A series of low-cost spacecraft buses have been designed which are sized to host dedicated sensor packages to be launched into low earth orbit on small inexpensive launch vehicles or in a Get-Away-Special Canister in the Space Shuttle. These buses facilitate realizing rapid on-orbit status by employing a standard system module with flexible options for attitude control and power. The buses may be configured for operational or experimental missions with lifetimes of a few months to several years. The series consists of three classes of spacecraft, each one sized to satisfy a range of requirements for mission in the areas of remote sensing, space experiments, technology testing, microgravity studies, surveillance, environmental and geophysical measurements, location determination, real-time and store-and-forward communications, and other space applications. Integral to each class of bus is a communications and data handling package which provides programmable mission activities under operator control through a companion low cost ground station. Parameters for size, power, and weight are scaled to the requirements of the payload. These buses permit rapid implementation of operational or experimental remote sensing programs within limiting monetary constraints.