The middle child of China’s space station family, Tiangong-2, wobbled in space but the authorities have nothing to say about that.

The popularity of Space Exploration can simply be judged by the fact that more and more powerful nations of the world are investing in it. Both Russia and the United States are competing in this industry for many years. Similarly, the European Space Agency has spent a lot to know about our surroundings. The latest entrants in this field are India and China who really have the financial strength to sustain in this expensive race. India’s mission to Mars certainly made a lot of headlines in 2013 as it was an extremely cost-efficient venture. China is arguably the leading economy of the world as they adapt rapidly to new things. They have achieved success in almost everything they have tried in the last 2-3 decades but they are facing quite a few problems in their efforts to explore space.

The journey of a Chinese space station called Tiangong-1 came to an end as it smashed into the Pacific Ocean a couple of months ago on 2^nd of April. This disappointing incident is still fresh in the memories of the Chinese Space Agency as their second space lab showed signs of another uncontrolled fall on 13^th June. Tiangong-2 fell about 100 kilometers and a lot of observers considered it to be the first move to junk the station as it is already in sleep mode after spending 2 years in orbit. Contrary to that, it rose back to its normal orbit, which is at a height of 390 kilometers from the surface of Earth, on 22^nd June. Jonathan McDowell, an Astronomer at the Harvard-Smithsonian Center for Astrophysics, observed the entire incident and told the world what he thinks about that. He said,

“I think part of this exercise was: Let’s just do a burn that loses a fair amount of fuel to really get good measurements of what the thrust of the engine is, what the [fuel efficiency] of the engine is.”

In simpler words, China has converted Tiangong-2 into a test bed for the rocket technology which is present on that space station. McDowell also mentioned that the officials want to see the reliability and efficiency of the propulsion system after spending two years in space. As Tiangong-2 has already completed its operational life, a possible explanation for doing so could be that the engine system of the next space station is either identical or very much similar to it. McDowell described it by saying,

“Engines are imperfect devices, and without direct testing it’s difficult to know precisely how they’ll perform in space. Doing a burn and then carefully measuring where the station ends up is a useful test. China is doing this sort of testing after Tiangong-2 has otherwise reached the end of its operational life. It suggests that the engine system you’re going to use on the next space station is either identical or very similar.”

According to the China Manned Space Engineering Office (CMSE), Tiangong-2 was launched with 1 ton of fuel. Considering the work it has done, the spacecraft still carries around 680 kilograms of fuel on board. If McDowell estimates are to be believed, Tiangong-2 can afford one more, even higher, dive-and-climb exercise and it will still have sufficient fuel for a controlled deorbit. However, CMSE might not go for that as it will bring this space station too close to the International Space Station. He also mentioned that it is quite possible that China doesn’t go for another engine test and decides to deorbit it straightaway after examining some other equipment of the Tiangong-2 like the battery and temperature controls.

According to McDowell, another possible reason for this activity could be to burn up some of that fuel in order to make the re-entry of Tiangong-2 less explosive. Despite all these speculations, we have not received any statement at all from the Chinese authorities as they are sticking to their past tradition of maintaining silence on such issues. Having said that, one thing that can be said assuredly is that CMSE has still got control over their second space lab and they can deorbit it any way they want.