Navigating the new frontier: rapid deployment and robust testing of satellite systems
StoryJune 20, 2024
Kyle MacCoy
NI (National Instruments)
The space industry is undergoing a significant transformation, with several trends shaping its future. The small-satellite revolution – due to the increased demand for satellites to perform unique missions and the focus on smaller, less expensive satellite constellations – is driving an increased focus on cost efficiency, reliable testing, rapid deployment, and scalability.
The space industry’s shift toward small satellites, innovative data link systems, and modern testing approaches requires engineers and systems to adapt to meet the demands of rapid deployment and evolving technology in order to ensure reliable communication in ever-expanding space endeavors. Data link system testing and emulation is critical to ensuring reliable data transfer once deployed to ensure safe and secure communication for satellite-to-satellite and satellite-to-ground systems. Use of complex technologies such as electronically scanned array (ESA) antennas and software-defined radio (SDR) back ends drive modularity and adaptability. Because traditional, monument-type test systems are not flexible or scalable enough to tackle these challenges, multifunctional instruments and platform-based test solutions offer a radical new method to future-proof systems for the coming satellite deployment wave.
Orbital solutions to terrestrial challenges
The space industry is currently undergoing a remarkable metamorphosis characterized by several interconnected trends. First, there has been a rapid surge in the number of companies and governmental entities venturing into outer space. These stakeholders are actively participating in satellite deployments, which are becoming more common. The driving force behind this growth lies in the burgeoning demand for space-based applications that serve critical national interests: In the defense and national-security arenas, satellites are being deployed to provide surveillance, reconnaissance, and communications capabilities crucial for safeguarding borders, monitoring potential threats, and ensuring strategic preparedness.
Broadband communication concerns are being tackled through the proliferation of internet services based on satellite communication. Satellites facilitate global connectivity, bridging gaps in remote theaters for rapid, real-time situational awareness. Even climate research, which can affect operational environment and resource allocation in new and expanding theaters of interest, relies heavily on satellite data. These orbiting observatories help scientists track weather patterns, study climate change, and assess environmental conditions globally.
The Space Development Agency predicted several years ago that as many as 50,000 satellites will circle the globe within the next decade. This ambitious endeavor encompasses both low-Earth orbit (LEO) and geosynchronous positions. The rapid deployment of such a substantial number of satellites presents logistical challenges: Engineers and space agencies must address issues related to launch coordination, orbital management, and efficient deployment strategies, all of which rely on safe, secure data transmittal and communication.
The space industry’s market value is undergoing notable expansion, with one estimate noting that it reached approximately $384 billion globally in 2022. This economic growth reflects the increasing importance of satellite technology and its multifaceted applications. The confluence of increased participation, satellite deployment, and market expansion underscores the urgency of addressing communications infrastructure challenges. As humans venture further into space, ensuring reliable data links between satellites and ground stations becomes paramount.
Importance of SATCOM data link and telemetry test
The influx of new space companies and the desire to deploy emerging technologies have created a critical need for robust testing of data link systems. These systems facilitate the transmission of data to and from Earth, and between satellites themselves, essential for the function of both individual satellites as well as extensive constellations. Engineers must ensure the reliability of communication links, whether it involves a satellite communicating with one or multiple ground stations in configurations such as two-way transmission, receive links, or “bent-pipe” setups in which the data transmitted to the satellite is sent right back down again, with the only processing performed being retransmitting of the signals.
The small-satellite constellations being deployed to facilitate new applications can range from one craft to several thousand, each satellite rapidly orbiting the earth. The shifting nature of deployments presents a challenge for communications and connectivity for both inter-satellite and ground-station data links. In response, cutting-edge communications systems have been developed using modern ESA antennas that can rapidly shift one or more beams without any mechanical movement. This setup enables the telemetry, tracking, and control (TT&C) of multiple satellites at once while in the field of view of the array.
More importantly, these ESA arrays are inherently modular and scalable, which means that ground terminals and payloads can be optimized for specific applications and missions. These data links are further supported via software-defined radio (SDR) backends, which enable adaptive and reconfigurable data links such as the protocols prescribed by the Consultative Committee for Space Data Systems (CCSDS), a multinational forum convened for the development of communications and data systems standards for spaceflight.
Testing the systems
Traditional testing of these systems typically requires a substantial setup involving a large rack of equipment. This includes vector network analyzers (VNAs), vector signal transceivers (VSTs), signal generators, and spectrum analyzers, along with specialized hardware like telemetry receivers or emulators, often necessitating a golden or already calibrated device under test (DUT). The assembly and maintenance of these racks is not only costly but also cumbersome, involving multiple equipment providers and extensive third-party software for integration. This “old-school” approach results in an inefficient and unscalable system, ill-suited to the accelerating pace of satellite production and the need for rapid deployment and upgrades of ground systems.
Further, each phase of the development cycle – from R&D and prototyping to component function and parametric testing, all the way through to final system validation – requires unique protocols and test capabilities. (Figure 1.)
[Figure 1 ǀ An engineer is shown preparing for satellite test in lab.]
The modern approach to satellite testing emphasizes the integration of functions and adaptability across the satellite’s lifecycle. Instruments that combine these capabilities facilitate a more streamlined process, allowing engineers to move swiftly and efficiently from concept to orbit. These instruments are scalable and upgradable, aligning with the fast-paced evolution of production rates and technological requirements with our burdensome upgrade and maintenance costs.
Solutions for SATCOM data link and telemetry validation
The best solution for SATCOM and telemetry systems validation consists of commercial off-the-shelf (COTS) modular hardware and flexible software tools to address RF signal fidelity, system-level validation, and digital system test requirements. Solutions built on modular test platforms such as PXIe can be customized and modified to meet specific I/O performance requirements. Instruments such as a VST, which combines both a vector signal generator (VSG) and a vector signal analyzer (VSA) can transmit and receive TT&C and SATCOM data link signals performing key signal fidelity measurements such as modulation accuracy, transmit power, and more.
A VST can be augmented with additional instruments such as a high-speed serial coprocessor with full-rate streaming to and from an open FPGA capable of hosting real-time, inline signal processing and channel models. With a coprocessor configuration, a VST is capable of being transformed into an RF channel emulator, unlocking the ability to perform full system-level validation. (Figure 2.)
[Figure 2 ǀ SATCOM telemetry validation with COTS NI PXIe modules.]
Digital system test can be accomplished with the use of flexible I/O modules and FPGAs [field-programmable gate arrays], as well as with a digital front-end configuration. Combining a large user-programmable FPGA with a serial or parallel digital I/O board to meet the system interfacing and IP protocol requirements of satellite payload subsystems allows unique test setups and protocols to be achieved with minimal investment in new hardware. Engineers can import custom digital protocols to emulate digital interfaces without using custom hardware.
The coming horizon of testing and deployment
As the space sector continues to expand, the importance of adopting these integrated and efficient testing solutions will also increase. With testing, users can ensure that new technologies can be deployed effectively, manage the increasing congestion in space, and maintain the integrity of essential satellite functions. This shift is not merely a response to current challenges but a proactive approach.
Kyle MacCoy has been in the aerospace, defense, and government sector for more than 15 years. He has worked as an engineer supporting the U.S. Navy and the Marine Corps on multiple vertical-lift platforms, in the commercial sector producing airliner hardware, and in the startup world to produce and launch space vehicles. Now with NI (part of Emerson), Kyle is fulfilling the role of solution marketer focusing on the SLV [satellite launch vehicle] applications in CNS [celestial navigation systems] and radar/electronic warfare. Readers may reach the author at [email protected].
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