SJ-21
TECHNOLOGY dossier

SJ-21

SJ-21

TECHNOLOGY Hardware RD FOUNDATION

01 Executive_Summary

Chinese co-orbital ASAT satellite launched October 2021. Demonstrated grappling capability by docking with and towing dead Beidou satellite in January 2022.

03 Deep_Dive_Intelligence

Intelligence Summary: SJ-21

Node Identity: SJ-21 is a technology categorized under "Hardware" in the china intelligence graph. Chinese co-orbital ASAT satellite launched October 2021. Demonstrated grappling capability by docking with and towing dead Beidou satellite in January 2022.

Research Evidence: The following findings from 1 research document reference this entity:

  1. China's co-orbital ASAT program spans multiple satellite missions: SJ-12 (2010, close approaches with SJ-06F in LEO at <300m), Shiyuan-7/Tansuo-3/4/5 (2013, robotic arm testing), Shijian-17 (2016, optical/SIGINT proximity operations in GEO), TJS-3 (2018, co-orbital ASAT development), and most notably SJ-21 (October 2021).
  2. SJ-21 docked with the defunct Beidou-2 G2 navigation satellite in January 2022 and towed it 3,000 km above the GEO belt — the first such demonstration by any nation other than the US.
  3. The SJ-21 grappling operation was a watershed moment proving China can physically capture and relocate satellites in GEO — the most valuable orbital regime for US military communications and early warning.

Strategic Relevance: SJ-21 is a tracked entity within the china network. With 6 documented connections to other entities, this node plays a significant role in the network topology.

Network Linkage: This entity maintains 6 documented connections in the intelligence network: SJ-21 example of Co-orbital ASAT; SJ-21 executed SJ-21 Towing Operation; SJ-21 operated by PLA Aerospace Force; PLA Aerospace Force operates SJ-21; Co-orbital ASAT represented by SJ-21; SJ-21 Towing Operation executed by SJ-21.

Source Documents: Evidence compiled from: FINDINGS_FROM_research-prompts-round91.md.

04 Network_Linkage

This entity maintains 6 documented connections in the intelligence network: SJ-21 example of Co-orbital ASAT; SJ-21 executed SJ-21 Towing Operation; SJ-21 operated by PLA Aerospace Force; PLA Aerospace Force operates SJ-21; Co-orbital ASAT represented by SJ-21; SJ-21 Towing Operation executed by SJ-21.

07 Key_Findings

  • ▸ ### Intelligence Summary: SJ-21 **Node Identity:** SJ-21 is a technology categorized under "Hardware" in the china intelligence graph.
  • ▸ Chinese co-orbital ASAT satellite launched October 2021.
  • ▸ Demonstrated grappling capability by docking with and towing dead Beidou satellite in January 2022.

10 FAQ

What is SJ-21? ▾
Identity: SJ-21 is a technology categorized under "Hardware" in the china intelligence graph. Chinese co-orbital ASAT satellite launched October 2021. Demonstrated grappling capability by docking with and towing dead Beidou satellite in January 2022.
What role does SJ-21 play in the research network? ▾
SJ-21 is classified under the "Hardware" category, belonging to the RD_FOUNDATION vertical group. This entity maintains 6 documented connections in the intelligence network: **SJ-21** example of **Co-orbital ASAT**; **SJ-21** executed **SJ-21 Towing Operation**; **SJ-21** operated by **PLA...
What evidence supports the SJ-21 assessment? ▾
The intelligence assessment for SJ-21 is supported by 4 primary sources and 1 citation. Key sources include "China's Shijian-21 towed dead satellite to a high graveyard orbit", "China's SJ-21 'tugs' dead satellite out of GEO belt: Trackers", and "Shi Jian 21 (SJ 21) - Gunter's Space Page". These documents provide the evidentiary basis for the analysis.
How does SJ-21 work? ▾
Identity: SJ-21 is a technology categorized under "Hardware" in the china intelligence graph. Chinese co-orbital ASAT satellite launched October 2021. Demonstrated grappling capability by docking with and towing dead Beidou satellite in January 2022.
Who developed SJ-21? ▾
SJ-21 is documented across 4 primary sources in the research archive.
How does SJ-21 fit into the broader intelligence network? ▾
This entity maintains 6 documented connections in the intelligence network: SJ-21 example of Co-orbital ASAT; SJ-21 executed SJ-21 Towing Operation; SJ-21 operated by PLA Aerospace Force; PLA Aerospace Force operates SJ-21; Co-orbital ASAT represented by SJ-21; SJ-21 Towing Operation executed by SJ-21.
What external sources document SJ-21? ▾
SJ-21 is documented by 4 external sources, including 2 news article, 1 database record, and 1 analysis article. Notable references include "China's Shijian-21 towed dead satellite to a high graveyard orbit", "China's SJ-21 'tugs' dead satellite out of GEO belt: Trackers", and "Shi Jian 21 (SJ 21) - Gunter's Space Page".
What is the historical timeline for SJ-21? ▾
SJ-21 is referenced across documents spanning 2010–2022, with activity noted in 2010, 2013, and 2016. This temporal range is derived from the primary source documents in the research archive.
How does SJ-21 relate to compact fusion research? ▾
Intelligence Summary: SJ-21 Node Identity: SJ-21 is a technology categorized under "Hardware" in the china intelligence graph. Chinese co-orbital ASAT satellite launched October 2021. Demonstrated grappling capability by docking with and towing dead Beidou satellite in January 2022. Research...
What documents should I read to learn more about SJ-21? ▾
To learn more about SJ-21, review the 4 primary sources, and related research finding linked in the source documents section of this dossier.

Citations 1

  1. [1]

Verified_Primary_Sources 4 SOURCES

secondary spacenews.com news_article
China's Shijian-21 towed dead satellite to a high graveyard orbit
Verifies: Shijian-21 docked with the defunct Beidou-2 G2 navigation satellite and towed it above the GEO belt; SJ-21 performed a large burn on January 22, 2022, taking Beidou-2 G2 approximately 3,000 km above the GEO belt; SJ-21 undocked from Beidou-2 G2 on January 26, 2022, leaving it in a disposal orbit; SJ-21 was launched in October 2021 and conducted sophisticated rendezvous and proximity operations
External Link ↗
secondary breakingdefense.com news_article
China's SJ-21 'tugs' dead satellite out of GEO belt: Trackers
Verifies: Commercial space monitoring firm ExoAnalytic Solutions tracked SJ-21 functioning as a space tug; SJ-21 performed close proximity operations around the Compass G2 (Beidou) satellite before docking; The satellite performed a large maneuver pulling the dead satellite out of GEO into a super-graveyard drift orbit; The observed capabilities are consistent with On-Orbit Servicing, Assembly, and Manufacturing (OSAM) but also have potential military applications
External Link ↗
primary space.skyrocket.de database_record
Shi Jian 21 (SJ 21) - Gunter's Space Page
Verifies: SJ-21 is a Chinese experimental space debris mitigation satellite launched October 24, 2021 on a CZ-3B/G2 rocket; COSPAR designation: 2021-094A; SJ-21 docked with defunct Beidou-2 G2 and performed an engine burn on January 21, 2022, moving it beyond the usual graveyard orbit; SJ-21 undocked on January 26, 2022, and returned to GEO
External Link ↗
secondary www.thespacereview.com analysis_article
A review of Chinese counterspace activities
Verifies: China has a long history of developing space weapons including co-orbital ASAT capabilities; SJ-21 demonstrated a capability to hide in the graveyard orbit beyond GEO and re-emerge to grapple a satellite in GEO; China's counterspace program spans multiple SJ satellite missions with proximity operations and robotic arm testing; The article places SJ-21 in the context of broader Chinese counterspace activities
External Link ↗
Locate on Graph ← Back to Dossiers
ID: SJ-21
Type: technology
Region: china
Last updated: Research database snapshot