China launched its third ocean survey satellite of the Haiyang-1 series on Friday, with the launch taking place from the Taiyuan Satellite Launching Center at 03:15 UTC. A Long March-2C (Chang Zheng-2C) rocket was used to loft the new satellite.
Haiyang-1C will be used to monitor and prevent oceanic pollution, resource investigation, construction of bayou and ports, and for the development of coastal areas, using the system to monitor ocean temperatures.
Onboard HY-1C there are two instruments: The China Ocean Colour & Temperature Scanner (COCTS), a medium-resolution optical imager developed by SITP (Shanghai Institute of Technical Physics) of CAS (China Academy of Sciences), and the Coastal Zone Imager (CZI), a multispectral push broom CCD instrument developed by the Beijing Institute of Space Machines and Electricity, CAST.
Developed for measuring the ocean color and sea surface temperature, the 50 kg COCTS will be used for determining the Aerosol Optical Depth, Aerosol column burden, biomass, the Colour Dissolved Organic Matter (CDOM) and the Earth surface albedo.
The 15 kg CZI will be used to analyze the vegetation and coastal zone, determining the biomass, the Fraction of Absorbed PAR (FAPAR), Fraction of vegetated land, Land cover and the Leaf Area Index (LAI). The CZI used on Haiyang-1C was improved to 50 m resolution (from 250 m from the Haiyang-1B) and also has a wider image swath.
On board are two new instruments, an ultraviolet imager and a calibration spectrometer. Also, an AIS system for ships tracking was added.
HY-1C is now able to image at up to 20 degrees pitch angles which would minimize problems from sun spots. The satellite lifetime is now five years (up from 3-5 years on HY-1B).
The structure of the spacecraft is based on the CAST968 bus, a box-shaped satellite with overall dimensions of 1.4 m x 1.1 m x 0.953 m. The spacecraft was designed and developed by the DFH (Dongfanghong Satellite Corporation Ltd.) from CAST. The total deployed length of HY-1 is about 7.5 m.
Launch mass of Haiyang-1C was 442 kg with a dry mass of 429 kg.
The CAST968 bus is the first modern small satellite bus developed by DFH and it has been successfully applied on several missions. The bus uses an integrated electronic system and its good performance and flexibility can meet broad payload requirements.
The CAST968 platform was built on eight subsystems: structure and mechanism, thermal control, attitude and orbit control, power supply, TT&C, antenna, housekeeping and electrical subsystems. The main structure of the bus was of aluminum honeycomb sandwich panels.
The spacecraft is 3-axis stabilized (Earth pointing) using bias momentum control. The AOCS (Attitude and Orbit Control Subsystem) used three magnetorquers and hydrazine propulsion for attitude control and orbit change maneuvers; the attitude accuracy was 0.4 deg in roll and pitch and 0.5 deg in yaw. Attitude sensing was provided by digital sun sensors and infrared Earth sensors.
The data sent from the HY-1 satellites is received and processed in several ground stations located at Beijing and Hangzhou – receive raw data in real time acquiring, processing, archiving and managing, distributing and analyzing, SanYa – receive raw data in real time and transfer to Beijing, and Mudanjiang.
The next satellite on the series, Haiyang-1D, is also scheduled for launch this year.
The Chang Zheng 2C (Long March 2C) is a Low Earth Orbit (LEO) launch vehicle derived from DF-5 ICBM.
It can be launched from either the Jiuquan Satellite Launch Center or the Taiyuan Satellite Launch Center, with some launched also taking place from the Xichang Satellite Launch Center.
The launch vehicle has three configurations. The basic two stage Long March-2C and the Long March-2C/SMA and the Long March-2C/SM, using upper stages.
The rocket is a two stage hypergolic launch vehicle with a total length of 35.15 meters, a diameter of 3.35 meters and a total mass of 192,000 kg. The first stage is equipped with four YF-20A engines. It has a length of 20.52 meters and a burn time of 122 seconds.
The second stage is equipped with one YF-22A engine and has a length of 7.50 meters with a burn time of 130 seconds.
Situated in the Kelan County in the northwest part of the Shanxi Province, the Taiyuan Satellite Launch Center (TSLC) is also known by the Wuzhai designation. It is used mainly for polar launches (meteorological, Earth resources and scientific satellites).
The launch center has two single-pad launch complexes, a technical area for rocket and spacecraft preparations, a communications center, a mission command and control center, and a space tracking center.
The stages of the rocket are transported to the launch center by railway and offloaded at a transit station south of the launch complex. They were then transported by road to the technical area for checkout procedures.
The launch vehicles are assembled on the launch pad by using a crane at the top of the umbilical tower to hoist each stage of the vehicle in place. Satellites were airlifted to the Taiyuan Wusu Airport about 300km away and then transported to the center by road.
The TT&C Centre, also known as Lüliang Command Post, is headquartered in the city of Taiyuan, It has four subordinate radar tracking stations in Yangqu (Shanxi), Lishi (Shanxi), Yulin (Shaanxi), and Hancheng (Shaanxi).