Three Japanese satellites — ChubuSat-2, ChubuSat-3, and Horyu-4 — carrying Amateur Radio payloads are expected to launch between 0845-0930 UTC on Friday, February 12 into a 575 kilometer, 31° inclination orbit. ChubuSat-2 and ChubSat-3 are message store-and-forward Amateur Radio payloads. Horyu-4 will transmit a telemetry in the 70 centimeter band.
According to Yasutaka Narusawa, JR2XEA, Nagoya University and Mitsubishi Heavy Industries cooperated in developing the 50 kg ChubuSat-2 (JJ2YPN) and ChubuSat-3 (JJ2YPO) microsatellites. They will head into space from the JAXA Tanegashima Space Center. The Komaki Amateur SATCOM Club will operate these satellites. ChubuSat-2 and 3 are piggy-back payloads on the ASTRO-H x-ray astronomical satellite. Both satellites were built by Nagoya University graduate students.
“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 mission statement on the ChubuSat website explains. “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.” ChubuSat-3 also will include a VHF/UHF message exchange payload.
ChubuSat-3 also will include a message exchange payload. According to the ChubuSat website, its primary mission is to observe the effects of global warming, such as reduction in the size of glaciers. For this mission, ChubuSat-3 has a high-resolution camera, which also will be used to observe space debris.
After separation, each satellite will transmit a UHF CW beacon message, including battery voltage and other data. Those copying the beacon message are invited to forward the data via e-mail. After on-orbit checkout — possibly 1 month after launch — the message exchange service will be activated. Users can send messages via the VHF uplink, which are written to onboard memory. By sending an inquiry message, “anyone can read your message with UHF downlink,” the ChubuSat website says.
The ChubuSat-2 uplink is 145.815 MHz FSK 1200 bps; the downlink is 437.100 MHz GMSK 9600 bps and CW. The ChubuSat-3 uplink is 145.840 MHz FSK 1200 bps; the downlink is 437.425 MHz GMSK 9600 bps and CW. Details on the uplink/downlink format have been posted on the ChubuSat website.
Horyu-4 has downlinks on 437.375 MHz and 2400.300 MHz 1200 bps AFSK, 9600 bps GMSK, S_BPSK, CW.
“Through the use of amateur frequencies, the Horyu-4 team would like to inspire interest in radio communication, promote research on radio communications technology, and participate to the skills improvement of beginners in radio communications, including our own freshly licensed Amateur Radio members!” an explanation on the Horyu-4 website offered.
Horyu-4’s primary mission is to measure discharge current waveforms and capture images of the discharges occurring on solar cells. The satellite also has a Facebook page.