Long March 4B launches new ocean observation satellite
China launched a new ocean observation satellite from the Jiuquan Satellite Launch Center on Monday.… The post Long March 4B launches new ocean observation satellite appeared first on NASASpaceFlight.com.
China launched a new ocean observation satellite from the Jiuquan Satellite Launch Center on Monday. Launch of the Haiyang-2C took place at 05:40 UTC under the power of a Long March-4B (Chang Zheng-4B) rocket.
The Haiyang-2 program represents the second generation of ocean observation and monitorization satellites, with the program being approved by the China National Space Administration in February 2007, for measurement of ocean dynamic and environmental parameters in the microwave region (permitting all-weather observations).
The requirements also call for collecting data on marine wind setup (wind vector), marine surface height, and SST (Sea Surface Temperature), along with aero-marine forecasts for the prevention and relief of disaster.
The design and development of the HY-2 series began in April 2007, with the program funded by the Chinese State Oceanic Administration. The satellites are operated by the National Satellite Ocean Application Service.
The Haiyang-2 satellites are part of a system consisting of ocean color remote sensing satellites, ocean dynamic environment satellites, and ocean surveillance satellites. The color remote sensing satellites use infrared remote sensing technology to monitor ocean pollution and topography in shallow waters.
The Haiyang-2 dynamic environment satellites utilize microwave remote sensing technology to monitor ocean wind fields and ocean surface temperatures, The Haiyang-3 ocean surveillance satellites will have the combined features of the Haiyang-1 and Haiyang-2 series.Chinese Forum Section
Onboard the new satellite are several instruments. The radar altimeter will be used for ocean topography, determining significant wave height and wind speed measurements on the sea surface. The instrument operates in two frequencies: 13.58 GHz and 5.25 GHz), and permits nadir-only viewing along with continuous sampling along the track.
The DORIS instrument (Doppler Orbitography and Radiopositioning Integrated by Satellite) will be used for precision orbitography, measuring the Doppler shift of signals from ground stations.
The Laser Retroreflector Array will be used for space geodesy and precision orbitography, with the Microwave Radiometer being used for all-weather sea-surface temperature and wind, and total-column water vapor. Finally, the Scatterometer will be used for determining the sea surface wind vector.
Other satellites in this series included the Haiyang-2A, which was launched on August 15, 2011, using a Long March-4B launch vehicle from the Taiyuan Satellite Launch Center.
The sister satellite to 2C was the Haiyang-2B – a CAST968 satellite platform developed by the DFH (Dongfanghong Satellite Corporation Ltd.), a spin-off company of CASC (China Aerospace Science &Technology Corporation). The satellite operates in a 973 km sun-synchronous orbit.
Its mission has two orbital phases: during the first two years it will have a 14-day cycle and then one year with a geodetic orbit – a 168-day cycle with a 5-day approximate subcycle.
The difference with the 2C satellite from its 2B sister is it uses a microwave radiometer imager and was placed into a 66-degree inclination LEO instead of SSO as in previous cases.
The feasibility study of the CZ-4 Chang Zheng-4 began in 1982 based on the FB-1 Feng Bao-1 launch vehicle. Engineering development was initiated in the following year. Initially, the Chang Zheng-4 served as a backup launch vehicle for Chang Zheng-3 to launch China’s communications satellites.
— Cosmic Penguin (@Cosmic_Penguin) September 21, 2020
After the successful launch of China’s first DFH-2 communications satellites by Chang Zheng-3, the primary mission of the Chang Zheng-4 was shifted to launch sun-synchronous orbit meteorological satellites. On the other hand, the Chang Zheng-4B launch vehicle was first introduced in May 1999 and developed by the Shanghai Academy of Space Flight Technology (SAST), based on the Chang Zheng-4.
The rocket can launch a 2,800 kg satellite into low Earth orbit, developing 2,971 kN at launch. With a mass of 248,470 kg, the CZ-4B is 45.58 meters long and has a diameter of 3.35 meters.
SAST began to develop the Chang Zheng-4B in February 1989. Originally, it was scheduled to be commissioned in 1997, but the first launch didn’t occur until late 1999. The modifications introduced on the Chang Zheng-4B included a larger satellite fairing and replacing the original mechanical-electrical control on the Chang Zheng-4 with electronic control.
Other modifications were improved telemetry, tracking, control, and self-destruction systems with smaller size and lighter weight, a revised nozzle design in the second stage for better high-altitude performance. Other improvements included a propellant management system for the second stage to reduce the spare propellant amount, thus increasing the vehicle’s payload capability and a propellant jettison system on the third-stage.
The first stage has a 24.65-meter length with a 3.35-meter diameter, consuming 183,340 kg of N2O4/UDMH (gross mass of the first stage is 193.330 kg).
Grid fins, aimed at aiding the disposal of the booster more accurately over land, were again employed.
Launch success has been confirmed with T-0 at 05:40 UTC.
Grid fins were flown on the first stage again…including one reused from an earlier Long March 4B launch in November 2019!https://t.co/iIJndUPrDY pic.twitter.com/M4MQbvQe7z
— Cosmic Penguin (@Cosmic_Penguin) September 21, 2020
The vehicle is equipped with a YF-21B engine capable of a ground thrust of 2,971 kN and a ground specific impulse of 2,550 Ns/kg. The second stage has a 10.40-meter length with a 3.35-meter diameter and 38,326 kg, consuming 35,374 kg of N2O4/UDMH.
The vehicle is equipped with a YF-22B main engine capable of a vacuum thrust of 742 kN and four YF-23B vernier engines with a vacuum thrust of 47.1 kN (specific impulses of 2,922 Ns/kg and 2,834 Ns/kg, respectively).
The third stage has a 4.93-meter length with a 2.9-meter diameter, consuming 12,814 kg of N2O4/UDMH. With a gross mass of 14,560 kg, it is equipped with a YF-40 engine capable of a vacuum thrust of 100.8 kN and a specific impulse in a vacuum of 2,971 Ns/kg.
The Jiuquan Satellite Launch Center, in Ejin-Banner – a county in Alashan League of the Inner Mongolia Autonomous Region – was the first Chinese satellite launch center and is also known as the Shuang Cheng Tze launch center.
The site includes a Technical Centre, two Launch Complexes, Mission Command and Control Centre, Launch Control Centre, propellant fuelling systems, tracking and communication systems, gas supply systems, weather forecast systems, and logistic support systems.
Jiuquan was originally used to launch scientific and recoverable satellites into medium or low earth orbits at high inclinations. All Chinese crewed missions are launched from this site.
The LC-43 launch complex, also known as the South Launch Site (SLS), is equipped with two launch pads: 91 and 94. Launch Pad 91 is used for the crewed Long March-2F launch vehicle (Shenzhou and Tiangong).
Launch Pad 94 is used for uncrewed orbital launches by the Long March-2C, Long March-2D, and Long March-4C launch vehicles.
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