Below are some questions and answers about the station, its reentry, and the past and future of China's ambitious space program.
WHAT HAPPENS AND HOW BIG IS THE DANGER?
The European Space Agency predicts that the station will return to the atmosphere between Saturday morning and Sunday afternoon – an estimate it calls "very variable," probably because the ever-changing shape of the upper atmosphere affects the speed of the objects falling into it ,
The Chinese Space Agency's latest estimate is the re-entry between Saturday and Wednesday.
Western space experts say they believe China has lost control of the station. Zhu Zongpeng, chief developer of the Chinese Space Laboratory, denied that Tiangong was out of control, but did not say what China would do to control the ship's re-entry.
Based on the orbit of Tiangong 1, it will come to Earth somewhere between latitudes 43 degrees North and 43 degrees South, or about anywhere across most of the United States, China, Africa, Southern Europe, Australia and South America. Out of reach are Russia, Canada and Northern Europe.
Due to its size, only about 10 percent of the spacecraft will likely survive reentry into space, especially the heavier components such as the engines. The probability of someone being hit by rubble on Earth is less than one in a trillion.
Ren Guoqiang, spokesman for the Chinese Ministry of Defense, told reporters on Thursday that Beijing has informed the United Nations and the international community about Tiangongs 1-launch through multiple channels
HOW TOGETHER IS MAN -MADE SPACE DEBRIS?
Debris from satellites, space launches and the International Space Station enter the atmosphere every few months, but only one person It is known that it was hit by either of them: the American Lottie Williams, who was hit by a falling piece in 1997 Delta II rocket was hit while training in an Oklahoma Park.
The most famous is America's 77-tone Skylab crashed through the atmosphere in 1979, scattering debris near the city of Perth in southwestern Australia, which seized $ 400 for garbage.
The dissolution of the Columbia Space Shuttle in 2,003 killed all seven astronauts and sent more than 80,000 debris on a large strip of the southern United States. No one on the ground was hurt.
In 2011, the NASA Atmospheric Research Satellite was considered a slight public risk when it came to Earth 20 years after its launch. Wreckage of the 6-ton satellite landed in the Pacific Ocean and caused no damage.
China's own space program was a matter of grave concern after a missile killing a Chinese satellite that was no longer operational in 2007 and a potentially dangerous debris cloud.
WHAT IS TIANGONG 1 AND WHAT IT HAS BEEN USED FOR?
Tiangong 1 was launched in 2011 and was China's first space station that served as a pilot platform for larger projects such as the Tiangong 2 launched in September 2016 and a future permanent Chinese space station
The station, whose name translates to "Heavenly Palace" That is, hosted two manned missions that included China's first female astronaut and served as a test platform for perfecting docking procedures and other operations. The last crew left in 2013 and the contact was interrupted in 2016. Since then, it has been increasingly observed from Earth while being monitored.
The station had two modules, one for their solar cells and motors, and one for an astronaut couple to live in and perform experiments. A third astronaut slept in the Shenzhou spacecraft docking at the station, which also included personal hygiene and food preparation facilities.
HOW EXTENDS CHINA'S SPACE PROGRAM?
Since China's first Crewed Mission in 2003 – to become only the third country after Russia and the US – it has embarked on increasingly ambitious projects, including a spacewalk and the landing of its Jade Rabbit Rover on the Moon.
China today operates the Tiangong 2 Precursor Space Station facility, while the 20 ton core module of the base station will be launched this year. The completed 60-tonne station is scheduled to go into operation in 2022 and remain operational for at least a decade.
China was excluded from the 420-tonne International Space Station, mainly due to US legislation that prohibits such cooperation and concerns about the Chinese military connections of the space program. China's space program is still very secret and some experts have complained that a lack of information about the design of Tiangong 1 makes it difficult to predict what might happen after its reentry.
A mission to land another rover on Mars and return samples will start in 2020. China also plans to become the first country to land a probe on the other side of the moon.
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