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Long March 7

The Long March 7 (Chinese: 长征七号运载火箭), or Chang Zheng 7 in pinyin, abbreviated LM-7 for export or CZ-7 within China, originally Long March 2F/H or Chang Zheng 2F/H, nicknamed Bingjian (冰箭; 'the Ice Arrow'), is a Chinese liquid-fuelled launch vehicle of the Long March family, developed by the China Aerospace Science and Technology Corporation (CAST).[4] It made its inaugural flight on 25 June 2016.

Long March 7
Long March 7 Y6 transporting to launch site
FunctionMedium to heavy
launch vehicle
ManufacturerCALT
Country of originChina
Size
Height
  • CZ-7: 53.10 m (174.2 ft)
  • CZ-7A: 60.13 m (197.3 ft) [1]
Diameter3.35 m (11.0 ft)
Mass
  • CZ-7: 597,000 kg (1,316,000 lb) [2]
  • CZ-7A: 573,000 kg (1,263,000 lb) [1]
Stages
  • CZ-7: Two
  • CZ-7A: Three [3]
Capacity
Payload to LEO (200 x 400 km x 42°)
Mass13,500 kg (29,800 lb)
Payload to GTO
Mass7,000 kg (15,000 lb) [3]
Payload to TLI
Mass5,000 kg (11,000 lb)
Payload to SSO
Altitude700 km (430 mi)
Mass5,500 kg (12,100 lb)
Associated rockets
FamilyLong March
ComparableDelta IV, Atlas V, Falcon 9 Block 5, GSLV Mk.III, H-IIA
Launch history
StatusActive
Launch sitesWenchang, LC-2
Total launches13 (7:7, 7A:6)
Success(es)12 (7:7, 7A:5)
Failure(s)1 (7:0, 7A:1)
First flight
  • Long March 7: 25 June 2016
  • Long March 7A: 16 march 2020
Last flight
  • Long March 7: 10 May 2023
  • Long March 7A: 3 November 2023
    (Both Active)
Boosters – K2 booster
No. boosters4
Height27 m (89 ft)
Diameter2.25 m (7 ft 5 in)
Powered by1 YF-100
Maximum thrustSL: 1,200 kN (270,000 lbf)
Vac: 1,340 kN (300,000 lbf)
Total thrustSL: 4,800 kN (1,100,000 lbf)
Vac: 5,360 kN (1,200,000 lbf)
Specific impulseSL: 300 s (2.9 km/s)
Vac: 335 s (3.29 km/s)
PropellantRP-1 / LOX
First stage – K3 core module
Diameter3.35 m (11.0 ft)
Powered by2 YF-100
Maximum thrustSea level: 2,400 kN (540,000 lbf)
Vacuum: 2,680 kN (600,000 lbf)
Specific impulseSea level: 300 s (2.9 km/s)
Vacuum: 335 s (3.29 km/s)
PropellantRP-1 / LOX
Second stage
Diameter3.35 m (11.0 ft)
Powered by4 YF-115
Maximum thrust706 kN (159,000 lbf)
Specific impulse342 s (3.35 km/s)
PropellantRP-1 / LOX
Third stage (CZ-7A)
Diameter3.0 m (9.8 ft)
Empty mass2,800 kg (6,200 lb)
Gross mass21,000 kg (46,000 lb)
Propellant mass18,200 kg (40,100 lb)
Powered by2 YF-75
Maximum thrust167.17 kN (37,580 lbf)
Specific impulse4,295 m/s (438.0 s)
Burn time478 seconds
PropellantLH2 / LOX

Designed as a replacement of the Long March 2F, Long March 7 and its variants are expected to be the workhorse of the fleet, projected to account for around 70% of all Chinese launches. Long March 7 will also play a critical role in the Chinese Space Station. It was used to launch the Tianzhou robotic cargo spacecraft, and will eventually replace the Long March 2F as China's crew-rated launch vehicle in the future.[4]

Since 2020, in addition to the base Long March 7 configuration, there is the Long March 7A (CZ-7A etc.) variant which differs from the base CZ-7 by the addition of a liquid hydrogen-liquid oxygen third stage inherited from the third stage of the Long March 3B.[3] The rocket has also been developed into the Long March 8.

History edit

 
Rendering of Long March 7

The Long March 7 project started in 2008 with the formation of the development team within the traditional designer of space launch vehicles, CALT.[5] With the acquisition of the RD-120 technology and development of the YF-100 and YF-115 engines, the original plan was to re-engine the Long March 2F. The Long March 2F/H, as it would have been called, would "just" switch from N2O4 / UDMH to a LOX / kerosene propellant and improved thrust engines to offer better performance. But the switch resulted in a cascade of changes that increased the project complexity significantly.[6]

At the same time, the original Long March 5 project was expected to include heavy, medium and light versions. Since the Long March 2F/H and the medium Long March 5 had significant overlaps, it was decided to merge both projects. This way, the high reliability and flight legacy components and technologies of the Long March 2F were merged with the new technologies developed for the Long March 5.[6] Although finished nearly at the same time, the Long March 6 was a completely separate product developed by a young team within SAST. As such, it shares little more than tank diameters and propulsion with the LM-5 and LM7, but does cover the range of payloads between the medium Long March 7 and the very light Long March 11.[7]

In 2010, the project name was changed officially to Long March 7. According to the project deputy manager, Zhang Tao, the project required eleven new major technologies. But the innovation was not only at the product level, but one at the process itself. This was, according to the project manager, Wang Xiaojun, the first time the whole process was developed in digital 3D, using computer-aided design directly to computer-aided manufacturing.[8]

The inaugural flight was successfully performed on 25 June 2016, at 12:00 UTC from the Wenchang, LC-2 launch pad. It launched in the LM-7 configuration with the addition of the simultaneously debuting Yuanzheng-1A upper stage; the flight performed its multi-orbit mission successfully.[9]

Design edit

The Long March 7 is the medium-lift variant of a new generation rocket family that includes the heavier-lift Long March 5 and the small-mid cargo Long March 6. The structure is based on the reliable, human-rated Long March 2F launch vehicle. It inherited the 3.35 m-diameter core stage and 2.25 m-diameter liquid rocket boosters. Where the earlier Long March 2 rocket family used expensive and dangerous N2O4 / UDMH propellants, the Long March 7 uses LOX and kerosene. The engines are shared with the Long March 5 and 6. The goal was to build a more cost-effective and less hazardous rocket family to replace today's Long March 2 and eventually the Long March 3.[10] It is capable of placing a 5,500 kg (12,100 lb) payload into a Sun-synchronous orbit (SSO) of 700 km (430 mi).[11]

Stages edit

The Long March 7 inherits the modular stages of the original Long March 5 project. As such, its first stage is the same module as the LM-5 boosters. It also shares tank diameters and engines with the Long March 6, but the design groups were completely different. The LM-5 and LM-7 were developed by China Academy of Launch Vehicle Technology (CALT), while the LM-6 was done by Shanghai Academy of Spaceflight Technology (SAST). Even the avionics are different.[7]

The basic Long March 7 can be optimized by varying the number of boosters or enhanced by the addition of upper stages. These stages allow more mission flexibility, like direct injection to higher orbits or multiple orbit deployment. They can also increase the performance significantly. Thanks to this modularity, performance can be dialed between 4,000 kg (8,800 lb) and 13,500 kg (29,800 lb) for LEO, 2,000 kg (4,400 lb) and 8,000 kg (18,000 lb) for SSO and 4,000 kg (8,800 lb) and 7,000 kg (15,000 lb) to Geostationary transfer orbit (GTO).[12][13]

Boosters edit

The Long March 7 can use 0, 2 or 4 boosters using RP-1 / LOX propellant.[14] They are powered by a single oxidizer-rich staged combustion YF-100 engine. Each boosters supplies 1,200 kN (270,000 lbf) at sea level and 1,340 kN (300,000 lbf) in vacuum of thrust. Its specific impulse is 300 s (2.9 km/s) at sea level and 335 s (3.29 km/s) in vacuum. Each module has its own single axis thrust vector control, and thus it required a special design in the control systems of the rocket to coordinate all the rocket's nozzles.[11][14] They use the legacy 2.25 m (7 ft 5 in) width of the Long March 2 and Long March 3 families, but due to the increased thrust of the YF-100 with respect to the YF-20 and YF-25, the boosters are almost twice as long, at 27 m (89 ft).[14] A Long March 7 rocket booster created a fireball visible from portions of Utah, Nevada, Colorado, Idaho and California on the evening of 27 July 2016; its disintegration was widely reported on social media, and the uncontrolled re-entry of such a five-ton object was regarded as a rare event.[15]

First stage edit

The first stage has 3.35 m (11.0 ft) diameter tanks carrying RP-1/LOX propellant. It is powered by two YF-100 engines, sharing the same propulsion elements as the boosters, only that for the first stage the engines can gimbal in two axes.[14] Also, this first stage is the same basic module as the Long March 5 boosters. The diameter was designed for land transport and as such, it will be able to launch from all the Chinese launch sites. This is a critical difference to the LM-5 that requires water transport for its core stages.[11] While it shares diameter and engines with the Long March 6 first stage, the development was completely separated and done by different groups.[7]

Second stage edit

The second stage also shares the first 3.35 m (11.0 ft) diameter tanks and propellant. It is powered by four oxidizer-rich staged combustion RP-1/LOX YF-115 engines. Two are fixed and two can gimbal in two axis.[14] It offers 706 kN (159,000 lbf) of thrust in vacuum with a specific impulse of 341.5 s (3.349 km/s).[11] While it shares engines with the Long March 6 second stage, the development were completely separated and done by different groups.[7]

Optional stages edit

Yuanzheng-1A edit

It can use the Yuanzheng-1A upper stage to increase payload to higher energy orbits and enable multiple ignition missions. Particularly, allows direct injection to SSO orbits.[16] The inaugural flight successfully used this upper stage to deliver multiple payloads to different orbits.[12]

Hydrogen stage edit

The Long March 7 is expected to be enhanced by a high-energy liquid hydrogen and liquid oxygen stage. This stage and the low inclination of Wenchang would enable to launch payload between 4,000 kg (8,800 lb) and 7,000 kg (15,000 lb) to Geostationary transfer orbit (GTO) orbit. That would be a 25% increase with respect to the previously most powerful Chinese launcher, the Long March 3B, but well below the Long March 5.[12] The Long March 7A variant, active since March 2020, accomplishes just this enhancement; it is made of the initial two stages of Long March 7, with a third stage powered by liquid hydrogen and liquid oxygen.

In the 2013 presentation of variations, a hydrogen-powered stage was also used as a second stage. It was not clear if it would be the same stage used as the second stage or a different stage. In both cases (second and third stage) they would be powered by the YF-75 or the YF-75D.[14]

Solid boosters edit

The 2013 presentation of the variation also proposed smaller 2 m (6 ft 7 in) diameter solid boosters as a cheaper option for smaller payloads.[14]

Avionics edit

After the inaugural flight, Song Zhengyu, Deputy Chief Control Systems Designer for the Long March 7 project, stated that the flight had proven indigenous avionics. They had to work with the local industry to develop space rated dual processor PLCs. It was also stated that the real-time operating system was also an indigenous development. The general design was based on a distributed architecture to enable scalability and fault tolerance. This avionics would be the base for most future developments and had been designed with reusability in mind.[17]

2013 proposed variations edit

In a paper published on the Manned Spaceflight publication of the CMSEO, the Long March 7 was presented as a family of launch vehicles.[14] The variations would be codified by a two number plus variable letters code, and a CZ-7 prefix in the form CZ-7##. The first digit would mean the number of stages in the core, which could be either 2 or 3. The second number would mean the number of boosters, which could be 0, 2 or 4, with an S appended if the boosters were of solid type. There was also proposed an alternative second stage powered by the LH/LOX propellant and dual YF-75 engines would be identified by appending an (HO) to the designation. At last, it could have an additional upper stage, later identified as the Yuanzheng-1A, that would be identified by appending to the designation /SM.[14]

For example, the version that debuted was codified under this nomenclature as the CZ-724/SM, since it had two RP-1/LOX core stages, four liquid boosters and was enhanced by the Yuanzheng-1A stage. A CZ-720 would have two RP-1/LOX stages and no boosters. A CZ-724S(HO) would have a RP-1/LOX first stage, a LH/LOX second stage and four solid boosters. A CZ-732 would have two RP-1/LOX stages, a LH/LOX third stage, and two liquid boosters. The paper expected the following performance from certain versions.[14]

Version LEO SSO GTO
CZ-720 2000 kg
CZ-722 7500 kg 1300 kg
CZ-724 13500 kg 5500 kg
CZ-720/SM 1000 kg
CZ-722/SM 4500 kg
CZ-724/SM 8500 kg
CZ-722S/SM 1800 kg
CZ-724S/SM 3900 kg
CZ-730 1200 kg
CZ-732 4500 kg
CZ-734 7000 kg
CZ-720(HO) 5500 kg 2900 kg 1500 kg
CZ-722S(HO) 7500 kg 4400 kg 2400 kg

The paper also presented the propulsion options for each stage. The RP-1/LOX second stage had only two YF-115 instead of the normal four, when used in the version with no boosters. It might have implied a different smaller upper stage or an under filled one.[14]

Version Boosters 1st Stage 2nd Stage 3rd Stage Maneuver Stage
CZ-720 0 YF-100 × 2 YF-115 × 2 / /
CZ-722 2.25 m liquid × 2 YF-100 × 2 YF-115 × 4 / /
CZ-724 2.25 m liquid × 4 YF-100 × 2 YF-115 × 4 / /
CZ-720/SM 0 YF-100 × 2 YF-115 × 2 / YF-50 × 1
CZ-722/SM 2.25 m liquid × 2 YF-100 × 2 YF-115 × 4 / YF-50 × 1
CZ-724/SM 2.25 m liquid × 4 YF-100 × 2 YF-115 × 4 / YF-50 × 1
CZ-722S/SM 2 m solid × 2 YF-100 × 2 YF-115 × 4 / YF-50 × 1
CZ-724S/SM 2 m solid × 4 YF-100 × 2 YF-115 × 4 / YF-50 × 1
CZ-720(HO) 0 YF-100 × 2 YF-75 × 2 / /
CZ-722(HO) 2.25 m liquid × 2 YF-100 × 2 YF-75 × 2 / /
CZ-724(HO) 2.25 m liquid × 4 YF-100 × 2 YF-75 × 2 / /
CZ-722S(HO) 2 m solid × 2 YF-100 × 2 YF-75 × 2 / /
CZ-724S(HO) 2 m solid × 4 YF-100 × 2 YF-75 × 2 / /
CZ-730 0 YF-100 × 2 YF-115 × 2 YF-75 × 2 /
CZ-732 2.25 m liquid × 2 YF-100 × 2 YF-115 × 4 YF-75 × 2 /
CZ-734 2.25 m liquid × 4 YF-100 × 2 YF-115 × 4 YF-75 × 2 /

CZ-7A variant edit

 
Rendering of CZ-7A

Since 2020, the base two-stage CZ-7 configuration has been supplemented by the CZ-7A variant. This variant employs the boosters and the first two stages of the base configuration, and add to this a third stage that employs two cryogenic YF-75 engines operating on LH2 and LOX liquid fuels; the third stage of the 7A variant is inherited from the third stage of the Long March 3B. (Note that the 7A variant is similar to the CZ-73X variants first proposed in 2013; see previous subsection).

The maiden CZ-7A was launched on 16 March 2020 at 13:34 UTC from Wenchang Satellite Launch Center on Hainan island. Two hours after launch, state news sources announced that the flight ended in failure; no causes for the failure were indicated initially. Launch preparations for the maiden flight continued in the weeks prior to launch despite measures taken to combat the spread of the COVID-19 virus in China.[18] In 2021, some observers speculated, based on unconfirmed Chinese Baidu posts, that the failure of the CZ-7A's maiden flight was caused by the loss of pressurization in one of its four boosters just prior to main engine cutoff and the staging of the first stage (about 168 seconds into the flight).[19]

The second CZ-7A launched successfully from Wenchang on 11 March 2021.[20] The launch vehicle carried the Shiyan-9 satellite to test new technologies such as space environmental monitoring, according to the China Aerospace Science and Technology Corporation (CASC).[21]

Launch Statistics edit

1
2
3
4
2016
2020
  •   Failure
  •   Partial failure
  •   Success
  •   Planned

List of launches edit

Flight number Date (UTC) Variant Launch site Upper stage Payload Orbit Result References
Y1 25 June 2016
12:00 [12]
7 Wenchang, LC-2 YZ-1A LEO Success [22][23]
Y2 20 April 2017
11:41 [24]
7 Wenchang, LC-2 None Tianzhou 1 LEO Success [25][26]
7A-Y1 16 March 2020
13:34
7A Wenchang, LC-2 None XJY-6-01 GTO Failure [3][27][28]
7A-Y2 11 March 2021
17:51
7A Wenchang, LC-2 None Shiyan 9 GTO Success [21][20]
Y3 29 May 2021
12:55
7 Wenchang, LC-2 None Tianzhou 2 LEO Success [29]
Y4 20 September 2021
07:10
7 Wenchang, LC-2 None Tianzhou 3 LEO Success [30]
7A-Y3 23 December 2021
10:12
7A Wenchang, LC-2 None Shiyan 12-01
Shiyan 12-02
GTO Success [31]
Y5 9 May 2022
17:56
7 Wenchang, LC-2 None Tianzhou 4 LEO Success [32]
7A-Y5 13 September 2022
13:18
7A Wenchang, LC-2 None ChinaSat 1E GTO Success [33]
Y6 12 November 2022
02:03
7 Wenchang, LC-2 None Tianzhou 5 LEO Success [34]
7A-Y4 8 January 2023
22:00
7A Wenchang, LC-2 None Shijian 23 GTO Success [35]
Y7 10 May 2023
13:22
7 Wenchang, LC-2 None Tianzhou 6 LEO Success [36]
7A-Y6 3 November 2023
14:54
7A Wenchang, LC-2 None TJS-10 GTO Success [37]

References edit

  1. ^ a b Jones, Andrew (16 February 2020). "China quietly rolls out new rocket to launch mystery satellite". SpaceNews. Retrieved 16 February 2020.
  2. ^ - 8 May 2020
  3. ^ a b c d Jones, Andrew (14 February 2020). "China prepares to launch new rockets as part of push to boost space program". SPACE.com. Retrieved 14 February 2020.
  4. ^ a b "2016年,还有哪些航天大事值得期待?| 科学人 | 果壳网 科技有意思" [What aerospace event to look for in 2016]. guokr.com (in Chinese). 3 March 2016. Retrieved 27 April 2016. 长征七号火箭原名长征二号F/H,最初可以看做长征二号F火箭换用YF-100和YF-115液氧煤油发动机的产物,但在实际研制中它应用了全数字化设计手段,代表了我国60年来运载火箭研制的最高水平
  5. ^ 8年历程 拓荒与先行 [The Eight Year Tale of Pioneer and Leading]. spacechina.com (in Chinese). 25 June 2016. Retrieved 27 June 2016.
  6. ^ a b 立项论证 平地起高楼 [Demonstration project launches]. spacechina.com (in Chinese). 25 June 2016. Retrieved 27 June 2016.
  7. ^ a b c d 突破运力"下限"的长征6号 [Advances in Light Capacity Long March 6] (in Chinese). Tencent Military Channel. 19 December 2013. Retrieved 3 August 2015.
  8. ^ 正式更名 迈出新一步 [Change of official name for a new step]. spacechina.com (in Chinese). 25 June 2016. Retrieved 27 June 2016.
  9. ^ Barbosa, Rui C. (25 June 2016). "China successfully debuts Long March 7 – Recovers capsule". NASASpaceFlight.com. Retrieved 2 July 2015.
  10. ^ SINA News Sina, 19 November 2010, [2]
  11. ^ a b c d "Chang Zheng-7 (Long March-7)". SinoDefence. Retrieved 2 July 2015.
  12. ^ a b c d 长征七号首飞成功 空间实验室任务大幕拉开 [Successful maiden flight of the Long March 7 mission Damulakai]. spacechina.com (in Chinese). 25 June 2016. Retrieved 25 June 2016.
  13. ^ 未来,长征七号火箭将"挑大梁" [Long March 7 to play the leading role in the future]. calt.com (in Chinese). China Academy of Launch Vehicle Technology. 28 June 2016. Retrieved 30 June 2016.
  14. ^ a b c d e f g h i j k Fan, Ruixiang; Rong, Yi (2013). 代中型运载火箭的发展展望 [Our prospective next-generation medium launch vehicle development]. 载人航天 [Manned Spaceflight] (in Chinese). China Manned Space Engineering Office. 2013 (2013, 01). doi:10.16329/j.cnki.zrht.2013.01.009. ISSN 1674-5825. Retrieved 30 June 2016.
  15. ^ Mike, Wall (28 July 2016). "Amazing Fireball Over Western US Caused by Chinese Space Junk". SPACE.com. Retrieved 28 July 2016.
  16. ^ [Scaled down return capsule that launched by the Long March-7 has landed successfully]. xinhuanet.com (in Chinese). 27 June 2016. Archived from the original on 22 August 2016. Retrieved 27 June 2016.
  17. ^ [Successful maiden flight of the Long March 7 demonstrate indigenous avionics]. cmse.gov.cn (in Chinese). China Manned Space Engineering Office. 27 June 2016. Archived from the original on 14 September 2016. Retrieved 29 June 2016.
  18. ^ Jones, Andrew (16 March 2020). "Launch of China's new Long March 7A ends in failure". SpaceNews. Retrieved 16 March 2020.
  19. ^ "FAILURE: XJY-6 - CZ-7A (Y1) - WSLC - March 16, 2020 (13:34 UTC)". NASA Spaceflight.com. Retrieved 20 September 2021.
  20. ^ a b Weitering, Hanneke (March 2021). "China's Long March 7A rocket launches on 1st successful flight". SPACE.com. Retrieved 13 March 2021.
  21. ^ a b Jessie Yeung. "China successfully launches Long March 7A rocket after failed first attempt". CNN. Retrieved 13 March 2021.
  22. ^ "Long March 7 Maiden Flight – T–1 minute to upper stage separation". youtube.com (in Chinese). CNTV. 24 June 2016. Archived from the original on 15 December 2021.
  23. ^ Kevin Anthony (27 July 2016). "ROCKET REENTRY – Lights up night sky! (Chang Zheng 7 Rocket)". Youtube. Archived from the original on 15 December 2021.
  24. ^ Ping, Wu (June 2016). "China Manned Space Programme: Its Achievements and Future Developments" (PDF). China Manned Space Agency. Retrieved 28 June 2016.
  25. ^ Rui C. Barbosa (19 April 2017). "Tianzhou-1 – China launches and docks debut cargo resupply". NASAspaceFlight.com.
  26. ^ "China's 'Heavenly Vessel' Sails into Orbit atop Long March 7 Rocket on Space Logistics Demonstration". Spaceflight 101. 20 April 2017.
  27. ^ "EPIC FAILURE: XJY-6 - CZ-7A (Y1) - WSLC - 16 March 2020 (13:34 UTC)". NASASpaceFlight.com. 16 March 2020. Retrieved 16 March 2020.
  28. ^ Barbosa, Rui (16 March 2020). "Long March 7A fails during Xinjishu Yanzheng-6 mission". NASASpaceFlight.com. Retrieved 16 March 2020.
  29. ^ "China launches new cargo ship to Tianhe space station module". space.com. Retrieved 30 May 2021.
  30. ^ "China launches cargo craft for space station supplies". Xinhua. 20 September 2021. Retrieved 20 September 2021.
  31. ^ Jones, Andrew (23 December 2021). "Long March 7A launches classified Shiyan-12 satellites". SpaceNews. Retrieved 23 December 2021.
  32. ^ Clark, Stephen (9 May 2022). "China launches Tianzhou 4 cargo ship for space station". Spaceflight Now. Retrieved 9 May 2022.
  33. ^ Davenport, Justin (13 September 2022). "Chang Zheng 7A launches military communications satellite". NASASpaceFlight. Retrieved 13 September 2022.
  34. ^ China Spaceflight [@CNSpaceflight] (18 April 2022). "Key takeaways from the press conference: 7 launches in total from Wenchang
    [...]
    07/24 CZ5B Wentian
    08/.. CZ7A ❓
    10/.. CZ5B Mengtian
    11/.. CZ7 Tianzhou-5
    12/.. CZ7A ❓
    2 crewed launches from Jiuquan
    06/05 SZ14
    12/.. SZ15" (Tweet). Retrieved 18 April 2022 – via Twitter.
  35. ^ China Spaceflight [@CNSpaceflight] (18 December 2022). "The next Long March 7A launch planned in December has been postponed to January 09, 2023. The rocket has been recently transported to Wenchang" (Tweet). Retrieved 18 December 2022 – via Twitter.
  36. ^ "China launches cargo mission to Tiangong space station". Space.com. Retrieved 10 May 2023.
  37. ^ "China launches new communication technology experiment satellite". Xinhua. 4 November 2023. Retrieved 4 November 2023.

long, march, chinese, 长征七号运载火箭, chang, zheng, pinyin, abbreviated, export, within, china, originally, long, march, chang, zheng, nicknamed, bingjian, 冰箭, arrow, chinese, liquid, fuelled, launch, vehicle, long, march, family, developed, china, aerospace, scienc. The Long March 7 Chinese 长征七号运载火箭 or Chang Zheng 7 in pinyin abbreviated LM 7 for export or CZ 7 within China originally Long March 2F H or Chang Zheng 2F H nicknamed Bingjian 冰箭 the Ice Arrow is a Chinese liquid fuelled launch vehicle of the Long March family developed by the China Aerospace Science and Technology Corporation CAST 4 It made its inaugural flight on 25 June 2016 Long March 7Long March 7 Y6 transporting to launch siteFunctionMedium to heavylaunch vehicleManufacturerCALTCountry of originChinaSizeHeightCZ 7 53 10 m 174 2 ft CZ 7A 60 13 m 197 3 ft 1 Diameter3 35 m 11 0 ft MassCZ 7 597 000 kg 1 316 000 lb 2 CZ 7A 573 000 kg 1 263 000 lb 1 StagesCZ 7 Two CZ 7A Three 3 CapacityPayload to LEO 200 x 400 km x 42 Mass13 500 kg 29 800 lb Payload to GTOMass7 000 kg 15 000 lb 3 Payload to TLIMass5 000 kg 11 000 lb Payload to SSOAltitude700 km 430 mi Mass5 500 kg 12 100 lb Associated rocketsFamilyLong MarchComparableDelta IV Atlas V Falcon 9 Block 5 GSLV Mk III H IIALaunch historyStatusActiveLaunch sitesWenchang LC 2Total launches13 7 7 7A 6 Success es 12 7 7 7A 5 Failure s 1 7 0 7A 1 First flightLong March 7 25 June 2016 Long March 7A 16 march 2020Last flightLong March 7 10 May 2023 Long March 7A 3 November 2023 Both Active Boosters K2 boosterNo boosters4Height27 m 89 ft Diameter2 25 m 7 ft 5 in Powered by1 YF 100Maximum thrustSL 1 200 kN 270 000 lbf Vac 1 340 kN 300 000 lbf Total thrustSL 4 800 kN 1 100 000 lbf Vac 5 360 kN 1 200 000 lbf Specific impulseSL 300 s 2 9 km s Vac 335 s 3 29 km s PropellantRP 1 LOXFirst stage K3 core moduleDiameter3 35 m 11 0 ft Powered by2 YF 100Maximum thrustSea level 2 400 kN 540 000 lbf Vacuum 2 680 kN 600 000 lbf Specific impulseSea level 300 s 2 9 km s Vacuum 335 s 3 29 km s PropellantRP 1 LOXSecond stageDiameter3 35 m 11 0 ft Powered by4 YF 115Maximum thrust706 kN 159 000 lbf Specific impulse342 s 3 35 km s PropellantRP 1 LOXThird stage CZ 7A Diameter3 0 m 9 8 ft Empty mass2 800 kg 6 200 lb Gross mass21 000 kg 46 000 lb Propellant mass18 200 kg 40 100 lb Powered by2 YF 75Maximum thrust167 17 kN 37 580 lbf Specific impulse4 295 m s 438 0 s Burn time478 secondsPropellantLH2 LOX edit on Wikidata Designed as a replacement of the Long March 2F Long March 7 and its variants are expected to be the workhorse of the fleet projected to account for around 70 of all Chinese launches Long March 7 will also play a critical role in the Chinese Space Station It was used to launch the Tianzhou robotic cargo spacecraft and will eventually replace the Long March 2F as China s crew rated launch vehicle in the future 4 Since 2020 in addition to the base Long March 7 configuration there is the Long March 7A CZ 7A etc variant which differs from the base CZ 7 by the addition of a liquid hydrogen liquid oxygen third stage inherited from the third stage of the Long March 3B 3 The rocket has also been developed into the Long March 8 Contents 1 History 2 Design 2 1 Stages 2 1 1 Boosters 2 1 2 First stage 2 1 3 Second stage 2 2 Optional stages 2 2 1 Yuanzheng 1A 2 2 2 Hydrogen stage 2 2 3 Solid boosters 2 3 Avionics 3 2013 proposed variations 4 CZ 7A variant 5 Launch Statistics 6 List of launches 7 ReferencesHistory edit nbsp Rendering of Long March 7The Long March 7 project started in 2008 with the formation of the development team within the traditional designer of space launch vehicles CALT 5 With the acquisition of the RD 120 technology and development of the YF 100 and YF 115 engines the original plan was to re engine the Long March 2F The Long March 2F H as it would have been called would just switch from N2O4 UDMH to a LOX kerosene propellant and improved thrust engines to offer better performance But the switch resulted in a cascade of changes that increased the project complexity significantly 6 At the same time the original Long March 5 project was expected to include heavy medium and light versions Since the Long March 2F H and the medium Long March 5 had significant overlaps it was decided to merge both projects This way the high reliability and flight legacy components and technologies of the Long March 2F were merged with the new technologies developed for the Long March 5 6 Although finished nearly at the same time the Long March 6 was a completely separate product developed by a young team within SAST As such it shares little more than tank diameters and propulsion with the LM 5 and LM7 but does cover the range of payloads between the medium Long March 7 and the very light Long March 11 7 In 2010 the project name was changed officially to Long March 7 According to the project deputy manager Zhang Tao the project required eleven new major technologies But the innovation was not only at the product level but one at the process itself This was according to the project manager Wang Xiaojun the first time the whole process was developed in digital 3D using computer aided design directly to computer aided manufacturing 8 The inaugural flight was successfully performed on 25 June 2016 at 12 00 UTC from the Wenchang LC 2 launch pad It launched in the LM 7 configuration with the addition of the simultaneously debuting Yuanzheng 1A upper stage the flight performed its multi orbit mission successfully 9 Design editThe Long March 7 is the medium lift variant of a new generation rocket family that includes the heavier lift Long March 5 and the small mid cargo Long March 6 The structure is based on the reliable human rated Long March 2F launch vehicle It inherited the 3 35 m diameter core stage and 2 25 m diameter liquid rocket boosters Where the earlier Long March 2 rocket family used expensive and dangerous N2O4 UDMH propellants the Long March 7 uses LOX and kerosene The engines are shared with the Long March 5 and 6 The goal was to build a more cost effective and less hazardous rocket family to replace today s Long March 2 and eventually the Long March 3 10 It is capable of placing a 5 500 kg 12 100 lb payload into a Sun synchronous orbit SSO of 700 km 430 mi 11 Stages edit The Long March 7 inherits the modular stages of the original Long March 5 project As such its first stage is the same module as the LM 5 boosters It also shares tank diameters and engines with the Long March 6 but the design groups were completely different The LM 5 and LM 7 were developed by China Academy of Launch Vehicle Technology CALT while the LM 6 was done by Shanghai Academy of Spaceflight Technology SAST Even the avionics are different 7 The basic Long March 7 can be optimized by varying the number of boosters or enhanced by the addition of upper stages These stages allow more mission flexibility like direct injection to higher orbits or multiple orbit deployment They can also increase the performance significantly Thanks to this modularity performance can be dialed between 4 000 kg 8 800 lb and 13 500 kg 29 800 lb for LEO 2 000 kg 4 400 lb and 8 000 kg 18 000 lb for SSO and 4 000 kg 8 800 lb and 7 000 kg 15 000 lb to Geostationary transfer orbit GTO 12 13 Boosters edit The Long March 7 can use 0 2 or 4 boosters using RP 1 LOX propellant 14 They are powered by a single oxidizer rich staged combustion YF 100 engine Each boosters supplies 1 200 kN 270 000 lbf at sea level and 1 340 kN 300 000 lbf in vacuum of thrust Its specific impulse is 300 s 2 9 km s at sea level and 335 s 3 29 km s in vacuum Each module has its own single axis thrust vector control and thus it required a special design in the control systems of the rocket to coordinate all the rocket s nozzles 11 14 They use the legacy 2 25 m 7 ft 5 in width of the Long March 2 and Long March 3 families but due to the increased thrust of the YF 100 with respect to the YF 20 and YF 25 the boosters are almost twice as long at 27 m 89 ft 14 A Long March 7 rocket booster created a fireball visible from portions of Utah Nevada Colorado Idaho and California on the evening of 27 July 2016 its disintegration was widely reported on social media and the uncontrolled re entry of such a five ton object was regarded as a rare event 15 First stage edit The first stage has 3 35 m 11 0 ft diameter tanks carrying RP 1 LOX propellant It is powered by two YF 100 engines sharing the same propulsion elements as the boosters only that for the first stage the engines can gimbal in two axes 14 Also this first stage is the same basic module as the Long March 5 boosters The diameter was designed for land transport and as such it will be able to launch from all the Chinese launch sites This is a critical difference to the LM 5 that requires water transport for its core stages 11 While it shares diameter and engines with the Long March 6 first stage the development was completely separated and done by different groups 7 Second stage edit The second stage also shares the first 3 35 m 11 0 ft diameter tanks and propellant It is powered by four oxidizer rich staged combustion RP 1 LOX YF 115 engines Two are fixed and two can gimbal in two axis 14 It offers 706 kN 159 000 lbf of thrust in vacuum with a specific impulse of 341 5 s 3 349 km s 11 While it shares engines with the Long March 6 second stage the development were completely separated and done by different groups 7 Optional stages edit Yuanzheng 1A edit It can use the Yuanzheng 1A upper stage to increase payload to higher energy orbits and enable multiple ignition missions Particularly allows direct injection to SSO orbits 16 The inaugural flight successfully used this upper stage to deliver multiple payloads to different orbits 12 Hydrogen stage edit The Long March 7 is expected to be enhanced by a high energy liquid hydrogen and liquid oxygen stage This stage and the low inclination of Wenchang would enable to launch payload between 4 000 kg 8 800 lb and 7 000 kg 15 000 lb to Geostationary transfer orbit GTO orbit That would be a 25 increase with respect to the previously most powerful Chinese launcher the Long March 3B but well below the Long March 5 12 The Long March 7A variant active since March 2020 accomplishes just this enhancement it is made of the initial two stages of Long March 7 with a third stage powered by liquid hydrogen and liquid oxygen In the 2013 presentation of variations a hydrogen powered stage was also used as a second stage It was not clear if it would be the same stage used as the second stage or a different stage In both cases second and third stage they would be powered by the YF 75 or the YF 75D 14 Solid boosters edit The 2013 presentation of the variation also proposed smaller 2 m 6 ft 7 in diameter solid boosters as a cheaper option for smaller payloads 14 Avionics edit After the inaugural flight Song Zhengyu Deputy Chief Control Systems Designer for the Long March 7 project stated that the flight had proven indigenous avionics They had to work with the local industry to develop space rated dual processor PLCs It was also stated that the real time operating system was also an indigenous development The general design was based on a distributed architecture to enable scalability and fault tolerance This avionics would be the base for most future developments and had been designed with reusability in mind 17 2013 proposed variations editIn a paper published on the Manned Spaceflight publication of the CMSEO the Long March 7 was presented as a family of launch vehicles 14 The variations would be codified by a two number plus variable letters code and a CZ 7 prefix in the form CZ 7 The first digit would mean the number of stages in the core which could be either 2 or 3 The second number would mean the number of boosters which could be 0 2 or 4 with an S appended if the boosters were of solid type There was also proposed an alternative second stage powered by the LH LOX propellant and dual YF 75 engines would be identified by appending an HO to the designation At last it could have an additional upper stage later identified as the Yuanzheng 1A that would be identified by appending to the designation SM 14 For example the version that debuted was codified under this nomenclature as the CZ 724 SM since it had two RP 1 LOX core stages four liquid boosters and was enhanced by the Yuanzheng 1A stage A CZ 720 would have two RP 1 LOX stages and no boosters A CZ 724S HO would have a RP 1 LOX first stage a LH LOX second stage and four solid boosters A CZ 732 would have two RP 1 LOX stages a LH LOX third stage and two liquid boosters The paper expected the following performance from certain versions 14 Version LEO SSO GTOCZ 720 2000 kg CZ 722 7500 kg 1300 kgCZ 724 13500 kg 5500 kgCZ 720 SM 1000 kgCZ 722 SM 4500 kgCZ 724 SM 8500 kgCZ 722S SM 1800 kgCZ 724S SM 3900 kgCZ 730 1200 kgCZ 732 4500 kgCZ 734 7000 kgCZ 720 HO 5500 kg 2900 kg 1500 kgCZ 722S HO 7500 kg 4400 kg 2400 kgThe paper also presented the propulsion options for each stage The RP 1 LOX second stage had only two YF 115 instead of the normal four when used in the version with no boosters It might have implied a different smaller upper stage or an under filled one 14 Version Boosters 1st Stage 2nd Stage 3rd Stage Maneuver StageCZ 720 0 YF 100 2 YF 115 2 CZ 722 2 25 m liquid 2 YF 100 2 YF 115 4 CZ 724 2 25 m liquid 4 YF 100 2 YF 115 4 CZ 720 SM 0 YF 100 2 YF 115 2 YF 50 1CZ 722 SM 2 25 m liquid 2 YF 100 2 YF 115 4 YF 50 1CZ 724 SM 2 25 m liquid 4 YF 100 2 YF 115 4 YF 50 1CZ 722S SM 2 m solid 2 YF 100 2 YF 115 4 YF 50 1CZ 724S SM 2 m solid 4 YF 100 2 YF 115 4 YF 50 1CZ 720 HO 0 YF 100 2 YF 75 2 CZ 722 HO 2 25 m liquid 2 YF 100 2 YF 75 2 CZ 724 HO 2 25 m liquid 4 YF 100 2 YF 75 2 CZ 722S HO 2 m solid 2 YF 100 2 YF 75 2 CZ 724S HO 2 m solid 4 YF 100 2 YF 75 2 CZ 730 0 YF 100 2 YF 115 2 YF 75 2 CZ 732 2 25 m liquid 2 YF 100 2 YF 115 4 YF 75 2 CZ 734 2 25 m liquid 4 YF 100 2 YF 115 4 YF 75 2 CZ 7A variant edit nbsp Rendering of CZ 7ASince 2020 the base two stage CZ 7 configuration has been supplemented by the CZ 7A variant This variant employs the boosters and the first two stages of the base configuration and add to this a third stage that employs two cryogenic YF 75 engines operating on LH2 and LOX liquid fuels the third stage of the 7A variant is inherited from the third stage of the Long March 3B Note that the 7A variant is similar to the CZ 73X variants first proposed in 2013 see previous subsection The maiden CZ 7A was launched on 16 March 2020 at 13 34 UTC from Wenchang Satellite Launch Center on Hainan island Two hours after launch state news sources announced that the flight ended in failure no causes for the failure were indicated initially Launch preparations for the maiden flight continued in the weeks prior to launch despite measures taken to combat the spread of the COVID 19 virus in China 18 In 2021 some observers speculated based on unconfirmed Chinese Baidu posts that the failure of the CZ 7A s maiden flight was caused by the loss of pressurization in one of its four boosters just prior to main engine cutoff and the staging of the first stage about 168 seconds into the flight 19 The second CZ 7A launched successfully from Wenchang on 11 March 2021 20 The launch vehicle carried the Shiyan 9 satellite to test new technologies such as space environmental monitoring according to the China Aerospace Science and Technology Corporation CASC 21 Launch Statistics edit1 2 3 4 2016 2020 Failure Partial failure Success PlannedList of launches editMain article List of Long March launches Flight number Date UTC Variant Launch site Upper stage Payload Orbit Result ReferencesY1 25 June 201612 00 12 7 Wenchang LC 2 YZ 1A Next Generation Crew Capsule Scale Model Star of Aoxiang Aolong 1 Tiange 1 Tiange 2 LEO Success 22 23 Y2 20 April 201711 41 24 7 Wenchang LC 2 None Tianzhou 1 LEO Success 25 26 7A Y1 16 March 202013 34 7A Wenchang LC 2 None XJY 6 01 GTO Failure 3 27 28 7A Y2 11 March 202117 51 7A Wenchang LC 2 None Shiyan 9 GTO Success 21 20 Y3 29 May 202112 55 7 Wenchang LC 2 None Tianzhou 2 LEO Success 29 Y4 20 September 202107 10 7 Wenchang LC 2 None Tianzhou 3 LEO Success 30 7A Y3 23 December 202110 12 7A Wenchang LC 2 None Shiyan 12 01Shiyan 12 02 GTO Success 31 Y5 9 May 202217 56 7 Wenchang LC 2 None Tianzhou 4 LEO Success 32 7A Y5 13 September 202213 18 7A Wenchang LC 2 None ChinaSat 1E GTO Success 33 Y6 12 November 202202 03 7 Wenchang LC 2 None Tianzhou 5 LEO Success 34 7A Y4 8 January 202322 00 7A Wenchang LC 2 None Shijian 23 GTO Success 35 Y7 10 May 202313 22 7 Wenchang LC 2 None Tianzhou 6 LEO Success 36 7A Y6 3 November 202314 54 7A Wenchang LC 2 None TJS 10 GTO Success 37 References edit nbsp Spaceflight portal a b Jones Andrew 16 February 2020 China quietly rolls out new rocket to launch mystery satellite SpaceNews Retrieved 16 February 2020 1 8 May 2020 a b c d Jones Andrew 14 February 2020 China prepares to launch new rockets as part of push to boost space program SPACE com Retrieved 14 February 2020 a b 2016年 还有哪些航天大事值得期待 科学人 果壳网 科技有意思 What aerospace event to look for in 2016 guokr com in Chinese 3 March 2016 Retrieved 27 April 2016 长征七号火箭原名长征二号F H 最初可以看做长征二号F火箭换用YF 100和YF 115液氧煤油发动机的产物 但在实际研制中它应用了全数字化设计手段 代表了我国60年来运载火箭研制的最高水平 8年历程 拓荒与先行 The Eight Year Tale of Pioneer and Leading spacechina com in Chinese 25 June 2016 Retrieved 27 June 2016 a b 立项论证 平地起高楼 Demonstration project launches spacechina com in Chinese 25 June 2016 Retrieved 27 June 2016 a b c d 突破运力 下限 的长征6号 Advances in Light Capacity Long March 6 in Chinese Tencent Military Channel 19 December 2013 Retrieved 3 August 2015 正式更名 迈出新一步 Change of official name for a new step spacechina com in Chinese 25 June 2016 Retrieved 27 June 2016 Barbosa Rui C 25 June 2016 China successfully debuts Long March 7 Recovers capsule NASASpaceFlight com Retrieved 2 July 2015 SINA News Sina 19 November 2010 2 a b c d Chang Zheng 7 Long March 7 SinoDefence Retrieved 2 July 2015 a b c d 长征七号首飞成功 空间实验室任务大幕拉开 Successful maiden flight of the Long March 7 mission Damulakai spacechina com in Chinese 25 June 2016 Retrieved 25 June 2016 未来 长征七号火箭将 挑大梁 Long March 7 to play the leading role in the future calt com in Chinese China Academy of Launch Vehicle Technology 28 June 2016 Retrieved 30 June 2016 a b c d e f g h i j k Fan Ruixiang Rong Yi 2013 代中型运载火箭的发展展望 Our prospective next generation medium launch vehicle development 载人航天 Manned Spaceflight in Chinese China Manned Space Engineering Office 2013 2013 01 doi 10 16329 j cnki zrht 2013 01 009 ISSN 1674 5825 Retrieved 30 June 2016 Mike Wall 28 July 2016 Amazing Fireball Over Western US Caused by Chinese Space Junk SPACE com Retrieved 28 July 2016 长征七号搭载的缩比返回舱成功着陆 Scaled down return capsule that launched by the Long March 7 has landed successfully xinhuanet com in Chinese 27 June 2016 Archived from the original on 22 August 2016 Retrieved 27 June 2016 控制系统多项 国产化 技术护航长七首飞成功 Successful maiden flight of the Long March 7 demonstrate indigenous avionics cmse gov cn in Chinese China Manned Space Engineering Office 27 June 2016 Archived from the original on 14 September 2016 Retrieved 29 June 2016 Jones Andrew 16 March 2020 Launch of China s new Long March 7A ends in failure SpaceNews Retrieved 16 March 2020 FAILURE XJY 6 CZ 7A Y1 WSLC March 16 2020 13 34 UTC NASA Spaceflight com Retrieved 20 September 2021 a b Weitering Hanneke March 2021 China s Long March 7A rocket launches on 1st successful flight SPACE com Retrieved 13 March 2021 a b Jessie Yeung China successfully launches Long March 7A rocket after failed first attempt CNN Retrieved 13 March 2021 Long March 7 Maiden Flight T 1 minute to upper stage separation youtube com in Chinese CNTV 24 June 2016 Archived from the original on 15 December 2021 Kevin Anthony 27 July 2016 ROCKET REENTRY Lights up night sky Chang Zheng 7 Rocket Youtube Archived from the original on 15 December 2021 Ping Wu June 2016 China Manned Space Programme Its Achievements and Future Developments PDF China Manned Space Agency Retrieved 28 June 2016 Rui C Barbosa 19 April 2017 Tianzhou 1 China launches and docks debut cargo resupply NASAspaceFlight com China s Heavenly Vessel Sails into Orbit atop Long March 7 Rocket on Space Logistics Demonstration Spaceflight 101 20 April 2017 EPIC FAILURE XJY 6 CZ 7A Y1 WSLC 16 March 2020 13 34 UTC NASASpaceFlight com 16 March 2020 Retrieved 16 March 2020 Barbosa Rui 16 March 2020 Long March 7A fails during Xinjishu Yanzheng 6 mission NASASpaceFlight com Retrieved 16 March 2020 China launches new cargo ship to Tianhe space station module space com Retrieved 30 May 2021 China launches cargo craft for space station supplies Xinhua 20 September 2021 Retrieved 20 September 2021 Jones Andrew 23 December 2021 Long March 7A launches classified Shiyan 12 satellites SpaceNews Retrieved 23 December 2021 Clark Stephen 9 May 2022 China launches Tianzhou 4 cargo ship for space station Spaceflight Now Retrieved 9 May 2022 Davenport Justin 13 September 2022 Chang Zheng 7A launches military communications satellite NASASpaceFlight Retrieved 13 September 2022 China Spaceflight CNSpaceflight 18 April 2022 Key takeaways from the press conference 7 launches in total from Wenchang 07 24 CZ5B Wentian08 CZ7A 10 CZ5B Mengtian11 CZ7 Tianzhou 512 CZ7A 2 crewed launches from Jiuquan06 05 SZ1412 SZ15 Tweet Retrieved 18 April 2022 via Twitter China Spaceflight CNSpaceflight 18 December 2022 The next Long March 7A launch planned in December has been postponed to January 09 2023 The rocket has been recently transported to Wenchang Tweet Retrieved 18 December 2022 via Twitter China launches cargo mission to Tiangong space station Space com Retrieved 10 May 2023 China launches new communication technology experiment satellite Xinhua 4 November 2023 Retrieved 4 November 2023 nbsp Wikimedia Commons has media related to Long March 7 Retrieved from https en wikipedia org w index php title Long March 7 amp oldid 1183534853, wikipedia, wiki, book, books, library,

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