SastoCube is an educational, non-flight satellite based on the universal, highly popular CubeSat standard with a backplane board design inspired by University Space Engineering Consortium’s (UNISEC) CubeSat Subsystem Interface Standard (CSIS) and Kyushu Institute of Technology’s (Kyutech) multi-award winning BIRDS Satellite Project‘s BUS interface. SastoCube incorporates a complete end-to-end system of entire satellite-like subsystems and a ground station.
The On-Board Computer, also called OBC, is the brains of SastoCube. Powered by an ARM Cortex processor, the OBC controls all the input and output (IO) pins, receives data from sensors, stores data on onboard SD card and forwards the data through the Communication System (COM) after receiving commands from the Ground Station (GS).
The Electrical Power System, also called EPS, regulates voltage and supplies power to SastoCube’s systems. Powered by an ARM Cortex processor, the EPS charges the battery through external power supply and using solar panels. SastoCube has a single 1600mAh battery. The system checks battery health by monitoring voltage and current flow. Built in Over-Charge Protection (OCP).
The Communication System, also called COM, receives and transmits data to and from the Ground Station (GS). The COM is the gateway to the On-Board Computer (OBC). The OBC collects data from sensors and stores the data on the onboard memory storage unit. The stored data is forwarded to the GS through the COM after it receives commands from the COM as well. SastoCube uses NRF to transmit wireless radio signals in the license free ISM band.
The Sensor Board hosts an array of sensors including, but not limited to, pressure, gyroscope, temperature, magnetometer, accelerometer, GPS and humidity. The GPS antenna is located at one of the exterior panels of the board. Sensor Board is essentially the mission board that users can enable and receive data wirelessly to their computer to complete different projects.
The Backplane Board acts as the medium of connection between all the subsystems. All the boards integrate into a single board through rigid electrical connectors. This reduces the number of wires making an easy plug-and-play approach to satellite integration.
SastoCube hosts four solar panel boards that cover four external sides of the satellite. While technically the boards are part of Electrical Power System (EPS), the solar panels are an integral part of external structure that covers the entire satellite.
SastoCube’s carefully crafted Structure is designed in such a way that users can easily follow instructions in the manual to assemble or dissemble the satellite. Based on the CubeSat standard and Japanese Aerospace Exploration Agency’s (JAXA) handbook, SastoCube’s structure has minimized the number of structure components and tools needed for integration.