[1] The Cute-1.7+APD II, 10 × 15 × 20 cm 3 in size and 5 kg in mass, is the third picosatellite developed by students at the Tokyo Institute of Technology. One of the primary goals of the Cute-1.7+APD II mission is to validate the use of avalanche photodiodes (APDs) as a radiation detector for the first time in a space experiment. While the mission itself is immature compared to the forefront satellites of space plasma physics, use of APDs offers various possibilities regarding a brand-new electron energy analyzer for medium-energy electrons and ions (1-100 keV), as well as a high-performance light sensor for the future X-ray astronomy missions. The satellite was successfully launched by ISRO PSLV-C9 rocket on 28 April 2008 and has since been in operation for more than a year. The Cute-1.7+APD II carries two reverse-type APDs to monitor the distribution of low-energy particles (mainly electrons and protons) down to 9.2 keV trapped in a low Earth orbit (LEO), including the South Atlantic Anomaly (SAA) as well as aurora bands. We present the design parameters and various preflight tests of the APDs prior to launch, particularly, the high counting response and active gain control system for the Cute-1.7+APD II mission. Examples of electron/proton distribution, obtained in continuous 12 h observations, will be presented to demonstrate the initial flight performance of the APDs in orbit.Citation: Kataoka, J., et al. (2010), In-orbit performance of avalanche photodiode as radiation detector on board the picosatellite Cute-1.7+APD II,

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The problem of high-speed maneuver with CMGs (Control Moment Gyros) is considered. In general, CMGs are mostly mounted on large spacecraft, such as ISS (International Space Station) or MIR space station because it is large in size and requires a substantial amount of power. The objective of this paper is to introduce the Micro-CMG, which has been jointly-developed by LSS and TAMAGAWA SEIKI Co., Ltd. This CMG is used to achieve the mission that the small satellite named TSUBAME observes the emission of gamma-ray burst. Furthermore, a time-optimal control problem is solved numerically using the gradient method to obtain the time-optimal input to the pyramid array of four CMGs. The solution gives some indication of the feasibility of the mission of TSUBAME.

The Laboratory for Space Systems at the Tokyo Institute of Technology has developed the nano-satellite Cute-1.7+APD. The satellite was launched by JAXA M-V-8 rocket on February 22, 2006 and operated for about a month. A successor to the Cute-1.7+APD was developed and is named Cute-1.7+APD II. This new satellite is based on its predecessor but has some modifications. In this paper an overview of the Cute-1.7 series and flight model development of Cute-1.7+APD II are introduced.

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