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NASA NTRS2022

Benefits and Challenges of CCSDS File Delivery Protocol as Applied to Europa Clipper

—This paper describes the use of the Consultative Committee for Space Data Systems (CCSDS) File Delivery Protocol (CFDP) on the Europa Clipper mission for both uplink and downlink of files. It includes an overview of CFDP, the history of why CFDP was chosen, how it benefits mission operations, some of the mission scenarios that stress CFDP, operability aspects, the best practices that Clipper adopted from other missions and some of the technical challenges with implementation, and verification and validation. The benefits to mission operations accrue because CFDP reduces the need for manual management of file transfer, including retransmission of missing data, and deletion of files only after confirmation of receipt by the ground. The challenges occur because CFDP is a round-trip protocol – it requires messages in both directions to complete a file transfer, and because it uses timers to ensure that control messages are resent if needed to prevent transactions from going stale. Any situations where communication is restricted to a single direction, interrupted, reordered, or backlogged can pose a challenge. There are also implementation challenges. Europa Clipper is the first mission at the Jet Propulsion Laboratory (JPL) to adopt class 2, fully acknowledged, CFDP for both uplink and downlink. The implementation needed new software, requirements and operational procedures. The experience of the Applied Physics Laboratory (APL) with CFDP from their previous missions was crucial to success for Europa Clipper. Because CFDP relies on timers and messages travel in both directions, verification and validation (V&V) requires new approaches. For certain scenarios, a live ground system talking to a live flight system with realistic simulated one-way light times, data rates and data outages must be used.

Albers, Joshua↗

NASA NTRS2004

Secure, Mobile, Wireless Network Technology Designed, Developed, and Demonstrated

The inability to seamlessly disseminate data securely over a high-integrity, wireless broadband network has been identified as a primary technical barrier to providing an order-of-magnitude increase in aviation capacity and safety. Secure, autonomous communications to and from aircraft will enable advanced, automated, data-intensive air traffic management concepts, increase National Air Space (NAS) capacity, and potentially reduce the overall cost of air travel operations. For the first time ever, secure, mobile, network technology was designed, developed, and demonstrated with state-ofthe- art protocols and applications by a diverse, cooperative Government-industry team led by the NASA Glenn Research Center. This revolutionary technology solution will make fundamentally new airplane system capabilities possible by enabling secure, seamless network connections from platforms in motion (e.g., cars, ships, aircraft, and satellites) to existing terrestrial systems without the need for manual reconfiguration. Called Mobile Router, the new technology autonomously connects and configures networks as they traverse from one operating theater to another. The Mobile Router demonstration aboard the Neah Bay, a U.S. Coast Guard vessel stationed in Cleveland, Ohio, accomplished secure, seamless interoperability of mobile network systems across multiple domains without manual system reconfiguration. The Neah Bay was chosen because of its low cost and communications mission similarity to low-Earth-orbiting satellite platforms. This technology was successfully advanced from technology readiness level (TRL) 2 (concept and/or application formation) to TRL 6 (system model or prototype demonstration in a relevant environment). The secure, seamless interoperability offered by the Mobile Router and encryption device will enable several new, vehicle-specific and systemwide technologies to perform such things as remote, autonomous aircraft performance monitoring and early detection and mitigation of potential equipment malfunctions. As an additional benefit, team advancements were incorporated into open standards, ensuring technology transfer. Low-cost, commercial products incorporating the new technology are already available. Furthermore, these products are fully interoperable with legacy network technology equipment currently being used throughout the world.

Ivancic, William D.↗

DOE OSTI2020

Dalton Project: A Python platform for molecular- and electronic-structure simulations of complex systems

The Dalton Project provides a uniform platform access to the underlying full-fledged quantum chemistry codes Dalton and LSDalton as well as the PyFraME package for automatized fragmentation and parameterization of complex molecular environments. The platform is written in Python and defines a means for library communication and interaction. Intermediate data such as integrals are exposed to the platform and made accessible to the user in the form of NumPy arrays, and the resulting data are extracted, analyzed, and visualized. Complex computational protocols that may, for instance, arise due to a need for environment fragmentation and configuration-space sampling of biochemical systems are readily assisted by the platform. The platform is designed to host additional software libraries and will serve as a hub for future modular software development efforts in the distributed Dalton community.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

NASA NTRS2010

Standards-Based Wireless Sensor Networking Protocols for Spaceflight Applications

Wireless sensor networks (WSNs) have the capacity to revolutionize data gathering in both spaceflight and terrestrial applications. WSNs provide a huge advantage over traditional, wired instrumentation since they do not require wiring trunks to connect sensors to a central hub. This allows for easy sensor installation in hard to reach locations, easy expansion of the number of sensors or sensing modalities, and reduction in both system cost and weight. While this technology offers unprecedented flexibility and adaptability, implementing it in practice is not without its difficulties. Recent advances in standards-based WSN protocols for industrial control applications have come a long way to solving many of the challenges facing practical WSN deployments. In this paper, we will overview two of the more promising candidates - WirelessHART from the HART Communication Foundation and ISA100.11a from the International Society of Automation - and present the architecture for a new standards-based sensor node for networking and applications research.

Wagner, Raymond S.↗

NASA NTRS2012

A Communications Network for Cislunar Operations

Reliable and efficient communications will be critical to the success of commercial flight operations in cislunar space. The Internet is not well-suited to meeting this requirement. But the Delay-Tolerant Networking (DTN) architecture is. The DTN protocols are well-documented and implementations are mature. We think DTN will be ready to support low-cost, low-risk cislunar networking by the time the vehicles are in place.

network↗

DOE OSTI2023

Gridtrust: Electricity Grid Root-of-Trust Decentralized Supply Chain Cyber-Security (Final Scientific/Technical Report)

GridTrust represents a departure from reliance on a single organization or a single person to multiple organizations and therefore multiple people across organizational structures. The motivating idea behind involving multiple organizations is the increase in security due to human factors. More specifically, the requirement that distinct people in different organizations sign off on a change or an update makes a cyberattack much less likely due to the inherent requirement that both organizations be penetrated and fooled. GridTrust focuses on the software update process as the primary exemplar for the research and development work. A novel hardware-based technology referred to as a Physical Unclonable Function (PUF) provides a microchip Root-of-Trust (RoT), i.e., a starting point for verifying that the hardware being communicated with is the hardware the control center believes the hardware to be. As a result, staff at power grid control centers can ensure the accurate and reliable identification of hardware devices from the outset. The GridTrust protocol introduces two key innovations, as detailed in this report. Firstly, the utilization of a PUF as a root-of-trust in the initial phase of a software or firmware update. Secondly, the application of multiple cryptographic signatures from two or more organizations to the update binary. These signatures are verified before implementing the update on a power grid device in the field. In terms of GridTrust hardware design, this report outlines two main components. The first is the GridTrust Native Device, integrating PUF technology intrinsically into the hardware device itself. The second is the GridTrust Interfacing Device, which incorporates PUF technology and multiple cryptographic signatures. These signatures are cross-checked within a separate hardware positioned between the power grid control center and the legacy power grid device, functioning as an intermediary. While the GridTrust Interfacing Device offers the advantage of being applicable to existing power grid equipment, it may have reduced security if the intermediary component is targeted. On the other hand, the GridTrust Native Device boasts increased security due to protocol integration within a unified form factor. The effectiveness of GridTrust technology has been extensively demonstrated, with multiple external red-team attackers unable to breach GridTrust's security measures. This was observed both in controlled laboratory settings during Phase 1 of the project and in real-world conditions within a City of Marietta substation during Phase 2 of the project.

24 POWER TRANSMISSION AND DISTRIBUTION↗

NASA NTRS1995

Marine optical characterizations

During the past three months, the MOCE Team conducted two field experiments in Mill Creek,Chesapeake Bay, from July 24 to August 4, and at the MOBY operations site at Snug Harbor, Honolulu, Hawaii, from August 15-30, prepared two technical memoranda, and continued MOCE-2 and MOCE-3 data reduction. The primary purposes of the experiments were to test the SeaWiFS 'remote sensing reflectance' protocol, obtain turbid water data for ocean color satellite algorithm development, perform calibration for both Near Infrared (NIR) and Visible Rainbow Spectrometer system, continue assembling the operational Marine Optical Buoy, and to test the MOBY cellular phone communications link at the Lanai mooring site.

Clark, Dennis K.↗

NASA NTRS2005

Internet-Based System for Voice Communication With the ISS

The Internet Voice Distribution System (IVoDS) is a voice-communication system that comprises mainly computer hardware and software. The IVoDS was developed to supplement and eventually replace the Enhanced Voice Distribution System (EVoDS), which, heretofore, has constituted the terrestrial subsystem of a system for voice communications among crewmembers of the International Space Station (ISS), workers at the Payloads Operations Center at Marshall Space Flight Center, principal investigators at diverse locations who are responsible for specific payloads, and others. The IVoDS utilizes a communication infrastructure of NASA and NASArelated intranets in addition to, as its name suggests, the Internet. Whereas the EVoDS utilizes traditional circuitswitched telephony, the IVoDS is a packet-data system that utilizes a voice over Internet protocol (VOIP). Relative to the EVoDS, the IVoDS offers advantages of greater flexibility and lower cost for expansion and reconfiguration. The IVoDS is an extended version of a commercial Internet-based voice conferencing system that enables each user to participate in only one conference at a time. In the IVoDS, a user can receive audio from as many as eight conferences simultaneously while sending audio to one of them. The IVoDS also incorporates administrative controls, beyond those of the commercial system, that provide greater security and control of the capabilities and authorizations for talking and listening afforded to each user.

Chamberlain, James↗

NASA NTRSDate not supplied

Distributed Spacecraft Autonomy - Development of Swarm Autonomy Capability and Scalability for Spacecraft

The Distributed Spacecraft Autonomy project is developing a suite of software tools that enable an operator to command and receive data from a swarm as a single entity, enable a swarm to autonomously coordinate its actions via distributed decision making and reactive closed-loop control, and model swarm behavior in the presence of anomalies or failures. Our use case is the mapping of the electron density of the ionosphere using radio tomography by coordinating the selection of appropriate GPS channels, and by recording Total Electron Count (TEC) measurements. DSA will be demonstrated onboard the NASA Ames Starling mission – a swarm of four small, LEO spacecraft, scheduled to launch in 2021. We will also perform a ground demonstration with simulated and hardware-in-the-loop elements, to validate the tools for controlling swarms of up to 100 assets. The capability to communicate autonomously between the swarm satellites is demonstrated via a sophisticated simulation architecture. Historical Plasmasphere TEC data obtained via dual-band Novatel GPS Receivers are utilized as a representative input dataset for the swarm. The representative TEC data and GPS satellite observability information is fed to the autonomous software package in place of a true real-time ground data collection process. The swarm satellites actively share status updates amongst one another and utilize multi-agent decision making to optimally identify regions of interest in the TEC distribution. The software, aware of the bandwidth limitations of the swarm satellites, prioritizes explorative measurements, which define the range of observability for the satellites, as well as exploitative measurements, which focus on maximizing the observance potential of regions with prolonged, elevated TEC density. The science of this study can ultimately be used to determine the dynamics and coupling of Earth’s magnetosphere, ionosphere, and atmosphere and their response to solar and terrestrial inputs. The findings can be applied to the imaging of critical, transient phenomena in the magnetosphere in later missions. Meanwhile, the swarm autonomy capabilities have far reaching potential in future satellite missions. As an experimental demonstration of the autonomous capabilities of the network, a message is first printed within a core Flight Executive (cFE) application. Two cFE applications that communicate with one another within the same core Flight System (cFS) are shown. Communication between mission applications on the internal cFE bus is extended to utilize Data Distribution Service (DDS) for vehicle-to-vehicle networking. The DDS middleware provides reliable delivery, routing, and topic subscription features over User Datagram Protocol (UDP). Leveraging Linux containerization, a networked set of satellite instances are generated by script to simulate swarm behavior. Swarm commanding and synchronization through the network is demonstrated under various topologies and data-loss conditions. Finally, autonomous swarm scalability from 2 satellites to 100 satellites is shown.

Distributed Autonomy↗

NASA NTRS2007

Digital Multicasting of Multiple Audio Streams

The Mission Control Center Voice Over Internet Protocol (MCC VOIP) system (see figure) comprises hardware and software that effect simultaneous, nearly real-time transmission of as many as 14 different audio streams to authorized listeners via the MCC intranet and/or the Internet. The original version of the MCC VOIP system was conceived to enable flight-support personnel located in offices outside a spacecraft mission control center to monitor audio loops within the mission control center. Different versions of the MCC VOIP system could be used for a variety of public and commercial purposes - for example, to enable members of the general public to monitor one or more NASA audio streams through their home computers, to enable air-traffic supervisors to monitor communication between airline pilots and air-traffic controllers in training, and to monitor conferences among brokers in a stock exchange. At the transmitting end, the audio-distribution process begins with feeding the audio signals to analog-to-digital converters. The resulting digital streams are sent through the MCC intranet, using a user datagram protocol (UDP), to a server that converts them to encrypted data packets. The encrypted data packets are then routed to the personal computers of authorized users by use of multicasting techniques. The total data-processing load on the portion of the system upstream of and including the encryption server is the total load imposed by all of the audio streams being encoded, regardless of the number of the listeners or the number of streams being monitored concurrently by the listeners. The personal computer of a user authorized to listen is equipped with special- purpose MCC audio-player software. When the user launches the program, the user is prompted to provide identification and a password. In one of two access- control provisions, the program is hard-coded to validate the user s identity and password against a list maintained on a domain-controller computer at the MCC. In the other access-control provision, the program verifies that the user is authorized to have access to the audio streams. Once both access-control checks are completed, the audio software presents a graphical display that includes audiostream-selection buttons and volume-control sliders. The user can select all or any subset of the available audio streams and can adjust the volume of each stream independently of that of the other streams. The audio-player program spawns a "read" process for the selected stream(s). The spawned process sends, to the router(s), a "multicast-join" request for the selected streams. The router(s) responds to the request by sending the encrypted multicast packets to the spawned process. The spawned process receives the encrypted multicast packets and sends a decryption packet to audio-driver software. As the volume or muting features are changed by the user, interrupts are sent to the spawned process to change the corresponding attributes sent to the audio-driver software. The total latency of this system - that is, the total time from the origination of the audio signals to generation of sound at a listener s computer - lies between four and six seconds.

Macha, Mitchell↗

DOE OSTI2021

Design and evaluation of a cyber‐physical testbed for improving attack resilience of power systems

Abstract A power system is a complex cyber‐physical system whose security is critical to its function. A major challenge is to model, analyse and visualise the communication backbone of the power systems concerning cyber threats. To achieve this, the design and evaluation of a cyber‐physical power system (CPPS) testbed called Resilient Energy Systems Lab (RESLab) are presented to capture realistic cyber, physical, and protection system features. RESLab is architected to be a fundamental platform for studying and improving the resilience of complex CPPS to cyber threats. The cyber network is emulated using Common Open Research Emulator (CORE), which acts as a gateway for the physical and protection devices to communicate. The physical grid is simulated in the dynamic time frame using Power World Dynamic Studio (PWDS). The protection components are modelled with both PWDS and physical devices including the SEL Real‐Time Automation Controller (RTAC). Distributed Network Protocol 3 (DNP3) is used to monitor and control the grid. Then, the design is exemplified and the tools are validated. This work presents four case studies on cyberattack and defence using RESLab, where we demonstrate false data and command injection using Man‐in‐the‐Middle and Denial of Service attacks and validate them on a large‐scale synthetic electric grid.

Sahu, Abhijeet↗

NASA NTRS2009

Delay/Disruption Tolerant Networks (DTN): Testing and Demonstration for Lunar Surface Applications

This slide presentation reviews the testing of the Delay/Disruption Tolerant Network (DTN) designed for use with Lunar Surface applications. This is being done through the DTN experimental Network (DEN), that permit access and testing by other NASA centers, DTN team members and protocol developers. The objective of this work is to demonstrate DTN for high return applications in lunar scenarios, provide DEN connectivity with analogs of Constellation elements, emulators, and other resources from DTN Team Members, serve as a wireless communications staging ground for remote analog excursions and enable testing of detailed communication scenarios and evaluation of network performance. Three scenarios for DTN on the Lunar surface are reviewed: Motion imagery, Voice and sensor telemetry, and Navigation telemetry.

Source record↗

NASA NTRSDate not supplied

Using Mesh Networking for A Dynamic Lunar Internet of Things (Liot)

The purpose of this project is to evaluate the feasibility of an IEEE 802.11 mesh protocol for lunar surface computing. This standard for wireless networking boosts speed, dependability and range of wireless transmissions. The concept is to integrate sensors (such as deployed science instruments) or Astronaut tools (such as a handheld spectrometer) that communicate with a node on a common cell. The nodes can extend the range of the cell and can dynamically reconfigure the data routing in case of another node failure. All of the data in a cell pass through a modem that communicates with a distant base station across a 4G link. The application of mesh networking to a potential lunar surface network increases robustness and fault tolerance over a traditional single-point modem system. By demonstrating the basic capability of a mesh network, the student team has learned about issues with power, distance, thermal, dust, radiation, data processing, and communication problems applicable to the lunar surface. This knowledge can feed into future NASA requirements to improve the capability of a LunaNET implementation for the Artemis program. This project follows 10 years of successful collaboration between NASA ARES, Texas Space, Technology, Applications and Research (T STAR) and Texas A&M University in a Public, Private, Academic (PPA) Partnership. NASA funds T STAR to mentor undergraduate Capstone teams in the College of Engineering Department to design, built, and test prototypes meeting NASA requirements. TAMU faculty lead the student teams in their academic class, and NASA Subject Matter Experts (SMEs) provide T STAR and students insight on requirements evolution, prior design projects, and future development goals.

Lunar Mesh Networking↗

DOE OSTI2022

Lessons Learned on the Interface Between Quantum and Conventional Networking

The future Quantum Internet is expected to be based on a hybrid architecture with core quantum transport capabilities complemented by conventional networking. Practical and foundational considerations indicate the need for conventional control and data planes that (i) utilize extensive existing telecommunications fiber infrastructure, and (ii) provide parallel conventional data channels needed for quantum networking protocols. We propose a quantum-conventional network (QCN) harness to implement a new architecture to meet these requirements. The QCN control plane carries the control and management traffic, whereas its data plane handles the conventional and quantum data communications. We established a local area QCN connecting three quantum laboratories over dedicated fiber and conventional network connections. We describe considerations and tradeoffs for layering QCN functionalities, informed by our recent quantum entanglement distribution experiments conducted over this network.

Alshowkan, Muneer↗

NASA NTRS1993

Newly available technologies present expanding opportunities for scientific and technical information exchange

The potential for expanded communication among researchers, scholars, and students is supported by growth in the capabilities for electronic communication as well as expanding access to various forms of electronic interchange and computing capabilities. Research supported by the National Aeronautics and Space Administration points to a future where workstations with audio and video monitors and screen-sharing protocols are used to support collaborations with colleagues located throughout the world. Instruments and sensors all over the world will produce data streams that will be brought together and analyzed to produce new findings, which in turn can be distributed electronically. New forms of electronic journals will emerge and provide opportunities for researchers and scientists to electronically and interactively exchange information in a wide range of structures and formats. Ultimately, the wide-scale use of these technologies in the dissemination of research results and the stimulation of collegial dialogue will change the way we represent and express our knowledge of the world. A new paradigm will evolve-perhaps a truly worldwide 'invisible college'.

Tolzman, Jean M.↗

NASA NTRS1996

Electronic-To-Optical-To-Electronic Packet-Data Conversion

Space-time multiplexer (STM) cell-based communication system designed to take advantage of both high throughput attainable in optical transmission links and flexibility and functionality of electronic processing, storage, and switching. Long packets segmented and transmitted optically by wavelength-division multiplexing. Performs optoelectronic and protocol conversion between electronic "store-and-forward" protocols and optical "hot-potato" protocols.

Monacos, Steve↗

NASA NTRS2004

Advanced Communications Architecture Demonstration Made Significant Progress

Simulation for a ground station located at 44.5 deg latitude. The Advanced Communications Architecture Demonstration (ACAD) is a concept architecture to provide high-rate Ka-band (27-GHz) direct-to-ground delivery of payload data from the International Space Station. This new concept in delivering data from the space station targets scientific experiments that buffer data onboard. The concept design provides a method to augment the current downlink capability through the Tracking Data Relay Satellite System (TDRSS) Ku-band (15-GHz) communications system. The ACAD concept pushes the limits of technology in high-rate data communications for space-qualified systems. Research activities are ongoing in examining the various aspects of high-rate communications systems including: (1) link budget parametric analyses, (2) antenna configuration trade studies, (3) orbital simulations (see the preceding figure), (4) optimization of ground station contact time (see the following graph), (5) processor and storage architecture definition, and (6) protocol evaluations and dependencies.

Carek, David Andrew↗

NASA NTRS2014

Fault-Tolerant Self-Stabilizing Distributed Clock Synchronization Protocol for Arbitrary Digraphs

A self-stabilizing network in the form of an arbitrary, non-partitioned digraph includes K nodes having a synchronizer executing a protocol. K-1 monitors of each node may receive a Sync message transmitted from a directly connected node. When the Sync message is received, the logical clock value for the receiving node is set to between 0 and a communication latency value (gamma) if the clock value is less than a minimum event-response delay (D). A new Sync message is also transmitted to any directly connected nodes if the clock value is greater than or equal to both D and a graph threshold (T(sub S)). When the Sync message is not received the synchronizer increments the clock value if the clock value is less than a resynchronization period (P), and resets the clock value and transmits a new Sync message to all directly connected nodes when the clock value equals or exceeds P.

Malekpour, Mahyar R.↗