The advanced spaceborne thermal emission and reflection radiometer (ASTER) is a facility instrument which has been selected by NASA to fly on the EOS-AM1 platform in 1998. Two independent cryocoolers are needed to cool down infrared detectors for the short-wave infrared radiometer (SWIR; 1.6 - 2.4 micrometer) and the thermal infrared radiometer (TIR; 8.3 - 11.3 micrometer). The goal in the development of the ASTER cryocooler is a durability of over 50,000 hours and mechanical vibration forces below 0.1 N in the frequency range from 40 Hz to 135 Hz in the directions of all three axes. A split- Stirling cycle cryocooler with clearance seals and linear electric motors is employed for this purpose. The compressor design for this adopts a piston driving mechanism which has a twin-opposed piston configuration, into one compression space. The mechanical vibration caused by an expander displacer is reduced by an active balancer. The cryocoolers for SWIR and TIR have a cooling capacity of 1.2 W at 70 K with power consumption lower than 55 W without control electronics. Two cryocoolers were evaluated from the viewpoint of cooling performance and mechanical vibration forces, and are presently undergoing life tests. The design concept and cryocooler performance test results which are indispensable for enduring a long life in space are described.