This topic page covers the design of communications subsystems for small satellites. This includes design of subsystem components; selection of commercial off-the-shelf (COTS) components; and integrated design and configuration of the complete subsystem. The communications subsystem enables a spacecraft to exchange data with Earth and other spacecraft for uplink of commands, downlink of housekeeping telemetry and payload data, and crosslink of data that facilitates coordination between spacecraft in a distributed mission architecture. Satellites primarily use radio frequency communications systems; however, recent advances in laser communications terminals and ground station services have made free-space optical links a viable alternative. A diverse array of smallsat RF components (i.e., radios and antennas) are available commercial off-the-shelf (COTS). Reliable and system-oriented design of this subsystem is important because the communications subsystem is often essential to facilitating on-orbit fault recovery; involves high-risk deployables; and drives attitude control, thermal, and power requirements.
Resources in this topic area are primarily website databases of smallsat COTS components and case studies for smallsat communications subsystem design.
Consider implementing a commercial constellation transceiver (e.g., Iridium transceiver) to act as a backup communication pathway and provide constant, low volume telemetry outside of ground station passes.
Calculate your link margin early in your design process and constantly review it during testing.
Consider performing over-the-air communications testing to verify link budgets.
If your design includes a compatible transmitter that operates in the amateur band, engage with the amateur radio community to connect with volunteers that can help you track and establish communications with your satellite.
It is extremely important to consider regulatory requirements when designing your communications system. The delays (and roadblocks) involved in the licensing process for operation in certain radio frequency bands could cause you to miss your launch opportunity.
SPOON is an online database of smallsat components such as payloads, flight processors, antennas, propulsion ... systems, equipment for ground stations, and power systems.
The CubeSatShop provides commercial-off-the-shelf (COTS) components from verified vendors for small satellites. ... This link directs users to the communication systems page where COTS hardware components can be purchased.
This annual state-of-the-art report from NASA provides "a survey of small spacecraft technologies sourced ... from open literature" with an introduction to each technology, development status and performance metrics for procurable systems, and descriptions of new technologies with reference missions. Section 9 of this report covers communications technologies.
This slide deck provides an overview of the OCSD (AeroCube-7) and R-Cubed (AeroCube-11) cubesats. Images ... of the communication subsystems are shown as well as the planned relay network with a GEO satellite and ground stations.
This article provides detailed information on CubeSat communications and the future direction of research ... in both industry and academia with respect to Internat of Things (IoT) networks. It includes an overview of CubeSat constellations, various communication links, link budget calculations, modulation and coding methods, and application layer protocols for CubeSats.
This article provides a detailed survey of the research being conducted on small satellites with inter-satellite ... communications. Additionally, it discusses the first three levels (i.e. physical, data link, and network) of the Open System Interconnection (OSI) model.
SMAD is a practical handbook for space mission engineering covering all aspects of a space system - from ... orbit and constellation design to operations. This chapter on communications discusses the overall communications architecture, data rates, link design, sizing of communications payloads, and special topics related to satellite communications.
This article discusses both S- and X-band communication systems used on smallsats, and more specifically ... cubesats. It provides analysis, test results, and direct comparisons between the two communication payload systems.
SMAD is a practical handbook for space mission engineering covering all aspects of a space system - from ... orbit and constellation design to operations. This section titled "Telemetry, Tracking, and Command" (TT&C) addresses subsystem requirements and design of the TT&C subsystem.
This article provides detailed information on link margin, link optimization, examples, and analysis ... insights. Section 2 discusses link analysis techniques with examples, equations, and figures to provide a brief overview of link analysis.