The KAISTSATs are a series of cost-effective microsatellites, developed and operated since 1992 by Satellite Technology Research Center, KAIST, Korea. The primary goal of the KAISTSAT program is to test novel technologies and payloads at low cost (~10 million $) and a short development period (~ 3 years). KAISTSATs 1-3 were launched in 1992, 1993 and 1999 and the latest one is due in 2002. The remarkable performances of KAISTSATs 1-3 have won international acclaim. For example, the 13.5-m resolution multispectral CCD camera on KAISTSAT3 has taken more than 800 scenes so far and proved its practical utility in forest fire monitoring, land classification and change detection. The far ultra-violet imaging spectrograph on KAISTSAT4 implements a novel concept for astronomical observation, developed jointly with U.C. Berkley. Also its data collection payload will enable the bilateral communication of ocean buoy data designed together with South Australian univ.. KAISTSAT5 and 6 are scheduled for launch in 2005 and 2008, and international collaboration is sought to develop new payloads and concepts. The stability of KAISTSAT bus has been verified by previous missions and its important specifications are as follows: total weight of ~ 100 kg; dimension of ~ 600 x 500 x 800 mm; sun-synchronous orbit at 700 - 1300 km; UHF/VHF/s-band communication; maximum payload weight of ~ 25 kg; maximum power allowed for a payload being ~ 40 W at 20% duty assuming the sun-lit period operation.