LIFETIME TESTING: ORBITEC utilizes burn-in to screen for and eliminate marginal devices, which cause time and stress dependent failures. The theory behind this activity is to verify performance capability and eliminate infant mortality (early life cycle failures). Powered life testing may also be employed to make predictions about failure-free operation and mission assurance.

The Arrhenius Accelerated Life Test model is one example where hardware can be tested for failure mechanisms that depend on chemical reactions, diffusion processes or migration processes. This covers many of the non- mechanical (or non material fatigue) failure modes that cause electronic equipment failure. These stresses simulate typical device performance at elevated temperatures and maximum operating voltages and use the relationship between temperature, voltage and time to derate failure rates obtained under these accelerated conditions to use conditions. ORBITEC utilizes a temperature controlled chamber where devices are stressed at temperatures beyond that expected in the associated flight application. Controller boards are electrically tested at various read points in order to determine, under these accelerated conditions, how the device might perform in infant life and long term life. Devices are required to satisfy all specifications over full voltage and temperature ranges at all read points, independent of the type of stress. Common test conditions for a piece of hardware designed to operate at a maximum expected temperature of 40°C would be tested at 125°C, in 1000 hour increments at 28.0 VDC.

Arrhenius Equation R = Ae^(-Ea/kT)

In which:
R = failure rate (or reaction rate)
A = empirical rate constant
E_a = activation energy (eV)
k = Boltzmann's constant (8.6 x 10-5 eV/K)
T = temperature in Kelvin (° C + 273.16° C)

So, for this particular failure mechanism, 4000 hours of testing at 125°C is equivalent to 209,840 hours (23.95 years) of operation at 40°C.