Chinese space lab expected to re-enter on Sunday night

The European Space Agency (ESA) has said that the Chinese defunct space lab, Tiangong-1, will re-enter Earth's atmosphere on Sunday night.

The Paris-based agency, which is managing the international campaign to follow the laboratory's fall, said on Saturday that the time and place of its re-entry continues to be a "highly variable" prediction affected by the changing solar activity, reported Efe news.

According to the agency, the chances of someone being hit by a piece of the space lab is 10 million times less than the annual probability of being hit by lightning.

ESA, which has a department specialising in space debris, recalled that at first the space ship's controlled re-entry into Earth's atmosphere was planned once its useful life was over, but Tiangong-1, which was launched in 2011, stopped functioning in March 2016.

Its re-entry into the atmosphere, therefore, will not be controlled and according to the latest calculations, it could occur between the latitudes of 43 degrees north and 43 degrees south, which includes a large part of the planet.

The Tiangong-1 will disintegrate during its re-entry and only a few parts of it will survive the process and reach Earth's surface, which, ESA noted, is largely covered with water or is uninhabited.

"The space lab will mostly be burnt up in the atmosphere and it's highly unlikely to cause any damage on the ground," Xinhua cited an article published by China Manned Space Engineering Office (CMSEO) as saying.

The re-entry process is usually divided into three phases. During the first phase, the atmospheric drag would rip solar arrays, antennas and other external parts off a spacecraft at an altitude of about 100 kilometres.

As it continues to fall, the main structure of the spacecraft would be burnt or explode from increasing heat and friction. It normally disintegrates at an altitude of about 80 kilometres.

The fragments would keep burning and most of them will be dissipated in the air. Only a small amount of debris will reach the ground, and will float down at a very slow speed due to their small mass.

The principal part of the space ship measures 10.4 metres long and is made up of two cylinders of approximately the same length, together with two solar panels of three by seven metres each.

Weighing less than 8.7 tonnes, it is much smaller than other objects that have entered the atmosphere in an uncontrolled way in the history of space flights. The record up to now was set by Skylab, which weighed 74 tonnes.

--IANS

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