China increases the pace with Long March 4B spy satellite launch

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Four days after the launch of Tianhui-1B mapping satellite, China has launched a new optical remote sensing satellite on May 10, 2012 from the Taiyuan Satellite Launch Center. Launch of Yaogan Weixing-14 (YG-14) satellite took place at 07:06UTC using a Long March 4B (Chang Zheng-4B) launch vehicle from the LC9 launch complex.

Another Chinese Launch:

Once again, the official Chinese media refer the new satellite as a new remote sensing bird that will be used for scientific experiments, land survey, crop yield assessment, and disaster monitoring. As was the case in the previous launches of the Yaogan Weixing series, western analysts believe this class of satellites is being used for military purposes.

Some believe that YG-14 is a new class of optical observation satellite containing sensors developed by CAST’s 508 institute and the Changchun Institute of Optics.

Together with Yangan Weixing-14 there was another passenger on board, the small 9.3 kg TT-1 (Tiantuo 1) that was built by the National University of Defense Technology. This project started in 2009 and is the first Chinese nano-satellite that integrates the functions of satellite control, power distribution, data transfer and attitude control onto a single integrated electronic board.

Tiantuo-1 will perform experiments on optical imaging, detection of on-orbit atomic oxygen intensity and receiving signals from the marine Automatic Identification System (AIS). Its dimensions are 425 mm x 410 mm x 80 mm.

This was the 162nd successful Chinese orbital launch, the 162nd launch of a Chang Zheng launch vehicle, the 38th successful orbital launch from Taiyuan and the second from Taiyuan this year, becoming the seventh successful orbital Chinese launch in 2012.

Looking back to the Yaogan Weixing launch series:

The first Yaogan Weixing satellite (29092 2006-015A) was launched by a Chang Zheng-4C (Y1) from the Taiyuan Satellite Launch Center on April 27, 2006. Developed by Shanghai Academy of Spaceflight Technology (SAST), the details about this satellite were closely guarded, but later it was said that this was the first Jianbing-5 satellite, equipped with the first space-based synthetic aperture radar (SAR).

The second satellite on the series, the Yaogan Weixing-2 (31490 2007-019A), was launched on 25 May, 2007, by a Chang Zheng-2D (Y8) from the Jiuquan Satellite Launch Center. Details were also restricted, though it is claimed that this spacecraft is an electro-optical military observation satellite also known as JB-6 Jianbing-6, complementing the results of the Yaogan Weixing-1. This satellite was developed by the China Academy of Space Technology (CAST).

Another SAR mission was launched on November 11, 2007 when the Yaogan Weixing-3 (32289 2007-055A) satellite was orbited by a Chang Zheng-4C (Y3) launch vehicle from Taiyuan.

Yaogan Weixing-4 (33446 2008-061A) was launched on December 1, 2008. This was the second electro-optical satellite on the series and was launched by a Chang Zheng-2D (Y9) from Jiuquan. Other satellite on the Jianbing-6 series were Yaogan Wexing-7 (36110 2009-069A), launched on December 9, 2009 from Jiuquan by a Chang Zheng-2D (Y10), and Yaogan Weixing-11 (37165 2010-047A) launched on September 22, 2010, by the Chang Zheng-2D (Y11) launch vehicle from Jiuquan.

The first second-generation electro-optical reconnaissance satellite developed by CAST, Yaogan Weixing-5 (33456 2008-064A), was launched on December 15, 2008. The launch took place from Taiyuan by the Chang Zheng-4B (Y20) rocket. Yaogan Weixing-12 (37875 2011-066B) was other second-generation electro-optical reconnaissance satellite, being launched on November 11th, 2011, by the Chang Zheng-4B (Y21) launch vehicle from Taiyuan.

Yaogan Weixing-6 (34839 2009-021A), launched by a Chang Zheng-2C-III (Y19) from Taiyuan on April 22, 2009, was a second-generation SAR satellite developed by SAST, having a spatial resolution of 1.5m.

Other second-generation SAR satellites were the Yaogan Weixing-8 (36121 2009-072A), launched on December 15, 2009, by the CZ-4C (Y4) also from Taiyuan, the Yaogan Weixing-10 (36834 2010-038A) launch on August 9, 2010, by the Chang Zheng-4C (Y6) launch vehicle from Taiyuan; and the Yaogan Weixing-13 (37941 2011-072A) launch on November 29, 2011, by the Chang Zheng-2C (Y20) launch vehicle from Taiyuan

The YaoGan Weixing-9 mission, launched March, 2010 from Jiuquan, had a different architecture from the previous missions on the series. Launched by Chang Zheng-4C (Y5) rocket, the mission placed a triplet of satellites in Earth orbit. Flying in formation these three satellites appeared to be like a type of NOSS system.

The CZ-4B Chang Zheng-4B launch vehicle:

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 back-up launch vehicle for Chang Zheng-3 to launch China’s communications satellites.

After the successful launch of China’s first DFH-2 communications satellites by Chang Zheng-3, the main mission of the Chang Zheng-4 was shifted to launch sun-synchronous orbit meteorological satellites. On other hand, the Chang Zheng-4B launch vehicle was first introduced in May 1999 and also developed by the Shanghai Academy of Space Flight Technology (SAST), based on the Chang Zheng-4.

The rocket is capable of launching 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 take place until late 1999. The modifications introduced on the Chang Zheng-4B included a larger satellite fairing and the replacement of the original mechanical-electrical control on the Chang Zheng-4 with an electronic control.

Other modifications were an improved telemetry, tracking, control, and self-destruction systems with smaller size and lighter weight; a revised nuzzle design in the second stage for better high-altitude performance; 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 first stage is 193.330 kg). 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. Having 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 vacuum of 2,971 Ns/kg.

The Taiyuan Satellite Launch Center:

Situated in the Kelan County on 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 center is at an altitude of 1400-1900m above sea level, and is surrounded by mountains to the east, south and north, with the Yellow River to its west. The annual average temperature is 4-10 degrees C, with maximum of 28 degrees C in summer and minimum of -39 degrees C in winter.

TSLC is suitable for launching a range of satellites, especially for low earth and sun-synchronous orbit missions. The center has state-of-the-art facilities for launch vehicle and spacecraft testing, preparation, launch and in-flight tracking and safety control, as well as for orbit predictions.

(Images via ChinaNews.cn).

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