China's second space station will soon disappear?

The space station recently abandoned by China has made a large unexplained oscillation in orbit this month. And the event left observers outside the China Space Engineering Bureau (CMSE) guessing the country's plans for the long-term future of Tiangong-2, the Average child of the family of the Chinese space station.

Tiangong-2, the successor to the Chinese space station Tiangong-1, which slammed into the Earth's atmosphere in March, plunged more than 50 miles (nearly 100 kilometers) on June 13th. At the time, most observers assumed the first step in a plan to unsubscribe from the station. After the show of the uncontrolled reopening of Tiangong-1 earlier in the year, it made sense that China wants to bring down Tiangong-2 in a more controlled manner as soon as possible. After all, China has already stopped using its small second station after the spacecraft has spent two years in orbit, and the country seems to have turned its attention to Tianhe, a much larger and more permanent station that should to be launched in 2022.

But after 10 days, at an altitude of 295 km (183 miles), Tiangong-2 resumed its normal orbital trajectory 390 km above the Earth. Tiangong-2 is just a little bigger than the Russian capsules used to transport astronauts to and from the International Space Station (ISS) and much smaller than the ISS itself. [In Photos: A Look at China’s Space Station That’s Crashing to Earth]

China keeps her mother, as usual, about the small orbital dance of her empty station, but astronomer Jonathan McDowell of the Harvard-Smithson Center for Astrophysics, who closely follows the Orbital vessels like Tiangong-2, think it's understood.

"I think part of this exercise was: Let's just make a burn that loses a good amount of fuel to really get good measurements of what the engine thrust is, what the [fuel efficiency] of the engine is, "said McDowell Live Science.

In other words, China seems to have turned Tiangong-2 from a temporary space station into a test bench for rocket technology already embedded, which would otherwise be unused in the absence of a crew.

Engines are imperfect devices, and without direct testing, it's hard to know exactly how they will work in the space. Making a burn and then carefully measuring where the station ends, McDowell said, is a useful test.

China is doing this kind of test after Tiangong-2 has reached the end of its operational life, McDowell said, "suggests that the engine system you are going to use on the next space station be the same or very similar."

Learning how engines work on Tiangong-2 could help Chinese engineers refine their plans for Tianhe.

When she launched Tiangong-2, China told the world that the station had a ton of fuel on board. Based on the various burns that the station has since executed, McDowell said he believes the Chinese spacecraft should still have about 1,500 pounds. (680 kilograms) on board. This is enough, he said, for the station to perform another dive like the previous maneuvers and that there is enough fuel for controlled deorbiting. (The station could also climb to an even higher altitude and then dive, but McDowell noted that such a maneuver could bring Tiangong-2 closer to the orbital altitude of the ISS than China does. would like to risk.)

Whatever the case may be, he said, he would not be surprised if China disorientated the station without further testing in the weeks or months ahead. CMSE is probably testing other equipment – like temperature controls and battery – aboard the Tiangong-2, in a way that observers can not detect, he said. But once that kind of activity is over, he said, there is a good chance that China will throw the empty orbiter into the ocean.

Originally posted on Live Science.