Vid showing BD-2 sats ...
This is a discussion on China's Space Program, News & Views within the Strategic Defense forums, part of the China Defense & Military category; Originally Posted by Quickie Only 5 of the 35 Beidou satellites are in GEO. The rest are in MEO. Coverage ...
Vid showing BD-2 sats ...
Some details on BD-2 system: link
- G6 is equiped with 4 chinese rubidium atomic clocks with an accuracy of 1 nanosecond.
- The first sats are equipped with two chinese clocks and two american clocks (accuracy of 9-10 second)
- The development of the Chinese atomic clock dates back to 1995, in 2000 the first laboratory prototype came out. Between 2003 and 2005, all sub-components of the prototype were certified. In 2007 the industrial prototype finished its development and has begun to equip the BD-2 sats.
The YG-16 (A/B/C) sats have arrived at JSLC on Sep 25. Tests will last approximately 2 months before the launch scheduled in late Nov.
The largest radio telescope in China will be commissioned in Shanghai tomorrow after two months of intensive testing. With a 65m diameter and a weight about 2600t It will be the fourth most powerful radio telescope in the world and is able to observe celestial objects 100 million light years from earth.
Last edited by escobar; 10-28-2012 at 08:51 PM.
The Five-hundred-meter Aperture Spherical Radio Telescope Project and its Early Science Opportunities: pdf
China unveils large radio telescope in Shanghai
A massive radio telescope for use in space observation was unveiled Sunday at the foot of Sheshan Mountain in Shanghai.
The telescope will be used to track and collect data from satellites and space probes.
The newly-built radio telescope can pick up eight different frequency bands and also track Earth satellites, lunar exploration satellites and deep space probes, said Hong Xiaoyu, head of the Shanghai Astronomical Observatory.
"We hope that the new radio telescope will go into operation earlier so that we can use it to observe the unmanned lunar probe Chang'e-2," said Wu Weiren, chief designer of the lunar orbiter project.
The telescope will be used for Very Long Baseline Interferometry (VLBI), a type of astronomical interferometry used in radio astronomy, as it can collect accurate data and increase its angular resolution during astronomical observation.
The engine in the circle is said to be a full-scale model of the YF660 and the third one from left is YF100.
5th manned space trip for next year
China's fifth manned space mission will lift off next year, Yang Liwei, China's first "taikonaut" - China's terms for its astronauts - and deputy director of the country's manned space program has confirmed.
The exact date of the launch will be decided after a full assessment of previous missions by spacecraft Shenzhou-8 and Shenzhou-9.
Yang said the Shenzhou-10 manned spacecraft will carry three taikonauts into space, and that the crew will include veterans and perhaps women. "It is possible that female astronauts will be on board," he added. The candidates will be decided early next year.
Next year's space mission mainly aims to consolidate and improve docking techniques, conduct more scientific experiments and solve problems discovered in the previous missions, said Yang.
"One success doesn't mean success every time," he told a news conference in Shanghai. "We would like to have more practice and improve the quality," Yang explained.
Yang was in town for the opening of an aerospace and aviation exhibition marking the 20-year anniversary of the launch of China's manned space program.
At the event, Yang also revealed that the Shenzhou-10 mission will adjust the working schedule and routine of taikonauts, laying the foundation for building a space station.
"Once established, the space station will provide a national-level platform for scientific research in outer space," Yang added. "So the next mission will also focus on technical breakthroughs in environmental control and life support systems."
After the Shenzhou-10 space mission, China is scheduled to launch the Tiangong-2 space lab module to research supply transport by cargo spaceships, another milestone for China's space program.
"Space travel won't be a problem for China in the future," Yang said.
The aviation exhibition, featuring 150 photographs, documents and other objects, is being held at Qian Xuesen Library and Museum of Shanghai Jiao Tong University. One of the highlights is the re-entry capsule of the Shenzhou-4 spaceship.
More details on this radio telescope:
- It is the third in the world to adopt active surface technique and has excellent surface accuracy.
- has a 130-meter long track, to support horizontal movement.
- The width of the track is accurate to within just point five millimeters and the telescope itself has over 1100 precision mechanisms.
- An official from China Electronics Technology Group Corporation says the completion of the radio telescope in Shanghai means that China’s industrial technology has reached the most advanced level in the world.
- Fan Youshan, Leader of China Electronics Technology Group Corp., said, "Large diameter radio telescopes are a hi-tech product. It has extremely high requirements for engineering mechanism design, machinery processing, industrial control, supercomputing, information analysis, and installation and construction."
- China also plans to build an antenna system for a 110m diameter radio telescope in the Xinjiang
- According to the SJ-9 sats orbits data, "everything is normal!" which means SoC2008 successfully passed last verification.
- Soc reduce spacecraft volume saving valuable space
- SpaceOS2 a second generation real-time multi-tasking OS is run on SoC2008 (SpaceOS1 is the first version used on TG-1)
- SpaceOS2 overall performance reached international advanced level and is equal to UT699 launched in Europe in 2010
- Second-generation SoC chip and multi-core high-performance SoC chip are already in development
- The first quad-core SoC to be used on the lunar and Beidou-2 following program will be available in 2013.
- Has also broad application in high-speed rail, nuclear power and marine tech
Last edited by escobar; 10-28-2012 at 08:09 PM.
Expected launch schedule:
The GF-4 sat is very noteworthy.2013: GF-1 (2m res pan-chromatic camera/8m res. multi-spectral camera/16m res. wide-angle multi-spectral camera)
2013: GF-2 (1m res pan-chromatic camera/4m res. multi-spectral camera)
2015: GF-3 (1m res C-band SAR)
2015: GF-4 (50m res fixed-point camera in GEO)
2015: GF-5 (visible light-near infrared hyper-spectral camera/full-frequency spectrometer/atmospheric greenhouse gas monitor/atmospheric trace gas absorption spectrometer atmospheric aerosol multi-angle photometer/atmospheric environment very-high resolution infrared radiation detector)
2016:GF-6 (2m res pan-chromatic camera/8m res multi-spectral camera/16m res wide-angle multi-spectral camera)
2018:GF-7 (hyper-spectral, sterographic and cartography cameras)
China has mastered the key technologies (grain integrity, nozzle thermal structure, engine ignition) of large solid rocket motors: link
I just find china has been working on a regional positioning system called CAPS (Chinese Area Positioning System) since 2002. its architecture is very interesting: pdf-1, pdf-2, link
The space segment consists of some Geostationary Earth Orbit (GEO) satellites and 2∼3 Inclined Geo-Synchronous Orbit (IGSO) satellites. Only a few satellites are needed to provide good area coverage and hence it is an ideal space segment for a regional navigation system. CAPS is also different from all the other navigation satellite systems in that the navigation messages are generated on the ground and uploaded to the communication satellites, with the satellites acting only as transponders.
A time transfer mode is used to transmit navigation signals, so no high-precision atomic clocks are required onboard the satellites; all of the transferred navigation signals are generated by the same atomic clock at the master control station on the ground. The determination of the clock offset is completely independent of the determination of satellite orbit, so the error of the clock offset has no impact on orbit determination. Therefore, a very high precision of satellite orbits, better than 4·2 cm (1 drms) can be obtained by the stations under regional distribution.
A prospective view of CAPS has concluded it to be a seamless, high accuracy, large capacity navigation and communication system which can be achieved by expanding it world wide and enhancing it with LEO satellites and mobile base stations. Hence, this system is a potential candidate for the next generation of radio navigation after GPS.
Last edited by escobar; 10-30-2012 at 08:17 PM.