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At least 793 records · Page 44

Modular Standards for Space Power Systems

This presentation presents an approach to provide commonality for future space power systems through a set of modular power standards. The approach presented breaks down the electrical power conversion and distribution system into the lowest level functions, which are represented by power electronics modules, and serve as the foundational building blocks of the system. A series of Modular Power Standards has been developed to define the functions and interfaces of the lowest level of the electrical power system, or for each type of power electronics module. The power electronics modules, when integrated with a common chassis and backplane, can then be built up into modular electronics assemblies, which have been demonstrated and characterized in a relevant ground test environment.

Gardner, Brent G.↗

The Parabolic Deformable Mirror Testbed at NASA Goddard Space Flight Center

One of the primary goals of future coronagraph space missions is to spectrally characterize Earth-like exoplanets. Observing efficiency is critical and directly related to how large of a field of view we can correct and the bandwidth of that correction. In addition to the coronagraph itself, the bandwidth and depth of contrast is related to the wavefront control system, which classically uses two deformable mirrors (DMs) in series. The minimum distance between these DMs is determined by the Talbot distance of the beam, meaning it scales as the square of the beam size. NASA Goddard is exploring an alternative design architecture to the two-DM approach in which the reimaging optics for the coronagraph are also deformable and we only retain a high-order pupil DM. With these off-axis parabolic elements being made deformable, the long propagation distance between the two DMs is eliminated. Goddard has procured an off-axis parabolic DM (PDM or OAP DM) from vendor ALPAO, France. A testbed is currently being built to test the PDM and demonstrate its utility for achieving high contrast in a coronagraph. The testbed is also being built with an integrated low-order wavefront sensing capability, allowing for integrated testing of a dynamic environment with multiple estimation and control loops.

Hari Subedi↗

Evaluating software defined networking solutions to reduce the digital attack surface of nuclear security systems

Most nuclear security systems used today were not designed for today’s threat environment. Systems that were intended to be stand alone are now interconnected. Devices that have a single purpose are built on multi-purpose platforms and communication protocols that, while effective, have no ability to authenticate authorized versus unauthorized commands. These attributes provide an attacker significant ability to affect the system, pivot throughout the interconnected networks, and remain undetected if he/she is able to compromise a single node. Software defined networking (SDN) has been used for years by information technology (IT) cloud service providers to quickly provision or remove servers or other systems to meet changing demand. The same concept has recently been applied to operational technology (OT) systems to enable very fast failover on critical systems that have stringent and deterministic (<5ms) transmit/receive times. By carefully engineering the communication flows through a network using preplanned routes and specific pathways it is possible to achieve deterministic and extremely reliable message delivery even when components fail. This engineering approach to network design has added security benefits including securing the networking control plane, eliminating network scanning and mapping, inhibiting ARP spoofing and host masquerading, eliminating unauthorized network pivoting and enabling greater situational awareness on the network. SDN in OT environments is new but early testing in electrical power and other critical infrastructure has shown it to be a very powerful tool for building reliable networks and reducing the digital attack surface of the network. The authors tested a software defined network switch on a simple physical protection system with components commonly found in nuclear security systems and found improved mitigations to denial of service attacks, lateral movement and network reconnaissance. The paper details the tests and their results.

Cyber security, Nuclear security, software defined↗

Easing the Control System Application Development for CMS Detector Control System with Automatic Production Environment Reproduction

The Detector Control System (DCS) is one of the main pieces involved in the operation of the Compact Muon Solenoid (CMS) experiment at the LHC. The system is built using WinCC Open Architecture (WinCC OA) and the Joint Controls Project (JCOP) framework which was developed on top of WinCC at CERN. Following the JCOP paradigm, CMS has developed its own framework which is structured as a collection of more than 200 individual installable components each providing a different feature. Everyone of the systems that the CMS DCS consists of is created by installing a different set of these components. By automating this process, we are able to quickly and efficiently create new systems in production or recreate problematic ones, but also, to create development environments that are identical to the production ones. This latter one results in smoother development and integration processes, as the new/reworked components are developed and tested in production-like environments. Moreover, it allows the central DCS support team to easily reproduce systems that the users/developers report as being problematic, reducing the response time for bug fixing and improving the support quality.

43 PARTICLE ACCELERATORS↗

Polyglot Framework

Polyglot utilizes a combination of custom and open source tools and libraries to provide developers with a consistent environment for building tools, etc. for a wide variety of targets with minimal changes to the code being built. It supports a variety of architectures and operating systems/firmware in as target-agnostic way as possible. This allows for developers to minimize the amount of time/effort required to port tools—in particular, forensic tools—to a wide variety of targets. The project is comprised of two main components: a frontend toolchain that understands how to utilize other tools in order to build code for a specific target, and a minimalistic C library specific to Polyglot. These collectively provide the method to build code for a specific target, and the capability for code to interact with the underlying operating system when run on the target. Both components are written in a way to minimize the amount of target-specific knowledge required to both develop and utilize the project.

Huddleston, TimothyA.↗

Polyglot C Library

The C library component of Polyglot. Polyglot utilizes a combination of custom and open source tools and libraries to provide developers with a consistent environment for building tools, etc. for a wide variety of targets with minimal changes to the code being built. It supports a variety of architectures and operating systems/firmware in as target-agnostic way as possible. This allows for developers to minimize the amount of time/effort required to port tools-in particular, forensic tools-to a wide variety of targets. The project is comprised of two main components: a frontend toolchain that understands how to utilize other tools in order to build code for a specific target, and a minimalistic C library specific to Polyglot. These collectively provide the method to build code for a specific target, and the capability for code to interact with the underlying operating system when run on the target. Both components are written in a way to minimize the amount of target-specific knowledge required to both develop and utilize the project.

Huddleston, TimothyA.↗

Generation of graphite particles by sliding abrasion and their characterization

Characterization of graphite particles (dust) produced by abrasion that would occur in a pebble bed reactor is of interest for reasons of safety, operation, and maintenance. To better understand this abrasion and particle generation, we have built a test apparatus to produce particles by sliding abrasion in a 1% to 5% relative humidity air environment. We have used a commercial-grade graphite in our experiments and have generated size distributions for the abraded particles. We have also fit lognormal functions to those size distributions (for use in computer codes); determined particle shapes; measured temperature and humidity during the tests; measured and calculated wear rates; and measured the surface roughness of both pretest and posttest samples, particle surface areas, pore volumes, and pore volume distributions of particles produced during abrasion of graphite surfaces under different loadings and sliding speeds. The experiments showed that as loading (analogous to pebble depth in the reactor) and sliding speed increase, so do the wear rates and numbers of particles produced, while surface roughness decreases, increases, and then decreases. Brunauer-Emmett-Teller measurements show that abrasion increases surface area from 0.583 m 2 /g in the bulk material to 555 m 2 /g in material abraded at high loading and high sliding speed. Wear rates range from 0.005 to 0.991 g/m per contact site. As a result, the size of the particles observed was <4000 nm. Finally, in all, our research shows that pebble abrasion is a complex process that is not constant during operation and thus should be considered for future work.

36 MATERIALS SCIENCE↗

Who watches the watchers?: preventing fault in a fault tolerance library

The Scalable Checkpoint/Restart library (SCR) was developed and is used by researchers at Lawrence Livermore National Laboratory to provide a fast and efficient method of saving and recovering large applications during runtime on high-performance computing (HPC) systems. Though SCR protects other programs, up until June 2017, nothing was actively protecting SCR. The goal of this project was to automate the building and testing of this library on the varying HPC architectures on which it is used. Our methods centered around the use of a continuous integration tool called Bamboo that allowed for automation agents to be installed on the HPC systems themselves. These agents provided a way for us to establish a new and unique way to automate and customize the allocation of resources and running of tests with CMake’s unit testing framework, CTest, as well as integration testing scripts though an HPC package manager called Spack. These methods provided a parallel environment in which to test the more complex features of SCR. As a result, SCR is now automatically built and tested on several HPC architectures any time changes are made by developers to the library’s source code. The results of these tests are then communicated back to the developers for immediate feedback, allowing them to fix functionality of SCR that may have broken. Hours of developers’ time are now being saved from the tedious process of manually testing and debugging, which saves money and allows the SCR project team to focus their efforts towards development. Thus, HPC system users can use SCR in conjunction with their own applications to efficiently and effectively checkpoint and restart as needed with the assurance that SCR itself is functioning properly.

97 MATHEMATICS AND COMPUTING↗

Component-specific modeling

The ability to accurately structurally analyze engine components to assure that they can survive for their designed lifetime in an increasingly harsh environment is discussed. Under the HOST (HOt Section Technology) program, advanced component-specific modeling methods, with built-in analysis capability, will be developed separately for burner liners, turbine blades and vanes. These modeling methods will make maximum use of, but will not rely solely on, existing analysis methods and techniques, to analyze the three identified components. Nor will the complete structural analysis of a component necessarily be performed as a single analysis. The approach to be taken will develop complete software analysis packages with internal, component-specific, self-adaptive solution strategies. Each package will contain a set of modeling and analysis tools. The selection and order of specific methods and techniques within the set to be applied will depend on the specific-component, the current thermo-mechanical loading, and the current state of the component. All modeling and analysis decisions will be made internally based on developed decision criteria within the solution strategies; minimal user intervention will be required.

Hirschbein, M. S.↗

A unified teleoperated-autonomous dual-arm robotic system

A description is given of complete robot control facility built as part of a NASA telerobotics program to develop a state-of-the-art robot control environment for performing experiments in the repair and assembly of spacelike hardware to gain practical knowledge of such work and to improve the associated technology. The basic architecture of the manipulator control subsystem is presented. The multiarm Robot Control C Library (RCCL), a key software component of the system, is described, along with its implementation on a Sun-4 computer. The system's simulation capability is also described, and the teleoperation and shared control features are explained.

Hayati, Samad↗

Nikon Camera

Nikon FM compact has simplification feature derived from cameras designed for easy, yet accurate use in a weightless environment. Innovation is a plastic-cushioned advance lever which advances the film and simultaneously switches on a built in light meter. With a turn of the lens aperture ring, a glowing signal in viewfinder confirms correct exposure.

Source record↗

Wheel Abrasion Experiment Conducted on Mars

Sojourner rover showing Lewis' wheel abrasion experiment. The Mars Pathfinder spacecraft soft-landed on Mars on July 4, 1997. Among the many experiments on its small Sojourner rover are three technology experiments from the NASA Lewis Research Center, including the Wheel Abrasion Experiment (WAE). The WAE was designed, built, delivered, and operated on Mars by a team of engineers and scientists from Lewis' Photovoltaics and Space Environments Branch. This experiment collected data to assess wheel surface wear on the Sojourner. It used a specially designed rover wheel, with thin films (200 to 1000 angstroms) of aluminum, nickel, and platinum deposited on black, anodized aluminum strips attached to the rover's right center wheel. As the wheel spun in the Martian soil, a photovoltaic sensor monitored changes in film reflectivity. These changes indicated abrasion of the metal films by Martian surface material. Rolling wear data were accumulated by the WAE. Also, at frequent intervals, all the rover wheels, except the WAE test wheel, were locked to hold the rover stationary while the test wheel alone was spun and dug into the Martian regolith. These tests created wear conditions more severe than simple rolling. The WAE will contribute substantially to our knowledge of Martian surface characteristics. Marked abrasion would indicate a surface composed of hard, possibly sharply edged grains, whereas lack of abrasion would suggest a somewhat softer surface. WAE results will be correlated with ground simulations to determine which terrestrial materials behave most like those on Mars. This knowledge will enable a deeper understanding of erosion processes on Mars and the role they play in Martian surface evolution. Preliminary results show that electrostatic charging of the rover wheels sometimes caused dust to accumulate on the WAE wheel, making interpretation of the reflectance data problematic. If electrostatic charging is the mechanism for dust attraction, this indicates that the Martian dust has a size somewhat smaller than 40 microns in diameter. The WAE experiment has detected electrostatic charging in the Martian environment for the first time; however, under conditions when the wheel is relatively clean of Martian dust, flight data now indicate that abrasion has also been detected. Crude limits so far place the hardness of the Martian dust at harder than aluminum but softer than nickel, and place the grain size at somewhat smaller than 40 microns.

Ferguson, Dale C.↗

Pre-Flight Testing and Performance of a Ka-Band Software Defined Radio

National Aeronautics and Space Administration (NASA) has developed a space-qualified, reprogrammable, Ka-band Software Defined Radio (SDR) to be utilized as part of an on-orbit, reconfigurable testbed. The testbed will operate on the truss of the International Space Station beginning in late 2012. Three unique SDRs comprise the testbed, and each radio is compliant to the Space Telecommunications Radio System (STRS) Architecture Standard. The testbed provides NASA, industry, other Government agencies, and academic partners the opportunity to develop communications, navigation, and networking applications in the laboratory and space environment, while at the same time advancing SDR technology, reducing risk, and enabling future mission capability. Designed and built by Harris Corporation, the Ka-band SDR is NASA's first space-qualified Ka-band SDR transceiver. The Harris SDR will also mark the first NASA user of the Ka-band capabilities of the Tracking Data and Relay Satellite System (TDRSS) for on-orbit operations. This paper describes the testbed's Ka-band System, including the SDR, travelling wave tube amplifier (TWTA), and antenna system. The reconfigurable aspects of the system enabled by SDR technology are discussed and the Ka-band system performance is presented as measured during extensive pre-flight testing.

Downey, Joseph A.↗

External Contamination Environment at ISS Included: Selected Results from Payloads Contamination Mapping Delivery 3 Package

The International Space Station is the largest and most complex on-orbit platform for space science utilization in low Earth orbit. Multiple sites for external payloads, with exposure to the associated natural and induced environments, are available to support a variety of space science utilization objectives. Contamination is one of the induced environments that can impact performance, mission success and science utilization on the vehicle. The ISS has been designed, built and integrated with strict contamination requirements to provide low levels of induced contamination on external payload assets.

Olsen, Randy↗

Gateway System Requirements

The Gateway Program (GW) System Requirements Document (SRD) is approved for the public domain to support NASA's Lunar Gateway Program. The main intent of these documents is to define top level functional and performance requirements for the systems that facilitate cooperative deep space exploration endeavors and execute lunar missions. The SRD defines NASA requirements for the procurement and development of the GW mission. The Gateway Program is a collaboration of US government, international partners and commercial providers. The Gateway SRD are expected to be used by all parties in development of the Gateway Program elements. For effective development and integration of the Gateway vehicle, all involved entities must use, and have awareness of, these high level program requirements to flow down to their respective developmental responsibilities so all Gateway elements will be operable as an entity. The Gateway SRD represents the requirements that are necessary for the Gateway mission. NASA has determined there is benefit to U.S. and foreign spacecraft developers to approve this information for the public domain because all the parties/participants need a common understanding of the requirements and the parameters under which they operate (size, shape, form fit and function). This will allow systems built by various nations and commercial entities to attach and function together properly and safely in the hostile environment of space.The Gateway SRD provides information regarding the current requirements for Gateway elements. Specifically, the Gateway SRD provide an overview of expected features and capabilities and requirements for safe integration of elements within the Gateway program. The SRD contains top-level functional and performance descriptions of the Gateway and definition of the interfaces limited to the scope necessary for integration purposes between Gateway elements. The documents do NOT contain detailed design information or any specifics of hardware or software implementation. The data approved for release does not include: manufacturing drawings, detailed interface control and design data, software code, detailed CAD models, structural or thermal models of the system, avionics or avionics box, board, or cable manufacturing information.

Adamek, Christopher↗

International Space Station (ISS) Thruster Plume Contamination and Erosion Control for Visiting Spacecraft

The ISS is the largest and most complex platform for space science utilization in low Earth orbit. Multiple sites for external payloads, with exposure to the associated natural and induced environments, are available to support a variety of space science utilization objectives. Contamination is one of the induced environments that can impact performance, mission success, and science utilization on the vehicle. The ISS has been designed, built, and integrated with strict contamination requirements to provide low levels of induced contamination both on the ISS vehicle’s own contamination-sensitive surfaces and on external payload assets.

Microscopy↗

Zero-G Experiments of the BionicWingsat - A 2U-Cubesat with Deployable, Biologically-Inspired Wings

In this paper, recent testing of a novel deployable structure with several potential applications in space will be described, with the focus on performed deployment experiments in a DLR Zero-g flight campaign and in ground tests. Through a cooperative effort of the German Aerospace Center (DLR) and the National Aeronautics and Space Administration (NASA), a biologically-inspired structurally-integrated membrane featuring distributed functional elements has been developed and integrated into the 2U CubeSat called BionicWingSat. Such a membrane structure could be useful for all sorts of applications in which a relatively flat area is desirable such as solar sails, drag sails, or solar shades. For SmallSats and CubeSats, the design proposed also has the desirable property of being self-deploying without the need for powered deployment mechanisms. Building on previous work inspired by the wings of earwigs, the research presented in this paper focuses on testing of developed design concepts for such structural systems. To do so 24 fully integrated wings on two BionicWingSats in 2U Cubesat format were experimentally deployed in a microgravity environment during a dedicated DLR Zero-g flight campaign in 2021. The results of these experiments, the built hardware and test articles, the test arrangement, as well as a comparison to ground tests are discussed in this paper.

Spacecraft structures↗

A Novel High-Temperature Generator/Motor Design: With Applications in Geothermal Drilling and Other Industries

The National Renewable Energy Laboratory (NREL), in partnership with Tetra Corporation and TPL Inc, has an ongoing ARPA-E project related to an advanced high-temperature geothermal drilling system, and the power electronics necessary for this system. As part of this work, NREL designed, built and tested a high-temperature generator for power generation in a 250 degrees Celsius downhole drilling environment. This design exceeded initial performance targets at elevated temperature. NREL is investigating alternative applications for this design, as either a generator or motor capable of efficient performance at high temperature.

alternator↗