Hawai'iSat-1: Development Of A University Microsatellite For Testing a Thermal Hyperspectral Imager

Abstract

The Hawaiʻi Space Flight Laboratory (HSFL) was established at the University of Hawaiʻi (UH) at Manoa for two primary purposes: (1) to educate students and help prepare them to enter the technical workforce, and (2) to help establish a viable space industry that will benefit the State of Hawaiʻi. The second HSFL space mission, currently scheduled to be launched in late 2012, is STU-2, which includes a spacecraft being designed and built by the HSFL called HawaiʻiSat-1. The Operationally Responsive Space (ORS) Office located at Kirtland Air Force Base in New Mexico oversees the LEONIDAS contract, under which the STU-2 mission and the HawaiʻiSat-1 satellite are being developed. The primary objectives for HawaiʻiSat-1 mission are: (1) to demonstrate the ability of the HSFL to design, build, and operate a small satellite in the 80-kg class as a platform to test new technologies; (2) support the C-band Radar Transponder Experiment (CRATEX) Payload; (3) support the testing of the Thermal Hyperspectral Imager being developed at UH; and (4) perform Earth imaging using the HSFL Imaging Payload. The CRATEX payload, provided by Vandenberg Air Force Base, uses C-band transponders and precise orbit determination (provided by onboard GPS receivers) to help the Department of Defense and NASA calibrate their C-band tracking radars around the world. The HawaiʻiSat-1 spacecraft will be placed into a 550-km circular 9 p.m. ascending Sun Synchronous Orbit to optimize its support of the CRATEX payload. The 85-kg HawaiʻiSat-1 spacecraft is 3-axis stabilized using three magnetic torque rods and a reaction wheel for attitude control; and three sun sensors plus two inertial measurement units (each including a 3-axis magnetometer) for attitude determination. Communication is provided by S-band and UHF-band transceivers linked to a ground station located in the Kauaʻi Community College in Hawaiʻi, and other partner ground stations. Control of the mission will be done in the HSFL Mission Operations Center located on the University of Hawaiʻi campus at Manoa. Integration and testing of the spacecraft will be done in the clean rooms at the HSFL facilities on the UH campus, which includes a 1.6 meter diameter thermal vacuum chamber. The HSFL is using a core team of experienced professionals supplemented with graduate and undergraduate students to design, build, and test the HawaiʻiSat-1 spacecraft within a period of approximately two years from System Requirements Review until ready for launch. To keep the spacecraft cost to a minimum, commercial-off-the-shelf (COTS) components will be used when possible. The fairly benign radiation environment of such a low altitude orbit and the use of aluminum sheeting to shield the critical avionics, make the risk of using COTS for a 2-3 year mission to be acceptable while greatly reducing the cost as compared to using space-hardened parts.