CZ-5 Space Launch Vehicle
China on 03 November 2016 launched its new heavy-lift carrier rocket Long March-5 from the Wenchang Space Launch Center in south China's Hainan Province. The rocket, which looked much "fatter" than other rockets of Long March series, blasted off at 8:43 p.m. Beijing Time from the launch center. The payload was successfully sent into a preset orbit about 30 minutes later. The State Administration of Science, Technology and Industry for National Defence later announced the complete success of the launch. The Long March-5 is a large, two-stage rocket with a payload capacity of 25 tonnes to low-Earth orbit, the largest of China's carrier rockets. According to China Aerospace Science and Technology Corporation (CASC), the developer of Long March-5, the rocket uses two kinds of fuel, kerosene and liquid oxygen as well as liquid hydrogen and liquid oxygen, rather than highly toxic propellant, making it more environmental friendly and less expensive. It is the second launch from the coastal Wenchang center. On June 25, China's new generation medium-sized Long March-7 made its debut at the site.
China planned to send two new models of carrier rocket in the Long March series on their maiden space trips in 2016, the China Aerospace Science and Industry Corporation (CASC) said on 16 January 2016. The country’s mst pwerful carrier rocket, Long March-5 has a payload capacity of 25 tonnes to low Earth orbit, or 14 tonnes to geostationary transfer orbit. It is scheduled to carry the Chang’e-5 lunar probe around 2017 to finish the last chapter in China’s three-step (orbiting, landing and return) moon exploration program. According to a CASC statement, which did not specify either of the rockets’ missions, Long March-5 was being tested at a launch site in south China’s Hainan Province.
“The two carrier rockets’ maiden flights will significantly boost our country’s ability to enter space and help realize leapfrog development in our space transportation system,” said the CASC. Both rockets were developed by the China Academy of Launch Vehicle Technology under the CASC.
Long March 5, the nation’s next-generation heavy lift launch system, is nearly 57 meters high, with a diameter of 5 meters. With a liftoff weight of around 800 metric tons, it will have a maximum payload capacity of 25 metric tons in low Earth orbit and 14 tons in geosynchronous transfer orbit, roughly comparable to the capacity of the United States’ Evolved Expendable Launch Vehicles, such as the Delta IV and Atlas V.
The rocket will use liquid oxygen/kerosene and liquid oxygen/liquid hydrogen as propellants for its engines, which means the craft will be more environmentally friendly than previous designs. The Long March 5 will be used to launch large lunar probes and the manned space station that China plans to send into orbit around 2020.
China will develop six configurations in its heavy-lift Long March 5 rocket family. The six designs will have different launch capacities. Engineers were initially focusing on the two types that will be used for the Chang'e-5 lunar probe and manned space station missions.
According to Premier Zhu Rongji's instruction in his Government Work Report at the Fourth Session of the Ninth National People's Congress, that the Chinese Government should lay emphasis on the important high-tech projects including a new generation launch vehicle. Now the advanced development of the new generation launch vehicle started completely. A symposium on reviewing the advanced development of China's new generation launch vehicle sponsored by Commission of Space, Technology and Industry for National Defense (COSTIND) was held in Beijing on 10 May 2001.
The technological way to develop a new generation of launch vehicles is as follows: "one emphasis, the development of two propulsion systems and three modules". The "One Emphasis" is to develop the heavy launch vehicle with a diameter of 5 meters. The "Two Systems" are two new propulsion systems: one uses the 500kN hydrogen and oxygen propellant engine and another uses the 1200kN liquid oxygen/kerosene engine. The diameters of the "Three Modules" are 5m, 3.35m and 2.25m respectively.
The new generation launch vehicle will use 120 ton liquid oxygen/kerosene rocket engine and 50 ton LH/LO engine as its propulsion system. Its payload capability into LEO will be 1.5-25 ton, and into GTO be 1.5- 14 ton. It will be characterized by large thrust, non-toxic and pollution free propellants, low cost and high reliability. It can meet the demands of the market at home and abroad within the next 10-30 years.
For the new generation of space launch vehicle China plans to develop one series, two kinds of engines and three modules. That means, China will take the LOX/kerosene and LOX/LH engines as propulsion systems and finally realize the generalization, seriation and modularization. This will require gradually developing the new generation of launch vehicles with 5m, 3.35m and 2.25m diameter modules respectively, among which the 5m diameter core stage will use 3.35m diameter module as its booster, 3.35m diameter core stage will use 2.25m diameter module as its booster. And the 3.35m and 2.25m modules also can be used independently.
China's new generation launch vehicle will be based on the basic version. With boosters added on it such launch vehicle can launch various payloads ranging from 10 tons to 25 tons and with the upper stage module it can launch GTO payloads ranging from 6 tons to 13 tons. After China's new generation launch vehicle is successfully developed, the LEO payload capability will surpass 20 tons, and can launch a 20 tonnage permanent man-tended space station, promoting the development of our space application industry. Because the new heavy launch vehicle has fewer engines that ignite on the ground, fewer stages (one and a half) and better manned environment, and use nontoxic propellants. The new launch vehicle can either launch a large space telescope to promote the development of our astronomy, or launch deep space probes, such as a large lunar probe and Martian probe to promote the development of deep space exploration science. As it can launch two 6-ton GTO satellites or one 12-ton very large GTO satellite, it can basically meet the needs of the launch of the geo-synchronous communications satellite within decades.
Once the Long March -5 booster has demonstrated a reasonable level high reliability it will be considered for manned flight operations according to Chinese officials.
In 2007, the Long March 5 was due to make its first flight in 2013. At the Global Space Development Summit held in Beijing on 23 – 25 April 2008, China announced that multiple hot-fire tests have been conducted on new oxygen/kerosene and oxygen/hydrogen rocket engine systems for the forthcoming Long March 5 booster line, and are being integrated with their airframes and tankage for initial launches as early as 2010.
In 2012, the target had slipped to 2014. The first prototype ground test, systems and dynamic test articles of the LM-5E booster was planned to be ready for testing in 2012 while the static test version of each stage were expected to be ready for static test firings demonstrations in 2013. The prototype LM-5E first flight test was tentatively planned for 2014. The LM-5E first stage clustered 120 metric ton [264,600 lbsf] thrust engine has already accumulated over 10,000 seconds burn time as of the summer of 2010 after many years of R&D.
On March 25, 2013 Bradley Perrett of Aviation Week & Space Technology reported that the Long March 5 wouldd not launch until 2015. "Our plan has encountered some difficulties," Liang Xiaohong, deputy head of the China Academy of Launch Vehicle Technology, told China Daily on March 04, 2013, referring to three failed experiments recently. The main difficulty lies in the rocket's structural elements, said Liang, who is also a member of the National Committee of the 12th Chinese People's Political Consultative Conference. Though China's Long March rockets have recorded more than 100 successful launches, the Long March-5 is a new challenge due to its larger size - a diameter of 5 meters, instead of the 3.35 meters of all previous launch vehicles.
The larger design enables the Long March-5 to send heavy satellites and space station components into orbit, and it has six vehicle configurations planned for different missions. "But when an object is bigger, its technical risks and functional defects are also magnified," Liang said. The increased size has challenged the mechanical machining capabilities of Chinese manufacturers, who have never produced rocket parts as big before and lack the necessary equipment and technology, he added. "The Long March-5 project has reached the basic industry's ceiling," Liang said.
Also, the potential risks of a larger launch vehicle in space are unknown, and the designers must gauge these for six configurations of the craft instead of one, he said. Failure to solve the problem has prompted the academy to push manufacturers to improve their level of mechanical machining.
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