China is set to launch more Beidou navigation satellites in November and complete the system by 2020, the head of the main contractor for China's space programme has said.
Lei Fanpei, chairman of the China Aerospace Science and Technology Corporation (CASC), made the comments at the recently concluded 19th National Congress of the Communist Party of China.
"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.
The construction of the 35-satellite navigation system is to be completely finished by 2020, Lei added.
The Beidou-3 satellites are helping take China's indigenous Global Navigation Satellite System, similar to the US' GPS, Russia's GLONASS and Europe's Galileo constellations, from regional coverage to providing services globally.
A number of Beidou launches had been planned for July onwards, with 6-8 satellites set to be placed in orbit.
Following these setbacks a Long March 3B is now being readied at the Xichang Satellite Launch Centre in Sichuan Province, southwest China, with November 3 the apparent launch date.
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.
Named after the Chinese term for the ‘plough’ or ‘Big Dipper’ constellation, the Beidou project was formally started in 1994, some 20 years after GPS. It is claimed the newer system will far exceed the accuracy of GPS.
Speaking on the goal of becoming one of the most innovative countries in the world, Lei said, "We are aware of the great responsibility we have. We need to make great efforts on scientific and technological innovation, especially to finish major special projects."
Lei Fanpei also said that China will have more than 200 spacecraft in orbit by the end of the decade, establishing a rate of more than 30 times launches each year.
Other upcoming launches for China include two Long March 2D rockets from the Jiuquan Satellite Launch Centre in the Gobi Desert, which could launch Jilin or Gaojing commercial Earth observation satellites, or as-yet mystery payloads.
The second launch of the Long March 6, a small space launch vehicle developed by the Shanghai Academy of Spaceflight Technology (SAST) and based on the boosters for the heavy-lift Long March 5, is also expected later in November, as is the second Long March 11 solid-fuelled launcher, carrying Jilin commercial remote sensing satellites.
China has attempted 10 orbital launches this year, with CASC stating early in the year it would aim to carry out nearly 30 launches. However, two failures have greatly impacted this schedule.
China successfully launched a new pair of navigation satellites – namely the Beidou-3M1 (Beidou-24) and Beidou-3M2 (Beidou-25) navigation spacecraft – on Sunday, using a Long March-3B/YZ-1 rocket that was marking its return. The launch took place at around 11:45 UTC from the LC3 Launch Complex of the Xichang Satellite Launch Center, Sichuan province. It took over four hours to complete the mission.
Chinese Launch:
The launch was previously scheduled for July. However, this was delayed until November due to a partial launch failure with the previous launch of this rocket during the Zhongxing-9A (ChinaSat-9A) mission, which resulted in the satellite being lofted to a lower than planned orbit.
Onboard the Long March-3B/Y1 launch vehicle were the Beidou-3M1 (Beidou-24) and Beidou-3M2 (Beidou-25) navigation satellites, the Medium Earth Orbit (MEO) component of the 3rd phase of the Chinese Beidou (Compass) satellite navigation system. The satellites are part of a fleet that will expand the system to a global navigation coverage.
The satellites are using a new bus that features a phased array antenna for navigation signals and a laser retroreflector, with a launch mass 1,014 kg. Spacecraft dimensions are noted to be 2.25 by 1.0 by 1.22 meters. Usually, the satellites reside in a 21,500 – 21,400 km nominal orbit at 55.5 degrees.
The Beidou Phase III system includes the migration of its civil Beidou 1 or B1 signal from 1561.098 MHz to a frequency centered at 1575.42 MHz – the same as the GPS L1 and Galileo E1 civil signals – and its transformation from a quadrature phase shift keying (QPSK) modulation to a multiplexed binary offset carrier (MBOC) modulation similar to the future GPS L1C and Galileo’s E1.
The Phase II B1 open service signal uses QPSK modulation with 4.092 megahertz bandwidth centered at 1561.098 MHz.
The current Beidou constellation spacecraft are transmitting open and authorized signals at B2 (1207.14 MHz) and an authorized service at B3 (1268.52 MHz).
Real-time, stand-alone Beidou horizontal positioning accuracy was classed as better than 6 meters (95 percent) and with a vertical accuracy better than 10 meters (95 percent).
The Compass Navigation Satellite System (CNSS) is China’s satellite navigation system, approved by the Chinese government in 2004, capable of providing continuous, real-time passive 3D geo-spatial positioning and speed measurement.
The Chinese navigation system is being developed and deployed in three phases. Phase 1 (starting in 2003), consisted of an experimental regional navigation system, BeiDou-1, which provided active navigation service.
Phase 2 (started in 2012), consisted of a reduced satellite constellation and provides open service over China. This phase aimed at deploying a system with passive positioning and timing capability over a regional area.
Phase 3 aims for full operational capability by 2020 with a constellation of 27 MEOs plus 5 GEOs and the existing 3 IGSOs satellites of the regional system. CNSS would provide global navigation services, similarly to the GPS, GLONASS or Galileo systems.
CNSS is expected to support two different kinds of general services: RDSS and RNSS. In the Radio Determination Satellite Service (RDSS), the user position is computed by a ground station using the round trip time of signals exchanged via GEO satellite. The RDSS long-term feature further includes short message communication (guaranteeing backward compatibility with Beidou-1), large volume message communication, information connection, and extended coverage.
The Radio Navigation Satellite Service (RNSS) is very similar to that provided by GPS and Galileo and is designed to achieve similar performances.
The long-term goal is to develop a global navigation satellite network similar to the GPS and GLONASS by 2020 eventually consisting a constellation of 35 vehicles, including 27 MEO (21,500 km orbits) satellites, three IGSO satellites (inclined at 55 degrees) and five GSO satellites.
The system will be dual-use, based on a civilian service that will provide an accuracy of 10 meters in the user position, 0.2 m/s on the user velocity and 50 nanoseconds in time accuracy; and the military and authorized user’s service, providing higher accuracies. The first phase of the project will involve coverage of the Chinese territory. However, the future Compass constellation will cover the entire globe.
Launch vehicle and launch site:
This mission is also the second flight of the Long March-3B/YZ-1 (Chang Zheng-3B/YZ-1) version of the Long March-3B.
The launcher was developed from the Chang Zheng-3A.
The CZ-3B features enlarged launch propellant tanks, improved computer systems, a larger 4.2 meter diameter payload fairing and the addition of four strap-on boosters in the core stage that provide additional help during the first phase of the launch.
The rocket is capable of launching an 11,200 kg satellite to a low Earth orbit or a 5,100 kg cargo to a geosynchronous transfer orbit.
The CZ-3B/G2 (Enhanced Version) launch vehicle was developed from the CZ-3B, increasing the GTO capacity up to 5,500kg. The CZ-3B/E has nearly the same configurations with CZ-3B bar its enlarged core stage and boosters.
On May 14, 2007, the first flight of CZ-3B/G2 was performed successfully, accurately sending the NigcomSat-1 into pre-determined orbit. With the GTO launch capability of 5,500kg, CZ-3B/G2 is dedicated for launching heavy GEO communications satellite.
The rocket structure also combines all sub-systems together and is composed of four strap-on boosters, a first stage, a second stage, a third stage and payload fairing.
The first two stages, as well as the four strap-on boosters, use hypergolic (N2O4/UDMH) fuel while the third stage uses cryogenic (LOX/LH2) fuel. The total length of the CZ-3B is 54.838 meters, with a diameter of 3.35 meters on the core stage and 3.00 meters on the third stage.
On the first stage, the CZ-3B uses a YF-21C engine with a 2,961.6 kN thrust and a specific impulse of 2,556.5 Ns/kg. The first stage diameter is 3.35 m and the stage length is 23.272 m.
Each strap-on booster is equipped with a YF-25 engine with a 740.4 kN thrust and a specific impulse of 2,556.2 Ns/kg. The strap-on booster diameter is 2.25 m and the strap-on booster length is 15.326 m.
The second stage is equipped with a YF-24E (main engine – 742 kN / 2,922.57 Ns/kg; four vernier engines – 47.1 kN / 2,910.5 Ns/kg each). The second stage diameter is 3.35 m and the stage length is 12.920 m.
The third stage is equipped with a YF-75 engine developing 167.17 kN and with a specific impulse of 4,295 Ns/kg. The fairing diameter of the CZ-3B is 4.00 meters and has a length of 9.56 meters.
The Yuanzheng-1 (“Expedition-1″) uses a small thrust 6.5 kN engine burning UDMH/N2O4 with specific impulse at 3,092 m/s. The upper stage should be able to conduct two burns, having a 6.5 hour lifetime and is capable of achieving a variety of orbits.
It will be adapted for use on the CZ-3A/B/C series mainly for direct MEO/GEO insertion missions (mostly for the navigation satellites of the Beidou GNSS).
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 center 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.
The CZ-3B launch pad is located at 28.25 deg. N – 102.02 deg. E and at an elevation of 1,825 meters.
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 Chang Zheng-3 (CZ3-1) was launched the Shiyan Weixing (14670 1984-008A) communications satellite into orbit.
Future launch plans:
November will see another two Chinese launches from the Taiyuan Satellite Launch Center. On November 15 a Long March-4C rocket will orbit a new polar-orbiting meteorological satellite, the Fengyun-3D satellite.
Three new Chinese commercial remote sensing satellites for high definition video will be orbited by a Long March-6 rocket on November 21.
Two other launches were being prepared for November launch dates, but at this time it is not certain that the missions will take place this month.
At the Jiuquan Satellite Launch Center a Long March-2D rocket is being prepared to launch an yet unknown payload and a Long March-11 solid launch vehicle was also being prepared to launch a new pair of Jilin satellites together with four Xiaoxiang/Tianyi satellites, the Quantutong-1 satellite, and the Kepler Cubesat-3U.
In December China will probably launch a new pair of Beidou-3M navigation satellites from Xichang and the Gaojing-3 civilian remote sensing satellite from Jiuquan.
Quelle: NS
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Update: 6.11.2017
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China launches two BeiDou-3 navigation satellites on single carrier rocket
China launched two BeiDou-3 satellites into space via a single carrier rocket to support its global navigation and positioning network at 7:45 p.m. Sunday. (Xinhua/Yang Zhiyuan)
XICHANG, Sichuan Province, Nov. 5 China launched two BeiDou-3 satellites into space via a single carrier rocket to support its global navigation and positioning network at 7:45 p.m. Sunday.
The satellites were aboard a Long March-3B carrier rocket which took off from Xichang Satellite Launch Center in the southwestern province of Sichuan.
This is the first two BeiDou-3 satellites launched by China, as its self-developed BeiDou Navigation Satellite System officially began to expand into a global network.
Named after the Chinese term for the plough or the Big Dipper constellation, the BeiDou project was formally initiated in 1994. It began to serve China in 2000 and the Asia-Pacific region at the end of 2012.
China plans to building BeiDou into a global positioning and navigation system by around 2020, making it the third country in the world after the United States and Russia to operate its own navigation system.
Compared to earlier generation satellites, the BeiDou-3 is able to send signals that are better compatible with other satellite navigation systems and provide satellite-based augmentation, as well as search and rescue services in accordance with international standards.
"New technology has significantly improved the performance of the BeiDou-3, with the signal accuracy in space higher than half a meter while its positioning accuracy has reached 2.5 to five meters, said Yang Changfeng, chief designer of the BeiDou system.
China plans to launch 18 BeiDou-3 satellites around the end of 2018 to expand the BeiDou services to the countries along the Belt and Road routes.
By around 2020, when the system goes global, it will have more than 30 satellites.
"Launches featuring two or more satellites on a single carrier rocket will be conducted regularly," said Ye Chengmin, deputy chief designer of the Long March-3A carrier rocket.
All the BeiDou satellites currently in space were sent up from Xichang Satellite Launch Center, said Lin Yunan, head of the human resources department of the center.
The BeiDou-3 satellites and the carrier rocket were developed by China Academy of Space Technology and China Academy of Launch Vehicle Technology, respectively.
Quelle: Xinhua
+++
China launches two Beidou satellites in return to flight for Long March 3B rocket
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 at 11:45 UTC (19:45 Beijing time), with the satellites inserted into preset medium Earth 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 was confirmed by Chinese state media just over four hours after 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.
China launches two Beidou-3 navigation satellites on Long March 3B carrier rocket
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 docking procedures 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.b
Quelle: gbtimes
