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At least 433 records · Page 24

Apollo Next Generation Sample Analysis (ANGSA): A Segue to the Next Era of Lunar Exploration and Sample Return Activities

In the fifty years since the first lunar samples were collected on Apollo 11, significant advancements have taken place in laboratory analysis, planetary science, and astromaterials curation. These advances are now being leveraged for the Apollo Next Generation Sample Analysis (ANGSA) Program, which aims to study specially curated Apollo samples that have never been studied before. Since Apollo 17 in 1972, a great deal has been learned about the Moon, including the unique environments of the poles. Building upon Apollo and remote sensing studies since then, the Artemis Program aims to explore the cold environments near the lunar south pole while achieving the concurrent goals of landing the first woman and the next man on the Moon by 2024. Recent developments for ANGSA have significantly accelerated our readiness for Artemis sample return, particularly in the area of cold sample studies. Four science teams were selected to study cold and/or volatile-bearing samples collected during the Apollo program. These samples have special storage and handling requirements that necessitate their processing in a -20°C environment that meets the Apollo materials and cleanliness requirements. NASA has recently undertaken the development and implementation of a cold sample processing facility to support ANGSA. A similar facility will be needed to process the cold, volatile-bearing samples planned to be returned by Artemis missions; therefore, ANGSA provides excellent preparation for Artemis’ future cold sample processing efforts. We will outline the goals of the ANGSA and Artemis programs, illustrating the complementary nature of the work for both. We will describe the efforts to date in designing, testing, and implementing a cold curation facility that meets the requirements of ANGSA and Apollo curation. We will then outline future work for that facility to reach operational readiness. Finally, we will present the sample collection and curation strategies for Artemis, showing how they overlap and build on ANGSA efforts. The development of cold curation at NASA represents a significant leap in the knowledge, experience, and technologies used in astromaterials curation, opening the door for new investigations of lunar volatiles, impacts, formation processes, prebiotic chemistry, and resource utilization, among many others.

Julie Mitchell↗

Mapping wall-to-wall fractional cover of Arctic tundra plant functional types in Alaska using 20-m spatial resolution satellite imagery and harmonized plot observations

Estimates of fractional cover (fCover) across given land surfaces are used to assess, and often model, vegetation composition and diversity, which are crucial for understanding the health and functioning of terrestrial ecosystems. Remote sensing provides a useful means for scaling local, plot-measured fCover estimates to regional scales. Leveraging a recently synthesized and harmonized plot database, this study generated wall-to-wall maps of fCover for six Alaskan-Arctic plant functional types (PFT), including non-vascular plants, forbs, graminoids, and deciduous and evergreen shrubs, using 20-m satellite data (Sentinel-1, Sentinel-2, ArcticDEM) using a machine learning regression approach, specifically the random forest (RF) algorithm, which is well-suited for handling nonlinear relationships and high-dimensional satellite datasets. This study additionally addressed the spatio-temporal inconsistencies e.g., sampling scale, plot size, and collection year in plot measured fCover by adopting a multivariate outlier detection approach—Cook’s distance—to identify high-quality plots for model training and validation. Our approach achieves high accuracy (R 2 = 0.59–0.93, root mean squared errors = 0.02–0.10 for all PFTs) between plot-observed and satellite-derived fCover when using high-quality plot samples. The mapped fCover characterizes the spatial patterns of different PFTs across the tundra biome at a 20-m resolution, providing key information needed for improved representation of Arctic tundra vegetation in terrestrial biosphere models to better understand climate-vegetation feedback across the Arctic tundra.

Arctic tundra↗

A high reliability battery management system

Over a period of some 5 years Canadian Astronautics Limited (CAL) has developed a system to autonomously manage, and thus prolong the life of, secondary storage batteries. During the development, the system was aimed at the space vehicle application using nickel cadmium batteries, but is expected to be able to enhance the life and performance of any rechargeable electrochemical couple. The system handles the cells of a battery individually and thus avoids the problems of over, and under, drive that inevitably occur in a battery of cells managed by an averaging system. This individual handling also allow cells to be totally bypassed in the event of failure, thus avoiding the losses associated with low capacity, partial short circuit, and the catastrophe of open circuit. The system has an optional capability of managing redundant batteries simultaneously, adding the advantage of on line reconditioning of one battery, while the other maintains the energy storage capability of the overall system. As developed, the system contains a dedicated, redundant, microprocessor, but the capability exists to have this computing capability time shared, or remote, and operating through a data link. As adjuncts to the basic management system CAL has developed high efficiency, polyphase, power regulators for charge and discharge power conditioning.

Moody, M. H.↗

The LANDSAT system operated in Brazil by CNPq/INPE - results obtained in the area of mapping and future perspectives

The LANDSAT system, operated in the country by CNPg/INPE since 1973, systematically acquires, produces, and distributes both multispectral and panchromatic images obtained through remote sensing satellites to thousands of researchers and technicians involved in the natural resources survey. To cooperate in the solution of national problems, CNPq/INPE is developing efforts in the area of manipulation of those images with the objective of making them useful as planimetric bases for the simple revision of already published maps or for its utilization as basic material in regions not yet reliability mapped. The results obtained from performed tests are presented and the existing limitations are discussed. The new system purchased to handle data from the next series of LANDSAT as well as from MAPSAT and SPOT which will be in operation within the 80's decade, and are designed not only for natural resources survey but also for the solution of cartographic problems.

Dejesusparada, N.↗

The tropospheric emission spectrometer (TES) for the Earth Observing System (EOS)

In recent years, increasing concern has been expressed about Global Change - the natural and anthropogenic alteration of the Earth's environment involving global greenhouse warming and the associated climate change, urban and regional atmospheric pollution, acid deposition, regional increases in tropospheric zone, and the decrease in stratospheric ozone. A common theme among these problems is that they all involve those tropospheric trace gases which are fundamental to the biosphere-troposphere interaction, the chemistry of the free troposphere itself, and troposphere-stratosphere exchange. The chemical species involved all have spectral signatures within the near and mid infrared that can now be measured by advanced techniques of remote-sensing infrared spectroradiometry. Such a system is the Tropospheric Emission Spectrometer (TES), now in Phase B definition for the Earth Observing System (EOS) polar platforms. TES addresses these objectives by obtaining radiometrically calibrated, linewidth-limited spectral resolution, infrared spectra of the lower atmosphere using both natural thermal emission and reflected sunlight (where appropriate) in three different, but fully programmable, modes: a gobal mode, a pointed mode, and a limb-viewing mode. The goals of TES, its instrumentation, operational modes, sensitivity and data handling are discussed.

Beer, R.↗

The Screwworm Eradication Data System (SEDS)

One of the objectives of the SEDS was to build a versatile, yet economical, interactive system on the existing digital PDP 11/45 computers used in the Skylab production processing system. Previous experience on various interactive systems gave some background in the best methods of handling image data, registering and correcting the data, and extracting useful information from the images. The screwworm was eliminated in many parts of the United States by air-dropping sterile screwworms in areas where screwworms breed. The reproduction of the screwworm can be more or less predicted based on weather conditions -- cold weather slows the breeding, warm weather fosters it, and some moisture appears to enhance breeding conditions which, in turn, improves the chances of screwworm population growth. To obtain temperature and moisture conditions from remote areas, the NOAA improved TIROS operational satellite was selected to give data from the very high resolution radiometer (VHRR). The VHRR is a two-channel scanning instrument sensitive to energy in the visible spectrum from 0.6 to 0.7 micrometers and the infrared spectrum from 10.5 to 12.5 micrometers.

Quinn, M. J.↗

Challenges and Opportunities for Next-Generation Manufacturing in Space

With commercial space travel now a reality, the idea that people might spend time on other planets in the future seems to have greater potential. To make this possible, however, there needs to be flexible means for manufacturing in space to enable tooling or resources to be created when needed to handle unexpected situations. Next-generation manufacturing paradigms offer significant potential for the kind of flexibility that might be needed; however, they can result in increases in computation time compared to traditional control methods that could make many of the computing resources already available on earth attractive for use. Furthermore, resilience is a significant focus of next-generation manufacturing strategies, and one way to enable resilience for space manufacturing would be to have backup controllers available on earth. These types of considerations raise questions about remote control and monitoring, as well as privacy of the data involved in such practices, that must be considered. This work provides a perspective on several topics tied to remote control and monitoring for manufacturing in space.

Kip Nieman↗

Evolution of the Space Station Robotic Manipulator

The Space Station Remote Manipulator System (SSRMS), Canadarm2, was launched in 2001 and deployed on the International Space Station (ISS). The Canadarm2 has been instrumental in ISS assembly and maintenance. Canadarm2 shares its heritage with the Space Shuttle Arm (Canadarm). This article explores the evolution from the Shuttle Canadarm to the Space Station Canadarm2 design, which incorporates a 7 degree of freedom design, larger joints, and changeable operating base. This article also addresses phased design, redundancy, life and maintainability requirements. The design of Canadarm2 meets unique ISS requirements, including expanded handling capability and the ability to be maintained on orbit. The size of ISS necessitated a mobile manipulator, resulting in the unique capability of Canadarm2 to relocate by performing a walk off to base points located along the Station, and interchanging the tip and base of the manipulator. This provides the manipulator with reach and access to a large part of the Station, enabling on-orbit assembly of the Station and providing support to Extra-Vehicular Activity (EVA). Canadarm2 is evolving based on on-orbit operational experience and new functionality requirements. SSRMS functionality is being developed in phases to support evolving ISS assembly and operation as modules are added and the Station becomes more complex. Changes to sustaining software, hardware architecture, and operations have significantly enhanced SSRMS capability to support ISS mission requirements. As a result of operational experience, SSRMS changes have been implemented for Degraded Joint Operations, Force Moment Sensor Thermal Protection, Enabling Ground Controlled Operations, and Software Commutation. Planned Canadarm2 design modifications include: Force Moment Accommodation, Smart Safing, Separate Safing, and Hot Backup. In summary, Canadarm2 continues to evolve in support of new ISS requirements and improved operations. It is a tribute to the design that this evolution can be accomplished while conducting critical on-orbit operations with minimal hardware changes.

Razvi, Shakeel↗

The Bristol method of satellite-improved rainfall monitoring

Remote sensing estimates of area average precipitation are useful to agricultural and climatological applications. Estimates obtained by active or passive microwaves, infrared and visible sensors may be augmented and improved using indirect measures of precipitation, such as the change in near surface soil moisture content caused by a particular event. Measurements of soil moisture using infrared radiances do not provide precipitation information in real time since the sky must clear. However, the resultant estimate of precipitation is a time integrated value which provides a significant savings in data handling and can overcome virtually all of the sampling problems associated with the monitoring of precipitation through storms of long duration.

Barrett, E. C.↗

Working in space

The capabilities of the NASA Neutral Buoyancy Simulator (NBS) water tank test facility are described, with reference to the proving of crew-operated mechanisms incorporated by the Space Telescope (ST). There are 24 Orbital Replaceable Units which are subject to handling in space by suited crewmen of the Space Shuttle, the largest of which is comparable to a telephone booth and weighs over 700 lb. The water volume of the simulator is sufficient to accept a full-size mockup of the Space Shuttle cargo bay, in which all ST operations will be conducted. Early ST simulations tested the mechanisms which astronauts would operate during contingency operations. More recently, the simulation tasks have reflected maintenance objectives of ST orbital life prolongation. With the recent addition of a fully functional Remote Manipulator System and the Manned Maneuvering Unit, the simulator constitutes the most complete training ground for extravehicular activities extant.

Sanders, F. G.↗

Surface and Atmospheric Parameter Retrieval From AVIRIS Data: The Importance of Non-Linear Effects

AVIRIS data represent a new and important approach for the retrieval of atmospheric and surface parameters from optical remote sensing data. Not only as a test for future space systems, but also as an operational airborne remote sensing system, the development of algorithms to retrieve information from AVIRIS data is an important step to these new approaches and capabilities. Many things have been learned since AVIRIS became operational, and the successive technical improvements in the hardware and the more sophisticated calibration techniques employed have increased the quality of the data to the point of almost meeting optimum user requirements. However, the potential capabilities of imaging spectrometry over the standard multispectral techniques have still not been fully demonstrated. Reasons for this are the technical difficulties in handling the data, the critical aspect of calibration for advanced retrieval methods, and the lack of proper models with which to invert the measured AVIRIS radiances in all the spectral channels. To achieve the potential of imaging spectrometry, these issues must be addressed. In this paper, an algorithm to retrieve information about both atmospheric and surface parameters from AVIRIS data, by using model inversion techniques, is described. Emphasis is put on the derivation of the model itself as well as proper inversion techniques, robust to noise in the data and an inadequate ability of the model to describe natural variability in the data. The problem of non-linear effects is addressed, as it has been demonstrated to be a major source of error in the numerical values retrieved by more simple, linear-based approaches. Non-linear effects are especially critical for the retrieval of surface parameters where both scattering and absorption effects are coupled, as well as in the cases of significant multiple-scattering contributions. However, sophisticated modeling approaches can handle such non-linear effects, which are especially important over vegetated surfaces. All the data used in this study were acquired during the 1991 Multisensor Airborne Campaign (MAC-Europe), as part of the European Field Experiment on a Desertification-threatened Area (EFEDA), carried out in Spain in June-July 1991.

Green Robert O.↗

Autonomous Radiation Mapping and Quantification using an Unmanned Ground Vehicle. Part II - Autonomous Navigation

Nuclear sites across the Unites States and other nations in the world, are prone to extreme radiation effects. To understand the radiation hazards, plan the cleanup efforts; and to meet the quality standards and guidelines, it is important to accurately characterize any nuclear facility. One of the current methods in characterizing facilities is the use of advanced autonomous systems. These are safe, efficient, and cost-effective tools, which can safely deploy state-of-the-art instrumentation without exposing workers to radiation risks. Conventional methods of taking radiation measurements by hand within or around the containment areas, and analyzing the collected data to obtain the result are: Ineffective, Puts scientists at risk of Radiation, Not cost-effective. The platform uses the Robotic Operating Systems (ROS) to integrate multiple sensors seamlessly. It can operate near real time by using a distributed processing system to handle large amounts of data: Surrounding cameras, A multi-channel 3D Lidar, Manipulator arm, High-performance gamma-ray spectrometer.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

Remote manual operator for space station intermodule ventilation valve

The Remote Manual Operator (RMO) is a mechanism used for manual operation of the Space Station Intermodule Ventilation (IMV) valve and for visual indication of valve position. The IMV is a butterfly-type valve, located in the ventilation or air circulation ducts of the Space Station, and is used to interconnect or isolate the various compartments. The IMV valve is normally operated by an electric motor-driven actuator under computer or astronaut control, but it can also be operated manually with the RMO. The IMV valve RMO consists of a handle with a deployment linkage, a gear-driven flexible shaft, and a linkage to disengage the electric motor actuator during manual operation. It also provides visual indication of valve position. The IMV valve RMO is currently being prepared for qualification testing.

Guyaux, James R.↗

A New Look into the Effect of Large Drops on Radiative Transfer Process

Recent studies indicate that a cloudy atmosphere absorbs more solar radiation than any current 1D or 3D radiation model can predict. The excess absorption is not large, perhaps 10-15 W/sq m or less, but any such systematic bias is of concern since radiative transfer models are assumed to be sufficiently accurate for remote sensing applications and climate modeling. The most natural explanation would be that models do not capture real 3D cloud structure and, as a consequence, their photon path lengths are too short. However, extensive calculations, using increasingly realistic 3D cloud structures, failed to produce photon paths long enough to explain the excess absorption. Other possible explanations have also been unsuccessful so, at this point, conventional models seem to offer no solution to this puzzle. The weakest link in conventional models is the way a size distribution of cloud particles is mathematically handled. Basically, real particles are replaced with a single average particle. This "ensemble assumption" assumes that all particle sizes are well represented in any given elementary volume. But the concentration of larger particles can be so low that this assumption is significantly violated. We show how a different mathematical route, using the concept of a cumulative distribution, avoids the ensemble assumption. The cumulative distribution has jumps, or steps, corresponding to the rarer sizes. These jumps result in an additional term, a kind of Green's function, in the solution of the radiative transfer equation. Solving the cloud radiative transfer equation with the measured particle distributions, described in a cumulative rather than an ensemble fashion, may lead to increased cloud absorption of the magnitude observed.

Marshak, Alexander↗

Earth Science Informatics Comes of Age

The volume and complexity of Earth science data have steadily increased, placing ever-greater demands on researchers, software developers and data managers tasked with handling such data. Additional demands arise from requirements being levied by funding agencies and governments to better manage, preserve and provide open access to data. Fortunately, over the past 10-15 years significant advances in information technology, such as increased processing power, advanced programming languages, more sophisticated and practical standards, and near-ubiquitous internet access have made the jobs of those acquiring, processing, distributing and archiving data easier. These advances have also led to an increasing number of individuals entering the field of informatics as it applies to Geoscience and Remote Sensing. Informatics is the science and technology of applying computers and computational methods to the systematic analysis, management, interchange, and representation of data, information, and knowledge. Informatics also encompasses the use of computers and computational methods to support decisionmaking and other applications for societal benefits.

Jodha, Siri↗

CoNNeCT Baseband Processor Module Boot Code SoftWare (BCSW)

This software provides essential startup and initialization routines for the CoNNeCT baseband processor module (BPM) hardware upon power-up. A command and data handling (C&DH) interface is provided via 1553 and diagnostic serial interfaces to invoke operational, reconfiguration, and test commands within the code. The BCSW has features unique to the hardware it is responsible for managing. In this case, the CoNNeCT BPM is configured with an updated CPU (Atmel AT697 SPARC processor) and a unique set of memory and I/O peripherals that require customized software to operate. These features include configuration of new AT697 registers, interfacing to a new HouseKeeper with a flash controller interface, a new dual Xilinx configuration/scrub interface, and an updated 1553 remote terminal (RT) core. The BCSW is intended to provide a "safe" mode for the BPM when initially powered on or when an unexpected trap occurs, causing the processor to reset. The BCSW allows the 1553 bus controller in the spacecraft or payload controller to operate the BPM over 1553 to upload code; upload Xilinx bit files; perform rudimentary tests; read, write, and copy the non-volatile flash memory; and configure the Xilinx interface. Commands also exist over 1553 to cause the CPU to jump or call a specified address to begin execution of user-supplied code. This may be in the form of a real-time operating system, test routine, or specific application code to run on the BPM.

Yamamoto, Clifford K.↗

Operational Performance of Sensor Systems Used to Determine Atmospheric Boundary Layer Properties as Part of the NASA Aircraft Vortex Spacing System Project

There has been a renewed interest in the application of remote sensor technology to operational aviation and airport-related activities such as Aircraft Vortex Spacing System (AVOSS). Radio Acoustic Sounding Systems (RASS), Doppler-acoustic sodars, Ultrahigh Frequencies (UHF) profilers and lidars have many advantages in measuring wind and temperature profiles in the lower atmospheric boundary layer since they can operate more or less continuously and unattended; however, there are limitations in their operational use at airports. For example, profilers deteriorate (limited altitude coverage or missing) in moderate or greater rain and can be affected by airplane targets in their field of view. Sodars can handle precipitation better but are affected by the high noise environments of airports and strong winds. Morning temperature inversions typically limit performance of RASS, sodars and profilers. Fog affects sonic anemometers. Lidars can have difficulties in clouds, fog or heavy precipitation. Despite their limitations these sensors have proven useful to provide wind and temperature profiles for AVOSS. Capabilities and limitations of these and other sensors used in the AVOSS program are discussed, parameter settings for the sensor systems are documented, and recommendations are made for the most cost-effective group of sensors for the future. The potential use of specially tuned dynamic forecast models and measurements from landing and departing aircraft are addressed.

Zak, J. Allen↗

Simulation of the Microwave Emission of Multi-layered Snowpacks Using the Dense Media Radiative Transfer Theory: the DMRT-ML Model

DMRT-ML is a physically based numerical model designed to compute the thermal microwave emission of a given snowpack. Its main application is the simulation of brightness temperatures at frequencies in the range 1-200 GHz similar to those acquired routinely by spacebased microwave radiometers. The model is based on the Dense Media Radiative Transfer (DMRT) theory for the computation of the snow scattering and extinction coefficients and on the Discrete Ordinate Method (DISORT) to numerically solve the radiative transfer equation. The snowpack is modeled as a stack of multiple horizontal snow layers and an optional underlying interface representing the soil or the bottom ice. The model handles both dry and wet snow conditions. Such a general design allows the model to account for a wide range of snow conditions. Hitherto, the model has been used to simulate the thermal emission of the deep firn on ice sheets, shallow snowpacks overlying soil in Arctic and Alpine regions, and overlying ice on the large icesheet margins and glaciers. DMRT-ML has thus been validated in three very different conditions: Antarctica, Barnes Ice Cap (Canada) and Canadian tundra. It has been recently used in conjunction with inverse methods to retrieve snow grain size from remote sensing data. The model is written in Fortran90 and available to the snow remote sensing community as an open-source software. A convenient user interface is provided in Python.

snowpacks↗