ITF-1 was launched from Tanegashima Space Center on Feb, 28, 2014. It reentered the atmosphere on Jun, 29, 2014.
ITF-1 Flight Model
We construct the network to interact with people who have experience receiving the signal from ITF-1.
We develop a new antenna without deployment mechanism and demonstrate in space.
We monitor FRAM microcomputer which has high radiation resistance, and others which have a good track performance in space.
ITF-1(Imagine The Future-1)
430MHz band/Morse (uplink)
430MHz, 144MHz band/F2D(DTMF) (downlink)
Attitude control system
ITF-1 adopted the passive magnetic control method by earth magnetism. ITF-1 used a permanent magnet and a hysteresis damper.
Attitude control components
For a magnetic material in a magnetic field, it is worked magnetic torque along direction which a magnetic moment in a magnetic material and magnetic field are parallel. A magnetic moment of permanent magnet loaded on ITF-1 interferes with earth magnetism, and ITF-1 will be able to control attitude direction.
Overview of permanent magnet
9.0 x 4.5 x 30.0 mm
30.0 mm direction
Surface magnetic flux density
150 deg C
ITF-1 will receive rotation kinetic energy from orbital deployer when it will be released. The rotation kinetic energy will constitute an obstacle to attitude control and ITF-1 needs to disperse it. However, since the atmosphere around ITF-1 is very dilute, a rotation kinetic energy dissipation rate is low and it takes a long time to stabilize attitude control. Therefore, ITF-1 uses the magnetic friction effect of hysteresis damper to disperse rotation kinetic energy and reduce the time to stabilize attitude control. We load two histerisis dampers on ITF-1.
Overview of hysterisis damper
1.0 x 1.0 x 70.0 mm (prism)
PC permalloy (themally treate
Structure team mainly handles the design and assembling of ITF-1.
Appearance of ITF-1
Material of ITF-1
Assembly of ITF-1 FM (1)
Assembly of ITF-1 FM (2)
Thermal control system
Thermal control team handles thermal analysis of ITF-1. We must prevent the temperature of all devices from exceeding limit temperature showed in following table. Thus, we analyze by method of panel point under high temperature worst condition and low temperature worst condition.
Range of limit temperature of devices in ITF-1
Power supply board
The result of analysis under high temperature worst condition and low temperature worst condition shows following figures. Thus, thermal design of ITF-1 covers the range of limit temperature of devices.
Result under high temperature worst condition
Result under low temperature worst condition
Power supply system
Power supply system consists of solar cells to generate electric power, battery, regulator to stabilize power supply part and power CPU to check discharge and charge. Satellite power supply bus adopts non-stabilized power supply system, in which solar cells or battery provide electric power and regulators stabilize voltage.
ITF-1 provides electric power generated by solar cells to devices and charging battery during sunshine. During shade, battery provides electric power to each devices instead.
Power supply system block diagram
ITF-1 has solar panels on four faces. In order to secure enough electric power, ITF-1 adopts Triple Junction GaAs solar cells which have sufficiently high efficiency of electric power generation.
Overview of Solar cell
Voltage at Pmax
Current at Pmax
40 x 80 mm
ITF-1 solar cells
ITF-1 adopts Li-ion battery. Solar cells generate electric power and charge battery during sunshine, and battery provides electric power to each devices only during shade.
ITF-1 has one Li-ion battery and stores it in battery box made of polyacetal resin to keep temperature. We design thermal condition to prevent the temperature of battery from exceeding 40 deg C and control the temperature by a heater to prevent it from falling below 0 deg C.
Power CPU adopts PIC16F877A. The works of Power CPU is followng below.
Power consumption of each devices
Communication system block diagram
Radio module / Antenna
ITF-1 has three radio module, DJ-C7 made by ALINCO, and two radio modules for 430 MHz band and one radio module for 144 MHz band. Antennas are 430 MHz monopole antenna, 430 MHz ultra small antenna, and 144 MHz ultra small antenna.
ultra small antenna