One Year On-Orbit Results of Improved Bus, LoRa Demonstration and Novel Backplane Mission of a 1U CubeSat Constellation

Abstract

The BIRDS series from Kyushu Institute of Technology has deployed 1U CubeSat constellations from International Space Station since 2017. BIRDS-3 was deployed in June 2019. Lessons learnt from BIRDS-1 and BIRDS-2 have been used to improve the bus system of BIRDS-3. Improvements have been made in On-Board Computer, Electrical Power and Communication systems. BIRDS-3 has implemented novel Backplane Mission which uses SoftCIB; an in-house designed software defined backplane interface board. The mission has the potential to standardize interface and cut down on development time. BIRDS-3 project has placed a LoRa module to check its performance in space. The module has the potential for future low-cost, low-powered Store and Forward mission and CubeSat communication system. This paper provides detailed information on the improved BIRDS bus system, LoRa Demonstration and Backplane Mission designs, and onorbit results since its deployment in June 2019. The results presented are based on cumulative operation time of three years for three satellites operating each for a year. The satellites are functional and will remain in orbit until summer of 2021.

Onboard Data Prioritization Using Multi-Class Image Segmentation for Nanosatellites

“…However, these frequency bands have limited bandwidth, which consequently limits the maximum downlink speed capability for these satellites as compared to higher frequency ranges. Only 25% of active nanosatellites operate within the higher frequency bands, such as the S-band (2.2-3.4 GHz), C-band (4-8 GHz), X-Band (8-12 GHz), and K band (18)(19)(20)(21)(22)(23)(24)(25)(26)(27). In these bands, satellites can achieve increased data transfer rates due to the broader bandwidth available.…”

“…Based on previous satellite missions [7], 10-15% of data packets downlinked to the ground station in a single operation pass are missing, which implies these packets must be re-downlinked two or three times before a full image can be reconstructed on the ground. A VGA (640 × 480) image is typically 28 KB, and a 1280 × 960 image is 60 KB, based on data collected from the BIRDS-4 Nanosatellite [21,22]. With this, it will take 1-2 days of operations to downlink a single VGA image and 3 days of continuous operations to downlink a 1280 × 960 image.…”

Scalable and Configurable Electrical Interface Board for Bus System Development of Different CubeSat Platforms

“…Another example is OBC-COM_1, which denotes the first pin connecting the OBC/EPS board and COM board. 21,22,27,28,37,38, and 42 are linked to the main PIC and routed to the mission board. These 11 pins serve as digital interfaces for the bus and the payload, whereas pins 31-34 are serial peripheral interface (SPI) connections to the flash memory (FM) that the main PIC and mission payload share.…”

“…This also makes the backplane significantly more adaptable, especially during the initial development phase when routing changes are expected. BIRDS-3 [21] Backplane; Interface between the main PIC and payloads Lattice ispMach4000ZE 5.8 ns 1.7~1.9 V Figure 4 illustrates how data communication is performed between the bus system and mission boards. The 11 digital interfaces from the bus are routed to the mission boards through the CPLD.…”