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About ChubuSat-2 Satellite

The ChubuSat-2 is now in the initial operation phase (on March 5, 2016).
  • The satellite communication via Amateur radio band was established
    • CW Beacon: The central frequency is 6 kHz lower than the expected value.
    • FM telemetry: The central frequency does not change, but a peak structure at +/-5 5 KHz is seen in the spectrum.
  • We have successfully received signals from ChubuSat-2.
Thank you for your reports on receiving signals from our satellite. We still need further information. We appreciate for your kind help.


  • Feb. 17, 2016 Launched from JAXA Tanegashima Space Center.
  • Jan. 15, 2016 ChubuSat-2 was transferred from JAXA Tsukuba Space Center to JAXA Tanegashima Space Center.
  • Dec. 11-20, 2015 Thermal vacuum test was completed.
  • Dec. 15, 2015 Preliminary license of radio stations was issued to ChubuSat-2.
  • Dec. 11, 2015  A launch date was determined to Feb. 12, 2016.
  • Nov.26-Dec.2, 2015 Satellite baking was completed
  • Nov.16-20, 2015 Vibration test was completed.
  • Nov.11-13, 2015 Separation Shock test was completed
  • Aug.27, 2014 ChubuSat-2 was selected as one of the piggyback payloads of ASTRO-H.

★Recent Pictures


E-mail: chubusat2 [at] frontier.phys.nagoya-u.ac.jp

ChubuSat-2 Satellite

Past Background and Overview

ChubuSat-2, so-called Kinshachi 2, is the second satellite of ChubuSat, a series of 50 kg-class microsatellite, following ChubuSat-1. The size is about 50 cm cubic, and the weight is about 50 kg. It was selected with ChubuSat-3 as one of the piggy-back payloads of the X-ray astronomical satellite ASTRO-H. Since then, it has been seriously developed in collaboration among Nagoya University, Daido University, and aerospace industrial small and medium-sized companies (MASTT: Monozukuri AeroSpace Technology Team). The ChubuSat-2 was already completed and is waiting for launch by H-IIA rocket at JAXA Tanegashima Space Center. The ChubuSat aims to activate aerospace industries around the Chubu region and accelerate the commercialization by successive launch.

Mission Purpose

The primary mission of ChubuSat-2 is to support ASTRO-H celestial observations by monitoring radiations which can be a background noise for onboard instruments of ASTRO-H in the same orbit and epoch as ASTRO-H. A message exchange service can be made publicly available to world-wide ham fans via amateur radio system onboard ChubuSat-2. Furthermore, we plan to observe solar neutrons which were proposed by graduate students in the ChubuSat instrument development project.

System Overview

1.Mission Instruments

ChubuSat-2 carries two types of mission instruments shown below.
  • Radiation Detector (RD): It can observe neutrons and gamma-rays in radiations. The semi-conductor photo-sensor MPPCs (Hamamatsu Photonics) and GAGG scintillators (Furukawa Elec.) are used in space for the first time. It was designed and developed by Nagoya University alone.
  • Infrared Camera: It provides ancillary data to RD

2.Attitude Control System

Solar-oriented control by sensing with a sun sensor, a geo-magnetic sensor and a gyro, and utilizing actuators: a reaction wheel and three-axis magnetic torquer.

3.Power System

Power generation by solar cell and power supply by nickel-hydrogen storage cell.

4.Communication System

ChubuSat-2 carries amateur radio and S-band antennae, and the amateur radio band will be open to public in the nominal operation.

Amateur Radio Information

★Orbit Information

The TLE is shown below as of 10 AM on March 5, 2016. (Satellite ID: 41338)
1 41338U 16012B   16064.66413417  .00001062  00000-0  78142-4 0  9993
2 41338  31.0035 213.2330 0014157  92.6443 267.5827 14.99218775  2454
The TLE is being updated.
The latest TLE is available at NORAD web site.

★CW Beacon Information

The CW beacon (437.100MHz ASK) format of the ChubuSat-2 is as follows.

「S1 ** ** ** **」
** indicates reception level, voltage of the secondary battery ch1, ch2, and ch3 respectively.
「S2 ** ** ** **」
** indicates voltage of the secondary battery ch4, temperature of the secondary battery A and B, solar cell (+Z axis) current respectively.
(interval and repetition from the top)

Reception level, the secondary battery voltage and temperature, solar-paddle (+Z axis) current are converted from original ADC values (0~255 in the HEX format) to ASCII characters.
A correspondence table between ADC values and actual physical properties is available here.
If you receive the Morse message from ChubuSat-2, please let us know via the e-mail address: chubusat2 [at] frontier.phys.nagoya-u.ac.jp .

★HK Telemery Information

  • Rate: 9600 bps
  • Frequency: 437.100 MHz
  • Modulation: GMSK
  • Protocol: KISS
  • Decode Sequence
    1. Receive KISS protocol packet data (2 packets/second)
    2. Detect and remove packet header(0xC0 0x10) and footer(0xC0)
    3. Inverse FEND transformation (0xDB+0xDC->0xC0,0xDB+0xDD->0xDB) into 492 bytes packet
    4. Divide the 492 bytes packet into four 123 bytes sub-packets
    5. Remove 16 bytes header and 3 bytes footer from each 123 bytes sub-packet into 104 bytes data
    6. Decode error-correcting code (source code) from each 104 bytes data into 71 bytes telemetry data (HK telemetry data)
  • Contents of 71 bytes telemetry data
  • Telemetry List
  • Notes : The telemetry list refers thermal sensor temperature conversion table.
If you receive the HK telemetry data, it would be appreciated for providing us the data in KISS format (.kss).

★Message Exchange Service Information

ChubuSat-2 provides the message exchange service. After the on-orbit checkout of the satellite (about one month after the launch), you can use the service, sending your message with amateur VHF (145.815MHz FSK 1200bps) then your message is written to the on-board memory. Anyone can read your message with amateur UHF (437.100MHz GMSK 9600bps) by sending inquiry message. The uplink/downlink format is available here.

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