Shijian Weixing
实践
Shíjiàn
Program overview
CountryChina People's Republic of China
OrganizationChina Academy of Space Technology (CAST)
PurposeUnknown, varied
StatusActive
Program history
Duration1971–Present
First flight3 March 1971
Successes36
Failures5
Launch site(s)
Vehicle information
Launch vehicle(s)

Shijian (simplified Chinese: 实践; traditional Chinese: 實踐; pinyin: Shíjiàn; lit. 'Practice', abbr. "SJ") is a series of satellites built and operated by the People's Republic of China. Some Shijian-series satellites have drawn significant concerns from the United States government and space observers who cite unannounced launches, undisclosed sub-satellites deployed in orbit, unusual orbital maneuvers, and demonstrated rendezvous proximity operations (RPO) including the close inspection and towing of other satellites.[1][2][3][4]

Little is known about the series and what differentiates it from other experimental satellite series launched by China such as the Chuangxin (Chinese: 创新; pinyin: Chuàngxīn; lit. 'Innovation') series or Shiyan (Chinese: 实验; pinyin: Shíyàn; lit. 'Experiment') series.[5] The China Aerospace Studies Institute of the United States Air Force asserts that Shiyan-series satellites play an earlier role in the systems development process testing various new technologies on a single bus while Shijan-series satellites are used to develop operational best practices and optimize the technologies previously tested on Shiyan-series satellites.[6] In this regard "Shijian" should be translated as "practice", "best practice", or "put into practice" while "Shiyan" ought to be translated as "experiment", "pilot", or "trial".

Notable satellites

Shijian-17

In a April 2021 written statement to the US Senate Armed Services Committee, General James H. Dickinson, Commander of United States Space Command (USSPACECOM) was the first US official to speak publicly on Shijian-17 warning of its counterspace capabilities. General Dickinson wrote "Beijing actively seeks space superiority through space and space attack systems. One notable object is the Shijian-17, a Chinese satellite with a robotic arm. Space-based robotic arm technology could be used in a future system for grappling other satellites."[7] Shijian-17's robotic arm also earned mention in the United States Department of Defense 2022 China Military Power Report.[8]

Shijian-17 has also prompted concern among observers who have tracked Shijian-17's unique orbital maneuvers. Since its launch, Shijian-17 has occupied a wide span of orbital positions within its geostationary orbit to dynamically adjust its position relative to neighboring satellites. These varied positions have ranged from 37.7°E over Africa to 180°E over the Marshall Islands, uncharacteristic of other satellites designed for communications. Shijian-17 has also positioned itself as close as 55 kilometers to other satellites for periods of a week or more while other geostationary satellites maintain an average 207-kilometer separation distance.[9][10][11]

Shijian-18

Shijian-18 was a Chinese communications and technology demonstration satellite developed and launched by the China Academy of Space Technology on 2 July 2017. It was the maidan flight of the DHF-5 satellite bus, which is designed with 16-year lifespan. Shijian-18 carried 18 experiments on board involving communications and space telescopes. It was lost after a malfunction on the Long March 5 rocket carrying the satellite. It would have been the heaviest geostationary satellite at the time of its launch,[12] with a launch mass of 7,600 kg (16,800 lb). The satellite incorporated a high-thrust ion propulsion system, a large trussed structure and a higher payload capacity.[13] More specifically, it used the LIPS-300 xenon thruster for orbit keeping, developed by the Lanzhou Institute of Physics. It was planned for the LIPS-300 system to be fully certified in this mission so that it could be used for geostationary and deep-space operations. The satellite would operate at the Ka band with 70 Gb/s capacity, capable of providing broadband internet to whole mainland China.[14]

Shijian-18 launched from the Wenchang Space Launch Site on 2 July 2017 at 11:23 UTC on board a Long March 5 rocket to a geostationary orbit. It was the rocket's second flight, the first being to launch Shijian-17.[15] The rocket encountered an anomaly shortly after launch, causing it to switch into a gentler trajectory. However, 45 minutes into the flight, it was declared a failure, with the loss of the payload.[16][17] The cause of the failure was later determined to be a faulty oxidizer turbopump, which has now been redesigned twice.[18] The rocket and payload crashed in the Pacific Ocean somewhere at the Philippine Sea.[19]

Shijian-21

In October 2021, China launched Shijian 21 (SJ-21) from Xichang Space Launch Center (XSLC) aboard a Long March 3B rocket into geosynchronous transfer orbit (GTO). Atypically, China issued no warnings prior to the launch confirming only after the satellite's successful launch.[20] China's official state news media organization, Xinhua News Agency, described SJ-21 as a On-Orbit Service, Assembly, and Manufacturing (OSAM) satellite that would be "mainly used to test and verify space debris mitigation technologies."[21][22][23] A month after its launch, SJ-21 drew some suspicion from space observers as an object, described to be an undeclared sub-satellite, began orbiting closely alongside SJ-21 shortly after its entry into geosynchronous orbit (GEO). The object was initially cataloged as a apogee kick motor (AKM) by the US Space Force's 18th Space Defense Squadron (SDS), however many doubt that a discarded motor would maintain the constant and proximate orbit with SJ-21 instead of gradually drifting away. SJ-21 drew further suspicion in January 2022 when ExoAnalytic Solutions, a commercial space monitoring firm, SJ-21 went "missing" from its orbital slot to dock with defunct Beidou G2 (Compass G2) navigation satellite capitalizing on the inability of optical satellites to track space-objects during the day. Shijian-21 then moved to an orbit 3,000 kilometers higher where it released the Beidou G2 satellite into graveyard orbit and returned to GEO.[24][25][26]

Many observers suspect the spacecraft, like many of China's Yaogan satellites, serve primarily military purposes under the cover of more mundane missions.[27][28] With SJ-21's demonstrate capability to tug satellites from their orbit and China's increasing interest in space power, the spacecraft likely also offers the Chinese government a tool for counterspace operations.[21][22][29][25] Victoria Samson, the Washington Office director for the Secure World Foundation said "You could look at China working to develop the capability to remove inactive satellites on orbit as a way in which it is being a responsible space actor and cleaning up debris that it caused. Or you could use the lens that a lot of the US-based China watchers use and say that this could indicate that China is developing an on-orbit offensive capability."[25][30] Samson also praised commercial space situational awareness (SSA) providers for presenting the public and academia with satellite tracking capabilities previously exclusive to government.[25] China received criticism for its lack of transparency on Shijian-21's operations.[25]

Satellites

Name Launch Function Orbit Orbital apsis Inclination SCN COSPAR ID Launch site Launcher Status
Shijian 1 3 March 1971 Particle measurements of cosmic rays[31] LEO 266 km × 1826 km 69.9° 5007 1971-018A JSLC Long March 1 Decayed
Shijian 2 19 September 1981 Space dust/debris and EM study[31] LEO 232 km × 1598 km 59.4° 12845 1981-093D JSLC Feng Bao 1 Decayed
Shijian 2A 19 September 1981 Space dust/debris and EM study[31] LEO 232 km × 1615 km 59.4° 12843 1981-093B JSLC Feng Bao 1 Decayed
Shijian 2B 19 September 1981 Space dust/debris and EM study[31] LEO 232 km × 1608 km 59.4º 12842 1981-093A JSLC Feng Bao 1 Decayed
Shijian 3 N/A Earth observation[32][33][34] Cancelled, replaced by CBERS ZY-1[32]
Shijian 4 8 February 1994 Space radiation monitoring[35][31] HEO 210 km × 36125 km 28.6º 22996 1994-010A XSLC Long March 3A Decayed
Shijian 5 10 May 1999 Test new minisatellite platform, particle measurement[31] SSO 569 km × 849 km 98.8° 25731 1999-025B TSLC Long March 4B Decayed
Shijian 6-01B 8 September 2004 Space environment monitoring or ELINT[36] SSO 585.4 km × 585.2 km 97.7° 28414 2004-035B TSLC Long March 4B Operational
Shijian 6-01A 8 September 2004 Space environment monitoring or ELINT[36] SSO 579.8 km × 596.7 km 97.7° 28413 2004-035A TSLC Long March 4B Operational
Shijian 6-02A 23 October 2006 Space environment monitoring or ELINT[36] SSO 591.0 km × 593.4 km 97.8° 29506 2006-046B TSLC Long March 4B Operational
Shijian 6-02B 23 October 2006 Space environment monitoring or ELINT[36] SSO 583.1 km × 587.7 km 97.8° 29505 2006-046A TSLC Long March 4B Operational
Shijian 6-03A 25 October 2008 Space environment monitoring or ELINT[36] SSO 576.5 km × 599.1 km 97.8° 33409 2008-053B TSLC Long March 4B Operational
Shijian 6-03B 25 October 2008 Space environment monitoring or ELINT[36] SSO 573.9 km × 600.1 km 97.9° 33408 2008-053A TSLC Long March 4B Operational
Shijian 6-04A 6 October 2010 Space environment monitoring or ELINT[36] SSO 585.9 km × 600.1 km 97.8° 37180 2010-051B TSLC Long March 4B Operational
Shijian 6-04B 6 October 2010 Space environment monitoring or ELINT[36] SSO 570.6 km × 606.8 km 97.8° 37179 2010-051A TSLC Long March 4B Operational
Shijian 6-05A 10 December 2021 Space environment monitoring or ELINT[36] SSO 467.5 km × 475.4 km 97.3° 49961 2021-122A JSLC Long March 4B Operational
Shijian 6-05B 10 December 2021 Space environment monitoring or ELINT[36] SSO 467.5 km × 475.4 km 93.9° 49962 2021-122B JSLC Long March 4B Operational
Shijian 7 5 July 2005 Unknown SSO 557.4 km × 605.5 km 97.7° 28737 2005-024A JSLC Long March 2D Operational
Shijian 8 9 September 2006 Space agricultural experiments[37] LEO 177 km × 445 km 63.0° 29385 2006-035A JSLC Long March 2C Decayed
Shijian 9A 14 October 2012 Optical imaging, environmental monitoring[38] SSO 622 km × 647 km 98.0° 38860 2012-056A TSLC Long March 2C Operational
Shijian 9B 14 October 2012 Optical imaging, environmental monitoring, LWIR[38] SSO 623 km × 649 km 97.99° 38861 2012-056B TSLC Long March 2C Operational
Shijian 10 5 April 2016 Retrievable microgravity experiments[39] LEO 234 km × 268 km 42.89° 41448 2016-023A JSLC Long March 2D Decayed
Shijian 11-01 12 November 2009 Launch warning, IR tracking[40] SSO 689.7 km × 708.1 km 97.9° 36088 2009-061A JSLC Long March 2C Operational
Shijian 11-02 29 July 2011 Launch warning, IR tracking[40] SSO 678.5 km × 701.3 km 98.4° 37765 2011-039A JSLC Long March 2C Operational
Shijian 11-03 6 July 2011 Launch warning, IR tracking[40] SSO 689.8 km × 704.1 km 97.8° 37730 2011-030A JSLC Long March 2C Operational
Shijian 11-04 18 August 2011 Launch warning, IR tracking[40] (Launch Failure) JSLC Long March 2C Payload lost in rocket failure[41]
Shijian 11-05 15 July 2013 Launch warning, IR tracking[40] SSO 689.4 km × 703.3 km 98.2° 39202 2013-035A JSLC Long March 2C Operational
Shijian 11-06 31 March 2014 Launch warning, IR tracking[40] SSO 692.3 km × 713.6 km 98.1° 39624 2014-014A JSLC Long March 2C Operational
Shijian 11-07 28 September 2014 Launch warning, IR tracking[40] SSO 690.6 km × 706.3 km 98.1° 40261 2014-059A JSLC Long March 2C Operational
Shijian 11-08 27 October 2014 Launch warning, IR tracking[40] SSO 685.0 km × 701.7 km 98.2° 40286 2014-066A JSLC Long March 2C Operational
Shijian 12 15 June 2010 Scientific research[42] SSO 575 km × 599 km 97.68° 36596 2010-027A JSLC Long March 2D Operational
Shijian 13 12 April 2017 High-throughput communications[43][44][45] GEO 35,765.3 km × 35,823.8 km 0.1° 42662 2017-018A XSLC Long March 3B Operational
Shijian 15 19 July 2013 Unknown payload deployment[46] SSO 670.6 km × 678.4 km 98.0° 39210 2013-037C TSLC Long March 4C Operational
Shijian 16-01 25 October 2013 Space environment monitoring or SIGINT[47][48] LEO 599 km × 616 km 74.98° 39358 2013-057A JSLC Long March 4B Operational
Shijian 16-02 29 June 2016 Space environment monitoring or SIGINT[47][48] LEO 596 km × 616 km 75.00° 41634 2016-043A JSLC Long March 4B Operational
Shijian 17 3 November 2016 Communications and debris inspection or counterspace[49] GEO 35,827.1 km × 35,835.4 km 2.2° 41838 2016-065A WSLC Long March 5 Operational
Shijian 18 2 July 2017 Test of new DFH-5 platform, telecom[50] (Launch Failure) WSLC Long March 5 Payload lost in rocket failure[51]
Shijian 20 27 December 2019 Test of new DFH-5 platform, experimental quantum telecom[52][53] GEO 35,774.9 km × 35,814.1 km 1.347° 44910 2019-097A WSLC Long March 5 Operational
Shijian 19 Delayed from 2019 to 2022[54] Returnable microgravity experiments[55][56] Planned: not yet launched JSLC Long March 2D Planned
Shijian 21 24 October 2021 Debris clean-up or counterspace[57][58] GEO 36,217.7 km × 36,217.7 km 8.580° 49330 2021-094A XSLC Long March 3B Operational
Shijian 21 (subsat) 24 October 2021 Unknown[58][59] 49382 2021-094C XSLC Long March 3B Operational
Sources: NORAD, NASA, USSPACECOM, Celestrak, Gunter's Space Page

See also

References

  1. ^ Dickinson, General James H. (21 April 2021). United States Space Command Presentation to the Senate Armed Services Committee U.S. Senate (PDF) (Report).
  2. ^ Roberts, Thomas G. (31 March 2021). "Unusual Behavior in GEO: SJ-17". Aerospace Security, Center for Strategic and International Studies (CSIS).
  3. ^ Tiwari, Sakshi (17 February 2022). "Strangling Like A Python, China Says Its Powerful 'Robotic Snake' Can Crush Enemy Satellites Like Never Before". The Eurasian Times.
  4. ^ Jones, Andrew (27 January 2022). "China's Shijian-21 towed dead satellite to a high graveyard orbit". SpaceNews.
  5. ^ Chia, Henry (7 December 2021). "What we know about China's Shijian-class satellites". asiaMARKETS.
  6. ^ Burke, Kristin (28 March 2022). "Initial Analysis of Two Chinese Satellite Series: Shi Jian and Shi Yan" (PDF). China Aerospace Studies Institute (March 2022).
  7. ^ Dickinson, General James H. (21 April 2021). United States Space Command Presentation to the Senate Armed Services Committee U.S. Senate (PDF) (Report).
  8. ^ 2022 Military and Security Developments Involving the People's Republic of China, Annual Report to Congress (PDF). Arlington, VA: United States Department of Defense. 2022. p. 93.
  9. ^ Roberts, Thomas G. (31 March 2021). "Unusual Behavior in GEO: SJ-17". Aerospace Security, Center for Strategic and International Studies (CSIS).
  10. ^ Clark, Colin (18 April 2018). "China Satellite SJ-17, Friendly Wanderer". Breaking Defense.
  11. ^ Tiwari, Sakshi (17 February 2022). "Strangling Like A Python, China Says Its Powerful 'Robotic Snake' Can Crush Enemy Satellites Like Never Before". The Eurasian Times.
  12. ^ "Shijian-18 – CZ-5 – Shijian-18 | Spaceflight101". Archived from the original on 2021-12-09. Retrieved 2021-12-09.
  13. ^ "Shijian-18 – CZ-5 – Shijian-18 | Spaceflight101". Archived from the original on 2021-12-09. Retrieved 2021-12-09.
  14. ^ "Shijian-18 – CZ-5 – Shijian-18 | Spaceflight101". Archived from the original on 2021-12-09. Retrieved 2021-12-09.
  15. ^ Clark, Stephen. "China launches Long March 5, one of the world's most powerful rockets – Spaceflight Now". Archived from the original on 2021-12-09. Retrieved 2021-12-09.
  16. ^ Clark, Stephen. "China launches Long March 5, one of the world's most powerful rockets – Spaceflight Now". Archived from the original on 2021-12-09. Retrieved 2021-12-09.
  17. ^ Goh, Deyana (2017-07-03). "Long March 5-Y2 fails, Shijian-18 satellite lost". SpaceTech Asia. Archived from the original on 2021-12-09. Retrieved 2021-12-09.
  18. ^ "Successful Long March 5 launch opens way for China's major space plans". SpaceNews. 2019-12-27. Archived from the original on 2021-05-06. Retrieved 2021-12-09.
  19. ^ Clark, Stephen. "China launches Long March 5, one of the world's most powerful rockets – Spaceflight Now". Archived from the original on 2021-12-09. Retrieved 2021-12-09.
  20. ^ Chia, Henry (7 December 2021). "What we know about China's Shijian-class satellites". asiaMARKETS.
  21. ^ a b Mowthorpe, Matthew; Trichas, Markos (1 August 2022). "A review of Chinese counterspace activities". The Space Review.
  22. ^ a b Burke, Kristin (9 December 2021). "China's SJ-21 Framed as Demonstrating Growing On-Orbit Servicing, Assembly, and Manufacturing (OSAM) Capabilities" (PDF). China Aerospace Studies Institute (Dec 2021).
  23. ^ Tingley, Brett (27 January 2022). "A Chinese Satellite Just Grappled Another And Pulled It Out Of Orbit". The War Zone (magazine).
  24. ^ SJ-21 Quick Look Report (January 2022) (Video presentation). ExoAnalytic Solutions. 28 January 2022.
  25. ^ a b c d e Jones, Andrew (27 January 2022). "China's Shijian-21 towed dead satellite to a high graveyard orbit". SpaceNews.
  26. ^ Hitchens, Theresa (26 January 2022). "China's SJ-21 'tugs' dead satellite out of GEO belt: Trackers". Breaking Defense.
  27. ^ Barbosa, Rui C. (22 April 2009). "Chinese launch again with YaoGan Weixing-6 remote sensing satellite". nasaspaceflight.com. NASASpaceFlight.com. Retrieved 23 April 2009.
  28. ^ "2006年4月27日 "遥感卫星一号"成功发射". www.xinhuanet.com. Xinhuanet. 27 April 2006. Archived from the original on 24 June 2021. Retrieved 16 June 2021.
  29. ^ Makichuk, Dave (8 November 2021). "Space Force tracks Shijian-21 satellite 'companion'". Asia Times.
  30. ^ Kramer, Herbert J. (31 January 2022). "Shijian-21". eoPortal.
  31. ^ a b c d e f "Shi Jian". eoPortal. 15 June 2012.
  32. ^ a b Chia, Henry (7 December 2021). "What we know about China's Shijian-class satellites". asiaMARKETS.
  33. ^ Krebs, Gunter D. (21 July 2019). "SJ 3". Gunter's Space Page.
  34. ^ Krebs, Gunter D. (26 December 2021). "CBERS 1, 2, 2B / ZY-1 01, 02, 02B". Gunter's Space Page.
  35. ^ Krebs, Gunter D. (21 July 2019). "SJ 4". Gunter's Space Page.
  36. ^ a b c d e f g h i j Krebs, Gunter D. (23 March 2022). "SJ 6-01, ..., 6-05". Gunter's Space Page.
  37. ^ Krebs, Gunter D. (14 September 2020). "SJ 8". Gunter's Space Page.
  38. ^ a b "Shi Jian-9". eoPortal. 26 October 2012.
  39. ^ Christy, Robert (20 April 2016). "Shijian 10". Orbital Focus.
  40. ^ a b c d e f g h Wade, Mark. "SJ-11". Astronautix.
  41. ^ Krebs, Gunter D. (14 September 2020). "SJ 11". Gunter's Space Page.
  42. ^ Barbosa, Rui C. (14 June 2010). "China launch Shi Jian-12 satellite on research mission". NASA Spaceflight.
  43. ^ "China to help Pakistan build larger capacity telecom network". The Nation (Pakistan). 21 February 2017. Archived from the original on 1 December 2020.
  44. ^ "China to launch first high-throughput communications satellite in April". Space Daily. 21 February 2017.
  45. ^ "China Focus: China launches 1st high-throughput communications satellite". Xinhua News Agency. 12 April 2017.
  46. ^ Christy, Robert (10 August 2013). "Shijian-15". Orbital Focus.
  47. ^ a b "SJ 16-02". N2YO.
  48. ^ a b Krebs, Gunter D. (11 April 2021). "SJ 16". Gunter's Space Page.
  49. ^ "In-Space Eavesdropping? – China's Shijian-17 completes High-Altitude Link-Up". Spaceflight101.
  50. ^ "Shijian-18 – CZ-5 – Shijian-18 | Spaceflight101". Archived from the original on 2021-12-09. Retrieved 2021-12-09.
  51. ^ Krebs, Gunter D. (22 December 2020). "SJ 18". Gunter's Space Page.
  52. ^ "Shijian-20". Next Spaceflight.
  53. ^ Chen, Stephen (27 July 2022). "China launches new satellite in 'important step' towards global quantum communications network". South China Morning Post.
  54. ^ @@ClosertoSpace (30 July 2021). "Contrairement à ce que l'on pourrait croire, le spatial chinois n'est pas exempt de retards. Exemple avec le lancement du satellite récupérable Shijian-19, prévu initialement en 2019, et actuellement planifié pour avril 2022..." [Contrary to what one might think, Chinese space is not free of delays. An example is the launch of the recoverable satellite Shijian-19, initially planned for 2019, and currently planned for April 2022...] (Tweet) (in French) – via Twitter.
  55. ^ "广梅一号"为苏区振兴插上翅膀" ["Guangmei No. 1" adds wings to the revitalization of the Soviet area]. Sina News (in Chinese). 11 June 2019.
  56. ^ Lanyue, Hu (10 July 2019). Yiming, Yang Chenggao (ed.). "能送半吨货往返太空!我国新一代商业返回式卫星拟明年首发" [Can send half a ton of cargo to and from space! my country's new generation of commercial returnable satellites to be launched next year]. China Aerospace Science and Technology Corporation (in Chinese).
  57. ^ Tingley, Brett (27 January 2022). "A Chinese Satellite Just Grappled Another And Pulled It Out Of Orbit". The War Zone (magazine).
  58. ^ a b Jones, Andrew (27 January 2022). "China's Shijian-21 towed dead satellite to a high graveyard orbit". SpaceNews.
  59. ^ Makichuk, Dave (8 November 2021). "Space Force tracks Shijian-21 satellite 'companion'". Asia Times.