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Old 18-12-2018, 12:58 PM
gary
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One analysis of the odd's of SpaceX’s Internet satellites will hit someone are high

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Originally Posted by Mark Harris, IEEE Spectrum, 17 Dec 2018
Here Are the Odds That One of SpaceX’s Internet Satellites Will Hit Someone

The FCC says hundreds of fragments from the Starlink constellation could reach the Earth’s surface every day.

The chance that SpaceX’s planned Starlink satellite constellation will cause an injury or death is 45 percent every six years, according to an IEEE Spectrum analysis of figures submitted by the company to the U.S. Federal Communications Commission.

Elon Musk hopes the nearly 12,000 satellites in the constellation will eventually carry half of all Internet traffic. The satellites will use laser and radio links to provide fast, cheap Internet access to people all over the world—and the associated service fees could help Musk fund his dream of colonizing Mars.

But what goes up, must come down, and the sheer scale of SpaceX’s orbital network means that it may only be a matter of time before the world sees the first injury or death from a plummeting satellite.
Quote:
Originally Posted by Mark Harris, IEEE Spectrum, 17 Dec 2018
SpaceX estimates that several kilograms of each 386-kilogram Starlink could reach the Earth’s surface with sufficient energy to harm or kill someone. NASA has fixed this figure at 15 joules—about the same wallop as a baseball traveling at 51 kilometers per hour. Depending on the satellite’s configuration, iron thruster components, stainless steel reaction wheels, or silicon carbide mirrors could survive the journey from orbit to your head.

When SpaceX plugged the numbers into NASA’s Debris Assessment Software, the package calculated that there was, at most, a 1 in 18,200 chance that an individual satellite in its LEO orbital shells would hurt or kill someone. VLEO satellites were generally slightly riskier, with up to a 1 in 17,400 chance. All figures are handily less than the 1 in 10,000 figure that NASA has adopted as a standard, and that U.S. and European space agencies require for space missions.

However, the FCC didn’t stop there. In March and June 2017, the FCC calculated the aggregate risk to humans from the entire constellation. Assuming the 11,927 satellites are launched on a regular basis, they will fail in the same way. Starting around six years from the first launch, an average of five satellites a day will reenter the Earth’s atmosphere, each with a tiny chance of failing to completely burn up, resulting in a part that could hit someone.

But with more than a thousand satellites falling a year, those tiny risks add up. The FCC figured out that, over their lifetime, satellites in the LEO shells posed a 1 in 5 risk of hurting or killing someone, and the VLEO satellites carried a 1 in 4 risk. IEEE Spectrum’s calculations using SpaceX’s most up-to-date information suggests that the overall risk of debris from the constellation causing an injury or death will be 45 percent.

This means that NASA’s software says that it is nearly as likely than not, that one of the Starlink satellites will injure or kill someone, about every six years.
Article here :-
https://spectrum.ieee.org/tech-talk/...ll-hit-someone
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Old 18-12-2018, 02:06 PM
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multiweb (Marc)
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A Starlink satellite never strikes twice.
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Old 24-12-2018, 04:25 PM
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Won’t be the first injury of this kind - there are examples of meteorites that have struck animals, various objects and yes, people.
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Old 24-12-2018, 08:18 PM
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sn1987a (Barry)
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What are the statistics on the projected number of lives saved every year with the deployment of this system and which statistical life is worth more?.
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Old 28-12-2018, 05:51 PM
Wavytone
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Liveable saved ? Nil, I would think. Lives lost ? A few, while building it and MANY more during its operational life.

Safe ? No. If the Australian WHS Act were applied in the US this project would be stopped pretty quickly as being unsafe and in conflict with the law.

1 in 18,200 is not very good at all - it’s comparable to the likelihood of being struck by lightning - and that happens to several people a year in Australia, never mind the rest of the world.

Environmentally friendly ? No way.

As an engineer I find the “techie” types remarkably ignorant when it comes to safety, through-life maintenance and worse still, an environmentally safe disposal of a system after its useful life has finished.

Last edited by Wavytone; 29-12-2018 at 11:40 AM.
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Old 28-12-2018, 06:14 PM
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Quote:
Originally Posted by Wavytone View Post
...
As an engineer I find the “techie” types remarkably ignorant when it comes to safety, through-life maintenance and worse still, an environmentally safe disposal of a system after its useful life has finished.

Ditto.

And add to this mix "entrepreneur" factor (making money), life could become really dangerous for many (of us mere mortals)
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