China's Space Program News Thread

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antiterror13

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Long March 3C in secretive launch with new Upper Stage
March 30, 2015 by Rui C. Barbosa no alt
The Chinese opened their 2015 campaign with the launch of a Long March 3C with the first of a new generation of navigation satellites. The launch – of what is believed to be a satellite called Beidou-3 M1 – took place at 13:52 UTC from the Xichang Satellite Launch Center, utilizing the debut use of the new Expedition-1 (Yuanzheng-1) upper stage.


Chinese Launch:

Monday’s launch involved a new series of satellites that is expected to mark an advancement in the completion of its Beidou Phase III program several years ahead of schedule, by as soon as 2017, rather than 2020.

However, the launch initially received a blackout in the Chinese media, with lift-off only confirmed by local observers. It took several hours – once the spacecraft was successfully deployed – for the Chinese media to acknowledge the launch.

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.

2015-03-30-143404The current (Phase II) B1 open service signal uses QPSK modulation with 4.092 megahertz bandwidth centered at 1561.098 MHz.

The current Beidou constellation of geostationary (GEO) – five inclined geosynchronous orbit (IGSO), and four middle Earth orbiting (MEO) – 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.

2015-03-30-143515The 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.

The new satellite uses a new bus that feature a phased array antenna for navigation signals and a laser retroreflector. Launch mass is about 800 kg and the satellites have an operational lifespan of 5 years.

Launch vehicle and launch site:

This mission was also the first flight of the Long March-3C/YZ-1 (Chang Zheng-3C/YZ-1) version of the Long March-3C.

The Long March-3C was developed to fill the gap between the Long March-3A and the Long March-3B, having a payload capacity of 3,800 kg for GTO or 9,100 kg for LEO. This is a three stage launch vehicle identical to the CZ-3B but only using two of the strap-on boosters on its first stage.

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65 Launch Vehicle Manuals (L2)
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CZ-3C provides two types of fairing and two kinds of fairing encapsulating process and four different payload interfaces, which is the same as CZ-3B launch vehicle. The various fairing and interface adapter and the suitable launch capacity make CZ-3C a good choice for the user to choose the launch service.

The development of the CZ-3C started in February 1999. The rocket has a liftoff mass of 345,000 kg, sporting structure functions to withstand the various internal and external loads on the launch vehicle during transportation, hoisting and flight.

The rocket structure also combines all sub-systems together and is composed of two strap-on boosters, a first stage, a second stage, a third stage and payload fairing.

The first two stages as well as the two strap-on boosters use hypergolic (N2O4/UDMH) fuel while the third stage uses cryogenic (LOX/LH2) fuel. The total length of the CZ-3C is 54.838 meters, with a diameter of 3.35 meters on the core stage and 3.00 meters on the third stage.

2014-10-23 14_43_48-Chang’e-2 - Google SearchOn the first stage, the CZ-3C uses a DaFY6-2 engine with a 2961.6 kN thrust and a specific impulse of 2556.2 Ns/kg. The first stage diameter is 3.35 m and the stage length is 26.972 m.

Each strap-on booster is equipped with a DaFY5-1 engine with a 704.4 kN thrust and a specific impulse of 2556.2 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 DaFY20-1 main engine (742 kN / 2922.57 Ns/kg) and four DaFY21-1 vernier engines (11.8 kN / 2910.5 Ns/kg each). The second stage diameter is 3.35 m and the stage length is 9.470 m.

The third stage is equipped with two YF-75 engines developing 78.5 kN each and with a specific impulse of 4312 Ns/kg. The fairing diameter of the CZ-3C is 4.00 meters and has a length of 9.56 meters.

2015-03-30-150757The Yuanzheng-1 (“Expedition-1″) uses a small thrust 6.5 kN engine burning UDMH/N2O4 with specific impulse at 3092 m/s. The upper stage should be able to conduct two burns and has a 6.5 hour lifetime.

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 centre has a dedicated railway and highway lead directly to the launch site.

2014-10-23 14_52_22-Xichang Satellite Launch Centre - Google SearchThe 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.
 

B.I.B.

Captain
I can't remember where.I came across an article that suggested that China was planning on launching a solar power station by 2050 or.earlier with the solar.panels covering 6sq miles
 

broadsword

Brigadier
Monday’s launch involved a new series of satellites that is expected to mark an advancement in the completion of its Beidou Phase III program several years ahead of schedule, by as soon as 2017, rather than 2020.

Great they can bring forward the completion date.

I can't remember where.I came across an article that suggested that China was planning on launching a solar power station by 2050 or.earlier with the solar.panels covering 6sq miles

China may build power station in space

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It will be well into the future.
 

Equation

Lieutenant General
20 MAY 2015
CHINA PLANS FIRST DARK SIDE OF THE MOON LANDING
130
You underestimate the power of the dark side.
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China is planning to land its probe, the Chang'e-4, and its accompanying rover, on the far side of the moon for the first time in human history.

"Other countries have chosen to land on the near side of the moon." Wu Weiren said to China Central Television. "Our next move probably will see some spacecraft land on the far side of the moon."

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14:42

An ideal landing spot would be the South Pole-Aitken basin, a massive impact crater which could offer more information about the moon's history.

The planned launch for the Chang'e-4 is 2020. The Chang'e-5 probe will launch in 2017, before the Chang'e-4, and will return from the moon from lunar samples. China is also planning a research mission to Mars in 2020.

Beijing is making giant leaps and bounds in space exploration recently, after the discovery of
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a couple of months ago.
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Ultra

Junior Member
Kind of old news, but since I didn't see anyone post it and this is kind of little known :

Pictures From China's New Satellite Gaofen-2 Show Incredible Detail, Right Down To Pedestrian Crossings
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Sep 30 2014, 11:39 AM

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Picture: China State Administration of Science, Technology and Industry for National Defense
Chinese space authorities have released the first set of
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.

Gaofen-2 was launched in August. The State Administration of Science, Technology and Industry for National Defense plans to use it for things such as disaster relief, land use surveillance and mineral resource surveys.

It can capture full colour pics at “sub-meter clarity” and gather information on objects from space in incredible detail.

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Picture: China State Administration of Science, Technology and Industry for National Defense
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Picture: China State Administration of Science, Technology and Industry for National Defense
Here’s some close up detail of the top picture which shows the central axis of Beijing:

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“The height of the highest building in Shanghai’s Lujiazui District is about 600 meters,” satellite expert with the China Aerospace Science and Technology Corporation
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.

“We can see its projection is longer than that of the Oriental Pearl TV Tower. We can measure and calculate the height of buildings via the length of their projection in the photos. Then we can judge the construction progress.”

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Picture: China State Administration of Science, Technology and Industry for National Defense
China plans on launching five more Gaofen satellites by 2020 as part of a high-definition observation project. All will specialise in different tasks, but combine their uses for detailed analyses.


Here’s a few direct hi-res links if you’ve got some time on your hands:

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Gaofen-1 was launched last year and for the most part has focused on monitoring the land and helping disaster relief efforts. Although late last month, it proved a handy means
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The Verge has a
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, including this stunning pic of a plateau cut by erosion:

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Ultra

Junior Member
Gaofen series of satellite is touted as China's first high definition earth observable satellite, the name "Gaofen" means "high definition". Gaofen-1 is a 2 m resolution satellite with a launch mass of 1080 kg. The thing I found it interesting is the fact that Gaofen-1 was launched in April 26, 2013.

Now Dubai, a country that has never launch a satellite before, designed and launched a earth observable satellite called DubaiSat-1 back in July 2009. DubaiSat-1 has a resolution of 2.5 m.

On 21 November 2013, same year China's Gaofen-1 was launched, Dubai launched DubaiSat-2, weighing only 300 kg, it has a highly advanced propulsion system known as The Hall Effect Propulsion System; along with the High Resolution Advanced Imaging System (HiRAIS) which can capture images at 1 m resolution.

It is almost not until almost a year later on September 2014, did China launched Gaofen-2 with a 1 m resolution camera.

So how did China lag so far behind in term of imaging satellite technology? China a supposed upcoming super power to challenge the US, can't even compare to Dubai, a country that has never launch a satellite before nor design one before managed to designed and launched satellites that's more advanced than China and years before China. Let's not even compare to India, a third world country with even smaller budget than China.

India launched Cartosat-1, a 2.5 m resolution rarth observation/remote sensing satellite back in May 2005, a good 8 years before China's Gaofen-1. They then follow up with Cartosat-2 which weighs only 680 kg and carries a camera with resolution of 0.8 m - a good 7 years before China's Gaofen-2. They followed up with Cartosat-2A and 2B, and now they are almost ready to launch Cartosat-3 in 2017, with a resolution of 0.25 m!

I just find it bizzare how China allows itself to lag so far behind in this key area, that even a complete novice to this sector like Dubai is able to outsmart China's best effort.


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