Kuniyuki Omagari

Tokyo Tech CubeSat: CUTE-I - Design & Development of Flight Model and Future Plan -

Laboratory for Space Systems, Tokyo Institute of Technology finished development of CUTE-I and is waiting for its launch on June 30, 2003. CUTE-I is the first CubeSat of Tokyo Institute of Technology, that is a 10 cm-edge cube-sized satellite of less than 1kg mass. CUTE-I has three missions such as communication, attitude sensing and deployment. to establish a bus component design for pico satellites like the CubeSat. In parallel with the CUTE-I development, we also developed a separation mechanism that is used to separate CUTE-I from the launcher on orbit. In this paper, we describe the design of CUTE-I and the separation mechanism as well as results of environment tests such as long-range communication test, thermal vacuum test, vibration test and separation test. We also mention a Tokyo Tech future plan on our satellite development.

NEW SPINNING DEPLOYMENT METHOD OF LARGE THIN MEMBRANES WITH TETHER CONTROL

In this paper, we propose one membrane deployment method: tether-controlled spinning deployment. Very large, thin and flexible membrane (sail) is packed and then is deployed in orbit. In the process of membrane deployment, we use controlled tethers to stably deploy the membrane. Some types of the system are proposed, and the characteristics and technical issues are briefly mentioned. Numerical simulation results using a distributed mass-tether network model show the potential advantage of the proposed method. An experimental set-up of the proposed deployment using the two-dimensional micro-gravity simulators developed at Tokyo Institute of Technology is introduced, and the result of preliminary deployment experiments with a thin membrane of 1m-sized is shown.

Tokyo tech nano-satellite Cute-1.7 + APD flight operation results and the succeeding satellite

Abstract The Laboratory for Space Systems, Tokyo Institute of Technology had developed a nano-satellite, Cute-1.7 + APD. The satellite was launched as one of the subpayloads of the JAXA M-V-8 rocket on February 22, 2006, and deployed into an orbit using a separation mechanism that is developed in this project. The satellite conducted missions including house-keeping data retrieval, use of COTS devices, attitude determination, and amateur radio cooperation for two months. The succeeding satellite is also planned to be launched in 2007.

Tokyo Tech 1kg Pico-Satellite CUTE-I-Development, Launch & Operations

Abstract Tokyo Institute of Technology, Laboratory for Space Systems had developed a 1 kg pico-satellite CubeSat, CUTE-I, and it was successfully launched on June 30 2003 by a Eurockots rocket. CUTE-I is one of the first launched CubeSats and also the smallest civilian satellites in the world, which are able to make dual-directional communications with the ground stations. In this paper, the total design of CUTE-I flight model and operation results focused on its attitude analyses are explained.

X-ray polarimetry small satellite TSUBAME

“TSUBAME” is a university‐built small satellite mission to measure polarization of hard X‐ray photons (30–100 keV) from Gamma‐ray bursts (GRBs) using azimuthal angle anisotropy of Compton‐scattered photons. Polarimetry in the hard X‐ray and soft γ‐ray band plays a crucial role in the understanding of high energy emission mechanisms and the distribution of magnetic fields and radiation fields. TSUBAME has two instruments: the Wide‐field Bust Monitor (WBM) and the Hard X‐ray Compton Polarimeter (HXCP). The WBM determines on board the direction of the burst occurrence with an accuracy of 10 degrees, then using a high speed attitude control device, the HXCP is pointed to the GRB within 10 seconds after the burst occurrence to promptly detect polarized X‐ray photons from the GRB.We present a TSUBAME mission overview, results of a Monte Carlo simulation of the X‐ray polarization measurement and the plans for the future of this mission.

In-orbit performance of avalanche photodiode as radiation detector onboard a pico-satellite Cute-1.7+APD II

Cute-1.7+APD II is the third pico-satellite developed by students at the Tokyo Institute of Technology. One of the primary goals of the mission is to validate the use of avalanche photodiodes (APDs) as a radiation detector for the first time in a space experiment. The satellite was successfully launched by an ISRO PSLV-C9 rocket in Apr 2008 and has since been in operation for more than 20 months. Cute-1.7+APD II carries two reversetype APDs to monitor the distribution of low energy particles down to 9.2 keV trapped in a Low Earth Orbit (LEO), including 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-hour observations, will be presented to demonstrate the initial flight performance of the APDs in orbit.

Development of the X-ray polarimetry small satellite "TSUBAME"

TSUBAME is a university‐built small satellite mission to measure polarization of hard X‐ray photons (30–100 keV) from gamma‐ray bursts using azimuthal angle anisotropy of Compton‐scattered photons. Polarimetry in the hard X‐ray and soft gamma‐ray band should play a crucial role in the understanding of high energy emission mechanisms and the distribution of magnetic fields and radiation fields. TSUBAME has two instruments: the Wide‐field Bust Monitor (WBM) and the Hard X‐ray Compton Polarimeter (HXCP). The WBM detects a burst and determines on board the direction of the burst occurrence with an accuracy of 10 degrees. The spacecraft is then slewed to the GRB in 15 seconds from the trigger using CMG, a high speed attitude control device. HXCP will measure the polarized X‐ray photons from the GRB while the spacecraft is slowly spinning around the bore sight. In this paper, we present an overview of the TSUBAME mission, its expected performance of X‐ray polarization measurement based on Monte Carlo simulation...

Micro Glavity Experiment of Variable Speed Control Moment Gyro at MG-LAB

Variable Speed Control Moment Gyro (VS-CMG) is a kind of CMG, which has its rotor speed controllable. This method increases degrees of freedom and makes it possible to control CMG in null space easily. On the other hand, another use of VS-CMG is focused in this paper, which uses only one VS-CMG to realize a line of sight control of a small spacecraft. This paper describes experimentally evaluation of the control logic to decrease the angular velocity of a spacecraft using a VS-CMG. A VS-CMG which was used in this experiment was developed for pyramid array of 4CMGs, based on two designing parameters, which are also described. In this paper, development of experiment setup and result are explained.