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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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At least 163 records · Page 9
All sourcesNASA NTRSDOE OSTI
NASA NTRS2014

Strategy for Ranking the Science Value of the Surface of Asteroid 101955 Bennu for Sample Site Selection for Osiris-REx

OSRIS-REx is NASA's New Frontiers 3 sample return mission that will return at least 60 g of pristine surface material from near-Earth asteroid 101955 Bennu in September 2023. The scientific value of the sample increases enormously with the amount of knowledge captured about the geological context from which the sample is collected. The OSIRIS-REx spacecraft is highly maneuverable and capable of investigating the surface of Bennu at scales down to the sub-cm. The OSIRIS-REx instruments will characterize the overall surface geology including spectral properties, microtexture, and geochemistry of the regolith at the sampling site in exquisite detail for up to 505 days after encountering Bennu in August 2018. The mission requires at the very minimum one acceptable location on the asteroid where a touch-and-go (TAG) sample collection maneuver can be successfully per-formed. Sample site selection requires that the follow-ing maps be produced: Safety, Deliverability, Sampleability, and finally Science Value. If areas on the surface are designated as safe, navigation can fly to them, and they have ingestible regolith, then the scientific value of one site over another will guide site selection.

Nakamura-Messenger, K.↗
NASA NTRS2013

Thermal Performance of the Mars Science Laboratory Rover During Mars Surface Operations

On November 26, 2011, NASA launched a large (900 kg) rover as part of the Mars Science Laboratory (MSL) mission to Mars. Eight months later, on August 5, 2012, the MSL rover (Curiosity) successfully touched down on the surface of Mars. As of the writing of this paper, the rover had completed over 200 Sols of Mars surface operations in the Gale Crater landing site (4.5 degrees South latitude). This paper describes the thermal performance of the MSL Rover during the early part of its two Earth-0.year (670 Sols) prime surface mission. Curiosity landed in Gale Crater during early Spring (Solar longitude=151) in the Southern Hemisphere of Mars. This paper discusses the thermal performance of the rover from landing day (Sol 0) through Summer Solstice (Sol 197) and out to Sol 204. The rover surface thermal design performance was very close to pre-landing predictions. The very successful thermal design allowed a high level of operational power dissipation immediately after landing without overheating and required a minimal amount of survival heating. Early morning operations of cameras and actuators were aided by successful heating activities. MSL rover surface operations thermal experiences are discussed in this paper. Conclusions about the rover surface operations thermal performance are also presented.

thermal performance↗
NASA NTRS1972

Solar electric low-thrust Mercury orbiter missions.

Results of a preliminary study of unmanned Mercury orbiter missions which might be flown in the early 1980s. Five different levels of orbiter size and complexity are considered, ranging from a small orbiter carrying 22 kg of low data-rate instruments to a dual satellite mission employing 110 kg of science instruments emphasizing regional and local scale surface imagery. An Intermediate-20 class launch vehicle is required to deliver a minimal surface-imaging science package into Mercury orbit using a ballistic mission mode. Employment of a 15 kW solar electric low-thrust stage permits delivery of the more capable dual satellite package with a Titan IIID (5)/Centaur.

Klopp, D. A.↗
NASA NTRSDate not supplied

Future Lunar Missions: the Need for Future Science Observations at the Lunar Surface

In the next few years, several opportunities are underway to take new science observations of the Moon. NASA’s novel Commercial Lunar Payload Services (CLPS) program seeks to acquire delivery services from 14 US companies. Nine funded task orders have been selected with payloads from multiple disciplines. Here we review the upcoming geophysical CLPS payloads and their measurement objectives then we provide a review of the Lunar Geophysical Network mission in development for a future opportunity to fly to the lunar surface.

Moons↗
NASA NTRS2004

Developing an Automated Science Analysis System for Mars Surface Exploration for MSL and Beyond

We are developing an automated science analysis system that could be utilized by robotic or human explorers on Mars (or even in remote locations on Earth) to improve the quality and quantity of science data returned. Three components of this system (our rock, layer, and horizon detectors) [1] have been incorporated into the JPL CLARITY system for possible use by MSL and future Mars robotic missions. Two other components include a multi-spectral image compression (SPEC) algorithm for pancam-type images with multiple filters and image fusion algorithms that identify the in focus regions of individual images in an image focal series [2]. Recently, we have been working to combine image and spectral data, and other knowledge to identify both rocks and minerals. Here we present our progress on developing an igneous rock detection system.

Gulick, V. C.↗
NASA NTRS2023

Validity of the Landsat Surface Reflectance Archive for Aquatic Science: Implications for Cloud-Based Analysis

Originally developed for terrestrial science and applications, the US Geological Survey Landsat surface reflectance (SR) archive spanning ~ 40 yr of observations has been increasingly utilized in large‐scale water‐quality studies. These products, however, have not been rigorously validated using in situ measured reflectance. This letter quantifies and demonstrates the quality of the SR products by harnessing a sizeable global dataset ( N = 1100). We found that the Landsat 8/9 SR in the green and red bands marginally meet the targeted accuracy requirements (30%), whereas the uncertainties in the blue and coastal‐aerosol bands ranged from 48% to 110%. We further observed > +25% biases in the visible bands of Landsat 5/7 SR, which can introduce an apparent downward trend when applied in time‐series analyses combined with Landsat 8/9. Users must exercise caution when using this archive for trend analyses, and progress in atmospheric correction is required to foster advanced applications of the Landsat archive for aquatic science.

Landsat, lakes, harmful algal blooms↗
NASA NTRS1985

Atmospheric and Science Complexity Effects on Surface Bidirectional Reflectance

Among the tools used in passive remote sensing of Earth resources in the visible and near-infrared spectral regions are measurements of spectral signature and bidirectional reflectance functions (BDRFs). Determination of surface properties using these observables is complicated by a number of factors, including: (1) mixing of surface components, such as soil and vegetation, (2) multiple reflections of radiation due to complex geometry, such as in crop canopies, and (3) atmospheric effects. In order to bridge the diversity in these different approaches, there is a need for a fundamental physical understanding of the influence of the various effects and a quantiative measure of their relative importance. In particular, we consider scene complexity effects using the example of reflection by vegetative surfaces. The interaction of sunlight with a crop canopy and interpretation of the spectral and angular dependence of the emergent radiation is basically a multidimensional radiative transfer problem. The complex canopy geometry, underlying soil cover, and presence of diffuse as well as collimated illumination will modify the reflectance characteristics of the canopy relative to those of the individual elements.

Diner, D. J.↗
NASA NTRS2012

Science Operations During Planetary Surface Exploration: Desert-RATS Tests 2009-2011

NASA s Research and Technology Studies (RATS) team evaluates technology, human-robotic systems and extravehicular equipment for use in future human space exploration missions. Tests are conducted in simulated space environments, or analog tests, using prototype instruments, vehicles, and systems. NASA engineers, scientists and technicians from across the country gather annually with representatives from industry and academia to perform the tests. Test scenarios include future missions to near-Earth asteroids (NEA), the moon and Mars.. Mission simulations help determine system requirements for exploring distant locations while developing the technical skills required of the next generation of explorers.

Cohen, Barbara↗
NASA NTRS2010

Principal Components Analysis of Reflectance Spectra from the Mars Exploration Rover Opportunity

In the summer of 2007 a global dust storm on Mars effectively disabled Opportunity's Miniature Thermal Emission Spectrometer (Mini-TES), the primary instrument used by the Athena Science Team to identify locally unique rocks on the Martian surface. The science team needs another way to distinguish interesting rocks from their surroundings on a tactical timescale. This study was designed to develop the ability to identify locally unique rocks on the Martian surface remotely using the Mars Exploration Rovers' Panoramica Camera (PanCam) instrument. Meridiani bedrock observed by Opportunity is largely characterized by sulfate-rich sandstones and hematite spherules. Additionally, loose fragments of bedrock and "cobbles" of foreign origin collet on the surface, some of which are interpreted as meteorites.

Mercer, C. M.↗
NASA NTRS2020

The Earth Surface Mineral Dust Source Investigation: An Earth Science Imaging Spectroscopy Mission

The Earth Surface Mineral Dust Source Investigation, EMIT, is planned to operate from the International Space Station starting no earlier than the fall of 2021. EMIT will use visible to short wavelength infrared imaging spectroscopy to determine the mineral composition of the arid land dust source regions of the Earth to advance our knowledge of the radiative forcing effect of these aerosols. Mineral dust emitted into the atmosphere under high wind conditions is an element of the Earth system with many impacts to the Earth’s energy balance, atmosphere, surface, and oceans. The Earth’s mineral dust cycle with source, transport, and deposition phases are studied with advanced Earth System Models. Because the chemical composition, optical and surface properties of soil particles vary strongly with the mineral composition of the source, these models require knowledge of surface soil mineral dust source composition knowledge to accurately understand dust impacts on the Earth system now and in the future. At present, compositional knowledge of the Earth’s mineral dust source regions from existing data sets is uncertain as a result of limited measurements. EMIT will use spectroscopically derived surface mineral composition to update the prescribe boundary conditions for state-of-the-art Earth System Models. The EMIT-initialized models will be used to investigate the impact of direct radiative forcing in the Earth system that depends strongly on the composition of the mineral dust aerosols emitted into the atmosphere. These new measurements and related products will be used to address the EMIT science objectives and made available to the science community for additional investigations. An overview of the EMIT science, development, and mission is presented in this paper.

Green, Robert O.↗
NASA NTRS2020

Venus Surface Platforms

Significant new science at Venus, particularly related to surface, interior, and surface/atmosphere interactions can be realized with surface platforms performing in-situ measurements. This white paper presents summary results of a Venus Surface Platforms Study performed with VEXAG support. The results suggest long-lived platforms, platforms at several locations taking simultaneous or coordinated measurements. platforms with greater sophistication than currently possible with Venus surface assets, and surface mobility will enable the new science needed per guiding documents such as the Planetary Decadal Survey Report. This white paper summary of the study reports on key relationships between the capabilities noted, the underlying technologies that will enable those capabilities, and the science to be expected with the new capabilities.

Venus↗