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Issue 70

04 Flash Archive · Members Only

China Launches Yaogan-34-04 Reconnaissance Satellite

15 Mar 2023: The final launch was the Yaogan (YG) 34-04 mission, carrying a SAST-built optical remote sensing satellite to LEO. The official use case for this satellite is “land census, urban planning, road network design, crop yield estimation, and disaster prevention and mitigation,” a commonly used placeholder for…

Author Greg Gillinger Published August 1, 2025

15 Mar 2023: The final launch was the Yaogan (YG) 34-04 mission, carrying a SAST-built optical remote sensing satellite to LEO. The official use case for this satellite is “land census, urban planning, road network design, crop yield estimation, and disaster prevention and mitigation,” a commonly used placeholder for satellites that carry a military classified use case. Launch Video.

– YG-34-04 current (as of 2 Apr 2023) orbit is lower than YG-34-01, 02 & 03. Currently YG-34-04 is in a 1,095x914km orbit but has an identical 63.4° inclination.

– The earlier Yaogan-34 series satellites are in 1,120 by 1,050-kilometer orbits and are also inclined by 63 degrees. The orbit closely matches that of three sets of Yaogan-31 designation satellite triplets.

– All four YG-31 triplets are accompanied by a YG-34 satellite.

  • YG-34-01 trails YG-31 D/E/F
  • YG-34-02 trails YG-31 G/H/J
  • YG-34-03 trails YG-31 J/L/M
  • YG-34-04 trails YG-31 A/B/C

– As we saw with all previous YG-34 satellites, expect YG-34-04 to gradually close the gap between itself and the YG-31 triplet it follows.

-The Yaogan-31 satellites’ orbits suggest they are analogous to US DoD Naval Ocean Surveillance System (NOSS) satellite triplets. Watch Video of Satellite Triplets (YG-16 & YG20).

– NOSS satellites locate and track ships at sea by detecting radio transmissions and analyzing them using time-difference-of-arrival (TDOA).

-China’s official release stated the Yaogan-34 series “is mainly used for land census, urban planning, and land confirmation. It can meet the needs of rapid earth observation revisitation and provide information for China’s “Belt and Road” construction.

– This suggests Yaogan-34 is an optical remote sensing satellite.

-Pairing an optical remote sensing satellite with the Yaogan 31 triplets could yield the ability to “tip and cue” between sensors and use imagery to confirm ship or other target locations and identities.

-All YG-34 and YG-31 satellites were launched from Jiuquan and used a LM-4C launch vehicle. YG-34 satellites were built by SAST while CAST manufactured the YG-31 satellites.

China is developing several symbiotic constellations made up of dissimilar satellites. The missions of these satellites and their capabilities have not been made public. However, like YG-31 and YG-34, the satellites have different manufacturers (CAST and SAST respectively.) YG-35 and YG-36 triplet satellites are also flown in a lead-trail formation with 2 of the satellites from DFH and the third from SAST. YG-32A and YG-32B also orbit in a lead-trail configuration and are believed to be SIGINT satellites.–

Yaogan-34-04 orbit relative to the Yaogan-31 A/B/C triplet

Yaogan-34-04 orbit relative to the Yaogan-31 A/B/C triplet

Yaogan-34 satellites trailing the four Yaogan-31 triplets

Yaogan-34 satellites trailing the four Yaogan-31 triplets

Yaogan-34-04 mission patch

Yaogan-34-04 mission patch