Flywheel energy storage systems have become an important research subject in recent years. They are also considered for space applications instead of hazardous and bulky electrochemical batteries. In this paper, a flywheel energy storage system has been designed for satellite attitude control systems. Power requirements of a small commercial satellite have been used as the starting point of the design. The designed system includes a BLDC motor. The machine is run as a motor for 60 min and the stored energy is discharged during the following 30 min to simulate low orbit satellite operation. Experimental results show that these systems can be used in space applications.