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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 541 records · Page 30
All sourcesNASA NTRSDOE OSTI
NASA NTRS2014

Core Formation and Evolution of Asteroid 4 Vesta

The howardites, eucrites, and diogenites (HEDs) are a suite of related meteorite types that formed by igneous and impact processes on the same parent body. Multiple lines of evidence, including infrared spectroscopy of the asteroid belt and the petrology and geochemistry of the HEDs, suggest that the asteroid 4 Vesta is the parent body for the HEDs. Observations by NASA's Dawn spacecraft mission strongly support the conclusion that the HEDs are from Vesta. The abundances of the moderately siderophile elements Ni, Co, Mo, W, and P in eucrites require that most or all of the metallic phase in Vesta segregated to form a core prior to eucrite solidification. These observations place important constraints on the mode and timescale of core formation on Vesta. Possible core formation mechanisms include porous flow, which potentially could occur prior to initiation of silicate melting, and metallic rain in a largely molten silicate magma ocean. Once the core forms, convection within the core could possible sustain a magnetic dynamo for a period of time. We consider each process in turn.

Kiefer, Walter S.↗
NASA NTRS2015

Experiments on Lunar Core Composition: Phase Equilibrium Analysis of A Multi-Element (Fe-Ni-S-C) System

Previous geochemical and geophysical experiments have proposed the presence of a small, metallic lunar core, but its composition is still being investigated. Knowledge of core composition can have a significant effect on understanding the thermal history of the Moon, the conditions surrounding the liquid-solid or liquid-liquid field, and siderophile element partitioning between mantle and core. However, experiments on complex bulk core compositions are very limited. One limitation comes from numerous studies that have only considered two or three element systems such as Fe-S or Fe-C, which do not supply a comprehensive understanding for complex systems such as Fe-Ni-S-Si-C. Recent geophysical data suggests the presence of up to 6% lighter elements. Reassessments of Apollo seismological analyses and samples have also shown the need to acquire more data for a broader range of pressures, temperatures, and compositions. This study considers a complex multi-element system (Fe-Ni-S-C) for a relevant pressure and temperature range to the Moon's core conditions.

Go, B. M.↗
NASA NTRS2014

Dynamic Responses of the Earth's Outer Core to Assimilation of Observed Geomagnetic Secular Variation

Assimilation of surface geomagnetic observations and geodynamo models has advanced very quickly in recent years. However, compared to advanced data assimilation systems in meteorology, geomagnetic data assimilation (GDAS) is still in an early stage. Among many challenges ranging from data to models is the disparity between the short observation records and the long time scales of the core dynamics. To better utilize available observational information, we have made an effort in this study to directly assimilate the Gauss coefficients of both the core field and its secular variation (SV) obtained via global geomagnetic field modeling, aiming at understanding the dynamical responses of the core fluid to these additional observational constraints. Our studies show that the SV assimilation helps significantly to shorten the dynamo model spin-up process. The flow beneath the core-mantle boundary (CMB) responds significantly to the observed field and its SV. The strongest responses occur in the relatively small scale flow (of the degrees L is approx. 30 in spherical harmonic expansions). This part of the flow includes the axisymmetric toroidal flow (of order m = 0) and non-axisymmetric poloidal flow with m (is) greater than 5. These responses can be used to better understand the core flow and, in particular, to improve accuracies of predicting geomagnetic variability in future.

secular variation↗
NASA NTRS2016

Hydrophilic-Core Microcapsules and Their Formation

Hydrophilic-core microcapsules and methods of their formation are provided. A hydrophilic-core microcapsule may include a shell that encapsulates water with the core substance dissolved or dispersed therein. The hydrophilic-core microcapsules may be formed from an emulsion having hydrophilic-phase droplets dispersed in a hydrophobic phase, with shell-forming compound contained in the hydrophilic phase or the hydrophobic phase and the core substance contained in the hydrophilic phase. The shells of the microcapsules may be capable of being broken down in response to being contacted by an alkali, e.g., produced during corrosion, contacting the shell.

Calle, Luz M.↗
NASA NTRS2016

Hydrophobic-Core Microcapsules and Their Formation

Hydrophobic-core microcapsules and methods of their formation are provided. A hydrophobic-core microcapsule may include a shell that encapsulates a hydrophobic substance with a core substance, such as dye, corrosion indicator, corrosion inhibitor, and/or healing agent, dissolved or dispersed therein. The hydrophobic-core microcapsules may be formed from an emulsion having hydrophobic-phase droplets, e.g., containing the core substance and shell-forming compound, dispersed in a hydrophilic phase. The shells of the microcapsules may be capable of being broken down in response to being contacted by an alkali, e.g., produced during corrosion, contacting the shell.

Calle, Luz M.↗
NASA NTRS2017

A Numerical Study on the Edgewise Compression Strength of Sandwich Structures with Facesheet-Core Disbonds

Damage tolerant design approaches require determination of critical damage modes and flaw sizes in order to establish nondestructive evaluation detection requirements. A finite element model is developed to assess the effect of circular facesheet-core disbonds on the strength of sandwich specimens subjected to edgewise compressive loads for the purpose of predicting the critical flaw size for a variety of design parameters. Postbuckling analyses are conducted in which an initial imperfection is seeded using results from a linear buckling analysis. Both the virtual crack closure technique (VCCT) and cohesive elements are considered for modeling disbond growth. Predictions from analyses using the VCCT and analyses using cohesive elements are in good correlation. A series of parametric analyses are conducted to investigate the effect of core thickness and material, facesheet layup, facesheet-core interface properties, and curvature on the criticality of facesheet-core disbonds of various sizes. The results from these analyses provide a basis for determining the critical flaw size for facesheet-core disbonds subjected to edgewise compression loads and, therefore, nondestructive evaluation flaw detection requirements for this configuration.

Bergan, Andrew C.↗
NASA NTRS2017

Examining the Possibility of Carbon as a Light Element in the Core of Mercury

Results from the MErcury Surface, Space ENvironment, GEochemistry and Ranging (MESSENGER) spacecraft have shown elevated abundances of C on the surface of Mercury. Peplowski et al. used GRS data from MESSENGER to show an average northern hemisphere abundance of C on the planet of 0 to 4.1 wt% C at the three-sigma detection limit. Confirmation of C on the planet prompts many questions regarding the role of C during the differentiation and evolution of Mercury. The elevated abundances of both S and C on Mercury's surface, coupled with the low abundances of iron, suggest that the oxygen fugacity of the planet is several log10 units below the Iron-Wustite buffer. These observations spark questions about the bulk composition of Mercury's core. This experimental study seeks to understand the impact of C as a light element on potential mercurian core compositions. In order to address this question, experiments were conducted at 1 GPa and a variety of temperatures (700 - 1500 C) on metal compositions ranging from Si5Fe95 to Si22Fe78, possibly representative of the mercurian core. All starting metals were completely enclosed in a graphite capsule to ensure C saturation at a given set of run conditions. All elements, including C, were analyzed using electron probe microanalysis. Precautions were taken to ensure accurate measurements of C with this technique including using the LDE2 crystal, the cold finger on the microprobe to minimize contamination and increase the vacuum, and an instrument with no oil based pumps. Based on the superliquidus experimental results in the present study, as Fe-rich cores become more Si-rich, the C content of that core composition will decrease. Furthermore, although C concentration at graphite saturation (CCGS) varies from a liquid to a solid, temperature does not seem to play a substantial role in CCGS, at least at 1 GPa.

Vander Kaaden, Kathleen↗
NASA NTRS2020

Investigating Local Buckling and Plastic Collapse in Multifunctional Sandwich Composite Cores using a Unit Cell Method

The primary goal of developing analytical models of composite sandwich cores has been to obtain simple expressions for elastic and failure response to improve the rapid analysis of composite structures. An earlier investigation by the authors was made to verify the accuracy of widely-used analytical models that calculate equivalent elastic moduli of a uniform homogeneous single layer of material in place of the complex honeycomb core properties in sandwich composites. This transformation of elastic properties permits a coarsening of the finite element model (FEM) of the core to a fraction of the computational cost in simulating the original complex core architecture. In addition, the core was assumed constructed of multi-layered isotropic walls to support potential additional functionality beyond simple load-carrying capability.

Erik Saether↗
NASA NTRS2021

Modeling and Analysis of Fluted-Core Composite Structures for Aerospace Applications

Fiber-reinforced composites are becoming more frequently used for aerospace applications, and because of mass and stiffness requirements, sandwich composites are often selected where shell-type structures are needed. However, traditional-core sandwich composites can exhibit certain manufacturing and in-service problems that have the potential to be alleviated through the use of other sandwich composite concepts. Fluted-core sandwich composite structures, which consist of integral angled web members with structural radius fillers, or noodles, spaced between laminate face sheets, is one such alternative and is considered herein. Because the noodles can consist of unidirectional fiber and can represent a significant amount of the total fluted-core cross section, accurate prediction of the structural response requires that the noodles be modeled with sufficient detail. Previous work showed that the structural response of fluted-core sandwich composite structures could be accurately represented with detailed finite element analysis using a combination of solid and shell elements. In these models, solid elements were used to represent the noodles and shell elements were used to represent the webs and faces. However, this previous solid-noodle modeling approach was also quite computationally intensive, and therefore not practical for large or complicated structures. In this document, a less computationally intensive shell-noodle approach, wherein the entire fluted-core sandwich composite construction is modeled with shell elements, is discussed and predicted structural responses are compared with those of the solid-noodle approach. It is found that by proper selection of certain geometric parameters (thickness and offset of the shell elements that represent the noodle), the shell-noodle modeling approach can be made “structurally equivalent” to the solid-noodle modelling approach.

Leonard Oremont↗
NASA NTRS2021

Experimental and Analytical Characterization of Fluted-Core Sandwich Composite Structures

As composite materials continue to gain wider acceptance for aerospace primary structures, experimental characterization and analysis methods must evolve, especially if new or underutilized composite structural concepts are to be successfully implemented. One such potentially underutilized concept is the fluted-core sandwich composite, which consists of facesheets separated by angled web members, and has a number of potential advantages over traditional-core (honeycomb, foam, etc.) sandwich composites. However, fluted-core sandwich composites also exhibit a behaviors not seen with traditional-core sandwich composites. For example, stable local buckling that can lead to material failure can occur in the facesheets between webs or in the webs themselves. Additionally, in the direction perpendicular to the webs, the effective transverse-shear stiffness is largely determined by the bending stiffnesses of the facesheets and the webs and is generally much lower than in the direction parallel to the webs. These local buckling and transverse-shear behaviors can have a large influence on material failure and global buckling, respectively. Thus, it is important to accurately characterize and model these behaviors. In this report, a series of experiments designed to elicit some of these fluted-core sandwich composite structural responses is discussed and the results are compared with results from a previously developed finite element analysis approach; qualitative and quantitative agreement between the experiment and analysis is shown.

Marc R. Schultz↗
NASA NTRS2021

Compression After Impact Strength Comparison of Rohacell Foam and Aluminum Honeycomb Core Sandwich Structure

This Technical Memorandum is a follow-on study to a previous one1 that examined the compression after impact (CAI) strength of carbon fiber sandwich structure with aluminum honeycomb core and Rohacell foam core with barely visible impact damage (BVID). In this current study a wider range of impact energies were utilized and the CAI strength assessed with these different damage severity levels. This was done to provide a more complete database for the two types of sandwich structure tested in these studies. In addition, the honeycomb sandwich specimens were tested with both the ‘L’ and ‘W’ directions aligned with the axis of compression loading. As in the study examining CAI strength with BVID1, the results were normalized by the mass of the sandwich structure. The results showed that the CAI strength did differ depending on the orientation of the core during testing and that when tested in the W-direction, the honeycomb core sandwich structure had about the same CAI strength as the foam core sandwich structure when normalized by the mass of the sandwich structures.

Sandwich Structure↗
NASA NTRSDate not supplied

Core Stage TVC Systems Engineering Challenges in Reusing Heritage Hardware

The Space Launch System (SLS) Core Stage (CS) Thrust Vector Control (TVC) system is comprised of 8 mechanical feedback Shuttle heritage Type III TVC actuators and four RS-25 engines, each attached to a Shuttle heritage gimbal block/bearing. Two actuators are used to move each engine in two planes perpendicular to one another (i.e., pitch and yaw). The TVC system design leverages hardware from the Space Shuttle program as well as new hardware designed specifically for the Core Stage. The Space Shuttle heritage hardware directly reused on SLS includes the Orbiter TVC hydraulic servo-actuators (with two slight design modifications), the Orbiter hydraulic circulation pumps, the Orbiter gimbal block/bearing, and the Solid Rocket Booster hydraulic pumps. The Core Auxiliary Power Unit (CAPU) is derived from the Orbiter Auxiliary Power Unit (APU). The Orbiter and Solid Rocket Booster APU turbines are powered by hot gas produced by catalyzed hydrazine decomposition. On the SLS Core Stage, the CAPU turbine is spun using cold gas tapped-off from the RS-25 to CS liquid hydrogen autogenous pressurization line. While direct reuse or slight modification of existing hardware may seem to be a triple-win for a program in cost, schedule, and technical risk mitigation, those benefits can only be realized when its degree of application in a new system is carefully and thoughtfully managed. The heritage hardware reuse should be prescribed within the heritage design capability and reuse environments must lie within the envelope of heritage qualification testing. Despite the significant test and flight experience of the Shuttle heritage hardware components, successful integration with the newly designed CS TVC components and incorporation into the stage design proved to be a challenge which required re-qualification of the heritage hardware as well as thorough integrated testing to support flight certification. Examples of the challenges that were overcome include: re-qualifying heritage hardware to survive new shock and vibration environments, certifying performance of extensively modified heritage hardware, regenerating design insight due to lack of available heritage vendor data, showing compliance to modern structural design standards, translation of heritage requirements for analog avionics to modern digital avionics, and interfacing heritage mechanical hardware with newly designed avionics. This paper is the second installment in a seven-paper series surveying the design, engineering, test validation, and flight performance of the Core Stage Thrust Vector Control system. This paper will discuss several engineering challenges encountered during the development process for SLS CS TVC and how they were successfully overcome to reach flight readiness.

Thrust Vector Control↗
NASA NTRSDate not supplied

Overview of the SLS Core Stage Thrust Vector Control System Design

The Space Launch System (SLS) Core Stage (CS) Thrust Vector Control (TVC) consists of four independent hydraulic systems. The SLS CS TVC system is comprised of 8 mechanical feedback Shuttle heritage Type III TVC actuators and four RS-25 engines, each attached to a Shuttle heritage gimbal block/bearing. Each hydraulic system nominally provides hydraulic power to one RS-25 engine and two actuators. Additionally, each system provides redundant control capability to one actuator on each of its neighboring systems. The RS-25 uses hydraulic power to control propellant valves, and the TVC actuators are used to move the engine in the pitch and yaw gimbal planes. The TVC system design leverages hardware from the Space Shuttle program as well as new hardware designed specifically for the Core Stage. The Space Shuttle heritage hardware directly reused on SLS includes the Orbiter TVC hydraulic servo-actuators (with two slight design modifications), the Orbiter hydraulic circulation pumps, the Orbiter gimbal block/bearing, and the Solid Rocket Booster hydraulic pumps. The Solid Rocket Booster APU turbines are powered by hot gas produced by a catalyzed hydrazine decomposition. The SLS Core Auxiliary Power Unit (CAPU) is derived from the Space Shuttle Orbiter Auxiliary Power Unit (APU); on the SLS Core Stage, the CAPU turbine is spun using cold gas tapped-off from the RS-25 to CS liquid hydrogen autogenous pressurization line. The remaining hardware in the TVC system (hydraulic Filter Manifold (FM), hydraulic Supply Accumulator (SA), hydraulic Return Accumulator (RA), Hydraulic Reservoir, Exhaust Gas Heat Exchanger (EGHE)) as well as the avionics providing control and telemetry (TVC Actuator Controller (TAC) and CAPU Controller (CAPUC) are new components developed for SLS. This paper is the first installment in a seven-paper series surveying the design, engineering, test validation, and flight performance of the Core Stage Thrust Vector Control system. In this paper, the overall design architecture of the CS TVC is presented, with a focus on the interfaces between the TVC actuators, the engines, their hydraulic power systems, and the avionics that provide commands from the SLS Vehicle Management (VM) software to effect stable and robust flight control for the integrated SLS launch vehicle.

Thrust Vector Control↗
NASA NTRSDate not supplied

Overview of the SLS Core Stage Thrust Vector Control System Design

The Space Launch System (SLS) Core Stage (CS) Thrust Vector Control (TVC) consists of four independent hydraulic systems. The SLS CS TVC system is comprised of 8 mechanical feedback Shuttle heritage Type III TVC actuators and four RS-25 engines, each attached to a Shuttle heritage gimbal block/bearing. Each hydraulic system nominally provides hydraulic power to one RS-25 engine and two actuators. Additionally, each system provides redundant control capability to one actuator on each of its neighboring systems. The RS-25 uses hydraulic power to control propellant valves, and the TVC actuators are used to move the engine in the pitch and yaw gimbal planes. The TVC system design leverages hardware from the Space Shuttle program as well as new hardware designed specifically for the Core Stage. The Space Shuttle heritage hardware directly reused on SLS includes the Orbiter TVC hydraulic servo-actuators (with two slight design modifications), the Orbiter hydraulic circulation pumps, the Orbiter gimbal block/bearing, and the Solid Rocket Booster hydraulic pumps. The Solid Rocket Booster APU turbines are powered by hot gas produced by a catalyzed hydrazine decomposition. The SLS Core Auxiliary Power Unit (CAPU) is derived from the Space Shuttle Orbiter Auxiliary Power Unit (APU); on the SLS Core Stage, the CAPU turbine is spun using cold gas tapped-off from the RS-25 to CS liquid hydrogen autogenous pressurization line. The remaining hardware in the TVC system (hydraulic Filter Manifold (FM), hydraulic Supply Accumulator (SA), hydraulic Return Accumulator (RA), Hydraulic Reservoir, Exhaust Gas Heat Exchanger (EGHE)) as well as the avionics providing control and telemetry (TVC Actuator Controller (TAC) and CAPU Controller (CAPUC) are new components developed for SLS. This paper is the first installment in a seven-paper series surveying the design, engineering, test validation, and flight performance of the Core Stage Thrust Vector Control system. In this paper, the overall design architecture of the CS TVC is presented, with a focus on the interfaces between the TVC actuators, the engines, their hydraulic power systems, and the avionics that provide commands from the SLS Vehicle Management (VM) software to effect stable and robust flight control for the integrated SLS launch vehicle.

Thrust Vector Control↗
NASA NTRSDate not supplied

Space Launch System: Core Stage Thrust Vector Control Systems Engineering Challenges in Reusing Heritage Hardware

The Space Launch System (SLS) Core Stage (CS) Thrust Vector Control (TVC) system is comprised of 8 mechanical feedback Shuttle heritage Type III TVC actuators and four RS-25 engines, each attached to a Shuttle heritage gimbal block/bearing. Two actuators are used to move each engine in two planes perpendicular to one another (i.e., pitch and yaw). The TVC system design leverages hardware from the Space Shuttle program as well as new hardware designed specifically for the Core Stage. The Space Shuttle heritage hardware directly reused on SLS includes the Orbiter TVC hydraulic servo-actuators (with two slight design modifications), the Orbiter hydraulic circulation pumps, the Orbiter gimbal block/bearing, and the Solid Rocket Booster hydraulic pumps. The Core Auxiliary Power Unit (CAPU) is derived from the Orbiter Auxiliary Power Unit (APU). The Orbiter and Solid Rocket Booster APU turbines are powered by hot gas produced by catalyzed hydrazine decomposition. On the SLS Core Stage, the CAPU turbine is spun using cold gas tapped-off from the RS-25 to CS liquid hydrogen autogenous pressurization line. While direct reuse or slight modification of existing hardware may seem to be a triple-win for a program in cost, schedule, and technical risk mitigation, those benefits can only be realized when its degree of application in a new system is carefully and thoughtfully managed. The heritage hardware reuse should be prescribed within the heritage design capability and reuse environments must lie within the envelope of heritage qualification testing. Despite the significant test and flight experience of the Shuttle heritage hardware components, successful integration with the newly designed CS TVC components and incorporation into the stage design proved to be a challenge which required re-qualification of the heritage hardware as well as thorough integrated testing to support flight certification. Examples of the challenges that were overcome include: re-qualifying heritage hardware to survive new shock and vibration environments, certifying performance of extensively modified heritage hardware, regenerating design insight due to lack of available heritage vendor data, showing compliance to modern structural design standards, translation of heritage requirements for analog avionics to modern digital avionics, and interfacing heritage mechanical hardware with newly designed avionics. This paper is the second installment in a seven-paper series surveying the design, engineering, test validation, and flight performance of the Core Stage Thrust Vector Control system. This paper will discuss several engineering challenges encountered during the development process for SLS CS TVC and how they were successfully overcome to reach flight readiness.

Thrust Vector Control↗
NASA NTRS2023

Development of Two High-Energy Bus ‘Cores’ for Rapid Support of Low-TRL and Educational Payloads: A Software-Configured EPS Combined with Flexible C&DH

For several years the TechEdSat flight series (TES-n), developed by the Nano Orbital Workshop (NOW) group at NASA Ames, has relied upon an in-house developed unit to serve both EPS (Electrical Power System) and C&DH (Command and Data Handling) roles along with low data-rate telemetry functions, i.e., serving as the ‘core’ of the spacecraft bus. This ‘core’ has a considerable task given the rapid cadence of the TES program and the typically low-TRL of payloads; configurability and compatibility are key to prevent mission-specific hardware. However, at only 15 watts the current core has become insufficient to support the program’s growing missions and increasingly demanding payloads. To this end, the NOW program is developing new cores to support two TES mission classes: a single-PCB ‘MiniCore’ designed to support 80-watt missions 6U or smaller in LEO, and a three-PCB, radiation-tolerant ‘StackCore’ designed to support 6U and larger missions over 500 watts in LEO and beyond. The ‘MiniCore’ design consists of three main segments: a processor-agnostic C&DH, a software-configured EPS, and a backup low data-rate radio. The design philosophy was to enable rapid-manufacture in a turbulent supply chain, hence the design consists of COTS parts with a focus on those able to be drop-in replaced with radiation-tolerant versions when demanded by the mission. As a single PC-104 sized circuit board, power density and ease of integration also dominated design, demanding the use of modern features such as single-point USB-C for easy charging and monitoring of the spacecraft on the ground. The ‘MiniCore’ can support 80 watts of load, 140 watt-hours of storage, and over 20 watts of optimized solar generation with extensive power monitoring throughout. The ‘MiniCore’ supports one battery pack, six solar-panels, six loads, five actuators, Iridium SBD, and an internal 802.15.4 network. Additionally, the processor-agnostic design can accept any PJRC Teensy 3.x or Adafruit Feather microcontroller unit to enable processor scaling with mission requirements or environment. It is expected a development unit of this design will be completed before conference. The ‘StackCore’ design consists of three stacked PC-104 sized circuit boards: one dedicated to power generation and storage, one dedicated to power distribution, and one dedicated to C&DH tasks. This delineation is necessary to support the transition from highly integrated ICs to discrete analog circuitry, enabling a primarily analog control power system able to operate without software in a radiation environment with finer monitoring compared to the ‘MiniCore’ design. The planned base architecture supports over 500 watts of load, 250 watt-hours of storage, and over 80 watts of optimized solar generation. The power distribution board allows for the use of daughter cards hosting custom converters or interfaces for payloads, in addition to the software-configured supplies used on the ‘MiniCore’. This core stack will be managed by a Vorago ARM M4 microcontroller and support the same wireless communications as the ‘MiniCore’, with optional integration of a NOW S-band radio and attitude determination sensors for ‘black box’ functionality. It is expected the prototype will still be in development during conference.

Spacecraft↗
NASA NTRSDate not supplied

Development of Two High-Energy Bus ‘Cores’ for Rapid Support of Low-TRL and Educational Payloads: A Software-Configured EPS Combined with Flexible C&DH

For several years the TechEdSat flight series (TES-n), developed by the Nano Orbital Workshop (NOW) group at NASA Ames, has relied upon an in-house developed unit to serve both EPS (Electrical Power System) and C&DH (Command and Data Handling) roles along with low data-rate telemetry functions, i.e., serving as the ‘core’ of the spacecraft bus. This ‘core’ has a considerable task given the rapid cadence of the TES program and the typically low-TRL of payloads; configurability and compatibility are key to prevent mission-specific hardware. However, at only 15 watts the current core has become insufficient to support the program’s growing missions and increasingly demanding payloads. To this end, the NOW program is developing new cores to support two TES mission classes: a single-PCB ‘MiniCore’ designed to support 80-watt missions 6U or smaller in LEO, and a three-PCB, radiation-tolerant ‘StackCore’ designed to support 6U and larger missions over 500 watts in LEO and beyond. The ‘MiniCore’ design consists of three main segments: a processor-agnostic C&DH, a software-configured EPS, and a backup low data-rate radio. The design philosophy was to enable rapid-manufacture in a turbulent supply chain, hence the design consists of COTS parts with a focus on those able to be drop-in replaced with radiation-tolerant versions when demanded by the mission. As a single PC-104 sized circuit board, power density and ease of integration also dominated design, demanding the use of modern features such as single-point USB-C for easy charging and monitoring of the spacecraft on the ground. The ‘MiniCore’ can support 80 watts of load, 140 watt-hours of storage, and over 20 watts of optimized solar generation with extensive power monitoring throughout. The ‘MiniCore’ supports one battery pack, six solar-panels, six loads, five actuators, Iridium SBD, and an internal 802.15.4 network. Additionally, the processor-agnostic design can accept any PJRC Teensy 3.x or Adafruit Feather microcontroller unit to enable processor scaling with mission requirements or environment. It is expected a development unit of this design will be completed before conference. The ‘StackCore’ design consists of three stacked PC-104 sized circuit boards: one dedicated to power generation and storage, one dedicated to power distribution, and one dedicated to C&DH tasks. This delineation is necessary to support the transition from highly integrated ICs to discrete analog circuitry, enabling a primarily analog control power system able to operate without software in a radiation environment with finer monitoring compared to the ‘MiniCore’ design. The planned base architecture supports over 500 watts of load, 250 watt-hours of storage, and over 80 watts of optimized solar generation. The power distribution board allows for the use of daughter cards hosting custom converters or interfaces for payloads, in addition to the software-configured supplies used on the ‘MiniCore’. This core stack will be managed by a Vorago ARM M4 microcontroller and support the same wireless communications as the ‘MiniCore’, with optional integration of a NOW S-band radio and attitude determination sensors for ‘black box’ functionality. It is expected the prototype will still be in development during conference.

Spacecraft↗
NASA NTRSDate not supplied

Development of Two High-Energy Bus ‘Cores’

For several years the TechEdSat flight series (TES-n), developed by the Nano Orbital Workshop (NOW) group at NASA Ames, has relied upon an in-house developed unit to serve both EPS (Electrical Power System) and C&DH (Command and Data Handling) roles along with low data-rate telemetry functions, i.e., serving as the ‘core’ of the spacecraft bus. This ‘core’ has a considerable task given the rapid cadence of the TES program and the typically low-TRL of payloads; configurability and compatibility are key to prevent mission-specific hardware. However, at only 15 watts the current core has become insufficient to support the program’s growing missions and increasingly demanding payloads. To this end, the NOW program is developing new cores to support two TES mission classes: a single-PCB ‘MiniCore’ designed to support 80-watt missions 6U or smaller in LEO, and a three-PCB, radiation-tolerant ‘StackCore’ designed to support 6U and larger missions over 500 watts in LEO and beyond. The ‘MiniCore’ design consists of three main segments: a processor-agnostic C&DH, a software-configured EPS, and a backup low data-rate radio. The design philosophy was to enable rapid-manufacture in a turbulent supply chain, hence the design consists of COTS parts with a focus on those able to be drop-in replaced with radiation-tolerant versions when demanded by the mission. As a single PC-104 sized circuit board, power density and ease of integration also dominated design, demanding the use of modern features such as single-point USB-C for easy charging and monitoring of the spacecraft on the ground. The ‘MiniCore’ can support 80 watts of load, 140 watt-hours of storage, and over 20 watts of optimized solar generation with extensive power monitoring throughout. The ‘MiniCore’ supports one battery pack, six solar-panels, six loads, five actuators, Iridium SBD, and an internal 802.15.4 network. Additionally, the processor-agnostic design can accept any PJRC Teensy 3.x or Adafruit Feather microcontroller unit to enable processor scaling with mission requirements or environment. It is expected a development unit of this design will be completed before conference. The ‘StackCore’ design consists of three stacked PC-104 sized circuit boards: one dedicated to power generation and storage, one dedicated to power distribution, and one dedicated to C&DH tasks. This delineation is necessary to support the transition from highly integrated ICs to discrete analog circuitry, enabling a primarily analog control power system able to operate without software in a radiation environment with finer monitoring compared to the ‘MiniCore’ design. The planned base architecture supports over 500 watts of load, 250 watt-hours of storage, and over 80 watts of optimized solar generation. The power distribution board allows for the use of daughter cards hosting custom converters or interfaces for payloads, in addition to the software-configured supplies used on the ‘MiniCore’. This core stack will be managed by a Vorago ARM M4 microcontroller and support the same wireless communications as the ‘MiniCore’, with optional integration of a NOW S-band radio and attitude determination sensors for ‘black box’ functionality. It is expected the prototype will still be in development during conference.

Avery Brock↗