Survey of Inter-satellite Communication for Small Satellite Systems: Physical Layer to Network Layer View

Small satellite systems enable whole new class of missions for navigation, communications, remote sensing and scientific research for both civilian and military purposes. As individual spacecraft are limited by the size, mass and power constraints, mass-produced small satellites in large constellations or clusters could be useful in many science missions such as gravity mapping, tracking of forest fires, finding water resources, etc. Constellation of satellites provide improved spatial and temporal resolution of the target. Small satellite constellations contribute innovative applications by replacing a single asset with several very capable spacecraft which opens the door to new applications. With increasing levels of autonomy, there will be a need for remote communication networks to enable communication between spacecraft. These space based networks will need to configure and maintain dynamic routes, manage intermediate nodes, and reconfigure themselves to achieve mission objectives. Hence, inter-satellite communication is a key aspect when satellites fly in formation. In this paper, we present the various researches being conducted in the small satellite community for implementing inter-satellite communications based on the Open System Interconnection (OSI) model. This paper also reviews the various design parameters applicable to the first three layers of the OSI model, i.e., physical, data link and network layer. Based on the survey, we also present a comprehensive list of design parameters useful for achieving inter-satellite communications for multiple small satellite missions. Specific topics include proposed solutions for some of the challenges faced by small satellite systems, enabling operations using a network of small satellites, and some examples of small satellite missions involving formation flying aspects.Comment: 51 pages, 21 Figures, 11 Tables, accepted in IEEE Communications Surveys and Tutorial

Quantum Communication Uplink to a 3U CubeSat: Feasibility & Design

Satellites are the efficient way to achieve global scale quantum communication (Q.Com) because unavoidable losses restrict fiber based Q.Com to a few hundred kilometers. We demonstrate the feasibility of establishing a Q.Com uplink with a tiny 3U CubeSat (measuring just 10X10X32 cm^3 ) using commercial off-the-shelf components, the majority of which have space heritage. We demonstrate how to leverage the latest advancements in nano-satellite body-pointing to show that our 4kg CubeSat can provide performance comparable to much larger 600kg satellite missions. A comprehensive link budget and simulation was performed to calculate the secure key rates. We discuss design choices and trade-offs to maximize the key rate while minimizing the cost and development needed. Our detailed design and feasibility study can be readily used as a template for global scale Q.Com.Comment: 24 pages, 9 figures, 2 tables. Fixed tables and figure

Satellite TT&C for Cubesats with Applications for Grissom-1

This thesis describes the assessment and analysis performed to characterize the communication subsystem used for command and telemetry transmission in support of the Grissom-1 Mission (GM1). The GM1 is unique in that it represents the pathfinder for a standardized 6U bus that serves as the basis for future CubeSat missions to host a variety of technical and scientific payloads, as prioritized by the Department of Defense, requiring flight demonstration or access to the orbital environment. Lab-based testing within an anechoic chamber provided link margin data required to characterize the command and telemetry links of the GM1. Experimental data describing the results of each test are also included. The research culminates in a full characterization of the software-defined radio, an analysis of the GM1 to MC3 communication interaction, and any limitations revealed as attributable to the 6U spacecraft. Collected data supports an analysis of the limitations inherent to the current GM1 communications subsystem configuration as operated at a variety of orbital distances plus recommended augmentations to the MC3 network to support those distances

Engineering Challenges of a CubeSat Mission Around the Moon: First Steps on the Path to SelenITA

Flying beyond Earth\u27s sphere of influence has been part of the main goals in space exploration. Efforts of the Artemis program now encompass different classes of missions, including CubeSats. With the challenges of deep space as mission drivers, planning, designing, launching, and operating a CubeSat for a Moon mission is proving to be a step up in difficulty. In this context, SelenITA Mission is conceived as a science mission supporting the Artemis efforts, planned to operate at Low-Lunar Orbit (LLO), flying below 200 km gathering space weather and geophysics observations, marking the first Brazilian mission to the Moon. This paper outlines the engineering challenges encountered this far in the development of SelenITA. It presents the aspects of lunar orbits and the effects of Moon\u27s potential field on a 12U CubeSat in LLO. A Reference Scenario is established, followed by an exploration of the extreme lunar environment\u27s effect on the satellite\u27s thermal, radiation, and power aspects. Communication limitations in the cislunar environment are analyzed, and strategies for the Attitude and Orbit Control Subsystem are discussed. The paper also addresses the challenges associated with delivery, uncertainties, and supply chain. A conceptual overview of the system is presented, concluding with the future steps

Design and Analysis of CubeSats in Low Earth Orbit

This work evaluated the power, propulsion, and telecommunications subsystems for CubeSats to support two missions in low earth orbit; a Rendezvous (formation flying) mission and a mission to explore extreme low earth orbit. After selecting a baseline set of hardware for each spacecraft, trade studies were performed to evaluate options. Chemical and electric propulsion options for both primary and attitude control were considered. Thrusters for attitude control were compared with reaction wheels and performance compared for both required maneuvers and disturbance torque compensation. Power subsystem trades considered different solar arrays and battery options. Telecommunication subsystem trades compared data link budgets for different orbit inclinations and receiving station networks

OPTIMIZATION OF INTER-CUBESAT COMMUNICATION LINKS

Cubesat constellations may become the next generation of communication backbone architecture to provide future worldwide communication services. In this thesis, we investigate the feasibility of deploying Cubesat constellations with inter-satellite links (ISL) for the delivery of continuous global communication. Cubesat constellation designs for various mission scenarios are proposed and verified using a simulation toolkit commonly used by space engineers. Link optimization to improve the overall theoretical data rate is also discussed. The results obtained affirm that a Cubesat constellation at an orbital height of 450 km can achieve a data rate of 11.46 kbps and requires the least number of satellites in the constellation. We ascertained that using ISL as the communication backbone in a network architecture, complete with space and globally distributed ground nodes, is achievable. In the near future, there is a high potential for the implementation of ISL with optical communication links, whereby there is assurance of a significantly higher data rate and lower power requirements.Civilian, Singapore Technologies ElectronicsApproved for public release; distribution is unlimited

Power Budgets for CubeSat Radios to Support Ground Communications and Inter-Satellite Links

CubeSats are a class of pico-satellites that have emerged over the past decade as a cost-effective alternative to the traditional large satellites to provide space experimentation capabilities to universities and other types of small enterprises, which otherwise would be unable to carry them out due to cost constraints. An important consideration when planning CubeSat missions is the power budget required by the radio communication subsystem, which enables a CubeSat to exchange information with ground stations and/or other CubeSats in orbit. The power that a CubeSat can dedicate to the communication subsystem is limited by the hard constraints on the total power available, which are due to its small size and light weight that limit the dimensions of the CubeSat power supply elements (batteries and solar panels). To date, no formal studies of the communications power budget for CubeSats are available in the literature, and this paper presents a detailed power budget analysis that includes communications with ground stations as well as with other CubeSats. For ground station communications we outline how the orbital parameters of the CubeSat trajectory determine the distance of the ground station link and present power budgets for both uplink and downlink that include achievable data rates and link margins. For inter-satellite communications we study how the slant range determines power requirements and affects the achievable data rates and link margins

Test and Evaluation of GRISSOM-1 CubeSat Communication Subsystem

The Grissom-1 mission (GM1), slated to launch in September 2022, is the first in a series of 6-Unit CubeSat satellites built and operated by the Air Force Institute of Technology’s (AFIT’s) Center for Space Research and Assurance (CSRA). Mission success for GM1 depends on a comprehensive campaign of testing and assessment to confirm the components, design, and assembly of all systems and subsystems within the satellite. This paper specifically focuses on the testing and analysis of all communication links between the spacecraft, the ground system, and the Satellite Operations Center (SOC) being hosted at the Air Force Instituteof Technology at Wright Patterson Air Force Base. Additionally, the paper will cover the potential for future missions for the GM1 based off the analysis of the current link. Specific to the GM1, analysis is performed on the spacecraft’s Cadet Plus software-defined radio (SDR), as developed by the Space Dynamics Laboratory, and its communication capabilities with the Mobile CubeSat Command and Control (MC3) network, the National Instruments USRP-2292 ground station SDR, and COSMOS Command and Control (C2) software. Testing and assessment occurred in both lab settings and simulated operational scenarios. This paper includes characterization of individual components, anechoic chamber downlink and uplink signal measurements and results, link margin calculations, plus direct point-to-point testing results. Experimental data describing the results of each test using the local instance of an MC3 ground station software. The research culminates in a full characterization of the Cadet Plus SDR, an analysis of the GM1 to MC3 communication interaction, and any limitations revealed as attributable to the 6U spacecraft

Inter-plane satellite matching in dense LEO constellations

Dense constellations of Low Earth Orbit (LEO) small satellites are envisioned to make extensive use of the inter-satellite link (ISL). Within the same orbital plane, the inter-satellite distances are preserved and the links are rather stable. In contrast, the relative motion between planes makes the inter-plane ISL challenging. In a dense set-up, each spacecraft has several satellites in its coverage volume, but the time duration of each of these links is small and the maximum number of active connections is limited by the hardware. We analyze the matching problem of connecting satellites using the inter-plane ISL for unicast transmissions. We present and evaluate the performance of two solutions to the matching problem with any number of orbital planes and up to two transceivers: a heuristic solution with the aim of minimizing the total cost; and a Markovian solution to maintain the on-going connections as long as possible. The Markovian algorithm reduces the time needed to solve the matching up to 1000x and 10x with respect to the optimal solution and to the heuristic solution, respectively, without compromising the total cost. Our model includes power adaptation and optimizes the network energy consumption as the exemplary cost in the evaluations, but any other QoS-oriented KPI can be used instead