Jun 20, 2019 08:00:00

Movie that actually tried 'A satellite has a possibility to hit our brain sky?'

As of June 2019, there are

more than 5000 satellites in the Earth's satellite orbit. In theory, most of the satellites should do their job and fall into the atmosphere and burn up, but I do not know if I actually do. So, the European Space Agency (ESA) is conducting an experiment to see what happens to the artificial satellite when it reproduces the time of the atmosphere entry where the temperature reaches 10,000 degrees, and the movie containing the appearance is released.

Melting a satellite, a piece at a time / Clean Space / Space Safety / Our Activities / ESA
http://www.esa.int/Our_Activities/Space_Safety/Clean_Space/Melting_a_satellite_a_piece_at_a_time

You can see in the following movie how a satellite component is being vaporized by a plasma jet with temperatures as high as several thousand degrees.

Melting a piece of a satellite-YouTube


When the movie starts, the monitor in the laboratory will show the satellite parts in a blue flame. In the upper right corner of the monitor screen, high temperature plasma is being ejected, and in the lower right corner, an image of the object seen from the side is displayed.

Shortly afterward, the exterior of the parts started to flow like a cheese in a buzz and bubbles.

As it is heated further, the inside of the parts also begins to melt this time ...

It became smaller while looking at it.

This is the situation after the experiment.

What was used in this experiment is the

magnetic torquer that controls the attitude of the satellite. The size of the parts is not as large as 4 cm by 10 cm, but because they are made of carbon fiber reinforced polymer composite material, they are one of the strongest parts among satellites. In the movie, in order to observe in detail how this magnetic Toruca behaves when entering the atmosphere, it was heated to several thousand degrees with a hypersonic plasma jet.

According to ESA's Tiago Soares, who led the experiment, “Testing in various settings eventually showed that the magnetic Toruca will evaporate almost completely, but that process is inconsistent with the previously predicted results. The data was also recorded. '

In fact, although extremely rare, there are cases where satellite and launcher parts have fallen to the earth without being burned out. One of them is the main propulsion fuel tank for the Delta II rocket that dropped to Texas on January 22, 1997. There was no particular damage caused by the fall, but because it is a mass of stainless steel weighing 250 kg, it could have been a catastrophe if it fell into a city area or a private house.

Also, in addition to the magnetic torquers used in the first experiment, parts of artificial satellites such as optical equipment, propellant pressure tanks and gyroscopes can endure into the atmosphere.

However, as mentioned above, the case where the satellite does not burn out is extremely rare, and it is said that even if it remains unburned, the possibility of causing damage is low. Even when China's Space Station “ Amamiya No. 1 ” falls out of control and reenters the atmosphere in April 2018, “The probability that fragments will harm the human body is one in a trillion” “Segments are someone The probability is estimated to be one-tenth of one millionth that a person is likely to be struck by lightning in one year, so it is better to pay attention to lightning strike information than worry that satellites will shake overhead It seems that it is better.