China's Space Program News Thread

[Quickie]

I thought sphere and dome shape structure can only apply to gravitational forces pushing down on the structure? Diving helmets for deep sea diving are pressurized as well, but they're not all sphere/dome shape like. Perhaps I'm wrong, does anyone know for sure?

AFAIK, the pressure in diving helmets are equalized with the external pressure, so there's some difference here compared to a space helmet. I believe the sphere should be able to withstand against pressure in both directions better than other shape.

 

[Maggern]

AFAIK, the pressure in diving helmets are equalized with the external pressure, so there's some difference here compared to a space helmet. I believe the sphere should be able to withstand against pressure in both directions better than other shape.

Yes. A dome is always stronger than any other shape when pushed downward (i.e. towards the inner circle). Thus a sphere is the most perfect shape in absorbing and distributing pressure from -all-sides. Consider how strong an egg is when exerting pressure from the top and bottom. Though it is not spherical, and you can easily break it from the sides. A sphere would be something in between. Though that being said, when you're only dealing with a dome or less, perhaps some form of other oval shape could be stronger. I guess the dome is much much simpler and cheaper to design than anything else, and is sufficient at the time being.

 

[LesAdieux]

Dragon is ready to fly, why is it so cheap?

the dragon spacecraft of SpaceX is ready to fly in a few hours, the essence of the porgramme is affordability, it is estimated that the Falcon 9 costs $30 millions only, roughly the same price of the LM-2F, given the fact that nothing novel is used, why is it so cheap comparing with all other US launch vehcles?

 

[Quickie]

Yes. A dome is always stronger than any other shape when pushed downward (i.e. towards the inner circle). Thus a sphere is the most perfect shape in absorbing and distributing pressure from -all-sides. Consider how strong an egg is when exerting pressure from the top and bottom. Though it is not spherical, and you can easily break it from the sides. A sphere would be something in between. Though that being said, when you're only dealing with a dome or less, perhaps some form of other oval shape could be stronger. I guess the dome is much much simpler and cheaper to design than anything else, and is sufficient at the time being.

The oval shape design would end up somewhat in a dilemma since it will always have a stronger side and a weaker side. Reducing the area of the weaker side will in effect be changing the shape to a sphere.

 

[LesAdieux]

Re: Dragon is ready to fly, why is it so cheap?

just visited the website of SpaceX, the Falcon 9 is actually priced at $54 million

 

[Broccoli]

Does anyone know how much composites are used in LM rockets?

 

[Quickie]

Wonder there's already a smart phone app for the Beidou Navigation Satellite System.

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by Staff Writers
Beijing, China (XNA) May 22, 2012

China's homegrown Beidou Navigation Satellite System, or Compass Navigation System, will be able to provide high-quality services to most users in the Asia-Pacific region this year, an unidentified official from the system's management office said Wednesday.

The official said at a seminar held in the southern city of Guangzhou that three satellites will be launched this year to help expand the system.

"With the trial run of the Beidou navigation service, we believe that China can provide high-quality satellite navigation services for most users in the Asia-Pacific region in 2012," said Xie Haizhong, general manager of the Beidou navigation science and technology department of Beijing Unistrong, a company that focuses on the global navigation satellite industry.

China began to build the Beidou system in 2000 with a goal of breaking its dependence on the U.S. Global Positioning System (GPS) and creating its own global positioning system by 2020. The Beidou system began providing initial positioning, navigation and timing operational services to China and its surrounding areas late last year.

Industrial experts said at the seminar that to insure the vitality of the Beidou system, its price must be near that of similar GPS systems.

Since its debut in 2000, the system has been widely used in transportation, fishery, hydrological monitoring, weather forecasting and disaster mitigation.

China to expand the Beidou satellite navigation service
The Third China Satellite Navigation Conference has opened in Guangzhou, South China's Guangdong Province. Satellite experts, government officials and business executives from China, the US, Russia, Europe and Japan are participating in the event.

The Beidou system chief designer, Sun Jiadong, said China will expand the Beidou satellite navigation service across the entire country.

Beidou is a satellite navigation system developed by China and has been providing services since the end of 2011. The conference is a key stage for China to exchange with the world in the field of satellite navigation know-how and to enhance innovation of its own satellite techniques.

Officials say China will launch three more satellites for the Beidou network this year and a global positioning satellite and navigation system will be completed by 2020.

Source: Xinhua News Agency

 

[CottageLV]

Wonder there's already a smart phone app for the Beidou Navigation Satellite System.

It is very easy, but has to have a built-in chip that is compatible with the Beidou system. It would be easy for the manufactures to do it. But it needs the backing of the central government to push it out. How widely adopted this services is by the general population will be depended on how hard they try. But I'm sure Lenovo will be one of the early waves to adopt it.

 

[hmmwv]

Almost all Chinese fishing vessels that travel beyond the territorial water are required to have Beidou 1 receivers, that's how they were able to text FLEC about them being captured by foreign law enforcement ships. Now both iPhone 4s and Xiaomi Phone have GPS/GLONASS chips, it'd be interesting to see to see a triple system phone.

 

[escobar]

Military COMSAT(Zhongxing) Launch time confirmed: May 26, 2012 at 15:56 UTC

NOTAM:

A0532/12 - A TEMPORARY RESTRICTED AREA ESTABLISHED BOUNDED BY N260808E1142921-N261444E1140013-N255857E1135553-N255223E1142456, BACK TO START. VERTICAL LIMITS: SFC-UNL.ALL ACFT ARE PROHIBITED TO FLY INTO THE AREA. SFC - UNL, 26 MAY 15:55 2012 UNTIL 26 MAY 16:39 2012. CREATED: 24 MAY 08:45 2012