What is the CubeSat standard and why is it significant?

CubeSat is a standardized small satellite format. Unit (U): 10x10x10 cm cube, ~1.33 kg mass. Common configurations: 1U, 2U, 3U, 6U, 12U. The standard defines: Physical dimensions and mass, Deployment system interface (P-POD, PPOD), and Materials and testing requirements. Significance: Dramatically reduced cost of space access (rideshare launches), Enabled university and small company missions, Standardized components (COTS availability), Rapid development cycles (months vs years), and Technology demonstration platform. Limitations: Small payload volume, Limited power and propulsion, and Shorter design life. CubeSats now perform Earth observation, communications, and science missions previously requiring larger satellites. The standard spawned an entire ecosystem of components, launch services, and operators.