In response to foreign media concerns that “Tiangong-1” has lost control and will crash into the Earth, Chinese space experts said the Tiangong-1 is expected to crash in the first half of this year and will be destroyed after falling into the atmosphere and the remaining wreckage will fall into the designated sea area. Harm the ground.
Temple One is China’s first target aircraft, launched on September 29, 2011, has been with the Shenzhou 8, 9, 10 spacecraft rendezvous and docking. On March 16, 2016, Temple One fully completed its mission to formally terminate its mission.
Science and Technology Daily reported that China Aerospace Science and Technology Group, the fifth chief architect of space laboratory system Zhu pointed out that China has been monitoring the Temple One, is expected to make it fall in the first half of this year. It crashes when it crashes into the atmosphere and the remaining debris will fall into the designated area without jeopardizing the ground.
Currently, the Chinese manned space engineering office is still regularly released the latest orbit status. The latest bulletin shows that on December 17-24, 2017, Temple One runs on an orbit with an average height of about 286.5 kilometers (the height of peri-site is about 272.6 kilometers, the height of apogee is about 300.4 kilometers and the inclination is about 42.85 degrees) Morphology did not anomalies.
Questioning whether the Chinese government has the ability to “precisely control” the fall of the Tiangong-1 on the outside world. The report said that letting large spacecraft accept controlled fall is a door technology, and is similar to returning satellites or spacecraft to the atmosphere. China has extensive experience.
Pang Zhihao, a Chinese aerospace expert, pointed out that when a controlled fall takes place, a brake command must be issued to the spacecraft at an appropriate position, angle and attitude so as to generate an appropriate braking force to leave the current orbit and enter the falling area trail of. In this regard, all aspects need careful calculation.
Taking Temple One as an example, Pang said that when a controlled fall occurs, it must first be adjusted to a state of “reverse,” and the original backward propeller should be turned to the front and the brake should be released from its original track through thrust reversals.
After entering the atmosphere, the ground command center also needs to control the attitude of the spacecraft. Pang Hao said that different from the round-trip spacecraft, controlled fall spacecraft to maintain the maximum resistance to the gesture to try to burn in the atmosphere.
The report said that Tiangong-1, weighing about 8.5 tons, is much smaller than the 20-ton Mir space station and the Salute series space station. As long as it burns well, it will not leave too many remains.
In addition, China has conducted many precise returns to control the Shenzhou spacecraft and return satellites. On November 1, 2014, the third phase of the lunar exploration project in China returned to the flight test unit and returned from lunar orbit at the second cosmic velocity (the lowest speed of gravity off the earth at a speed of 11.2 kilometers per second) “Way to slow down, and finally fell to a predetermined location in Inner Mongolia.
In the controlled fall, China in 2009, 400000 kilometers apart control Chang’e I satellite hit the moon rich sea area. In September 2017, the spacecraft was again controlled to depart from the orbit. After two braking attempts, the spacecraft was burned into the atmosphere and the debris fell into a deep-sea area in the South Pacific remote from the mainland.
source from : technews.tw
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