China’s new space plane returned to Earth on Sept. 6th.
But it left something behind in orbit, an item of unknown character called “Object A” by the US military.
Last night in the Netherlands, Marco Langbroek tracked it across the sky using a hand-pointed video camera.
“It showed slow but marked brightness changes, between magnitude +4 and invisible (fainter than +7),” says Langbroek. “The light curve shows two brightness peaks, and two major fading episodes. Peak-to-peak period is about 80 seconds, so if this is due to a tumble, it is a slow tumble.“
Object A is also a source of radio transmissions. Amateur radio operator Scott Tilley has detected it at 2280 MHz, and says that the radio signal waxes and wanes with a period near 80 seconds–akin to Langbroek’s light curve.
Had some time this morning to reduce the Chinese spaceplane OBJECT A data and compare to @Marco_Langbroek visual results. Interestingly the fading and null timing I was seeing was close to his 80 sec measurement. https://t.co/7FTrlJDTKE pic.twitter.com/tsJyb464La— Scott Tilley (@coastal8049) September 20, 2020
What does it all mean?
Speculation is that Object A is either an inspector satellite used to inspect the outside of the Chinese space plane before landing; or maybe some jettisoned support module.
This does not appear to be just a piece of debris. Radio observers discovered that it sends a signal in the L-band near 2280 MHz, something debris doesn’t do.
The Chinese spaceplane appears to have released a satellite object 46395. These observations indicate it emits on 2280MHz. The modulation appears unusual for a Chinese satellite. https://t.co/otnkC30sQf— Scott Tilley (@coastal8049) September 14, 2020
So, this appears to be an interesting object that had or has some function, including a radio data signal downlink. It does not appear to have manoeuvered so far, and if it is tumbling (see below) it isn’t likely to do so.
Speculation is that it is either an inspector satellite used to inspect the outside of the Chinese spaceplane before landing: or maybe some jettisoned support module. The ejection from the ‘Reusable Test Spacecraft’ appears to have taken place some two revolutions before landing, or perhaps even earlier