A Chinese satellite was recently observed grabbing another satellite and pulling it out of its normal orbit and into a “super-graveyard drift orbit.”
The maneuver raises questions about the potential applications of these types of satellites designed to maneuver close to other satellites for inspection or manipulation and adds to growing concerns about China's space programme, reports The Drive.
On January 22, China’s Shijian-21 satellite (SJ-21) disappeared from its regular position in orbit and was then observed executing a “large maneuver” to bring it closely alongside another satellite, a dead BeiDou Navigation System satellite. SJ-21 then pulled the dead satellite out of its normal geosynchronous orbit and placed it a few hundred miles away in what is known as a graveyard orbit.
A geosynchronous orbit allows satellites to match Earth's rotation. Located at 35,786 kilometers above the equator, this position is a valuable spot for monitoring weather, communications and surveillance. Distant orbits, on the other hand, are designated for defunct satellites at the end of their lives and are intended to reduce the risk of collision with operational assets.
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SJ-21's unusual maneuver was observed by commercial space awareness firm Exoanalytic Solutions. During a webinar hosted by the Center for Strategic and International Studies (CSIS) this week, Exoanalytic Solutions’ Brien Flewelling said the SJ-21 satellite “appears to be functioning as a space tug.” Space Command did not respond to a request for comment, Breaking Defense reports.
Also, this isn’t the first time SJ-21 has made headlines with its questionable behavior. In November 2021, a month after its launch, an unknown object was seen orbiting alongside it. At the time, Space Force designated the unidentified object as a spent apogee kick motor, but it was also reported that it might have been an experimental payload designed to test the satellite's ability to perform remote operations and manipulate other satellites.
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According to The Drive, the United States Air Force’s China Aerospace Studies Institute (CASI) published a report on Shijian-21 last year shortly after its unknown companion appeared. The report notes that “Even Chinese media, academics, and bloggers agree with Western analysts that remote proximity operation capabilities and robotic arm technologies are dual-use,” meaning they have potential military applications in addition to scientific or utility ones.
The report mentions unverified claims that SJ-21 might have some form of net used to capture space debris, claims which have also appeared on social media.
China launched a satellite called Shijian-21 in Nov. Look at these pictures to see what it can do. pic.twitter.com/YT7lgpOitA
— 彩云香江 (@louischeung_hk) January 4, 2022
Although according to Chinese state news outlets, SJ-21 was designed to “test and verify space debris mitigation technologies," the maneuver has raised concerns among other nations about these types of satellites and their potential for military use.
If SJ-21 can grab a dead satellite and move it out of orbit, there is likely little stopping it from doing the same thing to an operational one the military of other countries, including India, depend upon.