In-Orbit Results of a Commercial-of-the-Shelf (COTS) Imaging Payload for Birds-4 1U CubeSat Constellation

This paper presents the in-orbit results of a commercial-off-the-shelf (COTS) imaging payload deployed on the BIRDS-4 1U CubeSat constellation. The BIRDS-4 Satellite project, hosted at the Kyushu Institute of Technology, aims to develop Paraguay's first satellite while enhancing the standardized bus system for future missions. The imaging payload, utilizing proven components, consists of a microcontroller, dedicated flash memory, and a camera module with a modified lens. Mission-specific software complements the hardware, enabling various mission modes. The imaging payload achieves a 5MP camera resolution, a 125-degree diagonal field of view, a 1000km ground swath, and a 300m ground resolution. The paper provides detailed information about the payload design, mission modes, and specifications. The flight model successfully underwent ground tests, including thermal vacuum, vibration, and long-duration tests, validating its functionality. In orbit, the payload executed several mission modes, and images were downloaded through the BIRDS-4 ground station network. While the mission achieved medium success, capturing low-resolution images of Earth with identifiable land masses and images during release from the International Space Station (ISS), lessons learned were identified for future missions, such as improved satellite pointing, extended access time for image transfer, and enhanced mission execution commands. Noteworthy images, including Salar de Uyuni in Bolivia, the Parana River in Latin America, Shikoku Island in Japan, and a photo of the ISS and Earth, were captured and distributed for promotional and outreach activities. The obtained images, totaling 89 with 81 successfully downloaded, range from 3kB to 99kB in size, comprising 2.33 MB of data. The images were categorized into Earth, Solar Flare, Space, and Unknown. The paper concludes by highlighting the application of lessons learned in the subsequent iteration of the satellite developed locally by a new team from the Philippines.