关于我们 / About Us
  项目简介 / Introduction
  合作伙伴 / Partner
  聚焦·关注 / Focus
 
 
 
首页 Home -- 聚焦·关注 Focus  
 

China build on global market with Long March 3B/E launch of Eutelsat-W3C
--Source: www.nasaspaceflight.com October 7th, 2011 by Rui C. Barbosa--

After the TG-1 TinGong-1 launch success, China took another step in the international satellite market with the successful launch of the European Eutelsat-W3C communications satellite on Thursday. The launch took place at 08:21 UTC using a Long March 3B/E (Chang Zheng-3B/E) launch vehicle.

Chinese Launch:

According to Eutelsat, the new W3C satellite will provide significant new capacity for broadcasting, telecommunications and broadband services, replacing existing Eutelsat satellites at 16 degrees East. This is a leading position for broadcast markets in Central and Eastern Europe, and also provides video services to the islands in the Indian Ocean.

16 degrees East is one of Eutelsat’s most long-standing orbital locations, as satellites have been in service there continuously since 1988. Over more than two decades, it has developed into one of the company’s largest video locations, with more than 400 channels broadcast to an audience of over 11 million households.

Markets in the areas served by 16 degrees East have been experiencing solid growth, particularly in Central and Eastern Europe.

The availability of W3C will significantly increase capacity at 16 degrees East. The satellite will have four main coverage zones: high-power Ku-band coverage of Europe with a beam centred over Central Europe, particularly optimised for Direct-to-Home (DTH) reception in this region; extensive coverage across Extended Europe, including North Africa, the Middle East and Central Asia, via a Ku-band beam optimised for professional video links and data networks.

Ku-band coverage will include Sub-Saharan Africa and Indian Ocean islands for regional telecommunications and internet services (interconnection with Europe will also be possible with the African coverage through a combination of Ka-band frequencies in Europe and Ku-band frequencies in Africa); and a high-power Ku-band beam over Madagascar and the Indian Ocean Islands for DTH applications.

The W3C Satellite was designed and manufactured by Thales Alenia Space France for EUTELSAT. The satellite is based on the Spacebus 4000 C3 platform with a lift-off mass of 5,400 kg. With a design life of over 15 years, it has 56 operational transponders (53 in Ku-band and 3 in Ka-band) onboard, with an end-of-life power of 12kW.

On February, 2009 Eutelsat had picked China’s CZ-3B to launch its W3B satellite. However, on February 18, 2010, Thales Alenia Space announced that the W3B would be launched by an Ariane-5 ECA – announcing also that the W3C satellite would be launched by a Chinese vehicle.

W3B would be launched on October 28th, 2010 but the satellite suffered a sizeable leak in the propulsion system immediately after launch and was declared a total loss.

The Launcher:

To meet demand of the international satellite launch market – especially for high power and heavy communications satellites – the development of Chang Zheng-3B launch vehicle started in 1986 on the basis of the fight proven technology of Long March launch vehicles. The CZ-3B Chang Zheng-3B is the most powerful launch vehicle on the Chinese space launch fleet.

The CZ-3B features enlarged launch propellant tanks, better computer systems, a larger 4.2 meter diameter payload fairing and the addition of four strap-on boosters in the core stage that give an additional help in the first phase of the launch.

The rocket is capable of launching a 11,200 kg satellite to a low Earth orbit or a 5,100 kg cargo to a geosynchronous transfer orbit. The rocket has a total length of 54.84 meters and a core diameter of 3.35 meters.

In recent years, the CZ-3B/E (Enhanced Version) launch vehicle was developed on the basis of CZ-3B, increasing the GTO capacity up to 5.500kg. The CZ-3B/E has nearly the same configurations with CZ-3B except for its enlarged core stage and boosters.

On May 14, 2007, the first flight of CZ-3B/E was performed successfully, accurately sending the NigcomSat-1 into pre-determined orbit. With the GTO launch capability of 5.500kg, CZ-3B/E is dedicated for launching heavy GEO communications satellite.

This was the 148th successful Chinese orbital launch, the 148th launch of a Long March (Chang Zheng) launch vehicle, the seventh launch from Xichang in 2011 (the 66th overall from Xichang), and the 11th successful orbital launch for China in 2011.

Launch Procedures:

Launch countdown procedures started at T-7h 30m with the LOX fuelling of the third stage of the launch vehicle, followed with the LH2 fuelling at T-6h. At T-1h 20m the controllers powered on the control system of the launch vehicle and conduct a functional checkout. At 60 minutes prior to launch the telemetry system was powered up, followed by functional tests.

The air-conditioning to the fairing was ceased and disconnected at T-40m, followed by the uploading of the flight profile of the rocket. The pre-cooling of the third stage engine took place at T-22m followed at T-13m by the topping of the third stage propellants.

Between T-15m to T-13m the umbilical to the satellite was disconnected and at T-3m the Telemetry and Tracking Systems power was switched over. The fuelling lines were disconnected from the third stage, followed by the umbilical disconnections of Control System and the swing off of supporting arms of the umbilical tower. At T-30 seconds before the ignition the Telemetry and Tracking Systems were started.

Ignition of the four liquid strap-on boosters and the YF-25 first stage engine took place at T-0s. After clearing the launch tower, the launcher executed a pitch-over manoeuvre at T+10s. Booster separation took place at T+1m 21s, followed by first stage/second stage separation at T+1m 39.4s. The jettison of the fairing took place at T+3m 55.5s.

Second stage/third stage separation – and third stage first start – occurred at T+5m 44.2s at an altitude of 169 km. The shutdown of the third stage came at T+10m 20.4s, with the second third stage ignition taking place at T+21m 3.9s. This burn lasted for almost 3 minutes.

Spacecraft separation occurred at T+25m 42.8. Initial orbital parameters will be: perigee of 200 km altitude, apogee of 35,746.2 km altitude and inclination of 26,1 degrees. The satellite will then use its own engine to manoeuvre to geostationary orbit.

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, focusing on broadcast, communications and meteorological satellites.

The center’s headquarters is in Xichang City, a distance of 65 km from the launch site. The climate in the region is subtropical, with an average annual temperature of 16 degrees C. Ground wind in the region is generally very mild all the year round.

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 kilometres south-west of the launch pad, providing flight and safety control during launch rehearsal and launch.

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.

The first launch from Xichang took place at 12:25UTC on January 29, 1984, when the CZ-3 Chang Zheng-3 (CZ3-1) was launched the Shiyan Weixing (14670 1984-008A) communications satellite into orbit.

(Images via Chinanews.cn and Eutelsat).

 
Copyright © 2011,China Great Wall Industry Corporation,All Rights Reserved