Environmental Stress Systems, Inc. (ESS) grew out of Step Electronics, Inc. in Campbell, California, which was established in the 1980s as an international microwave component supplier. When the founders saw additional opportunities in diverse markets, the company was expanded into several new divisions. One of the divisions began manufacturing standard and custom thermal platforms in 1987. Eventually, each new division was set up as a separate company. ESS, Inc. was established in 1989 as a spin off from Step Electronics by the environmental test equipment design and manufacturing personnel. The business was moved to Sonora, California where it is still located today. Over the years the product line has expanded to provide an array of environmental stress screening products for the commercial, automotive, aerospace and military electronics industries.