KEPLER-21, also known as Kepler-21, is a 6U CubeSat satellite designed for Communication M2M/IoT purposes and was launched on April 15, 2023, from AFWTR Launch Site at SLC4E using the Falcon 9 launch vehicle. Manufactured by KEPLER/UTIAS, it has dimensions of 0.3 meters in length, 0.2 meters in diameter, and a span of 0.7 meters with a dry mass of 15 kg. The satellite is equipped with SDR and narrowband communications payload and uses solar cells along with batteries for power supply. It was stabilized by April 26, 2023, and its shape consists of a box with two panels.