Beijing launches three more amateur radio satellites

Chang Zheng-11 (CZ-11) launch September 25, 2015

Chang Zheng-11 (CZ-11) launch September 25, 2015

On September 25, 2015 at 01:41 UT Beijing launched three satellites with amateur radio payloads from the Jiuquan Satellite Launch Center (JSLC) in the Gobi desert, Inner Mongolia. They were carried on a new launcher, Beijing’s first solid-fuel rocket Chang Zheng 11 (CZ-11), and deployed in a 470 x 485 km, 97.3 degree inclination Sun Synchronous Orbit (SSO).

This launch occurred just over 5 days after nine satellites carrying amateur radio payloads were launched by Beijing from the Taiyuan Satellite Launch Center (TSLC) in Shanxi on September 19 at 23:01 UT.

The satellites were developed by students at the Nanjing University of Aeronautics and Astronautics in collaboration with the Shanghai Engineering Center for Microsatellites (SECM).

The main goal of the mission is to experiment with Software Defined Radio (SDR) in space. The amateur radio payloads will be used for exchanging Telemetry, Tracking and Command (TT&C) information with the amateur radio ground control station. Information about the telemetry will be made publicly available so that radio amateurs around the world may track and monitor the health of the satellites.

A Tianwang-1 2U CubeSat

A Tianwang-1 2U CubeSat

Other payloads include a video camera along with receivers for dual-band GPS/Beidou, Maritime Automatic Identification System (AIS) and Aeronautical Automatic Dependent Surveillance Broadcast (ADS-B).

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 at 1 Mbps and the CubeSat Space Protocol (CSP).

The TW-1A and TW-1B CubeSats are 2U (20x10x10cm) in size while TW-1C is 3U (30x10x10cm).

Michael Chen BD5RV reports the satellites have these downlinks in the 435-438 MHz ITU Amateur Satellite Service allocation:
• Tianwang-1A (TW-1A / SECM): Camera, 435.645 MHz GMSK 4800/9600 CSP TX interval 10s
• Tianwang-1B (TW-1B / NJUST-2): AIS, 437.645 MHz GMSK 4800/9600 CSP TX interval 20s
• Tianwang-1C (TC-1C / NJFA-1): ADS-B, 435.645 MHz GMSK 4800/9600 CSP TX interval 10s
Note: TW-1A and 1C use the same frequency.

On the same launch was the technology demonstration satellite Pujian-1 which has WiFi for intra-satellite communications.

Object identification from information supplied by Nico Janssen PA0DLO and Zhang Xuan BH4DBE:
TW-1A object 40928, 2015-051B
TW-1B object 40927, 2015-051C, (other IDs: TianWang 1B, NJUST-2)
TW-1C object 40926, 2015-051D
Pujian 1 object 40925, 2015-051A
Chang Zheng 11 (CZ-11) fourth stage object 40929, 2015-051E

Keplerian Two Line Elements (TLEs) ‘Keps’ for new satellites launched in past 30 days

Shanghai Engineering Centre for Microsatellites


IARU Satellite Frequency Coordination pages

Satellite tracking information

Adding new satellites to SatPC32, Gpredict and Nova