In mid-June, the Shijian-25 technology demonstration refueling spacecraft made its closest approach yet to its believed docking target, the Shijian-21 space debris mitigation satellite, to perform its spacecraft-to-spacecraft refueling test.
That test likely did not occur, as the two spacecraft were only in close proximity to each other for around one and a half hours. Meaning Shijian-25 and Shijian-21 possibly performed a rehearsal of expected maneuvers or a docking prior to the test was aborted. Additionally, no statements from involved agencies or enterprises were released regarding the spacecraft in June.
Both Shijian-25 and Shijian-21 remain operational and are recently heading back towards each other. On June 27th, COMSPOC, a space situational awareness firm, shared the following:
“As of 26 June, SHIJIAN-21 remained less than ~80 kilometers from SHIJIAN-25.
Meanwhile, USA 270 continued to occupy the mean longitude position of the pair. According to our Space Situational Awareness (SSA) software suite, both satellites performed several small maneuvers to come closer (<11 km).
Shijian-25 and Shijian-21’s position relative to USA-270, via COMSPOC.
“However, their maintained close proximity may suggest that docking has not occurred.”
Details regarding Shijian-25 and Shijian-21’s docking operations remain few, but at the 2021 Zhuhai Airshow the process was described as:
"[The] spacecraft will arrive at the rear of the satellite under the guidance of the ground dispatching system, and use the navigation system to track and approach the satellite autonomously. When it arrives within about 2 meters of the satellite, with the cooperation of the robotic arm, it will achieve a close connection with the satellite refueling port and deliver fuel to the satellite.”
For details regarding the test, we still have to wait for official word from one of China's space agencies and enterprises, which may announce the success of the test anywhere from a few days to several weeks afterward.
Although, as COMSPOC shared, U.S. military spacecraft USA-270 is hanging around near the two spacecraft. If deemed useful to disclose, the U.S. military could provide updates based on observations.
