The 4,450-hour airline transport pilot reported that he was having difficulty maintaining control of the single-engine experimental airplane while attempting to land. The pilot aborted the landing and executed a go-around. During the go-around, the pilot reported that the engine lost power. The pilot made a forced landing in a wet field one half-mile from the departure end of the 2,630-foot-long by 30-foot-wide asphalt runway. The airplane sustained structural damage to the main airplane truss, the left and right main landing gear spars, left and right wings, and the propeller. The weather reported at the time of the accident was wind from 150 degrees at 5 knots, clear skies, unlimited visibility, and a temperature of 70 degrees Fahrenheit. The reason for the reported loss of engine power could not be determined