NinjaSat Achievements and Lessons Learned

NinjaSat is a 6U CubeSat dedicated to X-ray astrophysics, launched on November 11, 2023. Scientific observations began on February 23, 2024, and as of June 27, 30 X-ray sources have been observed, yielding numerous scientific outputs. Beyond its primary mission of astronomical observations, NinjaSat has contributed to additional fields, including X-ray pulsar-based navigation, atmospheric studies using X-rays passing through Earth’s limb, investigations of atmospheric structure through orbital decay analysis, and studies of the relationship between the orbital radiation environment and solar activity. By expanding beyond its initial astronomical focus, NinjaSat has demonstrated the versatile potential of scientific CubeSats. This paper reviews NinjaSat’s one-and-a-half-year journey in orbit, highlighting its key achievements and the lessons learned.