CZ-7 Unmanned Medium Space Launch Vehicle
China will 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. A medium-sized rocket using liquid propellants, Long March-7 will carry up to 13.5 tonnes to low Earth orbit or 5.5 tonnes to sun-synchronous orbit at a height of 700 km. It will carry cargo craft for the planned space station.
“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.
A Long March-7 carrier rocket arrived at the launch site in the city of Wenchang of south China's Hainan province in February 2016. The liquid-fuelled carrier rocket is designed to launch China's first cargo spacecraft, which was under development. The unmanned cargo spacecraft will carry supplies to and refuel China's future manned space station. The Long March-2 and Long-March 3 are scheduled to retire within the next 10 years. The new generation, Long-March 7 is expected to take over 80 percent of the launch missions in the future. By early 2016, four Long March-7 rockets had been made.
The designation CZ-2F/H is no longer used and is now the CZ-7. The Long March 7 mid-sized launch vehicle is derived from components developed for the Long March-5 medium heavy lift booster. Some of the Long March 7 components are expected to be tested with the newer Long March -2F/G and Long March 2F/H boosters as a part of the graduated building block approach to developing this higher performance booster family. The new family of Long March-6, Long March-7 and Long March-5 constitute the new family of boosters to replace older existing boosters of the Long March family. Long March -6 is the lighter of the boosters while the Long March-5e is the origin system medium heavy lift booster largest of the family booster. Long march-7 fills a gap below and between the long March -5 and Long March-6 series.
This YF-100 engine utilizing kerosene, liquid oxygen propellants series of boosters in all cases are to do the building block technology demonstration path finding hard development work for the benefit of the Long March-5 medium heavy lift booster series. The LM-7 utilizes the K-3, 3.35 meter diameter Long March-5 first stage larger strap-on boosters as the main core stage with its two YF-100 Russian technology based engines while the core is surrounded by four K-2 one YF-100 engine 2.25 meter diameter stages identical to those two additional planned as the two strap-on booster in addition to the two 3.35 meter diameter strap-on’s of the Long March-5 booster first stage.
The Long March-7 is 53.1 meters long and 3.35 meters in diameter. Its launch weight will be about 593 metric tons. It can put a 13.5-ton payload into low Earth orbit and a 5.5-ton payload into a sun-synchronous orbit. The rocket has new engines and eco-friendly propellants.
The Long March-5 is designed to place 20-25 metric tonnes into low earth orbit utilizing four K-3 strap-on boosters, while the Long March-7 is designed to place 12,500kg payload into LEO, 13,500kg payload to a 400X200km LEO inclined at 42°, or 5,500kg payload to a 700km SSO. LM-7’s second stage core may be based on the derivation of the K-3 modules utilizing a single altitude version of the YF-100 engine. Whether some kind of UDMH/NTO or Hydrogen/Oxygen upper a third stage will be added to the Long March-7 series was initally uncertain. With a LOX/LH2 third-stage (with two YF-75 engines), the Long March-7 would be able to launch GEO satellites and lunar probes.
There is an increase in the configuration of the upper level / the upper level is distinguished, and the core level adopts the configuration of the oxyhydrogen engine, and the increase (HO) is used to distinguish it. For example, the two-stage configuration with two 2.25m-diameter solid fuel boosters and the core-level two adopting a hydrogen-oxygen engine is named CZ-722S (HO). According to the above naming rules, the basic CZ-7 code is CZ-724, abbreviated as CZ-7. Another example is to install the three-stage oxyhydrogen fuel of the Changjiajia series on the CZ-7 basic model, which becomes the Changzheng No. 7 (CZ-7A), code-named CZ-734, which can be used to launch 6-7 tons of GTO payload.
Initially it was planned that the year 2014 would see the debut of Long March-7, which is designed to send China's cargo spaceship to dock with a future space station, Liang Xiaohong, deputy head of the China Academy of Launch Vehicle Technology, told China Daily on March 04, 2013. The Long March-7 carrier rocket has a takeoff thrust of 700 metric tons, the second-largest after Long March-5 with 1,000 tons. "Scientists are mulling over the idea of using it to launch a manned spaceship in the future, too," said Liang. "If so, the Long March-7 will become the country's only rocket that can send manned and unmanned spacecraft into space."
By December 2014 Chinese engineers were nearing completion of the Long March-7 rocket and would soon test its compatibility with the launch site, the designers said. "We will perform the compatibility test for the Long March-7 and the Wenchang Satellite Launch Center in Hainan within a short time, and the rocket to be used in the test has been produced," said Tao Gang, general manager of the Tianjin Long March Launch Vehicle Manufacturing Co Ltd. Four Long March-7 rockets had been made to date, and three of them were used for static and thruster tests.
China launched its Long March-7 carrier rocket successfully late on 25 June 2016, hailed as a prelude for the country's five-year plan (2016-2020) for the space sector. China was expected to have more than 200 spacecraft in orbit by 2020 and perform about 30 launches per year on average, said Yang Baohua, deputy manager of China Aerospace Science and Technology Corporation (CASTC). The Long March-7 carrier rocket is expected to become the main carrier for space launches. It is a medium-sized, two-stage rocket that can carry up to 13.5 tonnes into LEO.
China carried out the development of a new generation of high-orbit carrier rocket CZ-7A, that is based on CZ-7, adding the CZ-3A third stage. It is capable of launching a GTO orbit satellite in from Wenchang Space Launch Site, Hainan, China, with a carrying capacity of not less than 7 Ton. This type of launch vehicle can fill the gap of 7.0t GTO capacity in China.To enhance the competitiveness of Chinese launch vehicles and match the top level of the international launch vehicle market.
The first launch of the CZ-7A on 16 March 2020 from Station 201, was reported as a failure, though at first there were two versions of the story. One is the fault happened before the third stage seperation, and the vehicle didn't reach the orbital velocity, splashed down in Pacific. The other is the third stage didn't start up successful, and the satellite was put in LEO.
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