TL;DR: China may be attempting a rendezvous with the American space plane (OTV-6) currently in orbit, with unknown intentions. Given the current US/China tensions, and Trump's emphasis on space, this seems perhaps important.
China is reported to be launching a experimental space plane at around 05:30 UTC (in about two hours, if I'm doing date and time zone conversions correctly from the original post). Before launch, China posts a "notice to mariners" describing areas in the ocean where launch debris may fall, so ships can stay out of the way. From the geometry of the launch site in combination with the areas described in the notice to mariners, it's possible to determine the launch trajectory, especially the inclination that is targeted in the launch (tilt of the orbit relative to the equator, or exactly how far north/south the satellite will fly on each orbit). In combination with the launch time, this defines the "orbital plane" (think of a sheet of paper that cuts through the center of the planet). Satellites can move easily within an orbital plane, but not easy to make any significant change in the orbital plane of a LEO (low Earth orbit) satellite, so the orbital plane is important for understanding where a satellite launched into space is going.
The United States has a spaceplane in orbit (OTV-6), launched in May. The American spaceplane is unmanned, sort of like a miniature space shuttle in shape and design, and is capable of staying in space for more than a year at a time. It's thought to be a platform for experimental technologies, but since it's classified we don't really know too many details. Amateur astronomers have been tracking the US spaceplane (OTV-6) that is currently in orbit, as it's pretty easy to see something that big in low orbit.
This report says, based on launch location/time and the notice to mariners information, the Chinese spaceplane appears to be going into the same orbital plane occupied by the American OTV-6 spaceplane!
We don't know for sure that this isn't a coincidence. If the spaceplane goes to a completely different altitude, it may not matter. But it sure looks suspicious. Eyes on this one.
This kind of thing is not unprecedented. There have been reports recently of Russian "inspector satellites" going in the same orbital planes as US spy satellites, and hovering nearby in a complex orbital dance. This Chinese launch has some similar characteristics, but we really don't know what China plans on doing, what their intentions may be … and I don't trust Chinese intentions.
Sort of odd here, is that this is the first flight of the Chinese spaceplane, and it seems surprising to me they'd send the first flight into a rendezvous with an American military spaceplane (instead of doing some more basic R & D first …)
Following text is from astronomer Marco Langbroek on the Seesat satellite forum. Images are from some of the twitter links.
http://www.satobs.org/seesat/Sep-2020/0016.html
Now this is interesting!
On twitter, based on NOTAM's for Jiuquan for a CZ-2F launch, there is
speculation about the launch of a Chinese experimental Space Plane tomorrow:
https://twitter.com/Cosmic_Penguin/status/1301512983550611458?s=20
Based on the NOTAM's I calculate an orbital inclination of ~45 degrees.
https://twitter.com/Marco_Langbroek/status/1301565723484004353?s=20
What is more: based on the time window, the launch will be into/near the plane
of the USAF X-37B OTV-6 space plane!
https://twitter.com/Marco_Langbroek/status/1301568954788438016?s=20
That will cause some sweat in the US I reckon!!!!