The Hawaii Space Flight Laboratory (HSFL) was established at the University of Hawaii at Manoa to educate students and help prepare them to enter the technical workforce, and to help establish a viable space industry that will benefit the State of Hawaii. In 2011 the first mission, STU-1, will be launched. It includes a spacecraft being designed and built by the HSFL called LEO-1. The primary objectives for LEO-1 mission are: (1) to demonstrate the ability of the HSFL to design, build, and operate a small satellite in the 50-kg class as a platform to test new technologies; and (2) support the C-band radar transponder experiment (CRATEX) for the USAF; the Coherent Electromagnetic Radio Tomography (CERTO) experiment for the Naval Research Laboratory; support the LEO-1 Solar Array Experiment; and to demonstrate the suitability of the LEO-1 spacecraft to test technologies suitable for missile detection and tracking. The radar calibration experiment uses C-band transponders and precise orbit determination to test new technologies designed to aid the Department of Defense to calibrate their radars around the world. The CERTO Doppler beacon provides accurate orbit determination using various ground stations around the world, but also provides data that will be used to help characterize the ionosphere for space weather monitoring. A secondary payload consists of two digital imagers to provide color images of the Earth. The LEO-1 spacecraft will be placed into a 600-km circular 9 p.m. ascending Sun Synchronous Orbit to optimize its support of the radar calibration experiment. The 60-kg LEO-1 spacecraft is 3-axis stabilized using three magnetic torque rods and a reaction wheel for attitude control; and two sun sensors, a 3-axis magnetometer, and an inertial measurement unit for attitude determination. Communication is provided by a UHF- transceiver linked to a ground station located in the Leeward Community College in Honolulu and other partner ground stations. Control of the mission will be done in the HSFL Mission Operations Center located on the University of Hawaii campus at Manoa. Integration and testing of the spacecraft will be done in the clean rooms at the HSFL facilities on the UH campus. The HSFL is using a core team of experienced professionals supplemented with graduate and undergraduate students to design, build, and test the LEO-1 spacecraft. Part of the design philosophy includes the development of two nearly identical spacecraft - the Engineering Model which will be used for integrated testing and then transitioned to be part of the tesbed/simulator for operations, and the Flight Model. Another means employed to keep the spacecraft cost to a minimum is the use of commercial-off-the-shelf (COTS) as much as possible.