Joseph Downey | Search NASA

NASA NTRS2025

Cognitive Engine One: A Cross-Layer Framework for Autonomy in Multi-Provider Space Communications Environments

Spacecraft information needs, along with the communications environments in which data transfers occur, are becoming increasingly dynamic. Earth orbit is served by dozens of ground station and relay satellite providers – each with unique protocols and service capabilities. In this context, we present a system to automate end-to-end space communications across the protocol stack for each of several providers. The proposed system schedules contacts with providers, configures point-to-point RF links, and ensures data is transferred to its destination. Data monitoring and rescheduling provide an automated failover capability in the event of unsuccessful contacts. We verify system performance in a high-fidelity emulation testbed. Results from several scenarios demonstrate favorable system performance across a variety of mission use cases.

space communications↗

NASA NTRSDate not supplied

Framework for NASA Space Relay Satellite Services over the Next Decade: Space Relay Partnership and Services Study

The United States National Space Policy provides guidance and directives for U.S. Government agencies to purchase commercial space services and capabilities to the maximum extent practical. In alignment with this guidance, the anticipated initial NASA near-Earth space relay operating capability over the next decade will be comprised of the existing NASA-owned Space Network infrastructure supplemented with commercially-owned and -provided relay satellites and their associated ground stations. NASA awarded contracts to eight study vendors in May 2019 to investigate the feasibility of applying commercial services concepts to the NASA user mission community. The studies, managed by NASA Glenn Research Center, detailed ten study topic areas. NASA completed the analysis and synthesis of these eight industry studies and other relevant information. The responses from the study vendors indicated a strong interest in providing commercial services to NASA missions, and included a wide range of proposed architectures and demonstration ideas. Overall, the responses indicated that a mature and healthy competitive environment exists across a broad spectrum of industry to deliver high-rate space relay services in the next three to five years. This paper will present an overview of the study, analysis and synthesis processes along with common themes and conclusions, and provide next steps and recommendations. The results of this study serve as a foundation for ongoing efforts to acquire interoperable space relay services for NASA missions from multiple commercial service providers.

Eric Knoblock↗

NASA NTRSDate not supplied

Development and Demonstration of a Wideband RF User Terminal for Roaming between Ka-band Relay Satellite Networks

The National Aeronautics and Space Administration (NASA) has provided low-latency communication relay services to science and exploration spacecraft for nearly four decades with the Tracking and Data Relay Satellite System (TDRSS). Through NASA’s Communications Services Project (CSP), the agency is pursuing a transition away from dedicated government-owned communication relay satellites and infrastructure in favour of commercially provided satellite communication (SATCOM) services. Many of these SATCOM services are offered in the K/Ka-band covering spectrum allocated to commercial, military, and civilian space operations. While these services were intended to provide broadband connectivity for terrestrial, maritime, and aviation customers, many can be tailored to support orbiting spacecraft. By introducing commercial SATCOM providers, NASA intends to create an interoperable network of networks which will enable missions to roam between multiple service providers. A key enabling technology needed for this vision is a multi-frequency (wideband), multi-waveform user terminal which can seamlessly roam between multiple providers. This paper discusses the development and ground demonstration of a new wideband RF user terminal prototype designed to roam across multiple networks over the Ka-band, allowing ubiquitous service, resiliency, and flexibility for the user.

satellite communication↗

NASA NTRSDate not supplied

Framework for NASA Space Relay Satellite Services over the Next Decade: Space Relay Partnership and Services Study

The United States National Space Policy provides guidance and directives for U.S. Government agencies to purchase commercial space services and capabilities to the maximum extent practical. In alignment with this guidance, the anticipated initial NASA near-Earth space relay operating capability over the next decade will be comprised of the existing NASA-owned Space Network infrastructure supplemented with commercially-owned and -provided relay satellites and their associated ground stations. NASA awarded contracts to eight study vendors in May 2019 to investigate the feasibility of applying commercial services concepts to the NASA user mission community. The studies, managed by NASA Glenn Research Center, detailed ten study topic areas. NASA completed the analysis and synthesis of these eight industry studies and other relevant information. The responses from the study vendors indicated a strong interest in providing commercial services to NASA missions, and included a wide range of proposed architectures and demonstration ideas. Overall, the responses indicated that a mature and healthy competitive environment exists across a broad spectrum of industry to deliver high-rate space relay services in the next three to five years. This paper will present an overview of the study, analysis and synthesis processes along with common themes and conclusions, and provide next steps and recommendations. The results of this study serve as a foundation for ongoing efforts to acquire interoperable space relay services for NASA missions from multiple commercial service providers.

Eric Knoblock↗

NASA NTRSDate not supplied

Onboard Doppler Compensation for Low-Rate Communications over Commercial Relay Satellites

NASA spacecraft performing scientific and exploration missions may increasingly communicate over commercial relay satellites, including those that operate at Ka-band. Ideally these spacecraft could use the same Ka-band terminal for low-rate telemetry/commanding. However, this use case presents an issue since most commercial relay systems were designed with terrestrial users in mind and cannot easily handle the Doppler effects of orbiting spacecraft. In this work we propose onboard Doppler compensation allowing spacecraft to use existing relay satellite infrastructure without modification. Specifically, we present a method for digital compensation based on a series of piecewise linear sweeps which minimizes resources used on the spacecraft’s radio. We perform orbital mechanics simulations to estimate the worst-case Doppler profiles experienced by spacecraft in several low-Earth orbits. We emulate these effects in a laboratory experiment and demonstrate the proposed technique will reduce Doppler effects by more than two orders of magnitude. The residual Doppler is small enough that modems used at commercial relay sites are able to receive error-free data even when operating at their lowest supported symbol rate.

Adam Gannon↗

NASA NTRSDate not supplied

Cloud-Based Demodulation and Data Distribution of a Satellite Downlink

Ground station networks connected to the cloud allow space missions to have global communications coverage without operating their own infrastructure. In this work, we describe the communications architecture for the TechEdSat-13 mission, which performed the first in-space characterization of a neuromorphic processor. The mission utilizes a commercial provider for S-band downlinks. A suite of cloud services and open-source software such as GNU Radio are leveraged to demodulate signals received by an AWS ground station during passes with TechEdSat-13 and store recovered data. Once a pass is scheduled, the entire process takes place without human intervention. On-orbit results the past year of operations are presented, demonstrating the advantages of this approach over traditional operator-owned ground stations. Use of software-defined radio makes possible custom signal processing. The homogeneity of apertures and their interfaces to the cloud simplifies scaling across many sites. This abundance of candidate links lays the groundwork for intelligent scheduling agents to optimize pass selection across several factors, automatically recover from failed contacts, and gather metrics to learn from past performance.

cloud demodulation↗

NASA NTRSDate not supplied

Emulated Spacecraft Communication Testbed for Evaluating Cognitive Networking Technology

The ability to emulate the full space protocol stack is an essential aspect required to evaluate and mature cognitive communication capabilities. The interaction between the physical layer and network layers is key to developing network optimizations for a dynamic and complex environment. We present a laboratory testbed for the evaluation of cognitive radio and networking techniques applied to space communications. The testbed is a high fidelity, flight-like hardware testbed consisting of software-defined radios, channel emulators, modems, and orbital analysis and scheduling software. The testbed uses RF links with signal quality, propagation delay, and Doppler effects driven by orbital mechanics simulations of emulated spacecraft. Our framework enables control of link bidirectionality, data rates, and interference sources. In addition to hardware radio nodes, the testbed can incorporate virtualized emulated nodes for larger and more challenging network scenarios. Our approach to a cognitive communication system uses delay tolerant networking (DTN) to mitigate the challenges of the space environment. While many DTN networks use only preplanned schedules, our system uses User-Initiated Service (UIS) to dynamically schedule service providers. Software-defined radio allows the system to adapt to a variety of service providers. Integration of DTN, UIS, and software-defined radio technologies provides a framework for the implementation of a cognitive communication system. This paper describes the testbed capabilities, network emulation approach, component integration, and initial end-to-end testing results.

cognitive radio↗

NASA NTRSDate not supplied

Evaluating a Cognitive Extension for the Licklider Transmission Protocol in a Spacecraft Emulation Testbed

In space communications, particularly when involving regions beyond cislunar space, the development of advanced networking solutions is essential to address the challenges posed by limited connectivity, substantial propagation delays, and radio signal variations. This study explores a data-driven approach to the Licklider Transmission Protocol (LTP), specifically focusing on dynamically adjusting the maximum payload size of segments. Prior research has emphasized the potential benefits of dynamically adjusting this parameter, introducing the concept of Cognitive LTP. This paper presents a software implementation of Cognitive LTP (CLTP) within an open-source Delay Tolerant Networking (DTN) framework, specifically the High-rate Delay Tolerant Networking (HDTN), and experimentally evaluates its performance under realistic space conditions. Leveraging the Cognitive Ground Testbed (CGT), developed by NASA GRC for spacecraft communication emulation, this study effectively bridges the gap between theoretical advancements and practical applications. By thoroughly analyzing CLTP’s functionality within the CGT, this research offers insights into the practical implications of adaptive networking strategies, emphasizing the importance of conducting tests in relevant environments for the maturation of space communication technologies.

Delay Tolerant Networking↗

NASA NTRSDate not supplied

Automated End-to-End Spacecraft Connectivity Across Diverse Links

An increasing variety of communications services are available to space missions. Yet varying standards between providers hinder adoption due to the complexity of managing many configurations. We present a software framework to automatically establish end-to-end communications during contacts with a provider by configuring spacecraft protocols at the physical, link, and network layers. Underlying protocols and routes are abstracted, allowing the user to simply send data to a destination with the framework ensuring its delivery. We evaluate a full implementation of the framework in laboratory experiments conducted on an emulated communications testbed. These tests demonstrate data delivery across three different services with rapid (<20s) reconfiguration as the spacecraft transitions between providers.

satellite communication↗