Lessons Learned and First Results of the E-Band CubeSat EIVE

Abstract The 6 Unit CubeSat EIVE was developed to to host a novel high-speed E-band transmitter payload. Challenging aspects for reliable and demanding satellite architectures were revealed during development and operations. Reliable communication buses such as CAN, RS485 or point-to-point links should be preferred over I2C or SPI. Experiences from the implementation of the individual subsystems are presented and lessons learned derived in this paper. The on-board data handling and communication system is based on a system-on-a-chip architecture and uses the CCSDS protocol via S-band. The FPGA section proved advantageous while the use of high-priority commands is essential for in-orbit debugging. The conservative approach to the design of the power system and the high effort to test the thermal design of the EIVE CubeSat led to a stable satellite regarding the power-budget and temperature ranges. The self-developed solar panels and their deployment mechanism worked as intended with many lessons learned in the process. A major part of the time spent on integration was on the harness. The attitude control system is based on self-developed components and commercially acquired units. With most of the attitude control components being tested and calibrated on a best effort basis, more resources should have been committed to testing the GNSS receivers and the star tracker on ground. A stable safe mode was achieved after multiple bugs fixes in the first weeks after the launch. Since then, steady progress towards nominal operation has been achieved.