5S: Design and In-Orbit Demonstration of a Multifunctional Integrated Satellite-Based Internet of Things Payload

The Satellite-based Internet of Things (S-IoT) system offers a promising solution for accessing IoT devices in areas where terrestrial networks are inaccessible. These devices have significant roles in various scenarios, including aeronautic and maritime surveillance, data collection from sensors, and distress signals, from sinking ships. However, covering numerous IoT targets with a minimal number of satellites poses a challenge. This article proposes a solution known as the 5S payload designed for S-IoT. The 5S payload integrates five subsystems into a single unit, comprising the following components: 1) automatic identification system (AIS) for ship surveillance; 2) very high-frequency data exchange system (VDES) enabling two-way communication for ships; 3) automatic dependent surveillance-broadcast (ADS-B) system for aircraft surveillance; 4) data collection system (DCS) for user-defined sensors; and 5) emergency search and rescue (ESR) system. The design of the 5S payload adheres to the CubeSat standard and occupies a compact 1.5U size, enabling rapid manufacturing and deployment. The feasibility of the 5S payload was demonstrated on the TianTuo-5 satellite launched on 23 August 2020. Additionally, this article presents in-orbit experimental results spanning three years to further illustrate the effectiveness of the 5S payload.