison with tectonic data of Africa, Europe and adjacent marine areas. A number of associations are evident to constrain analyses of the tectonic features and history of the region. The Precambrian shields of Africa and Europe exhibit varied magnetic signatures. All shields are not magnetic highs and, in fact, the Baltic shield is a marked minimum. The reduced-to-the-pole magnetic map shows a marked tendency for northeasterly striking anomalies in the eastern Atlantic and adjacent Africa, which is coincident to the track of several hot spots for the past 100 million years. However, there is little consistency in the sign of the magnetic anomalies and the track of the hot spots. Comparison of the radially polarized anomalies of Africa and Europe with other reduced-to-the-pole magnetic satellite anomaly maps of the Western Hemisphere support the reconstruction of the continents prior to the origin of the present-day Atlantic Ocean in the Mesozoic Era.

Hinze, W. J.↗
NASA NTRS1987

Enhanced LANDSAT images of Antarctica and planetary exploration

Since early in the LANDSAT program, black-and-white paper prints of band 7 (near infrared) of the LANDSAT multispectral scanner have been used extensively to prepare semicontrolled maps of Antarctica. Image-processing techniques are now employed to enhance fine detail and to make controlled image-mosaic maps in color. LANDSAT multispectral images of Antarctica help to expand our knowledge of extraterrestrial bodies by showing bare-ice areas as bright blue patches; on such patches meteorites tend to be concentrated and are collected. Many subtle flow features in Antarctic ice streams resemble features at the mouths of Martian outflow channels, which suggests that the channels also contained ice. Furthermore, flow lines in Antarctic ice sheets that merge with ice shelves resemble Martian flow features associated with dissected terrain along the Martian northern highland margin, and support the concept that ice was involved in the transport of material from the southern highlands to the northern lowland plains. In Antarctica, as on Mars, the virtual absence of fluvial activity over millions of years has permitted the growth of glacial and eolian features to unusually large sizes.

Lucchitta, B. K.↗
NASA NTRS1989

The extended red emission filaments in NGC 2023

Using the photographic unsharp masking technique and image cancellation, the high-frequency surface brightness fluctuations in the reflection nebula NGC 2023 have been imaged over 406 arcsec x 510 arcsec field. Maps with 1 arcsec resolution, centered on the illuminating star HD 37903, are presented for the photometric B and R bands. A system of narrow filamentary structures observable only in the R band are identified as extended red emission (ERE) features. These features are not associated with any apparent density enhancements in the nebula. Arguments are presented which link the ERE filaments to regions within the nebula where photodissociation of molecular hydrogen occurs.

Witt, Adolf N.↗
NASA NTRS1993

Molecular catastrophes and circumstellar SiO masers

Understanding the complex SiO maser regions of highly evolved stars can be improved through multiwavelength studies of 'premaser' stars, such as M0-M4 giants and semiregular variables, which can be placed on normal H-R diagrams unlike most of the OH-IR stars. I argue that SiO masers are a key part of the transformation of hot stellar plasma into cold circumstellar silicate dust, in the outflows from evolved, oxygen rich stars. Evidence for this statement rests on the following: (1) red giant mass loss originates in a stochastic, amsotropic manner; (2) SiO maser maps of Miras and red supergiants show numerous maser spots within a few stellar radii; (3) molecules and dust naturally form in a cooling outflow; (4) the IRAS Low Resolution Spectrometer provided evidence for diverse and variable 10 micron silicate features in Miras, and these shapes correlate well with the proposed maser chronology, suggesting a formation and annealing sequence. The theory for the occurrence of SiO masers involving thermal instability, related 'new' physics, recent calculations and a prediction are discussed.

Stencel, Robert E.↗
NASA NTRS1993

Approaches to high aspect ratio triangulations

In aerospace computational fluid dynamics calculations, high aspect ratio, or stretched, triangulations are necessary to adequately resolve the features of a viscous flow around bodies. In this paper, we explore alternatives to the Delaunay triangulation which can be used to generate high aspect ratio triangulations of point sets. The method is based on a variation of the lifting map concept which derives Delaunay triangulations from convex hull calculations.

Posenau, M.-A.↗
NASA NTRS1995

Reverberation mapping by regularized linear inversion

Reverberation mapping of active galactic nucleus (AGN) emission-line regions requires the numerical deconvolution of two time series. We suggest the application of a new method, regularized linear inversion, to the solution of this problem. This method possesses many good features; it imposes no restrictions on the sign of the response function; it can provide clearly defined uncertainty estimates; it involves no guesswork about unmeasured data; it can give a clear indication of when the underlying convolution model is inadequate; and it is computationally very efficient. Using simulated data, we find the minimum S/N and length of the time series in order for this method to work satisfactorily. We also define guidelines for choosing the principal tunable parameter of the method and for interpreting the results. Finally, we reanalyze published data from the 1989 NGC 5548 campaign using this new method and compare the results to those previously obtained by maximum entropy analysis. For some lines we find good agreement, but for others, especially C III lambda(1909) and Si IV lambda(1400), we find significant differences. These can be attributed to the inability of the maximum entropy method to find negative values of the response function, but also illustrate the nonuniqueness of any deconvolution technique. We also find evidence that certain line light curves (e.g., C IV lambda(1549)) cannot be fully described by the simple linear convolution model.

Krolik, Julian H.↗
NASA NTRS2000

SeaWinds Scatterometer on QuikSCAT Mission and the Emerging Land and Ocean Applications

Spaceborne scatterometers are active microwave radar instruments designed to acquire near-simultaneous, spatially collocated measurements of the normalized radar backscattering cross section (sigma0) of the global surface from several azimuth and/or incidence angles. The primary objective of the scatterometer mission is to measure the near-surface wind speed and direction over the global ocean using sigma0 measurements together with a wind geophysical model function. However, since sigma0 measurements are collected globally all the time, sigma0 data can also be used for global land and ice applications. In this paper, we will first present the objectives of the QSCAT mission, the instrument design, and the unique features of the Ku-band scatterometer currently in operation, called SeaWinds on QuikSCAT (QSCAT). We will then present some emerging land and ocean applications of the QSCAT data, which include (1) global snow detection and monitoring, (2) melt region mapping on the Greenland ice sheet, (3) Monsoon flood detection and monitoring, (4) soil wetness application at large scale, and (5) hurricane monitoring and tracking.

Tsai, W.-Y.↗
NASA NTRS2003

The Seasonal Behavior of Water Ice Clouds in the Tharsis and Valles Marineris Regions of Mars: Mars Orbiter Camera Observations

The Mars Orbiter Camera (MOC) was used to obtain global maps of the Martian surface. The maps used were acquired between March 15, 1999 (LS = 110 ) and July 31, 2001 (L(sub s) = 110), corresponding to approximately one and a quarter martian years. In this work we focused on water ice clouds associated with the surface features of Olympus Mons, Ascraeus Mons, Pavonis Mons, Arsia Mons, Alba Patera, and the Valles Marineris canyon system. Using these data, we have made three types of quantitative measurements to characterize the cloud activity: 1) cloud area and location, 2) cloud height, and 3) cloud optical depth. We have also searched for short period variations in the cloud areas.

J L Benson↗
NASA NTRS2005

Lunar and Planetary Science XXXVI, Part 8

The following topics were discussed: Why Small is Beautiful, and How to Detect Another 10 Billion Small Main Belt Asteroids; Basalts in Mare Humorum and S.E. Procellarum; Basalts in Mare Serenitatis, Lacus Somniorum, Lacus Mortis and Part of Mare Tranquillitatis; Revised Thorium Abundances for Lunar Red Spots; Integrating Global-Scale Mission Datasets - Understanding the Martian Crust; Comparing Goldstone Solar System Radar Earth-based Observations of Mars with Orbital Datasets; Water Ice Clouds in the Martian Atmosphere: A View from MGS TES; Lunar Meteorite Northeast Africa 001: An Anorthositic Regolith Breccia with Mixed Highland/Mare Components; One Spectrometer, Two Spectra: Complementary Hemispherical Reflectance and Thermal Emission Spectroscopy Using a Single FTIR Instrument; Alteration Phases Associated with High Concentrations of Orthopyroxene and Olivine on Mars; Experimental Crystallization of Fe-rich Basalt: Application to Cooling Rate and Oxygen Fugacity of Nakhlite MIL-03346; Thermo-Chemical Convection in Europa s Icy Shell with Salinity; Tectonic Pressurization of Aquifers in the Formation of Mangala and Athabasca Valles on Mars; 3D Structural Interpretation of the Eagle Butte Impact Structure, Alberta, Canada; Ultraviolet Views of Enceladus, Tethys, and Dione; Crustal Plateaus as Ancient Large Impact Features: A Hypothesis; New Observations of Crustal Plateau Surface Histories, Venus: Implications for Crustal Plateau Hypotheses; Detailed Mineralogical Characterizations of Four S-Asteroids: 138 Tolosa, 306 Unitas, 346 Hermentaria, and 480 Hansa; Working with Planetary Coordinate Reference Systems; Bilingual Map of Mercury; and The Io Mountain Online Database.

Source record↗