In 1958, Fairchild mesa transistors were considered for the D-17B Minuteman I guidance computer, but they did not meet military standards of reliability. Fairchild already had a solution in the planar technology of Hoerni proposed on December 1, 1957. In the spring of 1958, Hoerni and Last were spending nights on experiments with the first planar transistors. The planar technology later became the second most important event in the history of microelectronics, after the invention of the transistor, but in 1959 it went unnoticed. Fairchild announced the transition from mesa to planar technology in October 1960. However, Moore refused to credit this achievement to Hoerni, and in 1996 even attributing it to unnamed Fairchild engineers.