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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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NASA NTRS2009

Power Requirements for The NASA Mars Design Reference Architecture (DRA) 5.0

This paper summarizes the power systems analysis results from NASA s recent Mars DRA 5.0 study which examined three architecture options and resulting mission requirements for a human Mars landing mission in the post-2030 timeframe. DRA 5.0 features a long approximately 500 day surface stay split mission using separate cargo and crewed Mars transfer vehicles. Two cargo flights, utilizing minimum energy trajectories, pre-deploy a cargo lander to the surface and a habitat lander into a 24-hour elliptical Mars parking orbit where it remains until the arrival of the crew during the next mission opportunity approximately 26 months later. The pre-deployment of cargo poses unique challenges for set-up and emplacement of surface assets that results in the need for self or robotically deployed designs. Three surface architecture options were evaluated for breadth of science content, extent of exploration range/capability and variations in system concepts and technology. This paper describes the power requirements for the surface operations of the three mission options, power system analyses including discussion of the nuclear fission, solar photovoltaic and radioisotope concepts for main base power and long range mobility.

Cataldo, Robert L.↗

NASA NTRS2020

High-capacity ATHLETE Offloader Mobility Constructor Concept for Human Surface Exploration

Using cross-cabled, winch-tendon four-bar frames, a new Artemis-class ATHLETE system is a multi-limbed robotic mobility platform that is designed for surface traverse, precision placement, and offloading of heavy habitats and other large human exploration payloads from high-decked landers. Building upon lessons learned from the All-Terrain Hex-Limbed Extra-Terrestrial Explorer (ATHLETE) robotic mobility system developed for Constellation Lunar Surface Systems and Evolvable Mars Campaign, a high-capacity articulated crane / lift vehicle concept has been devised that would be equipped with multi-limb six-degree-of-freedom dexterity for a variety of tasks supporting planetary surface human exploration missions and outposts. The Artemis-class ATHLETE vehicle would use any combination of three to six wheel-onlimb combinations to provide a wide “outrigger” stance to transfer loads from a high center-of-gravity on sloped terrain to low stable carry configurations for long-distance traverses, and be capable of precision docking of payloads to previously positioned elements. The new vehicle concept improves upon previous Constellation-class ATHLETE versions by allowing modular hot-swapping of individual limbs to improve maintenance and flexibility. The extreme-capacity independent limbs can individually function as single cranes, and can be delivered separately via multiple lander manifests for later congregation into self-driving “Tri-ATHLETE” vehicles after delivery to the surface. This paper provides mission architecture targets and vehicle masses for stepped payload capacity values in Earth, Mars, and Lunar gravity environments, and discusses a variety of swappable tools, including wheeled mobility attachments, grippers, excavation tools, repair fixtures, ISRU extraction, winches, block & tackle rigging combinations, 3D printheads, and construction aids.

Wilcox, Brian↗

NASA NTRS1989

Robotic Vision Would Combine Optics And Microwaves

Conceptual robot-vision system processes data from both microwave and visible-wavelength sensors. Concept, called "fusion of sensors," yields better information on shapes of some objects than obtained from one type of sensor alone. Proposed system fuses data from television images with polarized low-resolution radar-scattering cross sections. Using iterative procedure, generates successive approximations to shape of target by minimizing differences between observed radar returns and radar returns observed if object characterized by computed scattering transfer matrix.

Krishen, Kuma↗

NASA NTRS1992

Numerical analysis of right-half plane zeros for a single-link manipulator

The purpose of this research is to further develop an understanding of how nonminimum phase zero location is affected by structural link design. As the demand for light-weight robots that can operate in a large workspace increases, the structural flexibility of the links become more of an issue in controls problems. When the objective is to accurately position the tip while the robot is actuated at the base, the system is nonminimum phase. One important characteristic of nonminimum phase systems is system zeros in the right half of the Laplace plane. The ability to pick the location of these nonminimum phase zeros would give the designer a new freedom similar to pole placement. The research targets a single-link manipulator operating in the horizontal plane and modeled as a Euler-Bernoulli beam with pinned-free end conditions. Using transfer matrix theory, one can consider link designs that have variable cross-sections along the length of the beam. A FORTRAN program was developed to determine the location of poles and zeros given the system model. The program was used to confirm previous research on nonminimum phase systems, and develop a relationship for designing linearly tapered links. The method allows the designer to choose the location of the first pole and zero and then defines the appropriate taper to match the desired locations. With the pole and zero location fixes, the designer can independently change the link's moment of inertia about its axis of rotation by adjusting the height of the beam. These results can be applied to inverse dynamic algorithms currently under development at Georgia Tech.

Girvin, Douglas Lynn↗

NASA NTRS1991

Numerical analysis of nonminimum phase zero for nonuniform link design

As the demand for light-weight robots that can operate in a large workspace increases, the structural flexibility of the links becomes more of an issue in control. When the objective is to accurately position the tip while the robot is actuated at the base, the system is nonminimum phase. One important characteristic of nonminimum phase systems is system zeros in the right half of the Laplace plane. The ability to pick the location of these nonminimum phase zeros would give the designer a new freedom similar to pole placement. This research targets a single-link manipulator operating in the horizontal plane and modeled as a Euler-Bernoulli beam with pinned-free end conditions. Using transfer matrix theory, one can consider link designs that have variable cross-sections along the length of the beam. A FORTRAN program was developed to determine the location of poles and zeros given the system model. The program was used to confirm previous research on nonminimum phase systems, and develop a relationship for designing linearly tapered links. The method allows the designer to choose the location of the first pole and zero and then defines the appropriate taper to match the desired locations. With the pole and zero location fixed, the designer can independently change the link's moment of inertia about its axis of rotation by adjusting the height of the beam. These results can be applied to the inverse dynamic algorithms that are currently under development.

Girvin, Douglas L.↗

NASA NTRS2010

Analysis of Snow Bidirectional Reflectance from ARCTAS Spring-2008 Campaign

The spring 2008 Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) experiment was one of major intensive field campaigns of the International Polar Year aimed at detailed characterization of atmospheric physical and chemical processes in the Arctic region. A part of this campaign was a unique snow bidirectional reflectance experiment on the NASA P-3B aircraft conducted on 7 and 15 April by the Cloud Absorption Radiometer (CAR) jointly with airborne Ames Airborne Tracking Sunphotometer (AATS) and ground-based Aerosol Robotic Network (AERONET) sunphotometers. The CAR data were atmospherically corrected to derive snow bidirectional reflectance at high 1 degree angular resolution in view zenith and azimuthal angles along with surface albedo. The derived albedo was generally in good agreement with ground albedo measurements collected on 15 April. The CAR snow bidirectional reflectance factor (BRF) was used to study the accuracy of analytical Ross-Thick Li-Sparse (RTLS), Modified Rahman-Pinty-Verstraete (MRPV) and Asymptotic Analytical Radiative Transfer (AART) BRF models. Except for the glint region (azimuthal angles phi less than 40 degrees), the best fit MRPV and RTLS models fit snow BRF to within 0.05. The plane-parallel radiative transfer (PPRT) solution was also analyzed with the models of spheres, spheroids, randomly oriented fractal crystals, and with a synthetic phase function. The latter merged the model of spheroids for the forward scattering angles with the fractal model in the backscattering direction. The PPRT solution with synthetic phase function provided the best fit to measured BRF in the full range of angles. Regardless of the snow grain shape, the PPRT model significantly over-/underestimated snow BRF in the glint/backscattering regions, respectively, which agrees with other studies. To improve agreement with experiment, we introduced a model of macroscopic snow surface roughness by averaging the PPRT solution over the slope distribution function and by adding a simple model of shadows. With macroscopic roughness described by two parameters, the AART model achieved an accuracy of about plus or minus 0.05 with a possible bias of plus or minus 0.03 in the spectral range 0.4-2.2 micrometers. This high accuracy holds at view zenith angles below 55-60 degrees covering the practically important range for remote sensing applications, and includes both glint and backscattering directions.

Lyapustin, A.↗

NASA NTRS2013

Lunar Polar In Situ Resource Utilization (ISRU) as a Stepping Stone for Human Exploration

A major emphasis of NASA is to extend and expand human exploration across the solar system. While specific destinations are still being discussed as to what comes first, it is imperative that NASA create new technologies and approaches that make space exploration affordable and sustainable. Critical to achieving affordable and sustainable exploration beyond low Earth orbit (LEO) are the development of technologies and approaches for advanced robotics, power, propulsion, habitats, life support, and especially, space resource utilization systems. Space resources and how to use them, often called In-Situ Resource Utilization (ISRU), can have a tremendous beneficial impact on robotic and human exploration of the Moon, Mars, Phobos, and Near Earth Objects (NEOs), while at the same time helping to solve terrestrial challenges and enabling commercial space activities. The search for lunar resources, demonstration of extraterrestrial mining, and the utilization of resource-derived products, especially from polar volatiles, can be a stepping stone for subsequent human exploration missions to other destinations of interest due to the proximity of the Moon, complimentary environments and resources, and the demonstration of critical technologies, processes, and operations. ISRU and the Moon: There are four main areas of development interest with respect to finding, obtaining, extracting, and using space resources: Prospecting for resources, Production of mission critical consumables like propellants and life support gases, Civil engineering and construction, and Energy production, storage, and transfer. The search for potential resources and the production of mission critical consumables are the primary focus of current NASA technology and system development activities since they provide the greatest initial reduction in mission mass, cost, and risk. Because of the proximity of the Moon, understanding lunar resources and developing, demonstrating, and implementing lunar ISRU provides a near and early opportunity to perform the following that are applicable to other human exploration mission destinations: Identify and characterize resources, how they are distributed, and the material, location and environment in which they are found; Demonstrate concepts, technologies, and hardware that can reduce the cost and risk of human exploration beyond Earth orbit; Use the Moon for operation experience and mission validation for much longer missions that are farther from Earth Develop and evolve ISRU to support sustained, economical human presence beyond Earth's orbit, including promoting space commercialization As Table 1 depicts, the Moon provides environments and resources applicable to Mars and NEOs. Two lunar ISRU resource and product pathways that have notable synergism with NEO, Phobos/Demos, and Mars ISRU are oxygen/metal extraction from regolith, and water/volatile extraction from lunar polar materials. To minimize the risk of developing and incorporating ISRU into human missions, a phased implementation plan is recommended that starts with prospecting and demonstrating critical technologies on robotic and human missions, then performing pilot scale operations (in non-mission critical roles) to enhance exploration mission capabilities, leading to full utilization of space resources in mission critical roles. Which lunar ISRU pathway is followed will depend on the results of early resource prospecting/proof-ofconcept mission(s), and long-term human exploration plans.

Sanders, Gerald B.↗

DOE OSTI2025

Solar Spectrum Conversion for an Algae Bioreactor (CRADA Final Report)

This project focused on developing advanced optical coatings to improve solar energy utilization. The research aimed to create lanthanide-doped upconversion nanoparticles (UCNPs) capable of capturing unused near-infrared (NIR) light from the sun and converting it into visible light (blue and red photons) that can be used for photosynthesis. The primary goal was to identify, synthesize, and integrate highly efficient UCNPs into a transparent thin-film device. Through a comprehensive workflow involving computer simulations, high-throughput robotic synthesis, and detailed optical characterization, the project successfully developed a high-performance material. The key technical achievement was the creation of a core-shell UCNP (NaYF₄:20%Yb³⁺, 2%Er³⁺ coated with a 10 nm NaYF₄ shell) that demonstrated a quantum yield of 3.2% for converting 980 nm NIR light into visible light. Transparent thin films fabricated from these nanoparticles showed excellent optical properties, confirming their potential for practical applications. This research adds to the scientific understanding of energy transfer in lanthanide materials and demonstrates a technically effective method for creating efficient light-converting coatings. The primary benefit to the public lies in the potential for these coatings to enhance the efficiency of solar-driven processes, such as boosting the growth of algae in photobioreactors for biofuel production.

14 SOLAR ENERGY↗

NASA NTRS2012

Mars Science Laboratory Engineering Cameras

NASA's Mars Science Laboratory (MSL) Rover, which launched to Mars in 2011, is equipped with a set of 12 engineering cameras. These cameras are build-to-print copies of the Mars Exploration Rover (MER) cameras, which were sent to Mars in 2003. The engineering cameras weigh less than 300 grams each and use less than 3 W of power. Images returned from the engineering cameras are used to navigate the rover on the Martian surface, deploy the rover robotic arm, and ingest samples into the rover sample processing system. The navigation cameras (Navcams) are mounted to a pan/tilt mast and have a 45-degree square field of view (FOV) with a pixel scale of 0.82 mrad/pixel. The hazard avoidance cameras (Haz - cams) are body-mounted to the rover chassis in the front and rear of the vehicle and have a 124-degree square FOV with a pixel scale of 2.1 mrad/pixel. All of the cameras utilize a frame-transfer CCD (charge-coupled device) with a 1024x1024 imaging region and red/near IR bandpass filters centered at 650 nm. The MSL engineering cameras are grouped into two sets of six: one set of cameras is connected to rover computer A and the other set is connected to rover computer B. The MSL rover carries 8 Hazcams and 4 Navcams.

Maki, Justin N.↗

NASA NTRS1991

SSSFD manipulator engineering using statistical experiment design techniques

The Satellite Servicer System Flight Demonstration (SSSFD) program is a series of Shuttle flights designed to verify major on-orbit satellite servicing capabilities, such as rendezvous and docking of free flyers, Orbital Replacement Unit (ORU) exchange, and fluid transfer. A major part of this system is the manipulator system that will perform the ORU exchange. The manipulator must possess adequate toolplate dexterity to maneuver a variety of EVA-type tools into position to interface with ORU fasteners, connectors, latches, and handles on the satellite, and to move workpieces and ORUs through 6 degree of freedom (dof) space from the Target Vehicle (TV) to the Support Module (SM) and back. Two cost efficient tools were combined to perform a study of robot manipulator design parameters. These tools are graphical computer simulations and Taguchi Design of Experiment methods. Using a graphics platform, an off-the-shelf robot simulation software package, and an experiment designed with Taguchi's approach, the sensitivities of various manipulator kinematic design parameters to performance characteristics are determined with minimal cost.

Barnes, John↗

DOE OSTI2020

An Algorithm to Retrieve Total Precipitable Water Vapor in the Atmosphere from FengYun 3D Medium Resolution Spectral Imager 2 (FY-3D MERSI-2) Data

The atmosphere has substantial effects on optical remote sensing imagery of the Earth’s surface from space. These effects come through the functioning of atmospheric particles on the radiometric transfer from the Earth’s surface through the atmosphere to the sensor in space. Precipitable water vapor (PWV), CO 2 , ozone, and aerosol in the atmosphere are very important among the particles through their functioning. This study presented an algorithm to retrieve total PWV from the Chinese second-generation polar-orbiting meteorological satellite FengYun 3D Medium Resolution Spectral Imager 2 (FY-3D MERSI-2) data, which have three near-infrared (NIR) water vapor absorbing channels, i.e., channel 16, 17, and 18. The algorithm was improved from the radiance ratio technique initially developed for Moderate-Resolution Imaging Spectroradiometer (MODIS) data. MODTRAN 5 was used to simulate the process of radiant transfer from the ground surfaces to the sensor at various atmospheric conditions for estimation of the coefficients of ratio technique, which was achieved through statistical regression analysis between the simulated radiance and transmittance values for FY-3D MERSI-2 NIR channels. The algorithm was then constructed as a linear combination of the three-water vapor absorbing channels of FY-3D MERSI-2. Measurements from two ground-based reference datasets were used to validate the algorithm: the sun photometer measurements of Aerosol Robotic Network (AERONET) and the microwave radiometer measurements of Energy’s Atmospheric Radiation Measurement Program (ARMP). The validation results showed that the algorithm performs very well when compared with the ground-based reference datasets. The estimated PWV values come with root mean square error (RMSE) of 0.28 g/cm 2 for the ARMP and 0.26 g/cm 2 for the AERONET datasets, with bias of 0.072 g/cm 2 and 0.096 g/cm 2 for the two reference datasets, respectively. The accuracy of the proposed algorithm revealed a better consistency with ground-based reference datasets. Thus, the proposed algorithm could be used as an alternative to retrieve PWV from FY-3D MERSI-2 data for various remote sensing applications such as agricultural monitoring, climate change, hydrologic cycle, and so on at various regional and global scales.

54 ENVIRONMENTAL SCIENCES↗

NASA NTRS1991

NASA's advanced space transportation system launch vehicles

Some insight is provided into the advanced transportation planning and systems that will evolve to support long term mission requirements. The general requirements include: launch and lift capacity to low earth orbit (LEO); space based transfer systems for orbital operations between LEO and geosynchronous equatorial orbit (GEO), the Moon, and Mars; and Transfer vehicle systems for long duration deep space probes. These mission requirements are incorporated in the NASA Civil Needs Data Base. To accomplish these mission goals, adequate lift capacity to LEO must be available: to support science and application missions; to provide for construction of the Space Station Freedom; and to support resupply of personnel and supplies for its operations. Growth in lift capacity must be time phased to support an expanding mission model that includes Freedom Station, the Mission to Planet Earth, and an expanded robotic planetary program. The near term increase in cargo lift capacity associated with development of the Shuttle-C is addressed. The joint DOD/NASA Advanced Launch System studies are focused on a longer term new cargo capability that will significantly reduce costs of placing payloads in space.

Branscome, Darrell R.↗

DOE OSTI2022

Low-Cost Preform and Molding Processes

The entry cost for prototyping a composite component for manufacture using automated, high rate processes is prohibitively expensive in many cases, especially for small business, where tooling costs may be several $100k. Discussions with industry also indicate that many small companies, tier 1 and 2 suppliers, have an interest to mold composite parts but do not want to deal with the capital cost, material handling issues, and labor associated with dry fiber preforming operations. While the molders may locate near the end user for logistics reasons, it may be more cost effective for the performer to remain regional and invest in capital equipment to support preform automation, thus keeping costs to a minimum. This project was designed to explore and demonstrate several options to meet these industry needs. Dry fiber preforming approaches were evaluated which allow for low pressure resin infusion, single sided tooling options such a vacuum assisted resin transfer molding (VARTM) or low pressure resin transfer molding (RTM-light). Unlike sheet molding compound, SMC compression molding where typical molding pressures of 1000 psi are required to push material into the desired location; positioning of a dry fiber preform into the desired location on the tool allows for low molding pressures of 10-50 psi. Lower molding pressures allow for use of low cost, additive fabrication of polymeric tooling. Polymeric tooling is suitable for rapid part prototyping and limited production. Dry fiber preforming approaches evaluated included use of commercial chopped strand mat, robotic chopper gun deposition, and continuous fiber preform augmentation using tailored fiber placement (TFP). Use of chopped strand mat does not require a robotic deposition method, however a cutting table is generally required and there is typically 20-30% scrap generation. While various fiber areal weights are available, the preform is not readily optimized for minimal fiber use or weight savings. In contrast, a robotic chopper gun approach allows for localized deposition where fiber is required to meet structural requirements. The robotic method is highly automated and minimizes fiber scrap, however the capital cost of the equipment and engineering labor for programming can result in higher preform cost compared to chopped strand mat in certain cases depending on preform complexity. Dry fiber preforming using the robotic chopper gun method allows for creation of three dimensional forms. This approach may be ideal for molding in-house, or if the preforms stack together densely to allow for efficient shipping. Applications evaluated for this program considered trade-off between fabrication of a fully 3D preform versus production of a flat preform which is designed to readily drape into the final desired shape. Such a preform design greatly simplifies robotic programming and requires no specialized tooling. The flat preforms are easily stacked and shipped to the final molding location. Flat preforms are much easier to augment with TFP continuous fiber to provide local reinforcement. The demonstration and evaluation of these preforming and tooling methods were completed on three component applications. The first application was a battery box cover for an electric vehicle which was highly three dimensional. The second demonstrator article was comprised of complex contours and was used to demonstrate the use of TFP and RTM-light molding process. The third demonstration article was the roof of an operator’s cab for large construction equipment. The roof is relatively flat however it is comprised of complex changes in thickness which clearly demonstrate the advantage of robotic chopper gun approach as compared to using numerous preform layers of chopped strand mat. The cost trades for the various preforming methods are summarized to help guide the reader as to preforming method considerations. Finally, these demonstrations all used glass fiber roving. A fourth, exploratory task was added to evaluate the ability to make preforms using Zoltek’s carbon fiber split tow roving. We were able to adapt the chopper gun to make flat preforms for laminate testing, but further development effort would be required to make suitable preforms.

36 MATERIALS SCIENCE↗

NASA NTRS2001

STS-105 Flight Day 4 Highlights

On this fourth day of the STS-105 mission, footage shows the Shuttle's robotic arm as it moves into position to grapple the Leonardo Multipurpose Module (LMPM) out of Discovery's payload bay and into position to be installed to the Unity Module on the International Space Station (ISS). The STS-105 crew (Commander Scott Horowitz, Pilot Frederick Sturckow, and Mission Specialists Daniel Barry and Patrick Forrester), Expedition 2 crew (Commander Yuriy Usachev and Flight Engineers James Voss and Susan Helms), and the Expedition 3 crew (Frank Culbertson, Jr., Mikhail Turin, and Vladimir Dezhurov) are seen as they unload LMPM and transfer racks to and from the Destiny Laboratory Module and the Space Shuttle.

Source record↗

NASA NTRS2006

In-Space Cryogenic Propellant Depot Potential Commercial and Exploration Applications

The key goals and objectives for an In-Space Cryogenic Propellant Depot are to support a safe, reliable, affordable and effective future human and robotic space exploration initiative. Previous studies have been conducted at the NASA Marshall Space Flight Center to determine technical requirements and feasibility for exploration and commercial potential of an in-space cryogenic propellant depot in low-Earth-orbit (LEO), low-Lunar orbit (LLO) and/or on the lunar surface. Results indicate that in-space cryogenic propellant depots are technically feasible given continued technology development and that there is a substantial growing market that depots could support. Systems studies showed that the most expensive part of transferring payloads to geo-synchronous-orbit (GEO) is the fuel. A cryogenic propellant production and storage depot stationed in LEO could lower the cost of missions to GEO and beyond. Propellant production separates water into hydrogen and oxygen through electrolysis. This process requires large amounts of power which is enabled by Space Solar Power technologies. Recent analysis indicate that in the coming decades there could be a significant demand for water-based propellants from Earth, moon, or asteroid resources if in-space transfer vehicles (upper stages) transitioned to reusable systems using water based propellants. This type of strategic planning move could create a substantial commercial market for space resources development, and ultimately lead toward significant commercial infrastructure development within the Earth-Moon system.

Howell, Joe T.↗

NASA NTRS2020

Challenges of Mars Sample Return Lander Entry, Descent, and Landing

The proposed Mars Sample Return (MSR) campaign would be perhaps the most ambitious robotic mission ever attempted in space exploration. The notional cam-paign consists of three Flagship-class missions operating in cooperation for over a decade in order to return samples of the Martian surface and atmosphere to Earth for analysis. The Mars 2020 rover, scheduled to launch in July 2020, will cache samples and place them on the surface for possible return. The second mission would be a Sample Return Lander (SRL) that consists of a small Sample Fetch Rover (SFR) to gather the samples, a Sample Transfer Arm (STA) to load the samples into a Mars Ascent Vehicle (MAV), and the MAV itself to launch the samples into orbit around Mars. The third mission would be an Earth Return Or-biter (ERO) designed to rendezvous and capture the Orbiting Sample (OS), return to Earth, and separate the Earth Entry Vehicle (EEV) for Entry, Descent, and Landing (EDL) at a location to be determined. This paper will focus on the SRL mission concept, specifically the EDL phase. Given the ambitious SRL sample re-trieval baseline surface mission, including a rocket launch of the samples into Mars orbit, it is estimated that the EDL system may be required to deliver as much as 2100 kg of dry mass to the surface. This represents an approximate 20-25% in-crease in mass capability over previous landed Mars missions. Additionally, there is a high probability that SRL would have to land very close to the samples on the surface to expedite retrieval operations; therefore, Pin Point Landing (PPL) accu-racy may be required. To address these challenges, promising EDL configuration augmentations were studied to include larger forebody/higher drag entry capsules, hypersonic/supersonic inflatable/non-inflatable aerodynamic decelerators, hypersonic trim tabs, ballute drag devices, larger parachutes, higher Mach and higher dynamic pressure parachute deployments, lower parachute deployment altitudes having shorter chute timelines necessitating more efficient terrain sensor strategies, and ad-ditional fuel for longer powered descent diverts to the target landing site. Over-arching the entire trade study was an attempt to stay as close to the experience base of past successful missions as possible to reduce implementation cost and risk. This paper will discuss the entire SRL EDL trade study in detail. The information presented about the potential MSR campaign is pre-decisional and is provided for planning and discussion purposes only.

Ivanov, Mark C.↗

NASA NTRS2012

Method and system for providing autonomous control of a platform

The present application provides a system for enabling instrument placement from distances on the order of five meters, for example, and increases accuracy of the instrument placement relative to visually-specified targets. The system provides precision control of a mobile base of a rover and onboard manipulators (e.g., robotic arms) relative to a visually-specified target using one or more sets of cameras. The system automatically compensates for wheel slippage and kinematic inaccuracy ensuring accurate placement (on the order of 2 mm, for example) of the instrument relative to the target. The system provides the ability for autonomous instrument placement by controlling both the base of the rover and the onboard manipulator using a single set of cameras. To extend the distance from which the placement can be completed to nearly five meters, target information may be transferred from navigation cameras (used for long-range) to front hazard cameras (used for positioning the manipulator).

Seelinger, Michael J.↗

NASA NTRS2022

A Novel Atmospheric Correction Algorithm to Exploit the Diurnal Variability in Hypertemporal Geostationary Observations

This study developed a new atmospheric correction algorithm, GeoNEX-AC, that is independent from the traditional use of spectral band ratios but dedicated to exploiting information from the diurnal variability in the hypertemporal geostationary observations. The algorithm starts by evaluating smooth segments of the diurnal time series of the top-of-atmosphere (TOA) reflectance to identify clear-sky and snow-free observations. It then attempts to retrieve the Ross-Thick–Li-Sparse (RTLS) surface bi-directional reflectance distribution function (BRDF) parameters and the daily mean atmospheric optical depth (AOD) with an atmospheric radiative transfer model (RTM) to optimally simulate the observed diurnal variability in the clear-sky TOA reflectance. Once the initial RTLS parameters are retrieved after the algorithm’s burn-in period, they serve as the prior information to estimate the AOD levels for the following days and update the surface BRDF information with the new clear-sky observations. This process is iterated through the full time span of the observations, skipping only totally cloudy days or when surface snow is detected. We tested the algorithm over various Aerosol Robotic Network (AERONET) sites and the retrieved results well agree with the ground-based measurements. This study demonstrates that the high-frequency diurnal geostationary observations contain unique information that can help to address the atmospheric correction problem from new directions.

atmospheric correction↗