The present invention relates to a system and method for the simultaneous testing of radiation, environmental and electrical reliability of multiple semiconductor devices. The system provides a simultaneous simulation of the space environment in which a device under test (DUT) is expected to operate under thereby providing an accurate test environment. One or more DUTs are simultaneously subject to each of a radiating dose, electrical bias and varying temperature. Additionally, each of the above may be varied over a range of values to provide test data under multiple testing conditions. Finally, a method for operating the system is provided which ensures reliable and high fidelity data from the system. The system comprises seven (7) interconnected subsystems, an electrical environmental subsystem, a radiation subsystem, an environmental control system, a radiation source control system, a temperature monitoring subsystem, an electrical stimulation and data acquisition subsystem and a data processing and analysis subsystem.