Raytheon introduced the Radarange, the first commercially successful home microwave oven, in 1947. The appliance grew out of wartime radar research by Raytheon engineer Percy Spencer, who discovered that microwave radiation could heat food.
The first Radarange was enormous, standing roughly six feet tall and weighing hundreds of pounds. It cost several thousand dollars, so it was not a practical kitchen appliance for most households. Raytheon later developed smaller models, and countertop microwave ovens became much more accessible in the 1960s and 1970s.
The word Radarange combines radar with range, reflecting the technology’s origin. A common misconception is that Spencer invented microwave radiation itself; rather, he recognized a useful cooking application for microwave energy produced by magnetrons. The early machine also used water cooling, unlike the air-cooled systems common in later domestic ovens.