China's Space Program News Thread

[SinoSoldier]

Two major headlines today:

1. The Chinese have tested the turbopump for the 1st stage engines of the CZ-9:

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It will be a key component to the 500-ton kerolox engine that will power the core and booster stages of the CZ-9.





2. An ignition experiment has been performed for China's largest solid-fueled rocket motor:

The motor is 3 meters in diameter and is, to date, the largest of its kind developed by the Chinese.

 

[SinoSoldier]

An interesting point is that the motor's diameter of 3 meters matches that of the P238 booster used on the Ariane 5-ECA and almost the 3.71 meters of the SRB's diameter.

Hence, given roughly comparable fuel composition (most likely ammonium perchlorate plus a binder-fuel hybrid) and internal fuel geometry (SRB uses a 6-point star), the maximum thrust should be comparable to that of the P238 and SRB.

 

[escobar]

China has completed the test ignition of its largest solid-fuel rocket motor in the northwest city of Xi'an.With a diameter of three meters, the solid-fuel rocket motor ran for 100 seconds after ignition, meaning that technologies of the engine can be used in space missions.

"The success marks a new height of our country's rocket-propelling ability with solid propellant, which ranks China among the top four in the world. The successfully tested technologies will be used in heavy-lift and large rockets for China's deep-space explorations and manned moon-landing," said Gao Bo, deputy head of the Academy of Aerospace Solid Propulsion Technology.

"Great propelling ability is an advantage of solid-fuel rocket motors. With such an advantage, we can launch larger rockets with heavier payloads," said Bai Yanjun, director of the solid-fuel dynamics lab of the academy.

 

[SinoSoldier]

The mentioned thrust (150 tons) is actually pretty low for a motor of that diameter.

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Interesting; it seems that two types of solid motors were tested: the shorter variant with a protruding nozzle and the longer one without a protruding nozzle.

Shorter variant (on right) & longer (on left):

 

[SinoSoldier]

So, apparently on the same day the 3-meter-diameter motor was tested, a new 2-diameter motor also underwent a successful firing. Its thrust is believed to be ~120 tons, but no confirmation was given.



According to the report regarding the 3-meter booster test, the design of a five-segment solid rocket booster would be completed by 2020. This would potentially power the CZ-9 heavy launch vehicle.

A simple calculation, under the assumption that total thrust is proportional to the length of the motor, would place a CZ-9-class solid-fuel strap-on booster in the (150/2)*50 = 1250 ton thrust range. This roughly corresponds to the ~1000 ton thrust claimed by GlobalSecurity.

 

[escobar]

China is transferring on Wednesday two of its Long March II F or CZ-2F carrier rockets to their launch site in the west of the country, to ready them for space laboratory and manned space travel missions. This is the first time that two CZ-2F rockets are being transferred to the launch center at the same time.

One of the carrier rockets is scheduled for launch in the third quarter of this year to send into space the space lab Tiangong-2. The other rocket is to lift off later with the Shenzhou-11 spacecraft carrying two astronauts to dock with Tiangong-2.

"We have to start the preparations of the second launch mission four days before the implementation of the first launch. During preparation of the rocket for launching Tiangong-2, we will not have enough personnel and vigor to prepare the other rocket, thus we adopt this measure so that it will take shorter time to get ready for both launch missions," said Zhang Zhi, the chief designer of the CZ-2F rockets.

"We will assemble the first rocket upright at the technological area and then transfer it to the launch area. Only after that can we assemble the second rocket. So one of the rockets will be ready for launch at the launch area, while the other will be assembled upright at the technological area," Zhang said.

Tiangong-2 will be capable of receiving manned and cargo spaceships, and will be a testing place for systems and processes for mid-term space stays and refueling in space, according to a statement issued by China's manned space engineering office.

During their planned 30 days of stay in the space laboratory, the two Chinese astronauts will carry out a variety of scientific researches and applications, like testing some key techniques and checking on the possibility of long-term human residence in space.

"Let's put it this way; it's the start of the final battle of the mission of Tiangong-2 space laboratory. We are going to complete the en-masse lifting and thorough checking of the rocket, upon its arrival at the launch center. The rockets have to be sent into space without a hitch hidden or otherwise. This is our ultimate goal," says Jing Muchun, chief commander of CZ-2F rockets.

Relatively few improvements have been made on the new type of CZ-2F rockets, compared with their immediate predecessors launched in 2011. This indicates the maturity of the techniques and technology used on this rocket.

 

[escobar]

China's lunar probe Chang'e-3 has collected plenty of scientific data on the moon in the past two years and a half, setting a record as the longest time to work on the lunar surface, said an official from the State Administration of Science, Technology and Industry for National Defense on Friday.

The Chang'e-3 lander is equipped with three categories of scientific devices, including a Descent Camera, an Extreme Ultraviolet Imager, a lunar-based optical telescope to explore the lunar, the universe and the plasmasphere around the earth.

"For example, by using the Lunar Penetrating Radar, we got the superficial structure on the lunar surface and the layered structure under 330 meters of the lunar. In addition, the Extreme Ultraviolet Imager captured the evolution of 15 plasma layers within the radius of the earth. The lunar-based optical telescope also toured the heaven, viewed different areas of the sky and got a lot of images," said Liu Tongjie, deputy director of the moon exploration center, State Administration of Science, Technology and Industry for National Defense.

The lunar probe gained 7TB of data including exploratory data, pictures and videos and the data has been sent to over 1,000 colleges, universities and scientific institutions in the Chinese mainland, the Hong Kong and Macao special administrative regions.

"Since the 1990s, the international community has conducted 13 lunar explorations, including five by the United States, and four by China that ranks the second in terms of both the number of times of exploration and the scientific achievements. We can say that China has reached the advanced level in some areas of lunar exploration, and this has stimulated the development of moon exploration in the world," said Liu.

 

[escobar]

China's lunar probe Chang'e-3 has collected a great amount of data and images of the moon in the past two and half years, getting three "first" research findings in the human lunar exploration history, according to the State Administration of Science, Technology and Industry for National Defense.

China's lunar probe Chang'e-3 entered its 33rd dormancy period on Thursday, a record for the longest work time by a lunar probe. Chang'e-3 obtained the world's first geological section map of the moon with a lunar penetrating radar, which provided an important scientific basis to know the evolution history of the moon and explore its resources.

The map showed the features and the evolution history of the geological structure that is 330 meters deep under the lunar surface, and discovered a new rock - the lunar basalt.

"The radar detected three layers of basalt under the ground, especially that the top layer was 195 meters deep. This indicates that until the late period, about more than two billion years, there were still huge amounts of magma that were erupting. This shows that the activity of the magma on the moon lasted longer than expected before," said Lin Yangting, a researcher of the Institute of Geology and Geophysics, Chinese Academy of Sciences.

In addition, Chang'e-3's latest data showed that the lunar soil is five meters deep, almost doubled the previous data obtained by other countries. In the mission of observing the universe, Chang'e-3 for the first time used an optical telescope to conduct a survey of the celestial body in the ultraviolet band at the north polar of the moon, with which astronomers can do comparison studies in the future.

Meanwhile, the telescope got the latest data about the water content on the lunar surface, proving for the first time that there is no water on the moon. "We measured the content of water on the lunar surface and above, and got the historically smaller value, which is also in line with the expectations of the experts on the formation of the moon," said Wei Jianyan, researcher of National Astronomical Observatory, Chinese Academy of Sciences.

The smaller the measured value, the smaller possibility of existence of water in figuring out whether there is water on the moon. The world's first extreme ultraviolet imager installed on the Chang'e-3 lander also obtained a large amount of plasmasphere images of the earth.

The plasmasphere is the first of the natural screens surrounding the earth, which can extend to around 40,000 kilometers away from the surface of the earth. It can prevent the interference of the solar wind, high-energy particles and most of the cosmic rays.

"The earth's plasmasphere is in the innermost of the earth's magnetosphere. If the magnetosphere is interfered, the shape, position and structure of the plasmasphere will be affected. Therefore by detecting the structure and evolution of the earth's plasmasphere, we can monitor the influence of the solar activities to the earth," said He Han, associate researcher of National Astronomical Observatory, Chinese Academy of Sciences.

The huge impulse of the solar storm will severely destroy the communication functions of the artificial objects that are running along the earth, such as the navigation satellite, the communication satellite and manned spacecrafts. It is the exclusive ability of Chang'e-3 to observe the change of the plasmasphere as an indicator to monitor the solar storm.

The extreme ultraviolet imager has currently collected more than 1,300 images of the earth's plasmasphere.

 

[escobar]

GF4 (50m resolution / 1min temporal resolution) HD dynamic cloud images for typhoon Nida

 

[escobar]

China lunar rover Jade Rabbit has stopped operations, according to an official announcement. The State Administration for Science, Technology and Industry for National Defense (SASTIND) said on Wednesday that Chang'e-3, China's first lunar lander, has operated on the moon for 31 months, exceeding its design life by 19 months. Chang'e-3 entered its 33th lunar night on July 28. A lunar night lasts approximately 14 earth days.