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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 181 records · Page 10

Optical Parametric Technology for Methane Measurements

Atmospheric methane (CH4) is the second most important anthropogenic greenhouse gas, with approximately 25 times the radiative forcing of carbon dioxide (CO2) per molecule. Yet, lack of understanding of the processes that control CH4 sources and sinks and its potential release from stored carbon reservoirs contributes significant uncertainty to our knowledge of the interaction between carbon cycle and climate change. At Goddard Space Flight Center (GSFC) we have been developing the technology needed to remotely measure CH4 from orbit. Our concept for a CH4 lidar is a nadir viewing instrument that uses the strong laser echoes from the Earth's surface to measure CH4. The instrument uses a tunable, narrow-frequency light source and photon-sensitive detector to make continuous measurements from orbit, in sunlight and darkness, at all latitudes and can be relatively immune to errors introduced by scattering from clouds and aerosols. Our measurement technique uses Integrated Path Differential Absorption (IPDA), which measures the absorption of laser pulses by a trace gas when tuned to a wavelength coincident with an absorption line. We have already demonstrated ground-based and airborne CH4 detection using Optical Parametric Amplifiers (OPA) at 1651 nm using a laser with approximately 10 microJ/pulse at 5kHz with a narrow linewidth. Next, we will upgrade our OPO system to add several more wavelengths in preparation for our September 2015 airborne campaign, and expect that these upgrades will enable CH4 measurements with 1% precision (10-20 ppb).

oscillator↗

Technology transfer metrics: Measurement and verification of data/reusable launch vehicle business analysis

Congress and the Executive Branch have mandated that all branches of the Federal Government exert a concentrated effort to transfer appropriate government and government contractor-developed technology to the industrial use in the U.S. economy. For many years, NASA has had a formal technology transfer program to transmit information about new technologies developed for space applications into the industrial or commercial sector. Marshall Space Flight Center (MSFC) has been in the forefront of the development of U.S. industrial assistance programs using technologies developed at the Center. During 1992-93, MSFC initiated a technology transfer metrics study. The MSFC study was the first of its kind among the various NASA centers. The metrics study is a continuing process, with periodic updates that reflect on-going technology transfer activities.

Trivoli, George W.↗

Triple-Pulse Integrated Path Differential Absorption Lidar for Carbon Dioxide Measurement - Novel Lidar Technologies and Techniques with Path to Space

The societal benefits of understanding climate change through identification of global carbon dioxide sources and sinks led to the desired NASA's active sensing of carbon dioxide emissions over nights, days, and seasons (ASCENDS) space-based missions of global carbon dioxide measurements. For more than 15 years, NASA Langley Research Center (LaRC) have developed several carbon dioxide active remote sensors using the differential absorption lidar (DIAL) technique operating at the two-micron wavelength. Currently, an airborne two-micron triple-pulse integrated path differential absorption (IPDA) lidar is under development. This IPDA lidar measures carbon dioxide as well as water vapor, the dominant interfering molecule on carbon dioxide remote sensing. Advancement of this triple-pulse IPDA lidar development is presented.

Singh, Upendra N.↗

Recent Advances in Spaceborne Precipitation Radar Measurement Techniques and Technology

NASA is currently developing advanced instrument concepts and technologies for future spaceborne atmospheric radars, with an over-arching objective of making such instruments more capable in supporting future science needs and more cost effective. Two such examples are the Second-Generation Precipitation Radar (PR-2) and the Nexrad-In-Space (NIS). PR-2 is a 14/35-GHz dual-frequency rain radar with a deployable 5-meter, wide-swath scanned membrane antenna, a dual-polarized/dual-frequency receiver, and a realtime digital signal processor. It is intended for Low Earth Orbit (LEO) operations to provide greatly enhanced rainfall profile retrieval accuracy while consuming only a fraction of the mass of the current TRMM Precipitation Radar (PR). NIS is designed to be a 35-GHz Geostationary Earth Orbiting (GEO) radar for providing hourly monitoring of the life cycle of hurricanes and tropical storms. It uses a 35-m, spherical, lightweight membrane antenna and Doppler processing to acquire 3-dimensional information on the intensity and vertical motion of hurricane rainfall.

Nexrad-In-Space (NIS)↗

Application of crossed beam technology to direct measurements of sound sources in turbulent jets, part 1

The mathematical bases for the direct measurement of sound source intensities in turbulent jets using the crossed-beam technique are discussed in detail. It is found that the problems associated with such measurements lie in three main areas: (1) measurement of the correct flow covariance, (2) accounting for retarded time effects in the measurements, and (3) transformation of measurements to a moving frame of reference. The determination of the particular conditions under which these problems can be circumvented is the main goal of the study.

Wilson, L. N.↗

Coherent infrared lidar mission and technology needs for measurements of transport and concentration of tropospheric trace species

The science justification and the feasibility of aircraft-based CO2 Doppler lidar measurements of transport between the free troposphere and the stratosphere (or planetary boundary layer) are discussed for a wide range of seasonal and geographic conditions. Ground-based coherent CO2 lidar aerosol scattering experiments using a stable ring resonator (about 50 mJ/pulse) CO2 laser with external injection locking are reported. Comparative studies of injection-locked CO2 laser unstable resonators and master oscillator power amplifiers are reported for future CO2 lidar missions with respect to requirements of pulse energy, duration/shape, frequency chirp, efficiency for heterodyne detection, and combined Doppler lidar and Differential Absorption Lidar missions.

Hess, R. V.↗

Utilizing Gaps and Key Performance Parameters to Inform NASA Environmental Control and Life Support Capability Technology Decisions

Human spaceflight is a complex endeavor requiring multiple capabilities for transportation, crew health, scientific goals, and safe return to Earth. The difference between spaceflight proven capabilities and those needed for future exploration architectures is defined as a capability gap. Capability gaps are not technology specific. Each capability gap may be closed with a wide array of technologies that have unique benefits and challenges. Determining what a capability’s relevant and distinguishing key performance parameters (KPPs) are for a mission is critical. Mass, power, and volume are always constrained and important, but defining these in a way normalized by performance is very important. KPP definition for reliability, dormancy, and integration needs are hard to define but critical. Outside of technical considerations, the programmatic factors of the estimated time to develop the technology vs when a mission element is also a strong consideration in which technologies should be pursued. The Environmental Control and Life Support (ECLSS) capability areas include: life support, environmental monitoring, fire safety, and logistics. These capability areas are decomposed to high level gaps. While KPPs should be technology agnostic, they can be used to both compare technologies and measure progress of technology development over time. KPPs help define when the gap is closed, and the core mission objectives can be accomplished. Proposed technology improvements to enhance a capability should balance improved KPPs and against investments in other capabilities that are not yet closed. A selection of ECLSS gaps and KPPs and their formulation, current state, and how they inform capability roadmap planning are discussed.

Life Support↗

Early performance of the 12-GHz, 200-watt transmitter experiment package in the communications technology satellite

Measured performance characteristics of the transmitter experiment package (TEP) aboard the Communications Technology Satellite for the first 90 operating days in orbit are presented. The TEP consists of a nominal 200-watt output stage tube (OST), a supporting power processing system (PPS), and a variable-conductance heat pipe system (VCHPS). The OST, a traveling-wave tube augmented with a 10-stage depressed collector, has an overall saturated average efficiency of 51.5 percent and an average saturated radiofrequency (RF) output power at center-band frequency of 240 watts. The PPS operated with a measured efficiency of 86.5 percent to 88.5 percent. The VCHPS, using three pipes to conduct heat from the PPS and the body of the OST to a 52-centimeter by 124-centimeter (20.5-in. by 48.75-in.) radiator fin, maintained by the PPS baseplate temperature below 50 C for all operating conditions. The TEP performance characteristics presented include frequency response, RF output power, efficiency, and distortions. Communications characteristics were evaluated by using both video and audio modulated signals.

Source record↗

Utilizing Gaps and Key Performance Parameters to Inform NASA Environmental Control and Life Support and Human Health and Performance Capability Technology Decisions

Human spaceflight is a complex endeavor requiring a multitude of capabilities for transportation, crew health, scientific goals, and safe return to Earth. The difference between spaceflight proven capabilities and those needed for a particular mission is defined as a capability gap. Capability gaps are not technology specific. Each capability gap is approachable with a wide array of technologies that have unique benefits and challenges. Determining what a capability’s relevant and distinguishing key performance parameters (KPPs) are for a mission is critical. Mass, power, and volume are always constrained and important, but defining these in a way normalized by performance is challenging. Additionally, KPP definition for reliability, dormancy, and integration needs are very important and still evolving. This paper provides the approach of the Environmental Control and Life Support – Crew Health and Performance (ECLSS-CHP) System Capability Leadership Team (SCLT) to defining gaps and KPPs in support of the NASA’s Capabilities Integration Team data call objectives. The nine ECLSS-CHP capability areas are decomposed to capabilities, gaps, and KPPs. Rather than defining very detailed gaps, ECLSS-CHP defines high-level gaps to be technology agnostic. Within a gap, detailed KPPs are defined to both compare technologies and measure progress within a technology over time. Ideally, KPPs are clearly defined, widely communicated both internally and externally, and provide a common nomenclature to describe the state of the art and the degree of improvement required for exploration missions. KPPs help define when the gap is closed and the core mission objectives can be accomplished. Further technology improvements to enhance the capability, as measured by improved KPPs, must then be weighed against investments in open capability gaps that prevent NASA from achieving its exploration missions. It is uncommon that a technology maturation to improve all the relevant KPPs simultaneously but using KPPs is a critical technology investment decision making component. In addition to traditional technology selections, KPPs are informing how investments in ground testing prior to and in parallel with ISS technology demonstrations are required to improve reliability KPPs. The collection of all major technology activities within a capability area are captured on technology roadmaps to communicate how diverse program activities are coordinated to close gaps and infuse into exploration mission needs. A selection of ECLSS-CHP gaps and KPPs and their formulation, current state, and how they inform capability roadmap planning are discussed. The paper will contain a summary of the approximately 60 gaps. Gaps are classified as to their type (architecture, knowledge, technology, developmental, or engineering) depending on the magnitude of the gap. The paper will provide brief overviews of a few major technology challenges and the technologies being considered, but will reference detailed papers for a more thorough treatment of the challenges and state of the art. Data analysis of the gaps is in work and results are not currently available for this abstract. It is anticipated the paper will include examples of select KPPs with descriptions as to why these are the relevant measures. Additionally some KPPs will be graphically presented over time to show progress to date and when performance targets need to be achieved to support exploration missions. Graphical summaries of how gaps closures with near term mission elements support follow-on mission elements will be provided.

Life Support↗

Utilizing Gaps and Key Performance Parameters to Inform NASA Environmental Control and Life Support and Human Health and Performance Capability Technology Decisions

Human spaceflight is a complex endeavor requiring multiple capabilities for transportation, crew health, scientific goals, and safe return to Earth. The difference between spaceflight proven capabilities and those needed for future exploration architectures is defined as a capability gap. Capability gaps are not technology specific. Each capability gap is approachable with a wide array of technologies that have unique benefits and challenges. Determining what a capability’s relevant and distinguishing key performance parameters (KPPs) are for a mission is critical. Mass, power, and volume are always constrained and important, but defining these in a way normalized by performance is challenging. Additionally, KPP definition for reliability, dormancy, and integration needs are very important and still evolving. This paper provides the approach of the Environmental Control and Life Support – Crew Health and Performance (ECLSS-CHP) System Capability Leadership Team (SCLT) has used to define gaps and KPPs in support of the NASA’s Capabilities Integration Team data call objectives. The nine ECLSS-CHP capability areas are decomposed to capabilities with ~76 gaps and supported with KPPs. Rather than defining very detailed gaps, ECLSS-CHP defines high-level gaps to be technology agnostic. Within a gap, detailed KPPs are defined to both compare technologies and measure progress within a technology over time. Ideally, KPPs are clearly defined, widely communicated both internally and externally, and provide a common nomenclature to describe the state of the art and the degree of improvement required for exploration missions. KPPs help define when the gap is closed, and the core mission objectives can be accomplished. Further technology improvements to enhance the capability, as measured by improved KPPs, must then be weighed against investments in open capability gaps that prevent NASA from achieving its exploration missions. It is uncommon that a technology maturation to improve all the relevant KPPs simultaneously but using KPPs is a critical technology investment decision making component. In addition to traditional technology selections, KPPs are informing how investments in ground testing prior to and in parallel with ISS technology demonstrations are required to improve reliability KPPs. The collection of all major technology activities within a capability area are captured on technology roadmaps to communicate how diverse program activities are coordinated to close gaps and infuse into exploration mission needs. A selection of ECLSS-CHP gaps and KPPs and their formulation, current state, and how they inform capability roadmap planning are discussed.

Life Support↗