Cryogenic coolers for small satellites require low power and minimum weight. The need for exceptional reliability in a space cooler is even more critical on small satellites since cooler redundancy is often not an option due to weight constraints. In this paper we report on a reliable, small, efficient, low-power, vibrationally balanced cooler designed specifically for use on small satellites.TRW has designed, built, and tested a miniature integral Stirling cooler for long-life space application. This efficient low-vibration cooler weighs 1.4 kg and was developed for cooling infrared sensors to temperatures as low as 50 K on lightsats.The vibrationally balanced nonwearing design Stirling cooler incorporates clearance seals maintained by flexure springs for both the compressor and the driven displacer. The design achieved its performance goal of 0.25 watt at 65 K for an input power to the compressor of 12 watts. The cooler recently passed launch vibration tests prior to its entry into an extended life-test and its first scheduled flight in 1995.