Quick on the heels of the September 19 launch of nine satellites carrying Amateur Radio payloads comes word that three more satellites were launched on September 25 from the Jiuquan Satellite Launch Center in Inner Mongolia’s Gobi Desert. The CubeSats, identified as Tianwang-1A (TW-1A; SECM-1), Tianwang-1B (TW-1B; NJUST-2), and Tianwang-1C (TW-1C; NJFA-1), were developed by students at the Nanjing University of Aeronautics and Astronautics in collaboration with the Shanghai Engineering Center for Microsatellites. TW-1A and TW-1B are 2 U CubeSats, while TW-1C is a 3U CubeSat.

The mission’s main goal is to experiment with software defined radio technology in space. The Amateur Radio payloads, which do not include any transponders, will serve to exchange telemetry, tracking, and command information with the ground control station. Telemetry data will be made public, so that radio amateurs around the world may track and monitor the health of the satellites.

Other payloads include a video camera, along with receivers for dual-band GPS/BeiDou, Maritime Automatic Identification System, and Aeronautical Automatic Dependent Surveillance Broadcast. Using MEMS based cold-gas micropropulsion, it is planned to demonstrate formation flying by two of the CubeSats along with inter-satellite communication using GAMALINK 2.4 GHz spread spectrum technology from Portugal.

According to Michael Chen, BD5RV, of CAMSAT, the satellites have downlinks in the 435-438 MHz Amateur-Satellite Service allocation. TW-1A transmits on 435.645 MHz (GMSK 4800/9600 baud, 10 second transmit interval); TW-1B on 437.645 MHz (GMSK 4800/9600 baud, 20 second transmit interval), and TW-1C on 435.645 MHz (GMSK 4800/9600 baud, 10 second transmit interval). Note that TW-1A and 1C use the same frequency. The satellites also may have downlink frequencies in the VHF range.

TW-1A is object 40928, 2015-051D; TW-1B, (NJUST-1) is object 40927, 2015-051C, and TW-1C is object 40926, 2015-051B.

On the same launch was the technology demonstration satellite Pujian-1, which includes WiFi technology for intra-satellite communication.

Trevor, M5AKA, said it’s believed that Beijing plans another Amateur Radio payload satellite launch on October 5. — Thanks to AMSAT News Service, AMSAT-UK