Development of Mission Payloads Onboard High Voltage Technology Demonstration Satellite HORYU-II

High Voltage Technology Demonstration Satellite HORYU-II is a nanosatellite (30-cm cubic shape, 7 kg) developed by students at the Kyushu Institute of Technology. One of the objectives of this satellite is orbital demonstration of high-voltage technologies. The satellite with the highest voltage generation in low earth orbit (LEO) has been the International Space Station, generating 160 V. In orbit, especially LEO, the use of high voltage over 200 V induces arcing. HORYU-II is aimed to demonstrate new designs of solar array that can generate the power, free of arcs, by producing 300 V via a specially designed solar array itself, not via a conventional dc/dc converter. If successful, HORYU-II will become the first spacecraft in the world that achieves 300 V photovoltaic power generations in space. In this paper, we describe the detail of the mission payload development and verification. Preliminary flight results obtained since the satellite´s launch on May 18, 2012 to the sun-synchronous orbit at 680-km altitude are also briefly presented.