A CubeSat is a small satellite assembled from standardized cube-shaped units, usually one or more “U” modules. The design makes it inexpensive, compact, and fast to build, which is why CubeSats are often used to test new hardware, software, sensors, and mission concepts before they are scaled to larger spacecraft.
In cyber security, CubeSats matter because their small size does not make them simple. They still rely on command-and-control links, telemetry, onboard software, firmware, and radio-frequency communications, all of which can be attacked or monitored. Limited power, memory, and processing capacity can also restrict how much security software they can run. Defenders use CubeSats to validate authentication, secure boot, update paths, and resilience against spoofing, jamming, or malicious command injection. Because they operate in orbit, these tests show whether a control works in the real environment, not just in a lab.