Abstract
The fourth small satellite project named "TSUBAME" has started by Lab for Space Systems (LSS) at Tokyo Institute of Technology. TSUBAME is the size of 30cm x 30cm x 30cm and weight of 30 kg. It has scientific and engineering missions: polarized X-ray observation of gamma ray burst by changing the attitude at high speed with CMGs. In this paper, an overview of TSUBAME and current status and future direction are introduced.