Yuanzheng (Chinese: 远征; pinyin: Yuǎn Zhēng; lit. 'Expedition') is a restartable upper stage developed by the China Academy of Launch Vehicle Technology (CALT) for the Long March rocket family.

Yuanzheng
ManufacturerCALT
Country of originChina
Used onLong March rocket family
(2C · 2D · 3B · 3C · 5 · 7)
Associated stages
ComparableFregat
Launch history
StatusActive
Total launches29
Successes
(stage only)
28
Failed1
Lower stage
failed
0
First flight30 March 2015
BeiDou I1-S
Last flight21 March 2024
Yunhai-2 Group 02
Launch date
Yuanzheng
Powered by1 × YF-50D[1]
Maximum thrust6.5 kN (1,500 lbf)[2]
Specific impulse315.5 seconds[2]
PropellantN2O4 / UDMH

The Yuanzheng stage enables the Chinese launch vehicles to deploy payloads directly to high-energy orbits such as medium Earth orbit (MEO) and geosynchronous orbit (GSO). Since the Long March third stage cannot restart, it cannot circularize a GSO or GEO orbit from a geosyncronous transfer orbit (GTO). With its restart capability, Yuanzheng has enabled the deployment of satellite pairs for the BeiDou Navigation Satellite System in MEO and communications satellites in GSO. This eliminates the need for the spacecraft to include a liquid apogee engine or an apogee kick motor.[3]

Yuanzheng has a thrust of 6.5 kN (1,500 lbf) with a specific impulse of 315.5 seconds. It uses the storable hypergolic propellants unsymmetrical dimethylhydrazine (UDMH) and dinitrogen tetroxide (N2O4), and can perform at least two burns within its rated life of 6.5 hours, sufficient to reach the transfer orbit apogee, and perform the circularization burn from there.[4]

Operational variants are designated YZ-1 for Long March 3B and 3C, YZ-1A for Long March 7, YZ-1S for Long March 2C, YZ-2 for Long March 5, and YZ-3 for Long March 2D.

Models edit

 
Yuanzheng upper stages from left to right: YZ-1, YZ-1A, YZ-1S, YZ-2, YZ-3

History edit

Yuanzheng was presented in a 2013 paper[3] and performed its first mission on 30 May 2015. The debut flight of the Long March 7 in 2016 included an improved version called Yuanzheng-1A that can flexibly deploy multiple payloads into various target orbits.[5] Further variants were later deployed for Long March 5 (YZ-2) in 2016, Long March 2C (YZ-1S) and Long March 2D (YZ-3) in 2018.

Flight

No.

Date (UTC) Carrier Rocket Stage Model Serial Number Launch site Mission Result
01 2015-03-30
13:52
Long March 3C YZ-1 Y1 Xichang BDS I1-S Success
02 2015-07-25
12:29
Long March 3B YZ-1 Y2 Xichang BDS M1-S / BDS M2-S Success
03 2016-02-01
07:29
Long March 3C YZ-1 Y3 Xichang BDS M3-S Success
04 2016-06-25
12:00
Long March 7 YZ-1A Y1 Wenchang Inaugural Mission Success
05 2016-11-3
12:43
Long March 5 YZ-2 Y1 Wenchang Inaugural Mission Success
06 2017-11-5
11:45
Long March 3B YZ-1 Y4 Xichang BDS-3 M1
BDS-3 M2
Success
07 2018-01-11
23:18
Long March 3B YZ-1 Y5 Xichang BDS-3 M7
BDS-3 M8
Success
08 2018-02-12
05:03
Long March 3B YZ-1 Y6 Xichang BDS-3 M3
BDS-3 M4
Success
09 2018-03-29
17:56
Long March 3B YZ-1 Y7 Xichang BDS-3 M9
BDS-3 M10
Success
10 2018-07-29
01:48
Long March 3B YZ-1 Y8 Xichang BDS-3 M5
BDS-3 M6
Success
11 2018-08-24
23:52
Long March 3B YZ-1 Y9 Xichang BDS-3 M11
BDS-3 M12
Success
12 2018-09-19
14:07
Long March 3B YZ-1 Y10 Xichang BDS-3 M13
BDS-3 M14
Success
13 2018-10-09
02:43
Long March 2C YZ-1S Y1 Jiuquan Yaogan 32A, 32B Success
14 2018-10-15
04:23
Long March 3B YZ-1 Y11 Xichang BDS-3 M15
BDS-3 M16
Success
15 2018-11-18
18:00
Long March 3B YZ-1 Y12 Xichang BDS-3 M17
BDS-3 M18
Success
16 2018-12-29
08:00
Long March 2D YZ-3 Y1 Jiuquan Yunhai-2 01, 02, 03, 04, 05, 06
Hongyan-1
Success
17 2019-09-22
21:10
Long March 3B/E YZ-1 Y13 Xichang BDS-3 M23
BDS-3 M24
Success
18 2019-11-23
00:55
Long March 3B/E YZ-1 Y14 Xichang BeiDou-3 M21
BeiDou-3 M22
Success
19 2019-12-16
07:22
Long March 3B/E YZ-1 Y15 Xichang BeiDou-3 M19
BeiDou-3 M20
Success
20 2021-08-24
11:15
Long March 2C YZ-1S Y2 Jiuquan RSW-01
RSW-02
unknown payload
Success
21 2021-11-03
07:43
Long March 2C YZ-1S Y4 Jiuquan Yaogan 32-02A, 32-02B Success
22 2022-05-20
10:30
Long March 2C YZ-1S Y5 Jiuquan LEO Test Sat 1/2
Digui Tongxin Weixing
Success
23 2023-07-09
11:00
Long March 2C YZ-1S Y3 Jiuquan Hulianwang Jishu Shiyan 1A
Hulianwang Jishu Shiyan 1B
Success
24 2023-11-16
03:55
Long March 2C YZ-1S Y9 Jiuquan Haiyang-3A Success
25 2023-11-23
10:00
Long March 2D YZ-3 Y2 Xichang Hulianwang Jishu Shiyan 2A
Hulianwang Jishu Shiyan 2B
Hulianwang Jishu Shiyan 2C
Success
26 2023-12-26
03:26
Long March 3B/E YZ-1 Y16 Xichang BeiDou-3 M25
BeiDou-3 M26
Success
27 2023-12-30
00:13
Long March 2C YZ-1S Y17 Jiuquan Hulianwang Jishu Shiyan 4A
Hulianwang Jishu Shiyan 4B
Hulianwang Jishu Shiyan 4C
Success
28 2024-03-13
12:51
Long March 2C YZ-1S Y18 Xichang DRO-A/B Failure
29 2024-03-21
05:27
Long March 2D YZ-3 Y3 Jiuquan Yunhai-2 Group 02 Success

Versions edit

Currently, there is known to be five versions:

  • Yuanzheng-1 (AKA YZ-1) (Chinese: 远征一号; pinyin: Yuǎn Zhēng Yī Hào; lit. 'Expedition One'): Initial version used with the Long March 3. It could perform missions of 6.5 hours, make two ignitions, perform one spacecraft deployment operation.[6][7]
  • Yuanzheng-1A (AKA YZ-1A) (Chinese: 远征一号甲; pinyin: Yuǎn Zhēng Yī Hào Jiǎ; lit. 'Expedition One A'): Improved version used with the Long March 7. Improved version with mission life extended to 48hs, capability to perform at least 9 ignitions and ability to do 7 different separation events. It also includes improved thermal control system, guidance algorithms and orbit planning for multiple payload deployment missions. It will be used as the base system for future deep space propulsion stages, space tugs and orbital servicing and debris removal spacecraft.[6][8]
  • Yuanzheng-1S (AKA YZ-1S) (Chinese: 远征一号商业型; pinyin: Yuǎn Zhēng Yī Hào Shāng Yè Xíng; lit. 'Expedition One Commercial Version'): Improved version used with the Long March 2C.
  • Yuanzheng-2 (AKA YZ-2) (Chinese: 远征二号; pinyin: Yuǎn Zhēng Èr Hào; lit. 'Expedition Two'): New version used with the 5.2 m (17 ft) Long March 5 upper stage.[9]
  • Yuanzheng-3 (AKA YZ-3) (Chinese: 远征三号; pinyin: Yuǎn Zhēng Sān Hào; lit. 'Expedition Three'): New version used with the Long March 2D.

References edit

  1. ^ "New Launch". www.casc11.com (in Chinese). Xi'an Aerospace Propulsion Institute. 2015-07-26. Retrieved 2015-08-02.
  2. ^ a b Norbert Bgügge. "Photo Gallery CZ-3CE". B14643.DE. Retrieved 2015-07-25.
  3. ^ a b Kun, Ma; Wu, Guo; Song, Guan; Zhibin, Ma; Tongyu, Li (2013). "上面级发展现状及趋势分析" [Development Status and Trend Analysis of Upper Stages]. Missiles and Space Vehicles (in Chinese). No.6 2013 (329): 24–28. doi:10.7654/j.issn.1004-7182.20130606 (inactive 31 January 2024). {{cite journal}}: |volume= has extra text (help)CS1 maint: DOI inactive as of January 2024 (link)
  4. ^ Norbert Bgügge. "YZ-1 space tug". B14643.DE. Archived from the original on August 25, 2015. Retrieved 2015-07-25.
  5. ^ "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]. www.spacechina.com (in Chinese). 2016-06-25. Archived from the original on 28 June 2016. Retrieved 2016-06-25.
  6. ^ a b "升级版的中国"太空摆渡车"将带来什么?" [What will enable the upgraded space bus?]. www.chinanews.com (in Chinese). 2016-06-25. Retrieved 2016-06-27.
  7. ^ "远征一号上面级" [Yuanzheng-1 Upper Stage]. www.chinaspaceflight.com (in Chinese). 2016-06-07. Retrieved 2016-06-30.
  8. ^ "远征一号甲上面级(YZ-1A)" [Yuanzheng-1A Upper Stage (YZ-1)]. www.chinaspaceflight.com (in Chinese). 2016-06-26. Retrieved 2016-06-30.
  9. ^ "远征二号上面级:今年发射的"长征五号"火箭将启用新研制上面级"远征二号"" [Yuanzheng-2 upper stage: this year's launch of the Long March 5 rocket upper stage will enable the development of new "Yuanzheng-2"]. www.chinaspaceflight.com (in Chinese). 2016-03-30. Retrieved 2016-06-30.