Long March (rocket)
Long March , LM for short ( Chinese 長征 / 长征 , Pinyin Chángzhēng , CZ for short ) is a series of launchers for the People's Republic of China manufactured by the China Aerospace Science and Technology Corporation , named after the heroic myth of the Communist Party of China .
Models
Old generation of the Langer March missile
There are several models of the launcher, some of which came from completely different development directions (even within a model series). The rockets are in-house developments of the People's Republic of China , based in part on the technology of Soviet rockets from the 1960s and 1970s. Lower stages and (if available) intermediate stages and boosters of the CZ-2 - CZ-4 series use UDMH as fuel and N 2 O 4 as oxidizer , as do the upper stages of the CZ-4 series. The upper grades of CZ-2 and CZ-3 use LH2 and LOX .
New generation of the Langer March missile
The CZ-5, CZ-6 and CZ-7 are a newly designed modular system made up of a few different individual parts and officially approved by the State Council of the People's Republic of China on August 8, 2006 . They do without the toxic and environmentally harmful UDMH / N 2 O 4 combination and use RP-1 / LOX for the booster of the CZ-5 and the derived sub-levels of CZ-6 and CZ-7 , for the main and second level of the CZ-5 LH2 / LOX. The lower stages of the CZ-7 consist e.g. B. from the same components as the booster of the CZ-5:
- K2-1 (small booster of the CZ-5, 2.25 m, 1 YF-100 RP-1 / LOX engine) as a booster
- K3-1 (large booster of the CZ-5, 3.35 m, 2 YF-100 RP-1 / LOX engines) as the main stage
Components of the CZ-5 to CZ-7
- Steps in diameters of 2.25 m, 3.35 m and 5.0 m
- 2 LH2 / LOX engines for the main and upper stage of the CZ-5:
- 2 RP-1 / LOX engines for boosters and the lower stages of the CZ-6 and CZ-7:
- YF-100 : staged combustion cycle, 180 bar combustion chamber pressure, 1,199.2 kN (I sp 2,942.0 Ns / kg) at sea level, 1,339.5 kN (I sp 3,286.2 Ns / kg) in a vacuum.
- YF-115 : staged combustion cycle, 120 bar combustion chamber pressure, 147.1 kN at sea level, 176.5 kN (I sp 3,349.0 Ns / kg) in a vacuum.
List of rocket models
The CASC has assigned the following designations (CZ designations are equivalent to the corresponding LM designations):
- CZ-1 series with models CZ-1 and CZ-1D - light launch vehicles (payload LEO 0.75 t)
- CZ-2 series with the models CZ-2C, CZ-2D, CZ-2E and CZ-2F - light to medium-weight, two-stage (partly manned) launch vehicles (payload LEO 2C 3.5 t, 2E / F 8.5 t )
- CZ-3 series with models CZ-3, CZ-3A, CZ-3B and CZ-3C - medium-weight three-stage launch vehicles for GTO (payload 1.5 t (CZ-3) to 5.2 t (CZ-3B) ) and interplanetary orbits
- CZ-4 series with the models CZ-4, CZ-4B and CZ-4C - medium-weight three-stage launchers for polar and sun-synchronous orbits (payload LEO 2.8-4.5 t)
- CZ-5 series - family of medium to heavy launch vehicles similar to the Ariane 5 , Delta IV , H-II B, Atlas V or Angara . The first launch took place on November 3, 2016.
- CZ-6 series - Light launch vehicle that uses a modified variant of the smaller CZ-5 boosters as the first stage. Its main purpose is to bring smaller payloads up to a weight of 1.5 tons into a sun-synchronous orbit. The first successful launch took place on September 19, 2015.
- CZ-7 series - medium-weight launcher, which, as the first stage, uses a modified variant of the larger CZ-5 boosters. It is intended to replace the hypergolic fueled CZ-2, CZ-3 and CZ-4 and is also intended for manned flights. The first launch took place on June 25, 2016.
- CZ-8 series - two-stage, partially reusable launch vehicle under development. The first stage of the CZ-8, based on the CZ-7, is intended to land vertically, as are its two side boosters. A payload capacity of 7.6 t in LEO, 5 t SSO and 2.8 t GTO is planned; First start in 2020 at the earliest.
- CZ-9 - three-stage super-heavy-lift launch vehicle for 140 t in LEO, 66 t in GTO, 50 t to the moon and 44 t to Mars. The CZ-9 is still in the early stages of development; whether it will actually be built has not yet been decided. The rocket could launch for the first time in 2028 and, with the next flight, bring a probe on its way to Mars, which will return to Earth with rock samples. From around 2030 manned missions to the moon are planned.
- CZ-11 series - solid rocket (with liquid fuel maneuvering stage) for emergencies, which should be constantly on standby. It can be stored for a long time and can be started immediately. The first launch took place on September 25, 2015.
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Launch centers
 
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Launch sites of the Langer Marsch launch vehicle family
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There are currently four launch centers in use for the various Langer Marsch missiles. In the medium term, the start center in Wenchang is to replace the start center in Xichang , as accidents there caused damage to residents due to the dense population.
- Since 1958 the Jiuquan Cosmodrome in the Gansu Province in the north of the country, for manned flights with the Shenzhou spaceship and for take-offs in low and medium orbits with medium inclination (CZ-1, CZ-2, CZ-4, CZ-11)
- since 1966 the Taiyuan Cosmodrome in Shanxi Province in the north of the country, mainly for take-offs in low sun-synchronous and polar orbits (CZ-1, CZ-2, CZ-4, CZ-6)
- since 1984 the Xichang cosmodrome in the Sichuan province inland, mainly for take-offs in geostationary orbits (CZ-2, CZ-3, CZ-4), but also for the lunar probes Chang'e-1 to Chang'e 5-T1 ( CZ-3)
- since 2016 the Wenchang Cosmodrome in the northeast of the island of Hainan in the extreme south of China, for take-offs into geostationary orbits and heavy loads in general (CZ-5, CZ-7)
Manned space travel
On October 15, 2003, the People's Republic of China succeeded in putting the Shenzhou 5 spacecraft with the taikonaut Yang Liwei on board into orbit around the earth with a “ Long March 2F ” launch vehicle . This makes China the third country after the Soviet Union and the USA to operate independently manned flights with missiles developed in-house. In the medium term, the " Long March 7 " (with spaceships of the Shenzhou series) and the " Long March 5 " (with the manned spaceship of the new generation ) will take over the transportation of space travelers. In the 2030s, manned missions to the moon are planned with the “ new generation manned rocket ”.
Accidents and their effects
A relatively strong variant is the Langer Marsch 3B (CZ-3B / LM-3B), which is specially designed for transporting communication satellites in geotransfer railways. This rocket is offered at a relatively low price on the international satellite launch market, but has so far only received a few launch orders because the USA sanctioned the import of US satellite technology to China. The official reason for the ban was the false starts of a CZ-2E and CZ-3B , which occurred in 1995 and 1996 , when the rockets exploded shortly after the start over a nearby village or fell on a mountain slope near the launch facility and many people were killed . The defects found were meticulously remedied and so the series were reliable afterwards. However, this was interpreted as a dangerous development by the United States Department of Defense , whereupon the United States tried to impose sanctions on the further export of Western satellite technology. The false starts in 1998 became part of the official justification for a tightening of the American technology sanctions as part of the International Traffic in Arms Regulations , which make it almost impossible for Western customers to launch their satellites with these rockets, as almost all larger satellites contain US components . Since the American president, according to an amendment to the Arms Export Control Act, has to confirm that every satellite business does not harm American start-up companies, the USA created an advantage for the domestic satellite start-up market.
In the case of the CZ-3B, which crashed on February 14, 1996, it took a year and a half before the fault - a faulty wire-bonded gold-aluminum contact in the power supply of the inertial navigation system - was found and rectified. On August 19, 1997 flight operations with the rocket were resumed. An incorrectly designed turbo pump on a CZ-5 engine had more serious consequences. After a false start on July 2, 2017, it took more than two years until the engine's turbine was redesigned and the next start could be carried out on December 27, 2019. As a result, important projects such as the Chang'e-5 lunar probe or the Chinese space station were severely delayed.
Damage limitation in regular operation
With the inland cosmodromes, especially in Xichang, there is a constant problem that missile stages and boosters that have burned down during regular operation can crash into populated areas. It is true that the missiles' trajectories are chosen so that they do not pass through cities and infrastructure facilities; In addition, the population of the affected regions is called upon to move to safe areas before each take-off. Although there have been no personal injuries in normal operations so far, this is meeting with falling acceptance in view of the increasing frequency of flights - in 2018, China was the country with the most rocket launches for the first time - and the compensation payments for broken roofs etc. are driving up take-off costs. That is why attempts are now being made to equip the rocket parts with steering devices so that the crash area can be narrowed down.
The CZ-2F, which has been in use since 1999, as the newest model in the CZ-2 series, already has fold-out grid fins that allow the fall of the first stage to run in a more controlled manner. In 2019, swiveling grid fins were tested for the first time on the first stage of a CZ-2C, as they have been in use since 2015 on the landable first stage of the American Falcon 9 rocket . The landing site was about three kilometers from the calculated point for that test. With a further development of this system, one would like to enable precise landings of the Langer Marsch 8 launcher, which is planned to be reusable . Grid fins were also tested for the first time in 2019 when a CZ-4B was launched. The planned crash area of the first rocket stage could be reduced by 85%. This method is now used regularly on the CZ-4B.
The Chinese Academy of Launch Vehicle Technology took a different approach to boosters . In March 2020, a system was tested on a CZ-3B for the first time in which a booster was first stabilized with a small parachute after being disconnected and then sank to earth on a steerable paraglider and at the same time transmitted its coordinates to a ground station. The search parties were able to retrieve the booster after just 25 minutes, whereas previously this could take several hours or, if landing in difficult terrain, half a month. With this method, the tanks of the stage, which may contain residues of the highly toxic and explosive fuel components 1,1-dimethylhydrazine and dinitrogen tetroxide , should also remain intact .
See also
Web links
Individual evidence
- ↑ 国家 航天 局 ： 中国 航天 事业 创建 60 年 60 件 大事 正式 公布. In: zhuanti.spacechina.com. October 12, 2016, accessed March 9, 2020 (Chinese).
- ↑ a b 中国 新一代 液氧 煤油 发动机 3 ： YF100 / 115 主要 特性 - 深 空 网. Archived from the original on March 4, 2016 ; accessed on May 6, 2020 (Chinese).
- ^ A b China successfully debuts Long March 7 - Recovers capsule. NASA Spaceflight.com, June 25, 2016, accessed June 29, 2016 .
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- ↑ China is planning around 50 launch missions in 2020 . German.China.org.cn, January 3, 2020.
- ^ Andrew Jones: China reveals details for super-heavy-lift Long March 9 and reusable Long March 8 rockets. In: spacenews.com. July 5, 2018, accessed March 7, 2019 .
- ^ Andrew Jones: China to launch new Long March 8 rocket by end of 2018. In: gbtimes.com. February 27, 2017, accessed March 6, 2019 .
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- ↑ Ernst Messerschmid, Stefanos Fasoulas: Space systems: An introduction with exercises and solutions. Springer 2017, ISBN 978-3-662-49638-1 , page 375; limited preview in Google Book search.
- ↑ Bradley Perrett: Chinese Working On Giant Engine For Long March 9. In: Aviation Week . March 12, 2018, accessed March 11, 2019 .
- ↑ China's first solid-fuel rocket to debut before 2016. China Daily, March 2, 2013, accessed September 27, 2015 .
- ↑ China debuts Long March 11 lofting Tianwang-1 trio. NASA Spaceflight.com, September 24, 2015, accessed September 27, 2015 .
- ↑ Ryan Zelnio: A short history of export control policy. In: thespacereview.com. January 9, 2006, accessed March 25, 2020 .
- ^ Debra Werner and Andrew Jones: China could launch another Long March 5 by year's end. In: spacenews.com. September 11, 2019, accessed March 25, 2020 .
- ↑ Chen Lan: Mist around the CZ-3B disaster (part 1). In: thespacereview.com. July 1, 2013, accessed March 9, 2020 .
- ↑ Mark Wade: Chang Zheng 3B in the Encyclopedia Astronautica, accessed on March 9, 2020 (English).
- ↑ Andrew Jones: China targets late 2020 for lunar sample return mission. In: spacenews.com. November 1, 2019, accessed March 9, 2020 .
- ↑ 找到 了！ 长征 三号 乙 运载火箭 助推器 残骸 在 余庆 、 石阡 找到 了. In: sohu.com. June 23, 2020, accessed June 23, 2020 (Chinese).
- ↑ 我国 首次 “栅格 舵 分离 体 落 区 安全 控制 技术” 试验. In: www.bilibili.com. August 13, 2019, accessed March 19, 2020 (Chinese).
- ↑ 胡 喆: 我国 成功 完成 首次 火箭 落 区 安全 控制 技术 验证. In: www.xinhuanet.com . July 28, 2019, accessed March 19, 2020 (Chinese).
- ↑ 长 四乙 验证 栅格 舵 技术 中国 可 重复 用 火箭 迈 成功 一步. In: mil.news.sina.com.cn. November 4, 2019, accessed March 19, 2020 (Chinese).
- ↑ 郑莹莹 、 郭超凯: 长征 四号 火箭 今年 “首 秀” 采用 精准 落 区 技术 “指 哪 落 哪”. In: chinanews.com. July 3, 2020, accessed July 4, 2020 (Chinese).
- ↑ 我国 火箭 残骸 伞降 控制 系统 可行性 得到 验证. In: www.spaceflightfans.cn. March 19, 2020, accessed March 19, 2020 (Chinese).
- ↑ 我国 火箭 残骸 精准 定位 技术 研究 取得 重大 突破. In: www.spaceflightfans.cn. March 16, 2020, accessed March 19, 2020 (Chinese).
- ↑ 赵 艺 涵: 我国 首次 火箭 残骸 伞降 着陆 画面 披露. In: sasac.gov.cn. April 9, 2020, accessed April 9, 2020 (Chinese). Includes photos of the booster that landed.