Naoki Miyashita

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.

High-performance image acquisition & processing unit fabricated using COTS technologies

It is becoming imperative to have visual capabilities for space activities. There are increasing opportunities to use visual images coupled with image processing technologies for spacecraft sensing and control. To fill this need, we have developed a small, low-cost, high-performance image acquisition and processing unit (HP-IMAP), which uses commercial off-the-shelf technologies. In 2010, the HP-IMAP was launched to monitor a deployable structure. Herein, we describe the HP-IMAP and discuss its qualification tests.

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.

JetGun Sat “TOPPU”

In this paper, we report a conceptual design of micro-satellite for the verification of formation flying technologies. This satellite is a type of mothership-daughtership configuration called TOPPU which means a gust wind. The two satellites are connected by a tether; the mothership satellite has a docking mechanism installed, and a reel mechanism as well as gas jet gun to perform various orbital experiments. The system design of TOPPU is discussed, as is the progress of satellite system development.

Development of Mono-Propellant Propulsion System for A Japanese Microsatellite "Hodoyoshi-1"

As the development of microsatellite is recently increasing in the world, miniaturization of elements for space use is strongly desired to make efficient use of microsatellite with respect to its dimensions, cost, and capability of space mission. As for propulsion, chemical propulsion is the most suitable to microsatellite with progress in miniaturization because of its high thrust density, short term injection, and easiness to handle. However, the conventional propulsion for satellite is difficult to handle the propellant, hydrazine, due to its toxicity and high cost, so that universities and non-governmental associations developing their microsatellites have not installed such propulsion so far. Accordingly, we have been developing a propulsion system for microsatellites based on Hydrogen Peroxide because of its little toxicity, low cost, and handling properties compared to the conventional propulsion system. Thus, we completed a mono-propellant propulsion system for microsatellite with the policies of SAFTY FIRST and EFFECTIVE COTS. Now we are planning to demonstrate our propulsion system in a Japanese microsatellite, Hodoyoshi-1, to execute its phase shift in orbit. The propulsion system has a mono-propellant thruster with 500mN of thrust and 80 seconds of specific impulse. We already evaluated its performance in injection tests on ground and in vacuum, and are planning to conduct the detailed vacuum test and mechanical environment test such as vibration test for its launch. In this paper, we present the innovative propulsion system and its injection test.

A high-performance image acquiring and processing unit using a FPGA

Visual images are essentially important in space systems not only for simple monitoring but also base of various kind of sensing. Previously, camera systems and image processing units used to be designed separately. Compact image acquisition and processing systems with high performance can be obtained by integrating image processing units into cameras. We have developed a compact, multi functional, integrated image acquisition and processing unit. This unit comprises a CMOS image sensor, SDRAM, flash memory, and an FPGA that includes a CPU core. The unit is less than 70 mm cube and its weight is less than 300 g. It can perform image acquisition, and multifunctional image processing and compression; the compressed images can be decompressed flexibly as required. In this paper, we present an outline of the image acquisition and processing unit.

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.

Ground experiment system of reconfigurable robot satellites

Future in-orbit servicing missions will include capturing, inspecting and repairing damaged satellites, constructing large space structures, and supporting EVA (extra vehicular activities) of astronauts. In order to conduct the above missions, we have proposed a system of reconfigurable robot satellite clusters. The system consists of multiple satellites with reconfigurable arms. Utilizing its reconfigurability and mobility, the system can perform the tasks as well as far-site installation of a reconfigurable arm for constructing and inspecting structures. In order to investigate the proposed system, we construct a ground experiment system consisting two configurable arm models, three floating satellite simulators with gas-thrusters and a ground station. One arm is a reconfigurables brachiating space robot, RBR we have developed and the other is a newly developed one that consists of two parts; an arm part of 5 degrees of freedom with two reconfigurable end-effectors and a pivot; a docking part with two degrees of freedom. In the paper, we introduce the experimental system and the reconfigurable arms and show the results of functional and demonstration experiments using the system.

Titech CanSat Project 2000: Report of Sub-orbital Flight and Balloon Experiment

We have participated in the ARLISS (A Rocket Launch International Student Satellite) project since 1999 to design, manufacture and operate small satellites on students’ initiative. These satellites called CanSat are the size of soft drink can (350ml). We launch CanSats from the Black Rock desert in Nevada to 12,000ft using an amateur rocket, and drop them with a parachute. In this paper, we describe the subsystem design, mission and some results of the experiments on each CanSat, and report the results of an additional experiment using a balloon.