Chameleon 12U to 27U Modular Bus that greatly reduces the satellite development timeline (3 to 4 years to under 18 months), and rapidly integrate and test ISR, Earth Observation and Remote Sensing, and other advanced DoD, Aerospace Industry and/or commercial payloads (1 year to under 3 months) for LEO Constellations to increase resiliency and works in a contested environment (EMP, RF emissions, etc.) . The Chameleon Bus will address these issues by providing an open modular, scalable, and reconfigurable (OMSR) solution which will drastically decrease the time required for design, fabrication (3D Printed), payload integration and test. It will add value for military relevance (disaggregation missions) and significantly reduce development timelines and life cycle cost (< 1/10). The 12U or 27U Bus standardizes satellite bus subsystem electrical and mechanical interfaces, and reduces non-recurring engineering costs, and enables rapid payload integration.