Defunct space lab to re-enter Earth’s atmosphere
BEIJING: China’s defunct and reportedly outof-control Tiangong 1 space station is expected to re-enter Earth’s atmosphere sometime this weekend. It poses only a slight risk to people and property on the ground, since most of the bus-size, 7.7-tonne vehicle is expected to burn up on re-entry, although space agencies don’t know exactly when or where that will happen.
Below are some questions and answers about the station and its re-entry.
The European Space Agency predicts the station will re-enter the atmosphere between Saturday morning and Sunday afternoon – an estimate it calls “highly variable”, likely because the ever-changing shape of the upper atmosphere affects the speed of objects falling into it.
The Chinese space agency’s latest estimate puts re-entry between Saturday and Wednesday.
Western space experts say they believe China has lost control of the station. China’s chief space laboratory designer Zhu Zongpeng has denied Tiangong was out of control, but has not provided specifics on what, if anything, China is doing to guide the craft’s re-entry.
Based on Tiangong 1’s orbit, it will come to earth somewhere between 42.7 degrees of latitude north and 42.7 degrees south, or roughly somewhere over most of the United States, China, Africa, Southern Europe, Australia and South America. Out of range are Russia, Canada and northern Europe.
Based on its size, only about 10% of the spacecraft will likely survive after being burned up on re-entry, mainly its heavier components such as the engines. The chances of any person on earth being hit by debris is considered less than one in a trillion.
Debris from satellites, space launches and the International Space Station enters the atmosphere every few months, but only one person is known to have been hit by any of it: American woman Lottie Williams, who was struck but not injured by a falling piece of a US Delta II rocket while exercising in an Oklahoma park in 1997.