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David Israel

Publications and source records attributed to David Israel.

14 records
All sourcesNASA NTRSDOE OSTI
NASA NTRSDate not supplied

LunaNet: A Flexible and Extensible Lunar Exploration Communications and Navigation Infrastructure and the Inclusion of SmallSat Platforms

As NASA establishes a sustained presence on the Moon and ventures further into the solar system, the need for a robust interplanetary communications and navigation architecture increases. LunaNet, an extensible and scalable lunar communications and navigation architecture, is being developed to answer this growing need. The LunaNet architecture will provide users with three services: networking services, positioning, navigation and timing services, and science utilization services. With LunaNet in place, users will experience an operational environment similar to that experienced by users on Earth. The agency’s plan for solar system exploration necessitates both government and commercial participation, and the LunaNet architecture supports this goal as well, encouraging global participation from commercial and international partners, other government agencies, academia, and federally funded research development centers. This paper provides a high-level description of the LunaNet architecture, discusses how SmallSat platforms and technologies may provide critical capabilities, and defines the role that SmallSats can play within the architecture.

Communications↗
NASA NTRSDate not supplied

Onelink Session

Thank you for attending NASA’s first-ever OneLink Session. During the event you will learn about the Near Space Network, the changes NASA has made to network architecture, the Commercialization, Innovation, and Synergies (CIS) office, and our goals for fostering industry partnerships.

commercialization↗
NASA NTRSDate not supplied

Laser Communications Relay Demonstration: Experiments With Delay Tolerant Networking

The Laser Communications Relay Demonstration (LCRD) is a NASA mission that is presently providing a link between two optical ground stations on Earth and geosynchronous orbit; this capability will be extended to include a laser terminal on the International Space Station (ISS). From a practical perspective, LCRD provides a 1Gbps Ethernet link with an anticipated round-trip time of 4 seconds. Delay Tolerant Networking (DTN) is being used to transcend LCRDs capabilities from a point-to-point link to true network connectivity. Indeed, integrating the LCRD link into any network, such as one aboard the ISS, adds new hops and paths. In this paper, we detail DTN experiments conducted using LCRD to demonstrate how DTN and optical capabilities complement each other to enable the next generation of space communication modalities. We conclude with considerations on using LCRD to connect the ISS to the optical ground stations.

Alan Hylton↗
NASA NTRSDate not supplied

Insights and Observations from Operating a Geostationary Laser Communication Relay Mission: Operational Lessons from NASA’s Laser Communications Relay Demonstration (LCRD) and Associated Optical Ground Stations (OGSs)

The NASA Laser Communications Relay Demonstration (LCRD) has operated on orbit for the last two years. The LCRD Mission consists of a geostationary payload and two optical ground stations. This technology demonstration mission is NASA’s first two-way, end-to-end optical communications relay. LCRD has performed an extensive experiment campaign to analyze laser communication performance for extended operations. This paper discusses various lessons learned while operating the optical relay mission from early commissioning through two years of operation. Before launch, engineers and operators performed analyses to generate operational procedures based on expected LCRD performance. However, only operation on orbit can supply actual performance data. Additional topics covered in this paper include pre-launch and commissioning testing, ephemeris generation and cadence, environmental configurations, and accommodation concerns. The addition of Integrated Laser Communications Relay Demonstration Low Earth Orbit User Modem and Amplifier Terminal (ILLUMA-T) to the optical network supplemented the LCRD team’s operational experiences and enabled them to garner new lessons learned. The authors of this paper include day-to-day flight leads who consulted with on-console operators, engineers, and subject matter experts analyzing data and experiment results to gather the lessons learned described in this paper. LCRD is a joint project involving NASA Goddard Space Flight Center (GSFC), the California Institute of Technology Jet Propulsion Laboratory (JPL), and Massachusetts Institute of Technology Lincoln Laboratory (MIT LL).

Lessons Learned↗
NASA NTRSDate not supplied

Insights and Observations From Operating A Laser Communication Terminal on the International Space Station (ISS)

The Integrated Laser Communication Relay Demonstration (LCRD) Low Earth Orbit User Modem and Amplifier Terminal (ILLUMA-T) is the first user platform for NASA’s first laser communication relay, LCRD. ILLUMA-T is hosted on the International Space Station (ISS) as an external payload of the Japanese Experiment Module – Exposed Facility (JEM-EF) situated in slot 3. The LCRD payload is hosted on the STPSat-6 spacecraft, which orbits Earth in a geostationary orbit at position 112 W. The ILLUMA-T-to-LCRD system provides a bidirectional, space-to-ground laser communication relay link transferring data up to 1.2 Gbps utilizing two optical ground stations (OGS), OGS-1 in California and OGS-2 in Hawai’i. This paper describes lessons learned from operating the ILLUMA-T system and examines topics such as the end-to-end system availability, predictive versus actual ephemeris, acquisition adjustments, modem timing and handshaking, the terminal’s physical placement and accommodations, and experiment development, execution, and analysis. The authors of this paper operate both the LCRD and ILLUMA-T laser terminals on a daily basis including pass planning, procedure execution, acquisition analysis, and real-time terminal commanding and telemetry monitoring. LCRD is a joint project involving NASA Goddard Space Flight Center (GSFC), the California Institute of Technology Jet Propulsion Laboratory (JPL), and Massachusetts Institute of Technology Lincoln Laboratory (MIT LL). The ILLUMA-T payload is managed by NASA GSFC in Greenbelt, Maryland whose partners include the ISS program office at NASA’s Johnson Space Center (JSC) in Houston, Texas; the Huntsville Operations Support Center (HOSC) at Marshall Space Flight Center (MSFC) in Huntsville, Alabama; the Glenn Research Center (GRC) in Cleveland, Ohio; and the MIT LL in Lexington, Massachusetts. ILLUMA-T is funded by the Space Communications and Navigation (SCaN) Program at NASA Headquarters in Washington, D.C.

Laser Communications↗
NASA NTRSDate not supplied

Completion of NASA’s Two-Year Laser Communications Relay Demonstration (LCRD) Experiment Program

The National Aeronautics and Space Administration’s (NASA) Laser Communications Relay Demonstration (LCRD) completed its two-year experiment program in June 2024. The LCRD geosynchronous payload includes two laser communications terminals interconnected via an onboard electronic switch. The payload relays data between two optical ground stations located in California and Hawaii and can also exchange data with an RF ground station in New Mexico. The addition of the Integrated LCRD Low-Earth Orbit (LEO) User Modem and Amplifier Terminal (ILLUMA-T) on the International Space Station in 2023 enabled data relay demonstrations between a laser terminal in low Earth orbit and either one of the optical ground stations or the RF ground station. The experiment program has included a variety of experiments originating within the LCRD project, NASA, and industry. The experiments have included measurements of the effects of the atmospheric optical channel (turbulence, weather) on the performance and availability of laser communications, adaptive optics characterization, demonstration of optimetrics techniques, and demonstration of Delay/Disruption Tolerant Networking (DTN). Furthermore, various future operational scenarios including robotic and exploration missions and various network service configurations have been emulated. This conference paper provides an overview and highlights of the LCRD experiment program with an emphasis on activities and results since the start of the ILLUMA-T testing in December 2023. A discussion of the expectations for the next phase of the LCRD mission, as well as how LCRD results may be applied to future applications is also included. LCRD is a joint project involving NASA Goddard Space Flight Center (GSFC), the California Institute of Technology Jet Propulsion Laboratory (JPL), and Massachusetts Institute of Technology Lincoln Laboratory (MIT LL).

Laser communications↗
NASA NTRSDate not supplied

The International Space Station, Optical Communications, and Delay Tolerant Networking: Towards A Solar System Internet Architecture

As Delay Tolerant Networking (DTN) matures as a software product its use cases have extended to infrastructural and architectural studies, bringing DTN closer to a widespread, operational technology. While it is known that a DTN can be configured, given complete information about a system of nodes, to provision a system with a complete network capability, what remains is to tackle practical considerations such as scalability, networking best practices, and how to establish service providers. In this paper, we document progress towards a scalable DTN architecture that was tested across multiple organizational and project boundaries; our approach was tested across nodes flying on the International Space Station (ISS) connected to a ground network. The network consists of four main network areas: the ISS, the White Sands Complex (WSC), the Mission Cloud Platform (MCP), and NASA’s Huntsville Operations Support Center (HOSC). The connections on the ground (WSC, MCP, and HOSC) are straightforward technically, but represent administrative and non-technical challenges that had to be overcome. The connection from the ISS to WSC was realized through a hybrid optical/RF means. In particular, NASA’s Integrated Laser Communications Relay Demonstration (LCRD) can form a relay from lowEarth-orbit (LEO) to the Earth, and was used in conjunction with the LCRD LEO User Modem and Amplifier Terminal (ILLUMA-T) on the ISS to form a link to one of three geographically diverse ground stations. A major goal was to achieve communications while keeping the ISS nodes unaware of ground station choices and scheduling. These disparate links were networked using High-rate DTN (HDTN), which enabled the desired architecture. The network architecture, tests, HDTN performance metrics, and general observations made are all discussed in detail, including a discussion on the successful utilization of the DTN security standard known as DTN Bundle Protocol Security (BPSec). We conclude with suggestions for next steps, and in particular focus on extending this architecture to the Near Space Network (NSN) and the upcoming LunaNet.

Alan Hylton↗