China added Yaogan 17, a group of three Electronic / Signals Intelligence satellites, to its network of military satellites on September 1 (September 2 local time). It is the third in a series, which was preceded by Yaogan 9 on March 2010 and Yaogan 16 on November 2012.
The cluster of satellites can be used in conjunction to analyse and locate the position of various objects based on their electronic emissions and the time difference of arrival technique in a manner reminiscent of the United States Naval Ocean Surveillance System (NOSS).
Another significant development is China's demonstrated ability to orbit satellites with much enhanced ability to maneuver in space and in a very precise manner.
Unlike most satellites which tend to follow a fixed orbit for most of their life span and have very rudimentary maneuverability, these satellites are closer to unmanned aircraft which can change their orbit in space periodically and on demand.
Using this ability, the satellite can change orbit to approach another satellite in space and follow it very closely along its orbit. Such an ability can be very useful in a civilian role.
For example, the satellite can be used to inspect other satellites in case of damage or other malfunction. They could even be used to replace certain parts or other repairs.
However, such a level of precise maneuverability also has military applications. By attaching these maneuverable satellites with various payloads, they could be used to target and either temporarily interfere or disrupt and even permanently disable satellites that are crucial to an adversary.