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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 487 records · Page 27
All sourcesNASA NTRSDOE OSTI
NASA NTRS1987

Auxiliary propulsion system flight package

Hughes Aircraft Company developed qualified and integrated flight, a flight test Ion Auxiliary Propulsion System (IAPS), on an Air Force technology satellite. The IAPS Flight Package consists of two identical Thruster Subsystems and a Diagnostic Subsystem. Each thruster subsystem (TSS) is comprised of an 8-cm ion Thruster-Gimbal-Beam Shield Unit (TGBSU); Power Electronics Unit; Digital Controller and Interface Unit (DCIU); and Propellant Tank, Valve and Feed Unit (PTVFU) plus the requisite cables. The Diagnostic Subsystem (DSS) includes four types of sensors for measuring the effect of the ion thrusters on the spacecraft and the surrounding plasma. Flight qualifications of IAPS, prior to installation on the spacecraft, consisted of performance, vibration and thermal-vacuum testing at the unit level, and thermal-vacuum testing at the subsystem level. Mutual compatibility between IAPS and the host spacecraft was demonstrated during a series of performance and environmental tests after the IAPS Flight Package was installed on the spacecraft. After a spacecraft acoustic test, performance of the ion thrusters was reverified by removing the TGBSUs for a thorough performance test at Hughes Research Laboratories (HRL). The TGBSUs were then reinstalled on the spacecraft. The IAPS Flight Package is ready for flight testing when Shuttle flights are resumed.

Collett, C. R.↗
NASA NTRS2008

Test and Verification Approach for the NASA Constellation Program

This viewgraph presentation is a test and verification approach for the NASA Constellation Program. The contents include: 1) The Vision for Space Exploration: Foundations for Exploration; 2) Constellation Program Fleet of Vehicles; 3) Exploration Roadmap; 4) Constellation Vehicle Approximate Size Comparison; 5) Ares I Elements; 6) Orion Elements; 7) Ares V Elements; 8) Lunar Lander; 9) Map of Constellation content across NASA; 10) CxP T&V Implementation; 11) Challenges in CxP T&V Program; 12) T&V Strategic Emphasis and Key Tenets; 13) CxP T&V Mission & Vision; 14) Constellation Program Organization; 15) Test and Evaluation Organization; 16) CxP Requirements Flowdown; 17) CxP Model Based Systems Engineering Approach; 18) CxP Verification Planning Documents; 19) Environmental Testing; 20) Scope of CxP Verification; 21) CxP Verification - General Process Flow; 22) Avionics and Software Integrated Testing Approach; 23) A-3 Test Stand; 24) Space Power Facility; 25) MEIT and FEIT; 26) Flight Element Integrated Test (FEIT); 27) Multi-Element Integrated Testing (MEIT); 28) Flight Test Driving Principles; and 29) Constellation s Integrated Flight Test Strategy Low Earth Orbit Servicing Capability.

Strong, Edward↗
NASA NTRS2010

Lunar Atmosphere and Dust Environment Explorer Integration and Test

The Lunar Atmosphere and Dust Environment Explorer (LADEE) is a NASA collaborative flight project to explore the lunar exosphere. It is being developed through a unique partnership between NASA's Ames Research Center (ARC) and Goddard Space Flight Center (GSFC). Each center brings its own experience and flight systems heritage to the task of integrating and testing the LADEE subsystems, instruments, and spacecraft. As an "in-house" flight project being implemented at low-cost and moderate risk, LADEE relies on single-string subsystems and protoflight hardware to accomplish its mission. Integration and test (l&T) of the LADEE spacecraft with the instruments will be performed at GSFC, and includes assembly, integration, functional testing, and flight qualification and acceptance testing. Due to the nature of the LADEE mission, l&T requirements include strict contamination control measures and instrument calibration procedures. Environmental testing will include electromagnetic compatibility (EMC), vibro-acoustic testing, and thermal-balance/vacuum. Upon successful completion of spacecraft l&T, LADEE will be launched from NASA's Wallops Flight Facility. Launch of the LADEE spacecraft is currently scheduled for December 2012.

Wright, Michael R.↗
NASA NTRSDate not supplied

S-Band Transponder Multi-Network Compatibility, Space Environment and Radiation Testing

This paper presents the development and testing of the Software Define Radio (SDR) transceiver to meet the emerging needs for SmallSat communication and navigation. Vulcan Wireless and NASA Goddard Space Flight Center (GSFC) collaborated in testing the Vulcan Wireless S-band SDR engineering model. Apart from testing, communication link analysis was performed for a Low Earth Orbit (LEO) 400 km scenario. The results of the compatibility, radiation, environmental testing, and link analysis are presented. Also, this paper reviews a set of SmallSat missions under development at NASA GSFC.

Software Define Radio, transceiver, S-band↗
NASA NTRS2022

Actuator and Motor Control End-to-End V&V on the Mars 2020 Rover

The Mars 2020 Perseverance rover is the most advanced robotic exploration system ever sent to another planet. To support the complex scientific and mobility needs of the mission, the rover utilizes 33 actuators, three multi-degree-of-freedom force-torque sensors, fifteen single or dual-speed resolvers, two solenoid valves, and twelve contact switches. The control for these actuators and sensors is achieved by several levels of flight software, coordinated between two computers with varying bandwidth control loops. Furthermore, the actuators and sensors were integrated into multiple larger robotic mechanisms that were delivered by different organizations at various points in the Integration and Test (I&T) timeline. All of this created a very complex Verification and Validation (V&V) scenario involving multiple subsystems and teams, several hardware and software testbeds with varying levels of fidelity, and significant systems engineering to ensure the overall I&T schedule could be maintained while ensuring system hardware safety.This paper details the integrated V&V effort across multiple teams and venues to provide full coverage of all necessary functionality, performance, and fault protection. First, it provides an overview of how the V&V campaign was subdivided among teams and venues and provides descriptions of the various hardware configurations used to support the testing. The Mars 2020 implementation of the plan incorporates many of the lessons learned from Mars Science Laboratory’s test campaign, and these value-added modifications are discussed here. Also included in this section is the system-level environmental testing approach used for mechanisms. Second, the paper describes the phased approach used by the teams to support new hardware and software deliveries to testbed and Systems I&T. In this approach the test campaign was built upon higher-level mechanism needs for performance, functionality, and safety at specific times in the campaign. Finally, the paper discusses lessons learned from the V&V campaign that should be applied to future large-scale motion control testing efforts.

Borne, Davis↗
NASA NTRS2016

Transient Thermal Analysis of the 12.5 KW HERMeS Hall Thruster

NASA’s Dawn spacecraft entered orbit around the dwarf planet Ceres on March 6, 2015 thereby becoming the first mission to orbit two celestial bodies outside of the Earth-moon system. This feat was made possible due to the use of electric propulsion (EP) to provide the 11 km/s of delta-V that was necessary. This type of propulsion is also enabling for many of NASA’s future missions, such as the proposed Asteroid Redirect Robotic Mission (ARRM). Specifically, the Hall Effect Rocket with Magnetic Shielding (HERMeS) is the propulsive design baseline due to its long operational lifetime and high specific impulse. Extensive modeling is required to verify the thruster's predicted thermal performance and survival during the bounding mission phases. Since the thruster would constrain plasma on the order of tens of thousands of hours, components in the thruster must be able to accommodate much higher sustained temperatures than typical spacecraft hardware. Furthermore, the high temperatures necessitate care in analyzing thermal gradients within the thruster. In this paper, we describe a thermal model of the HERMeS thruster and focus upon the thruster's transient performance under different initial firing conditions. The thruster's transient thermal response is critical to verify margin in the thermal stresses inherent in the thruster and to determine safe start-up procedures to protect the thruster's critical components. This model is used to perform transient thermal analysis of the thruster during startup and shutdown, provide temperature maps for structural analysis, and plan for thermal cycle testing conducted at JPL. The thermal cycle testing includes thruster starts at the cold temperature limits and operation at maximum expected external heat flux. This work will support laboratory environmental testing of the HERMeS thruster, which is being conducted at JPL in 2016.

Reilly, Sean↗
NASA NTRS2019

Lessons Learned from the Flight Unit Testing of the Near Earth Asteroid Scout Flight System

The Near Earth Asteroid Scout flight mission is set to launch on the maiden voyage of the Space Launch System as a secondary payload. The spacecraft will be jettisoned in cis-lunar space and embark on an ambitious 2.5 year mission to image an asteroid. The spacecraft is uniquely equipped with an 85m2 solar sail as the main propulsion system. The monolithic sail system is designed to package within a 6U volume for launch and then deploy during flight. The NEA Scout team has presented in the past to the International Symposium on Solar Sailing topics related to the engineering development unit and design efforts to achieve flight hardware build. This paper will focus on the lessons learned from building and testing the NEA Scout flight system. Focus will be on the mechanical, software, and electrical interfaces as well as preparation for subsystem environmental tests, including thermal vacuum. Due to the unique design of the spacecraft, the solar sail subsystem was required to be located in the center of the spacecraft. This requirement lead to design challenges such as designing and accommodating critical cable harnesses to run through the center of the sail subsystem, packaging and deployment design of the sail subsystem, and integrated testing efforts through an avionics test bed to verify and validate a complete system architecture.

Lockett, Tiffany Russell↗
NASA NTRSDate not supplied

NavCube3-mini Lunar GNSS Receiver

This paper describes development and testing of NASA Goddard Space Flight Center’s new NavCube3-mini (NC3m) spaceborne, weak-signal GNSS receiver, which targets all Earth orbit regimes with special focus on lunar applications. NC3m derives from the ground-breaking Magnetospheric Multiscale (MMS) mission Navigator GPS receiver. The MMS-Navigator (launched 2015) holds a Guinness World Record for highest altitude GPS fix and is currently in a highly elliptic orbit with a 29 Earth radii apogee, nearly half lunar distance. NC3m has reduced size, weight, and power compared to the MMS-Navigator, making it suitable for smallsat applications, and adds multi-frequency and multi-GNSS capabilities, among other improvements. A NC3m engineering test unit was subjected to and successfully completed a comprehensive Technology Readiness Level 6 (system/subsystem model or prototype demonstration in a relevant environment) testing campaign in the second half of 2022. This involved high-fidelity simulations in LEO, GEO, and lunar regimes and full environmental testing, including vibration, thermal vacuum, and electromagnetic compatibility. An overview of the NC3m receiver, the test setup, and a sample of results is presented. The results include predicted performance at high-altitude and in the lunar regime.

NavCube3↗
NASA NTRS1976

Contamination control in hybrid microelectronic modules

Thin and thick film test specimens were utilized to study the effects of silicone and epoxy hybrid microcircuit coatings on 0.025 mm diameter aluminum and gold ultrasonic bonds, and 0.051 diameter gold pulsed-thermocompression bonds. Chip-to-substrate and substrate-to-substrate geometries were included. Because sealed packages were utilized, a test pattern design was incorporated that allowed the determination of bond failures by making resistance measurements external to the package after the various environmental tests. All wire bonds were non-destructively pull tested prior to sealing. Tests included the PIN test, temperature cycling, and high temperature storage.

Himmel, R. P.↗
NASA NTRS1992

Solar extreme ultraviolet sensor and advanced langmuir probe

For more than two decades, the staff of the Space Physics Research Laboratory (SPRL) has collaborated with the Goddard Space Flight Center (GSFC) in the design and implementation of Langmuir probes (LP). This program of probe development under the direction of Larry Brace of GSFC has evolved methodically with innovations to: improve measurement precision, increase the speed of measurement, and reduce the weight, size, power consumption and data rate of the instrument. Under contract NAG5-419 these improvements were implemented and are what characterize the Advanced Langmuir Probe (ALP). Using data from the Langmuir Probe on the Pioneer Venus Orbiter, Brace and Walter Hoegy of GSFC demonstrated a novel method of monitoring the solar extreme ultraviolet (EUV) flux. This led to the idea of developing a sensor similar to a Langmuir probe specifically designed to measure solar EUV (SEUV) that uses a similar electronics package. Under this contract, a combined instrument package of the ALP and SEUV sensor was to be designed, constructed, and laboratory tested. Finally the instrument was to be flight tested as part of sounding rocket experiment to acquire the necessary data to validate this method for possible use in future earth and planetary aeronomy missions. The primary purpose of this contract was to develop the electronics hardware and software for this instrument, since the actual sensors were suppied by GSFC. Due to budget constraints, only a flight model was constructed. These electronics were tested and calibrated in the laboratory, and then the instrument was integrated into the rocket payload at Wallops Flight Facility where it underwent environmental testing. After instrument recalibration at SPRL, the payload was reintegrated and launched from the Poker Flat Research Range near Fairbanks Alaska. The payload was successfully recovered and after refurbishment underwent further testing and developing to improve its performance for future use.

Voronka, N. R.↗
NASA NTRS1974

Rain droplet erosion mechanisms in transparent plastic materials

Tests were conducted to determine the damaging effects of rain erosion on optically transparent materials. The rotating arm test equipment used for the tests is described. Typical transparent materials such as those found in windshields, infrared windows, lasers, and television systems were tested. Nominal velocities of 400, 500, and 600 miles per hour and rainfall conditions of one inch per hour simulated rainfall were used in the tests. It was determined that an 80 percent reduction in laser transmittance can occur in plastics submitted to rain erosion. Significant results of the environmental tests are explained.

Schmitt, G. F., Jr.↗
NASA NTRS1978

Design and fabrication of solar cell modules

A program conducted for design, fabrication and evaluation of twelve silicon solar cell modules is described. The purpose of the program was to develop a module design consistent with the requirements and objectives of JPL specification and to also incorporate elements of new technologies under development to meet LSSA Project goals. Module development emphasized preparation of a technically and economically competitive design based upon utilization of ion implanted solar cells and a glass encapsulation system. The modules fabricated, tested and delivered were of nominal 2 X 2 foot dimensions and 20 watt minimum rating. Basic design, design rationale, performance and results of environmental testing are described.

Shaughnessy, T. P.↗
NASA NTRS1992

TQM in a test environment

In response to the changing aerospace economic climate, Martin Marietta Astronautics Group (MMAG) has adopted a Total Quality Management (TQM) philosophy to maintain a competitive edge. TQM emphasizes continuous improvement of processes, motivation to improve from within, cross-functional involvement, people empowerment, customer satisfaction, and modern process control techniques. The four major initiatives of TQM are Product Excellence, Manufacturing Resource Planning (MRP II), People Empowerment, and Subcontract Management. The Defense Space and Communications (DS&C) Test Lab's definition and implementation of the MRP II and people empowerment initiatives within TQM are discussed. The application of MRP II to environmental test planning and operations processes required a new and innovative approach. In an 18 month span, the test labs implemented MRP II and people empowerment and achieved a Class 'A' operational status. This resulted in numerous benefits, both tangible and intangible, including significant cost savings and improved quality of life. A detailed description of the implementation process and results are addressed.

Chambers, Gary D.↗
NASA NTRS2017

NASA's Advanced Solar Sail Propulsion System for Low-Cost Deep Space Exploration and Science Missions that Use High Performance Rollable Composite Booms

Several low-cost solar sail technology demonstrator missions are under development in the United States. However, the mass saving derived benefits that composites can offer to such a mass critical spacecraft architecture have not been realized yet. This is due to the lack of suitable composite booms that can fit inside CubeSat platforms and ultimately be readily scalable to much larger sizes, where they can fully optimize their use. With this aim, a new effort focused at developing scalable rollable composite booms for solar sails and other deployable structures has begun. Seven meter booms used to deploy a 90 m2 class solar sail that can fit inside a 6U CubeSat have already been developed. The NASA road map to low-cost solar sail capability demonstration envisioned, consists of increasing the size of these composite booms to enable sailcrafts with a reflective area of up to 2000 m2 housed aboard small satellite platforms. This paper presents a solar sail system initially conceived to serve as a risk reduction alternative to Near Earth Asteroid (NEA) Scout's baseline design but that has recently been slightly redesigned and proposed for follow-on missions. The features of the booms and various deployment mechanisms for the booms and sail, as well as ground support equipment used during testing, are introduced. The results of structural analyses predict the performance of the system under microgravity conditions. Finally, the results of the functional and environmental testing campaign carried out are shown.

Fernandez, Juan M.↗
DOE OSTI2024

Saccharomycotina yeasts defy long-standing macroecological patterns

The Saccharomycotina yeasts (“yeasts” hereafter) are a fungal clade of scientific, economic, and medical significance. Yeasts are highly ecologically diverse, found across a broad range of environments in every biome and continent on earth; however, little is known about what rules govern the macroecology of yeast species and their range limits in the wild. Here, we trained machine learning models on 12,816 terrestrial occurrence records and 96 environmental variables to infer global distribution maps at ~1 km2 resolution for 186 yeast species (~15% of described species from 75% of orders) and to test environmental drivers of yeast biogeography and macroecology. We found that predicted yeast diversity hotspots occur in mixed montane forests in temperate climates. Diversity in vegetation type and topography were some of the greatest predictors of yeast species richness, suggesting that microhabitats and environmental clines are key to yeast diversity. We further found that range limits in yeasts are significantly influenced by carbon niche breadth and range overlap with other yeast species, with carbon specialists and species in high-diversity environments exhibiting reduced geographic ranges. Finally, yeasts contravene many long-standing macroecological principles, including the latitudinal diversity gradient, temperature-dependent species richness, and a positive relationship between latitude and range size (Rapoport’s rule). These results unveil how the environment governs the global diversity and distribution of species in the yeast subphylum. These high-resolution models of yeast species distributions will facilitate the prediction of economically relevant and emerging pathogenic species under current and future climate scenarios.

59 BASIC BIOLOGICAL SCIENCES↗
NASA NTRS1974

The standardized functional support sectional for the Small Astronomy Satellite (SAS)

The standardized functional support section for the improved Small Astronomy Satellite (SAS) spacecraft, which can be used virtually without change for a wide variety of experimental packages and missions, is described. This functional support section makes the spacecraft remarkably flexible for a small satellite. Able to point its thrust axis to any direction in space, it can also spin or slow its outer body rotation to zero for star- or earth-locked pointing of side-viewing experiments. It features a reprogrammable telemetry system, a delayed command system, and an improved control system. Experiments can be built independently and attached to the SAS spacecraft just prior to final acceptance testing and launch. The spacecraft subsystems are described in detail. Included are a summary of the spacecraft characteristics, special design considerations, project reliability requirements, and environmental test conditions. It is intended that this new functional support section afford virtual off-the-shelf availability of the SAS spacecraft to independently built experiments, thus providing quick response time and minimum cost in meeting a wide variety of experimenter needs.

Townsend, M. R.↗
NASA NTRSDate not supplied

RST Optical Telescope Integration and Test Preparation

The OTA for the Nancy Grace Roman Space Telescope includes the primary mirror, secondary mirror, and aft optics for guiding light into the Wide Field Instrument and the Coronagraph Instrument. The telescope is taking shape as the tested optical mirror assemblies are integrated. The assemblies have been thermal cycled to the cold temperatures for infrared operation, load tested to launch loads, vibration tested, and optically tested. Testing included launch-level vibration testing of the 2.4-meter light-weighted primary mirror assembly. In addition, the telescope control electronics (TCE) box has been fully assembled and the environmental testing of the TCE is progressing. Pictures and descriptions of the integration and test progress are provided, along with performance results measured at these levels of assemblies. Planning and test equipment preparation for the telescope thermal vacuum testing continues including plans to take advantage of the large dynamic range available with focus diversity phase retrieval and a Shack-Hartmann wavefront sensor for the gravity-sagged primary mirror.

Tony L Whitman↗