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Liftoff of the Long March 3C rocket taking the Beidou-3 navigation satellite. The mission launched from the Xichang Satellite Launch Center in Sichuan Province at 21.50 Beijing time on March 31, 2015. CNS
China on Sunday added two more satellites to its Beidou navigation and positioning system following the launch of a Long March 3B rocket from Xichang launch centre.
The launch vehicle lifted off from Xichang in the hills of southwestern Sichuan Province around 11:40 UTC (19:40 Beijing time), with the satellites to be inserted into preset orbits by a Yuanzheng-1 upper stage.
With no launch coverage, the first indications of liftoff came from Chinese social media channels, including amateur footage.
Launch success is expected to be confirmed by Chinese state media within a few hours of liftoff.
The satellites - originally intended for launch in July - will become the 21st and 22nd operational satellites in the Beidou project, which when complete provide will provide China with its own global navigation and positioning satellite system.
This was the first launch for the Long March 3B since a partial failure of the rocket in June. The issue meant the Zhongxing-9A telecommunication satellite found itself in a much lower than intended orbit and needed to use its own propulsion – intended for station-keeping - to perform 10 orbit adjustments to reach its intended geostationary orbit at an altitude of 36,000 km above the equator. This reduced the satellite’s lifetime from a designed 15 years to around just five years.
The failure of the second heavy-lift Long March 5 launch vehicle in July then brought a halt to all Chinese launches for nearly three months.
Having restarted space launches with of a trio of Yaogan-30 reconnaissance satellites in late September and a remote sensing satellite for Venezuela last month, China’s space launch teams could see a hectic finish to the year.
The Long March 5 (Y2) rocket lifts off from Wenchang at 19:23:23 local time on July 2, 2017. CNS
China's space activities in 2017
This was China’s 11th launch of the year, including nine of various Long March rockets, developed by the main contractor for the space programme, the China Aerospace Science and Technology Corporation (CASC), and two solid rocket launches by a ‘sister’ state-owned enterprise, CASIC, the country’s main missile maker.
China has now launched 253 Long March rockets, with the first taking place on April 24, 1970. Of these, 239 have been successful, with eight failures and six partial failures, bringing a success rate of 94.5 percent.
This was the 41st launch of a Long March 3B, the first of which resulted in catastrophe in February 1996.
China had aimed to launch around 30 times in 2017 before the two above failures brought a halt to activity. SpaceX, a private American company, may now launch as many or perhaps more times than China this year, after quickly and successfully bouncing back from a catastrophic ‘fast fire’ on the pad last September. The same day, China suffered the loss of its Gaofen-10remote sensing satellite, grounding the Long March 4C carrier rocket.
The major success for China in 2017 has been the launch of its first cargo spacecraft, Tianzhou-1, which trialled three rendezvous and dockingprocedures followed by orbital refuelling tests with Tiangong-2. This marks a major milestone in plans for the country to establish its own large, modular space station.
Apparent footage from Tianzhou-1 as it reentered the atmosphere on September 22, 2017 following the completion of its mission. CCTV
China's Beidou navigation system
Beidou is China’s alternative to America's GPS, Russia’s GLONASS and Europe’s Galileo positioning and navigation satellite systems.
Named after the Chinese term for the ‘plough’ or ‘Big Dipper’ constellation, the project was formally started in 1994, some 20 years after GPS. It is claimed the newer system will far exceed the accuracy of GPS.
Lei Fanpei, chairman of CASC, said at the recently concluded 19th National Congress of the Communist Party of China, that, "More groups of Beidou-3 satellites will be sent into space starting from this November, and the basic construction of the Beidou Navigation Satellite System will be completed by the end of next year," he said.
A Beidou satellite inside the payload fairing ready for stacking at Xichang in 2016. CASC
The Beidou-3 satellites launched today will help take China's indigenous Global Navigation Satellite System (GNSS), similar to the US' GPS, Russia's GLONASS and Europe's Galileo constellations, from regional coverage to providing services globally.
The construction of the 35-satellite navigation system – with five in geosynchronous orbit, three in inclined geosynchronous orbits, and 27 in lower, medium Earth orbits - is to be completed by 2020, Lei added.
Wu Yanhua, deputy head of the China National Space Administration (CNSA), said earlier in the year that China plans to cover all countries along the Belt and Road initiative – Chinese President Xi Jinping’s signature grand project - with its homegrown Beidou navigation system by 2018.
By establishing its own constellation of GNSS satellites, the Chinese government aims to cut previous reliance on American GPS services that would not be available to the People's Liberation Army in the event of conflict, such as targeting, positioning and locating, and synchronising operations.
As well as seeing the breaking of its dependency on American GPS services as a national security imperative, Chinese authorities have stated that Beidou, or BDS, is designed to meet economic and social development requirements and boost the country’s IT applications and hi-tech sectors.
Just like other GNSS, Beidou has many civil applications, such as navigation for shipping, air and road traffic for vehicles and users carrying receivers in devices like navigators and smartphones, as well as mapping and surveying, and other applications.
An illustration demonstrating a number of civil and military uses for Beidou GNSS. CSNO
Beidou satellites are based on DFH-3 satellite buses developed by the China Academy of Space Technology (CAST), a subsidiary of CASC. Another, the China Academy of Launch Vehicle Technology (CALT), is the developer of the Long March 3B rocket used for launches. The Chinese Academy of Sciences (CAS) also has institutes involved in the Beidou satellite project.
https://gbtimes.com/china-launches-...-in-return-to-flight-for-long-march-3b-rocket