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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 73 records · Page 4
All sourcesNASA NTRSDOE OSTI
NASA NTRS2015

Advanced UVOIR Mirror Technology Development for Very Large Space Telescopes

The Advanced Mirror Technology Development (AMTD) project is in phase 2 of a multiyear effort, initiated in FY 2012. This effort is to mature, by at least a half Technology Readiness Level step, the critical technologies required to enable 4-meter or larger ultraviolet, optical, and infrared (UVOIR) space telescope primary mirror assemblies for both general astrophysics and ultra-high contrast observations of exoplanets. AMTD continues to achieve all of its goals and has accomplished all of its milestones to date. This has been achieved by assembling an outstanding team from academia, industry, and government with extensive expertise in astrophysics and exoplanet characterization, and in the design/manufacture of monolithic and segmented space telescopes; by deriving engineering specifications for advanced normal-incidence mirror systems needed to make the required science measurements; and by defining and prioritizing the most important technical problems to be solved. Our results have been presented to the CoPAG and Mirror Tech Days 2013, and proceedings papers of the 2013 and 2014 SPIE Optics & Photonics Symposia have been published.

Effinger, Mike↗
NASA NTRS2016

Surgical Capabilities for Exploration and Colonization Space Flight - An Exploration Symposium

Surgical capabilities in human space flight, whether on a space-based platform in low Earth orbit or on a long duration planetary exploration mission, will be challenging to conduct for a variety of reasons, some of which will be ameliorated by training, technology, and pre-flight planning. Nevertheless, inherent risks and challenges remain. Early space missions did not have any surgical capability. It was not until NASA's Skylab mission that serious consideration was given to this fundamental medical care capability. Over the past 30 years, subject matter experts have been brought together for discussion on the myriad of challenges and opportunities in this endeavor. The last such meeting was held in 2005 at the NASA Johnson Space Center. As we continue to move forward with human space flight activities for the International Space Station and beyond, the capabilities of information technology, robotics, sensors and imaging have rapidly changed since the last gathering of expertise. In December 2015, through sponsorship of the National Space Biomedical Research Institute (NSBRI), a diverse group of individuals from government, academia, and industry representing three countries gathered at the NSBRI Space 4 Biomedicine facility in Houston, TX. This two day symposia included comprehensive sessions that addressed the challenges that we all face in developing, deploying, and utilizing surgical care capabilities in all human space missions, regardless of mission duration or profile. The symposium benefited from the knowledge and experience of three seasoned NASA physician astronauts, Drs. Jay Buckey, Thomas Marshburn, and Lee Morin. At the end of the first day, the assembled group heard from the crew members about their experiences and their ideas. It is clear that the discussion of surgical capabilities is part of the larger discussion of consideration of advanced healthcare, including critical care, on exploration space missions. This report represents the culmination of the symposium, capturing knowledge, experience, conceptual dialogue, and a narrative that can be used in supporting the development of future programs and potential policy. Each of the presentations that were provided by the guest speakers is included in the appendices. Those presentations that are not included were due to sensitivity of the material or at the request of the speaker. In addition, each speaker was offered an opportunity to provide comments in a 'lightning round' format. All of these comments and speaker abstracts also appear in the appendices. At the conclusion of the second day, a discussion was held that reviewed the priorities that perhaps add value to decision makers. These are also summarized. This report will serve as the final product of this symposium. Additional material may be produced for the peer-reviewed literature.

Doarn, Charles R.↗
NASA NTRS2018

Testing and Maturing a Mass Translating Mechanism for a Deep Space CubeSat

Near Earth Asteroid (NEA) Scout is a deep space satellite set to launch aboard NASA’s Exploration Mission 1. The spacecraft fits within a CubeSat standard 6U (about 300 x 200 x 100 mm) and is designed to travel 1 AU over a 2.5 year mission to observe NEA VG 1991. The spacecraft will use an 86 square meter solar sail to maneuver from lunar orbit to the NEA. One of the critical mechanisms aboard NEA Scout, the Active Mass Translator (AMT), has gone through rigorous design and test cycles since its conception in July of 2015. The AMT is a two-axis translation table required to balance the spacecraft’s center of mass (CM) and solar sail center of pressure (CP) while also trimming disturbance torque created by off-nominal sail conditions. The AMT has very limited mass and volume requirements, but is still required to deliver a large translation range—about 160 x 68 mm—at sub mm accuracy and precision. The system must accommodate and protect a shielded wire harness and coax cables during translation. Lastly, the system has been constrained to operate in complete exposure to space with limited power and data budgets for mechanical and thermal needs. The NEA Scout team has developed and carried out a rigorous test suite for the prototype and engineering development unit (EDU). These tests uncovered numerous design failures and led to many failure investigations and iteration cycles. This paper will site each discovery and discuss at length the most surprising and difficult failures to date as the NEA Scout AMT moved through functional, random vibration, thermal vacuum, harnessing, and design life verification testing. A paper was previously presented at the 43rd Aerospace Mechanisms Symposia entitled, “Development of a High Performance, Low Profile Translation Table with Wire Feedthrough for a Deep Space CubeSat”. This paper will make note of specific lessons learned from the test activities: testing ideologies for high-risk missions, thermal mitigation design for small mechanisms, non-flight qualified stepper motor accommodation, harnessing volume allocation/design, and ground testing of mechanisms developed for zero-g environments.

Few, Alex↗
NASA NTRS2018

Testing and Development of NEA Scout Solar Sail Deployer Mechanism

The Near Earth Asteroid (NEA) [1] Scout is a deep space CubeSat designed to use an 86 m2 solar sail to navigate to a near earth asteroid called VG 1991. The solar sail deployment mechanism aboard NEA Scout has gone through numerous design cycles and ground tests since its conception in 2014. An engineering development unit (EDU) was constructed in the spring of 2016 and since then, the NEA Scout team has completed numerous ground deployments aiming to mature the deployment system and the ground test methods used to validate that system. Testing a large, non-rigid gossamer system in 1G environments has presented its difficulties to numerous solar sailing programs before, but NEA Scout's size, sail configuration, and budget has led the team to develop new deployment techniques and uncover new practices while improving their test methods. The program has planned and completed 5 separate full scale sail deployments to date, with a flight sail deployment test scheduled for FY18. The paper entitled "Design and Development of NEA Scout Solar Sail Deployer Mechanism" [2] was presented at the 43rd Aerospace Mechanisms Symposia. Since then, the system has matured and completed ascent vent, random vibration, boom deployment and sail deployment tests. This paper will discuss the lessons learned and advancements made while working on solar sail deployment testing and mechanical redesign cycles.

Few, Alex↗
NASA NTRS2018

Testing and Maturing a Mass Translating Mechanism for a Deep Space CubeSat

Near Earth Asteroid (NEA) Scout is a deep space satellite set to launch aboard NASA's Exploration Mission 1. The spacecraft fits within a CubeSat standard 6U (about 300 x 200 x 100 mm) and is designed to travel 1 AU over a 2.5 year mission to observe NEA VG 1991. The spacecraft will use an 86 sq.m solar sail to maneuver from lunar orbit to the NEA. One of the critical mechanisms aboard NEA Scout, the Active Mass Translator (AMT), has gone through rigorous design and test cycles since its conception in July of 2015. The AMT is a two-axis translation table required to balance the spacecraft's center of mass (CM) and solar sail center of pressure (CP) while also trimming disturbance torque created by off-nominal sail conditions. The AMT has very limited mass and volume requirements, but is still required to deliver a large translation range-about 160 x 68 mm-at sub mm accuracy and precision. The system is constrained to operate in complete exposure to space with limited power and data budgets for mechanical and thermal needs. The NEA Scout team developed and carried out a rigorous test suite for the prototype and engineering development unit (EDU). These tests uncovered numerous design failures and led to many failure investigations and iteration cycles. A paper was previously presented at the 43rd Aerospace Mechanisms Symposia entitled, "Development of a High Performance, Low Profile Translation Table with Wire Feedthrough for a Deep Space CubeSat". This paper will make note of specific lessons learned: manufacturing philosophy, testing ideologies for high-risk missions, thermal mitigation design for small, motor-driven mechanisms.

Few, Alex↗
NASA NTRS2019

ARMD Workshop on Materials and Methods for Rapid Manufacturing for Commercial and Urban Aviation

This report documents the goals, organization and outcomes of the NASA Aeronautics Research Mission Directorate’s (ARMD) Materials and Methods for Rapid Manufacturing for Commercial and Urban Aviation Workshop. The workshop began with a series of plenary presentations by leaders in the field of structures and materials, followed by concurrent symposia focused on forecasting the future of various technologies related to rapid manufacturing of metallic materials and polymeric matrix composites, referred to herein as composites. Shortly after the workshop, questionnaires were sent to key workshop participants from the aerospace industry with requests to rank the importance of a series of potential investment areas identified during the workshop. Outcomes from the workshop and subsequent questionnaires are being used as guidance for NASA investments in this important technology area.

Ransom, Jonathan B.↗
NASA NTRSDate not supplied

rHEALTH Laboratory Analyzer - ISS Increment 66 Tech Demo

A multilateral, web-based symposium, featuring ISS Increment 66 investigations will be held on December 14, 15 and 16, 2021 beginning at 0600 CST each day. The purpose of this event is for Principal Investigators to present their science objectives, testing approach, and measurement methods to agency scientists, managers, and other investigators. Participation is encouraged to gather a global picture of the science planned to be performed on ISS during Increment 66. Please note that only Increment 66 new investigations and those that have not been covered by previous science symposia will be included. We will be in touch with the investigations’ POCs to confirm the presentations and identify the speakers as we develop the preliminary agenda for the Symposium. The agenda and additional details will be distributed prior to the symposium. Presentations will be organized by discipline and will be allotted 15 minutes to highlight the main contributions of their experiment. There will be a short question and answer period after each discipline group session is complete. Please include back-up material as needed. The presentations may be made available to ISS crew members as review material for on-orbit science preparation and/or public outreach activities. Therefore, please ensure a comprehensive presentation (additional back-up material may be provided). The presentations should briefly cover the following: - Science background and hypothesis - Investigation goals and objectives - Measurement approach - Importance and reason for ISS - Expected results and how they will advance the field - Earth benefits/spin-off applications Please note that all presentations and discussions should be limited to content approved for export and information that can be shared with participants and the general public.

Laboratory Analysis↗
DOE OSTI2025

Validation Testing for Molten Chloride Reactor Experiment Equipment Removal and Disposal Techniques

The Molten Chloride Reactor Experiment (MCRE) will be the first reactor featuring a fast-spectrum molten chloride circulating nuclear fuel system in the world. Planning for equipment removal and disposal (ERD) of MCRE has identified several technology gaps due to the unique environment of this nuclear experiment. Some of the gaps arise from the application of existing disassembly and/or sizing methods to novel material forms or in novel configurations. Others arise from unknown material behavior. This paper summarizes proposed test plans for ERD validation experiments to address these complicated or unknown equipment removal procedures. At the Waste Management Symposia in 2024, the Idaho National Laboratory (INL) MCRE ERD team presented the challenges associated with hosting multiple nuclear experiments in series with only brief transition periods between systems. Such difficulties include higher dose rates, the presence of radioisotopes infrequently encountered in reactor decommissioning and radioactive waste management, lack of intrinsic remote-operations infrastructure in the test bed, space constraints in the test bed, and contamination minimization requirements. To address these challenges, remote or semi-remote technologies are planned to be implemented in a non-hot cell environment with limited space availability. The team also discussed how a systems engineering approach is being used for conceptual development and design of equipment removal systems to address these challenges. For example, to reduce constraints for the removal of more difficult components, non-activated, noncontaminated elements are planned to be taken out first where possible. Still, there are complexities associated with the remaining components. In this work, the operational framework for MCRE ERD was reviewed for technical gaps and open questions, and test plans were drafted to address these areas. The tests plans were written for the following categories: vision systems, pipe cutting, drill/grout/filler, flush salt, and miscellaneous, with the miscellaneous group consisting of tests like techniques for removing bearings and reflector bricks. The test plans explore material, infrastructure, and staffing requirements needed for test execution. The test plans additionally focus on the evaluation of success. Determining the outcome of a test is imperative - as these explorative actions have the potential to rearrange or re-scope planned ERD activities. Success criteria identified thus far include required tool output, required area(s), debris production and mitigation, and repeatability. Test plans are an essential aspect of the systems engineering approach to MCRE ERD. They are used as the beginning steps in defining use cases for the ERD system. Performance of the validation tests is expected to begin in the summer of 2025 and will take approximately 9 to 12 months to complete. Execution of these plans will be expedited by specifying test needs ahead of time, facilitating efficient interactions with any subcontractors tasked with running the requested tests. Evaluating the outcomes of these tests will inform MCRE ERD procedures and timing and will also identify additional technical constraints for the MCRE ERD System. This upfront process optimization effort will help the project save time and resources at the end of the experiment.

21 - SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLAN↗
NASA NTRS2004

Daytime Water Detection by Fusing Multiple Cues for Autonomous Off-Road Navigation

Detecting water hazards is a significant challenge to unmanned ground vehicle autonomous off-road navigation. This paper focuses on detecting the presence of water during the daytime using color cameras. A multi-cue approach is taken. Evidence of the presence of water is generated from color, texture, and the detection of reflections in stereo range data. A rule base for fusing water cues was developed by evaluating detection results from an extensive archive of data collection imagery containing water. This software has been implemented into a run-time passive perception subsystem and tested thus far under Linux on a Pentium based processor.

COMPONENT REPORTS↗
NASA NTRS2005

Initial Kernel Timing Using a Simple PIM Performance Model

This presentation will describe some initial results of paper-and-pencil studies of 4 or 5 application kernels applied to a processor-in-memory (PIM) system roughly similar to the Cascade Lightweight Processor (LWP). The application kernels are: * Linked list traversal * Sun of leaf nodes on a tree * Bitonic sort * Vector sum * Gaussian elimination The intent of this work is to guide and validate work on the Cascade project in the areas of compilers, simulators, and languages. We will first discuss the generic PIM structure. Then, we will explain the concepts needed to program a parallel PIM system (locality, threads, parcels). Next, we will present a simple PIM performance model that will be used in the remainder of the presentation. For each kernel, we will then present a set of codes, including codes for a single PIM node, and codes for multiple PIM nodes that move data to threads and move threads to data. These codes are written at a fairly low level, between assembly and C, but much closer to C than to assembly. For each code, we will present some hand-drafted timing forecasts, based on the simple PIM performance model. Finally, we will conclude by discussing what we have learned from this work, including what programming styles seem to work best, from the point-of-view of both expressiveness and performance.

BRIEFING CHARTS↗
NASA NTRS2004

Rapid Protein Separations in Microfluidic Devices

This paper describes fabrication of glass and plastic microfluidic devices for protein separations. Although the long-term goal is to develop a microfluidic device for two-dimensional gel electrophoresis, this paper focuses on the first dimension-isoelectric focusing (IEF). A laser-induced fluorescence (LIF) imaging system has been built for imaging an entire channel in an IEF device. The whole-channel imaging eliminates the need to migrate focused protein bands, which is required if a single-point detector is used. Using the devices and the imaging system, we are able to perform IEF separations of proteins within minutes rather than hours in traditional bench-top instruments.

MICROFLUIDICS↗
NASA NTRS2000

The Effect of Companions on the SIM Reference Frame

The Space Interferometry Mission (SIM) is a 10-m Michelson space-based optical interferometer designed for precision astrometry (4 microarcseconds, 3 microarcseconds/year) with better accuracy than before over a narrow field of view. One of the primary objectives of the SIM instrument is to determine accurately the directions to a grid of stars, together with their proper motions and parallax, improving a priori knowledge by nearly three orders of magnitude over Hipparcos and one order of magnitude over FAME's planned accuracy (Johnston, 2000). The instrument does not measure directly the angular separation between stars, but rather it measures the projection of each star's direction vector onto the interferometer baseline vector by measuring the pathlength delay of starlight as it passes through the two arms of the interferometer. The accuracy and stability of SIM's celestial reference frame is subject to degradation over the 5-year mission from the reflex motion induced by massive companions of the objects used to construct the celestial reference frame. The authors present the results of simulations that show the sensitivity of reference frame accuracy to companions as a function of mass and period. They assume that pre-launch ground surveys will eliminate all objects with RMS radial velocity greater than 10 m/s. They further assume that the standard astrometric parameters of position, parallax, and proper motion plus acceleration terms in right ascension and declination will be allowed to absorb reflex motion.

ASTROMETRY↗
NASA NTRS2000

Observational Model for Precision Astrometry with the Space Interferometry Mission

The Space Interferometry Mission (SIM) is a space-based 10-m baseline Michelson optical interferometer operating in the visible waveband that is designed to achieve astrometric accuracy in the single digits of the microarcsecond domain. Over a narrow field of view SIM is expected to achieve a mission accuracy of 1 microarcsecond. In this mode SIM will search for planetary companions to nearby stars by detecting the astrometric "wobble" relative to a nearby reference star. In its wide-angle mode, SIM will provide 4 microarcsecond precision absolute position measurements of stars, with parallaxes to comparable accuracy, at the end of its 5-year mission. The expected proper motion accuracy is around 3 microarcsecond/year, corresponding to a transverse velocity of 10 m/ s at a distance of 1 kpc. The basic astrometric observable of the SIM instrument is the pathlength delay. This measurement is made by a combination of internal metrology measurements that determine the distance the starlight travels through the two arms of the interferometer, and a measurement of the white light stellar fringe to find the point of equal pathlength. Because this operation requires a non-negligible integration time, the interferometer baseline vector is not stationary over this time period, as its absolute length and orientation are time varying. This paper addresses how the time varying baseline can be "regularized" so that it may act as a single baseline vector for multiple stars, as required for the solution of the astrometric equations.

TILE OBSERVATIONS↗
NASA NTRS2000

Estimation of EOP From VLBI: Direct Approach

The currently adopted strategy of Earth Orientation Parameters (EOP) estimation from Very Long Baseline Interferometry (VLBI) is to estimate six parameters: Universal Time 1 (UT1), UT1 rate, pole positions, and nutation offsets for each 24-hour session independently. Then the resulting time series of raw EOP are filtered and a regression analysis is performed to obtain nutation coefficients, polhode of the pole, and other physical parameters. Thus, the latter parameters are obtained indirectly in two stages. An alternative approach of direct estimation of the final EOP is presented. Pole coordinates and UT1 are considered as a sum of three components: the low-period component that is modeled by a cubic spline, the harmonic component that includes forced nutation, precession and sub-daily variations of EOP, and the stochastic component that is modeled by a linear spline with segment length 1-2 hours. All parameters are obtained in a single LSQ solution using all available data.

POLAR MOTION↗
NASA NTRS2000

Dynamical Reference Frame: Current Relevance and Future Prospects

Planetary and lunar ephemerides are no longer used for the determination of inertial space. Instead, the new fundamental reference frame, the International Celestial Reference Frame (ICRF), is inherently less susceptible to extraneous, non-inertial rotations than a dynamical reference frame determined by the ephemerides would be. Consequently, the ephemerides are now adjusted onto the ICRF, and they are fit to two modern, accurate observational data types: ranging (radar, lunar laser, spacecraft) and Very Long Baseline Interferometry (VLBI) (of spacecraft near planets). The uncertainties remaining in the inner planet ephemerides are on the order of 1 kilometer, both in relative positions between the bodies and in the orientation of the inner system as a whole. The predictive capabilities of the inner planet ephemerides are limited by the uncertainties in the masses of many asteroids. For this reason, future improvements to the ephemerides must await determinations of many asteroid masses. Until then, it will be necessary to constantly update the ephemerides with a continuous supply of observational data.

VLBI (VERY LONG BASELINE INTERFEROMETRY)↗
NASA NTRS2005

Evaluation of Decision Trees for Cloud Detection from AVHRR Data

Automated cloud detection and tracking is an important step in assessing changes in radiation budgets associated with global climate change via remote sensing. Data products based on satellite imagery are available to the scientific community for studying trends in the Earth's atmosphere. The data products include pixel-based cloud masks that assign cloud-cover classifications to pixels. Many cloud-mask algorithms have the form of decision trees. The decision trees employ sequential tests that scientists designed based on empirical astrophysics studies and simulations. Limitations of existing cloud masks restrict our ability to accurately track changes in cloud patterns over time. In a previous study we compared automatically learned decision trees to cloud masks included in Advanced Very High Resolution Radiometer (AVHRR) data products from the year 2000. In this paper we report the replication of the study for five-year data, and for a gold standard based on surface observations performed by scientists at weather stations in the British Islands. For our sample data, the accuracy of automatically learned decision trees was greater than the accuracy of the cloud masks p < 0.001.

AVHRR (ADVANCED VERY HIGH RESOLUTION RADIOMETER)↗