China launch again – Long March 3A launches FengYun-2F

by Rui C. Barbosa

For their second launch of 2012, the Chinese have launched the FengYun-2F geostationary meteorological satellite from the Xichang Satellite Launch Center using their Long March 3A (Chang Zheng-3A-Y22) rocket from pad LC3. Launch took place at 00:56 UTC on Friday.

Chinese Launch:

Developed by the Shanghai Academy of Space Flight Technology (SAST) and China Academy of Space Technology (CAST), this meteorological satellite series had already seen the launch of four operational satellites, with two more scheduled before the new FengYun-4 satellites enters service.

The most important instrument on FY-2F is the IVISSR is a multi-purpose imaging Vis/IR radiometer.

This instrument is designed to address more objectives by appropriate blending of the characteristics of spectral coverage and resolution, spatial resolution, radiometric accuracy, etc. It will cover the full Earth disk and will operate in VIS – TIR with five channels. Spectral coverage in bands of Vis, NIR, SWIR, MWIR and TIR.

The instrument will be used for determining the atmospheric temperature (column/profile), cloud liquid water (column/profile), cloud type, precipitation rate (liquid) at the surface, short-wave Earth surface bi-directional reflectance, sea surface temperature, ocean imagery, land surface temperature, vegetation type and land surface imagery. FY-2F is also equipped with a solar X-ray detector for monitoring and early warning of solar flares.

The development of the FY-2 geosynchronous meteorological satellite series started in the 1980s. The first satellite was ready for launch in 1994, however, when the satellite was being loaded with propellant in the process facilities at the Xichang Satellite Launch Center, it exploded killing one technician and injuring 31 others.

The explosion destroyed the satellite and it took three years to prepare a replacement after the redesign of the propellant tank system. The first FY-2 satellite to reach orbit, FY-2A FengYun-2A (24834 1997-029A), was eventually launched by the CZ-3 Chang Zheng-3 (Y11) launcher from the LC1 launch platform at Xichang on 10 June 1997.

This satellite was operational until April 1998 when problems started. The control of the satellite was regained on December 1998, but the capabilities of the satellite were now very limited with only six images a day. The satellite was later moved to 86.6 degrees East when meteorological operations ended.

In general the FengYun-2 satellites are spin-stabilised satellites with a total mass of 1,369kg at launch and 536kg in orbit. The satellites carry a scanning radiometer with an S-band and a UHF data transmitter.

The two principal sensors work in the visible and infrared spectrum, with best resolution of 1.25km and 5.0km respectively. A water vapour sensor is also carried onboard the satellites.

With a designed operational lifetime of three years, the satellites normally operate at 105 degrees E in the geosynchronous orbit.

Launch history:

FY-2B (26382 2000-032A) was launched at 1150UTC on June 25, 2000 by the Chang Zheng-3A (Y12) rocket from the LC1 launch platform from the Xichang launch centre on 10 June 1997. This was the last CZ-3A launch. FY-2B operated at 86.6 degrees East.

The last satellite of the original FY-2 series, FY-2C (28451 2004-042A) was launched at 0120UTC on October 19, 2001 by the CZ-3A Chang Zhng-3A (Y9) rocket from the LC3 launch platform at Xichang. This satellite operated on the original location of 105 degrees East. The three first satellites are now retired.

FY-2D (29640 2006-053A) was launched by the CZ-3A (Y11) at 053:23UTC on December 8, 2006 and FY-2E (33463 2008-066A) was launched at 0054:04UTC on December 23, 2008 by the Chang Zheng-3A (Y20) launch vehicle. The FY-2D is operational at 86.6 degrees East while FY-2E is operational at 105 degrees East. Two more satellites are schedule for launch on 2012 (FY-2G) and 2014 (FY-2H).

FengYun-2F was launched by a CZ-3A Chang Zheng-3A launch vehicle on its 23rd.

The CZ-3A is a three-stage liquid launch vehicle, which has inherited the mature technology of the CZ-3 Chang Zheng-3. An upgraded liquid hydrogen and liquid oxygen cryogenic third stage has been developed to enable CZ-3A performing greater geostationary transfer orbit (GTO) capability.

The CZ-3A is equipped with a more flexible and sophisticated control system which supports substantial attitude adjustments to orient the payloads before spacecraft separation and provides adjustable satellite spin-up rotation rate. It has paved the way for the development of CZ-3B Chang Zheng-3B and CZ-3C Chang Zheng-3C, and become the basic type of GTO launch vehicles.

The CZ-3A is mainly used for GTO missions; it also can be used for LEO, SSO and polar orbit missions, as well as dual-launch and multiple-launch missions. The launch capacity of the CZ-3A to GTO is 2,650 kg, the lift-off mass is 241,000 kg, the overall length is 52.5 meters, the diameter of first stage and second stage is 3.35 meters, the diameter of third stage is 3.0 meters, and the maximum fairing diameter is 3.35 meters.

The first stage and second stage of CZ-3A employ storable propellants, i.e. unsymmetrical dimethy1 hydrazine (UDMH) and nitrogen tetroxide (N­2O4), and the third stage uses cryogenic propellants, i.e. liquid hydrogen (LH2) and liquid oxygen (LOX).

On the first stage the CZ-3A uses a DaFY6-2 engine with 2961.6 kN of thrust, while the second stage is equipped with a DaFY20-1 main engine (742 kN) and four DaFY21-1 vernier engines (11.8 kN each). The third stage is equipped with two YF-75 engines (78.5 kN each).

The fairing diameter of the CZ-3A is 3.35 meters and has a length of 8.89 meters.

CZ-3A consists of rocket structure, propulsion system, control system, telemetry system, tracking and safely system, coast phase propellant management and attitude control system, cryogenic propellant utilization system, separation system and auxiliary system, etc.

The launch success rate of CZ-3A is 100 percent since its maiden flight on February 8, 1994 when it successfully launched two experimental satellites (the Shi Jian-4 and the Kua Fu-1, a DFH-3 model). And it was awarded the “Gold Launch Vehicle” title by China Aerospace Science and Technology Corporation in June, 2007.

This was the 157th successful Chinese orbital launch, the 157th launch of a Chang Zheng launch vehicle, the 1st launch from Xichang in 2012 (69th overall), and the 2nd orbital launch for China in 2012.

Launch Site:

The Xichang Satellite Launch Centre is situated in the Sichuan Province, south-western China and is the country’s launch site for geosynchronous orbital launches.

Equipped with two launch pads (LC2 and LC3), the centre has a dedicated railway and highway lead directly to the launch site. The Command and Control Centre is located seven kilometers south-west of the launch pad, providing flight and safety control during launch rehearsal and launch.

Down range Tracking and Control stations of the launch center are located in Xichang City and Yibin City of Sichuan Province, and Guiyang City of Guizhou Province. Each of them houses tracking and measurement equipment for the powered phase of a launch vehicle flight.

Other facilities on the Xichang Satellite Launch Centre are the Launch Control Centre, propellant fuelling systems, communications systems for launch command, telephone and data communications for users, and support equipment for meteorological monitoring and forecasting.

During 1993-1994 Xi Chang underwent extensive modernization and expansion, in part due to the requirements of the CZ-3 launcher family and in part to meet commercial customer needs.

The first launch from Xichang took place at 12:25UTC on January 29, 1984, when the CZ-3 Chang Zheng-3 (Y1) was launched the Shiyan Weixing (14670 1984-008A) communications satellite into orbit.

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