The Hughes' 601 satellite -- now the Boeing 601-- was designed for the higher-power missions of the 1990s. The model was introduced in 1987 to meet anticipated requirements for high-power, multiple-payload satellites for such uses as direct television broadcasting to small antennas, mobile communications, and private business networks, and is the world's most-purchased satellite model. The Boeing 376 is second only to the Boeing 601 in popularity. The 376 spacecraft is spin stabilized, a concept developed at Hughes and used in its communication and scientific satellites for more than 20 years.