What's new

China Space Military:Recon, Satcom, Navi, ASAT/BMD, Orbital Vehicle, SLV, etc.

Construction of World's Largest Radio Telescope Begins in Southwest China
2011-01-27


Workers in southwest China's Guiyang Province have started leveling the ground upon which a five-hundred-meter aperture spherical telescope (FAST) will stand, local authorities said Wednesday.


Located in Pingtan County, the telescope will be the world's largest, the size of 30 football fields.

Its construction has begun after 14 years of preparation and two years of land surveys and resident relocations, Pingtang County government officials said.

The telescope's main spherical reflector will be made up of 4,600 panels.

Construction will be complete in 2016.

The sparsely populated, underdeveloped region will provide the quiet environment the telescope needs to capture electromagnetic waves.

The facility, at a cost of more than 667 million yuan (101.3 million U.S. dollars), will improve China's astronomical observation abilities.

It will help Chinese and international astronomers discover some of the secrets of the universe.
(Source: Xinhua)
24227035_25c6b45e0e.jpg

fdgfy.jpg

hfggf.jpg
 
The mirror pieces of very large telescopes like these will require precise calibration system as they tend to distort under their own weight overtime, since glass is a form of liquid. (assuming that is what they made the reflectors out of).

Also for the sun shinning at the middle of noon what would be the converged power?
 
The mirror pieces of very large telescopes like these will require precise calibration system as they tend to distort under their own weight overtime, since glass is a form of liquid. (assuming that is what they made the reflectors out of).

Also for the sun shinning at the middle of noon what would be the converged power?

glass does distort under its own weight but not because they are a liquid, i think i read this somewhere on wiki's common misconceptions page
 
There is a difference between a thin window glass panel and lenses used in large telescopes:

Lens sag is a problem that sometimes afflicts very large refracting telescopes. It is the equivalent of mirror sag in reflecting telescopes. It occurs when the physical weight of the glass causes a distortion in the shape of the lens because the lens can only be supported by the edges. A mirror on the other hand can be effectively supported by the entire opposite face, making mirror sag much less of a problem. One expensive solution to lens sag is to place the telescope in orbit around the Earth.

There are structural problems involved in manufacturing and manipulating large-aperture lenses. Since a lens can only be held in place by its edge, the center of a large lens will sag due to gravity, distorting the image it produces. The largest practical lens size in a refracting telescope is around 1 meter[14]. In contrast, a mirror can be supported by the whole side opposite its reflecting face, allowing for reflecting telescope designs that can overcome gravitational sag. The largest reflector designs currently exceed 10 meters in diameter.

Even though in reflecting telescopes the problem is less severe, it will still have an affect on any large lense with curvature.

Random search on google came up with this bad quality pdf as an example:
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20000091030_2000123150.pdf
 
Last edited:
China Mars probe to be launched in November - People's Daily Online February 21, 2011

dragonspace-spix-lg.jpg


China's first Mars probe will be launched from a Russian rocket in November, said local media on Monday.

The Mars explorer, Yinghuo-1, marks the country's first attempt at deep space exploration after its sending a probe to the moon.

The 110-kilogram micro-satellite was originally planned to be launched in October 2009 from the Baikonur Cosmodrome in Kazakhstan but the launch was postponed.

The orbiter is due to probe the Martian space environment with a special focus on what happened to the water that are supposed to have existed on the planet. China is aiming to build a space exploration program on par with those of the United States and Russia.

China currently has a probe -- the Chang'e 2 -- orbiting the moon and carrying out various tests in preparation for the expected 2013 launch of the Chang'e-3, which it hopes will be its first
unmanned lunar landing.


People's Daily Online
 
China achieves key aerospace breakthrough - People's Daily Online February 25, 2011

On Feb. 24 it was is reported that during the 12th Five-Year Program (2011-2015), the China Aerospace Science and Technology Corporation will complete a number of key aerospace projects, which include a manned space program, a lunar exploration program, a second generation navigation system and a high-resolution of the earth observation system.

Other major science and technology tasks will also be carried out, such as breakthroughs in space rendezvous and docking techniques, a lunar landing probe, a new type of delivery vehicles and a series of core technologies.

China Aerospace Science and Technology Corporation indicated that the group will go all out to complete the work of aerospace research and production test, which has successfully completed missile weapons experiments and 20 spacecraft launches in order to lay foundations for rapid development of China's space industry.

By Zhang Qian, People's Daily Online
 
China to conduct over 20 space missions in 2011 - People's Daily Online March 02, 2011

China plans to carry out more than 20 space missions this year, an acceleration of efforts to improve its space technologies, an expert said Tuesday.

The figure would see a big increase from the 15 space missions China conducted in 2010, Qi Faren, former chief designer for Shenzhou spaceships said.

Qi, a member of the 11th National Committee of the Chinese People's Political Consultative Conference, made the remarks before the annual session of the country's top political advisory body, which is scheduled to open Thursday.

He said China would enhance its capabilities of space exploration, land observation and information technology in the next five years. The country would also seek breakthroughs in the innovation of space technologies and applications that are not advanced enough to meet the nation's needs, he said.

China should intensify efforts to develop technologies for space exploration, he said, adding that the efforts aim for an effective and peaceful use of space resources.

China would further step up international cooperation for manned space programs and open its future space station to foreign astronauts and scientists, Qi said.

Source:Xinhua
 
China to set up global navigation system by 2020 - People's Daily Online March 02, 2011

China will establish a global navigation system by 2020, said Qi Faren, expert of Chinese space technology on Tuesday.

Qi, a member of the 11th National Committee of the Chinese People's Political Consultative Conference, made the remarks before the annual session of the country's top political advisory body, which is scheduled to open Thursday.

The navigation and positioning satellite is essential for a country in the development of economy and national defense. With the spread of globalization, the role of communication and navigation in production and homeland security will become increasingly evident, Qi said.

Qi introduced China's three-step plan to set up and improve the global navigation system.

The first step is building a regional navigation system. The Beidou No. 1 satellite positioning system marks the completion of this step. It is independently-developed and researched by China and can provide users 24-hour services covering China and the surrounding areas.

"But the regional navigation cannot meet the current demand. A growing China needs to establish a global positioning system according to its development," Qi said. So the Beidou No.2 satellite, a global satellite poisoning system, came into being and will be finished during the second and the third steps.

In the second step, China will launch 12 to 14 satellites during the preliminary phase of the Twelfth Five-Year Plan (2011-2015). These satellites will forma a regional and autonomous navigation and positioning system.

The third step is that by the end of 2020, China will have more than 30 satellites around the world.

The Beidou No. 2 satellite will provide navigation, positioning and orbit determination services for users in China and surrounding areas. It is equivalent to a China-made GPS. Where the United States GPS can apply, the Beidou No.2 satellite can too, Qi said.

In the Chinese market, Qi said the most popular use of the global satellite navigation system is in the in-car navigation equipment, and United States GPS services have a lion share in China's market. After the Bedou No. 2 satellite is put into use, it will compete with the Unites States GPS.

Building a global navigation system is very significant to China and the rest of the world. It is the embodiment of China's national capability and will enhance China's ability in information usage. It will also form a satellite application industry and develop into a strategic emerging industry to provide services to people.

Qi Faren is an academician of the Chinese Academy of Engineering and the International Academy of Astronautics. He has served as chief designer of the Shenzhou spacecraft and China's manned space program.

By Liang Jun, People's Daily Online
 
China's probe to land on moon's surface in 2013 - People's Daily Online March 02, 2011

Chang'e-3 lunar probe has entered the prototype development stage, and it will be launched in 2013 at the Xichang Satellite Launch Center on a mission to achieve a soft landing on the moon's surface, said Ye Peijian, chief scientist of deep space exploration at the China Academy of Space Technology.

He said that the Chang'e-3 lunar probe with "legs" and wheels is a brand-new spacecraft for China, so the technology is difficult to master.

"The biggest difficulty of the Chang'e-3 is how to land on the lunar surface steadily," Ye said.

Ye said it must be a soft landing, not a hard hit. A soft landing cannot use a parachute because there is a vacuum on the moon. The probe will instead use anti-thrust to slow down the speed of the engine.

Ye said that there are five landing sites that have been pre-selected for Chang'e-3 lunar probe. The Sinus Iridum is the first choice in the first task because it is a flat region that is well-lit and easily observable.

Ye Peijian said the Chang'e-3 lander will carry seven sets of scientific instruments and several cameras to conduct different scientific exploration missions as well as take photos of the Earth and other celestial bodies.

The lunar rover will also have eight instruments, including a panoramic camera and lunar exploration radar. The lunar rover will use automated navigation, turning, route selection, climbing and obstacle avoidance and then transmit the data back to Earth by itself or through the lander.

According to reports, after the launch of Chang'e-3, the Chang'e-4 lunar probe will also be launched. The Chang'e-3 and Chang'e-4 will together complete the task of landing on the moon in the second phase of China's lunar exploration, which is the implementation of a lunar soft landing and automatic inspections investigation.

By Yan Meng, People's Daily Online
 
Female astronauts train for in-orbit docking test - People's Daily Online March 03, 2011

P201103031611163639270181.jpg

The picture shows the experimental cabin of the Temple 1 spatial target aircraft. (Photo by Agencies)

Now that the launch time of the Temple 1 target aircraft and the Shenzhou 8 spaceship has been set, two newly-selected female astronauts have begun to participate in the training program with others, according to news from the authorities yesterday.

The China Manned Space Engineering Office announced on March 2 that the Temple 1 has presently completed all types of tests on system performance, interface matching between systems and simulated flight. It will carry out the next stage of mechanic and thermal property tests soon.

P201103031611322023023474.jpg

The picture shows the experimental cabin of the Temple 1 spatial target aircraft. (Photo by Agencies)

The Temple 1 is a spatial target aircraft that China designed for the next step in the construction of a space station. Its main tasks include helping to complete the flight test of the space rendezvous and docking as a target. It will also protect the astronauts in orbit during the short-term residency for work and ensure their safety as well as carry out spatial applications, aerospace medical experiments, space science experiments and space station technology tests.

By Li Mu, People's Daily Online
 
On-track for China's first space lab by 2016 - People's Daily Online March 04, 2011

China will launch its first space laboratory before 2016, a senior space technology expert said on Thursday.

"With the technological program ready, the lab's research and development are going smoothly," said Qi Faren, former chief designer of Shenzhou (divine –ship) spaceships.

As the second phase of China's manned space program, the lab - likely to be named Tiangong-2 - will gradually be developed into the core module or experiment module, said Qi.

Qi, a member of the 11th National Committee of the Chinese People's Political Consultative Conference, was speaking before the annual session of the country's top political advisory body opened yesterday.

China is to launch its first unmanned space module, Tiangong-1 - or Heavenly Palace - in the second half of this year, serving as a platform for spacecraft to rendezvous and dock, allowing for the building of the space station. It will dock with the unmanned Shenzhou VIII spacecraft, which will be launched two months after Tiangong-1.

Both Tiangong-1 and Shenzhou VIII will be launched by a modified Long March II-F carrier rocket, said Liang Xiaohong, a senior executive of the China Academy of Launch Vehicle Technology, at the annual session of the country's top political advisory body.

Researchers have made nearly 170 modifications to the original Long March II-F model, Liang said. He also said China would launch two other spacecraft in the coming two years, Shenzhou IX and Shenzhou X, both of which would dock with Tiangong-1.

Qi predicted that China will have its own space station before 2020.

Meanwhile, Liang said that the world's largest design, production and testing base for rockets is being built in north China's Tianjin City. The first phase of the rocket industrial base in Tianjin's Binhai New Area will be completed this year. Twenty of the 22 plants are already completed.

Liang also said development of China's new generation of carrier rockets, Long March V, are going according to plan and expected to catch up with the US Delta-4H rockets in payload capacity.

These would have a maximum low Earth-orbit payload capacity of 25 tons and high Earth-orbit payload capacity of 14 tons, he said. Liang predicted it could meet China's requirements for up to 50 years.

Looking further ahead, Liang revealed that scientists are studying the feasibility of designing a powerful carrier rocket with a payload of 130 tons for a manned moon landing. He did not provide a timetable for the development.

China launched its first lunar probe in 2007. A second was launched last October. Last year, China conducted 15 space missions.

People's Daily Online / Xinhua
 

Pakistan Affairs Latest Posts

Back
Top Bottom