Within a week, China has added two more satellites to its network of military satellites. The first on October 15th was Shijian 16, the next-generation of electronic / signals intelligence (ELINT / SIGINT) satellites.
The Shijian 16 is the first of a new series that will succeed the Shijian 6 series, which consisted of four pairs with two satellites each. The Shijian 6 satellites were launched between 2004 and 2010.
The second satellite to be launched was the Yaogan 18 on October 29th. The Yaogan 18 is a Synthetic Aperture Radar (SAR) satellite, similar to Yaogan 6 and Yaogan 13 that preceded it.
The SAR satellites complement imagery provided by other Yaogan
satellites equipped with an optical payload. They tend to have lower
resolution, but do not suffer from some of the restrictions that limit
SAR satellites can be used where optical cannot such as to penetrate through cloud and other ground cover up to a certain depth depending on a number of factors.
China has also conducted further tests toward a preliminary launch-on-demand capability. Satellites up to a certain size can be launched from mobile launchers on very short notice as a backup.
The solid-fuel rockets used are relatively small and compact, unlike the larger liquid-fuel rockets normally used. Both rockets and satellites can be serially produced and stored for a certain amount of time.
Satellites are usually launched from fixed installations after some extended preparation time. During a crisis these installations, which tend to be quite large, are vulnerable to an attack and cannot be relied upon should they be needed.
Therefore, there's a real need for an alternative to be available to augment existing surveillance / reconnaissance capabilities or to replace space assets that may have been disabled through various means.