Shunsuke Araki
(Osaka Institute of Technology, Japan)

The Project of Osaka Institute of Technology Electric-Rocket-Engine onboard Small Space Ship (PROITERES) was started at Osaka Institute of Technology in 2007. In PROITERES, a nano-satellite with electrothermal pulsed plasma thrusters (PPTs) will be launched in 2011. The main mission is to achieve powered flight of nano-satellite by an electric thruster and to observe Kansai district in Japan with a high-resolution camera. The orbit raising of the satellite in Sun Synchronous Orbit will be carried out by the PPTs. In this paper, the attitude control system of the PROITERES satellite for observation with a high-resolution camera and for firing of PPTs was introduced.

Seigo Tokuyama
(Kobe University, Japan)

The ground stations are essential and necessary for the communication with micro-satellites, which aims at communicating with the satellite and getting information in real-time through the internet anytime and anywhere. The purpose of this project is realizing the ground station using the active phased array antenna. The major benefit of the active phased array antenna is to control the beam direction electrically without mechanical drive. Therefore, it will be free from mechanical maintenances and it can make possible to construct the receiving antenna in the region where the conventional parabolic antennas are difficult to be built. The whole sky must be freely scanned to track the satellites for the ground receiving station. The characteristics of one element must be almost omni-directional for the phased array antenna to realize freely scanning in the whole sky. We have newly developed the three dimension omni-directional antenna at the X band which is composed only three printed dipole antennas. The output of the three printed dipole antennas are combined in phase to receive the signal of the circular polarization. The detailed result will be described in our presentation.

Ayana Ohta
(Kobe University, Japan)

We are newly developing ground receiving stations for communications with nano-satellites using active phased array antenna rather than conventional parabolic antenna. This receiving system has a great advantage of the maintenance free. It is very easy to construct the worldwide nano-satellite receiving network, which can receive signals from the nano-satellites anywhere and anytime. The active phased array antenna is composed of the dipole antenna, the amplifier, the frequency mixer, the phase shifter, and the computer for phase synthesis. In this study, we designed the frequency mixer, the phase shifter, and the phase synthesis by using the computer. The phase shifter is connected to the LO input of the frequency mixers, and change the phase of the LO signal. As a result, the phases of the received X-band signal can be controlled with the computer, which is connected via the internet for the remote control. We have succeeded in two following items. One is to down-convert the received X-band signal to around 80MHz using the frequency mixers. The other is to develop an analog phase shifter for X-band using 3dB hybrid. We will present our results in detail in our presentation.

Hidekazu Masuda
(University of Shinshu, Japan)

In recent years, the requirement of high-speed data transmission is increasing for the Earth observation satellite with high resolution images and some scientific missions. So it will be expected to develop small antenna pointing mechanisms mounted on a small satellite. In this paper, we present the X-band Antenna Pointing Mechanism X-ANT onboard ASNARO which is the small earth observation satellite. ASNARO, which is being developed by NEC and USEF under the contact with NEDO, is a small LEO satellite for earth observation with optical sensor in a sub-meter class of GSD. The stored image data are transmitted to the ground station by the X-band transmitter and the directional antenna mounted on X-ANT. This Antenna Pointing Mechanism APM was developed by Tamagawa-seiki. Co. cooperated with Shinshu University. This paper represents the thermal design of X-ANT. The thermal vacuum test and thermal analysis (using Thermal Desktop) of the X-ANT was performed. Then we calibrated the analysis parameters based on result of the test. According to these results, we decided the thermal design of the X-ANT. Finally, X-ANT satisfies the required temperature level of satellite components during the whole period of mission. Now, we are developing smaller APM for small satellite.