China space lab mostly burns up on re-entry in south Pacific

China's defunct Tiangong 1 space station mostly burned up on re-entry into the atmosphere over the central South Pacific on April 2, Chinese space authorities said. The experimental space laboratory re-entered around 8:15 a.m. Beijing time, the China Manned Space Engineering Office said.

Scientists monitoring the craft's disintegrating orbit had forecast the craft would mostly burn up and would pose only the slightest of risks to people. Analysis from the Beijing Aerospace Control Centre showed it had mostly burned up. Brad Tucker, an astrophysicist at Australian National University, said that Tiangong 1′s re-entry was "most successful" and that it would have been better if the space station had not been spinning toward Earth. "It could have been better, obviously, if it wasn't tumbling, but it landed in the Southern Pacific Ocean, and that's kind of where you hope it would land," Tucker said.

"It's been tumbling and spinning for a while, which means that when it really starts to come down it's less predictable about what happens to it," Tucker said. He likened it to an aeroplane landing, saying it's more difficult to predict where a plane that is "shaking around and moving" will land than one that is smoothly descending. Launched in 2011, Tiangong 1 was China's first space station, serving as an experimental platform for bigger projects, such as the Tiangong 2 launched in September 2016 and a future permanent Chinese space station. Two crews of Chinese astronauts lived on the station while testing docking procedures and other operations. Its last crew departed in 2013 and contact with it was cut in 2016.

Since then, it has orbited gradually closer and closer to Earth on its own while being monitored. Earlier forecasts had said that only about 10 per cent of the bus-sized, 8.5-ton spacecraft would likely survive re-entry, mainly its heavier components such as its engines. "The biggest takeaway from this is that as we put more things into space, all countries, we have to be aware that we do have to plan for these sorts of issues that are happening," Tucker said. Roger Thompson, a senior engineering specialist with the Aerospace Corporation in Virginia, said modelling of Tiangong 1′s re-entry by monitors in the US had been highly accurate, leaving him feeling "great" about their predictions. "We believe it was an uncontrolled entry," Thompson said, adding that the corporation's own estimate had been just 15 minutes behind the time announced by China.