Thirtieth flight of the Long March 4C
The second Chinese launch of the year 2021, took place on January 29 from the space center of Jiunquan, in the Gobi Desert, in the north-west of the country. Ten days after the last satellite of the mobile telephone network was sent to a geostationary transfer orbit Tiantong.
The mission was entrusted to a medium power launcher Long March 4C with three floors, used for the thirtieth time since April 2006.
Three new satellites were thus placed in low orbit (1,091 km x 1,098 km, tilted 63.4 °) Yaogan, baptized 31-2A, 31-2B and 31-2C.
Seven Yaogan satellites (including two trios) were launched last year.
Observation satellites… military
The Yaogan satellites, the first of which dates back to April 2006 (aboard the first Long March 4C), seem to be built by the Center des petits satellites de l ‘Academy of Sciences Chinese, and operated by Helmet (China Society for Aerospace Science and Technology).
Behind the name Yaogan (or Yaogan Weixing, which means Remote sensing satellite in Chinese), it is not clear what payloads are actually on board: optical telescopes, synthetic aperture radars (SAR), even material for electromagnetic intelligence (Elint)…
Officially, their mission is Earth observation, to aid in crop assessment, disaster prevention, urban planning as well as scientific experiments.
But their military nature is no longer in doubt today.
Seventh trio for maritime observation
The Yaogan 31s (a first batch of which was launched in April 2018) are no exception, presented by the state news agency Xinhua (New China) as being intended for monitoring the electromagnetic environment and for other technological aspects.
However, the trio actually seems to belong to a sub-category of ocean surveillance satellites for monitoring foreign naval movements, deployed in orbits inclined by 63 ° since March 2010 on the occasion of seven distinct missions (Yaogan 9, 16 , 17, 20, 25, 31-1 and 31-2).
The Yaogan 31s could even be their new generation.
An inclination of 63 ° in any case allows the satellites to follow a trajectory which goes from the south of Alaska to the South Shetland Islands, north of the Antarctic Peninsula.
These sentries would be comparable to American satellites Noss (Naval Ocean Surveillance Satellites) used since 1976 for maritime surveillance and early warning, also in trios and in comparable orbits.