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New Long March 5B Uncontrolled Reentry Tracked by Aerospace's Experts

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Re: New Long March 5B Uncontrolled Reentry Tracked by Aerospace's Experts

#101
post #61
post #58

Earlier quoted context omitted.

Such decisions cannot be made in a binary, absolutist way. Risk is reduced to some minimal level, not to zero. The risk here was very low.

And you know this risk was low because? Are you saying that you had more information on this than those agencies tracking the reentry? Otherwise you are speculating.

NASA's policy is to avoid uncontrolled reentry when the chance of killing someone is greater than 10^-4.

How valuable is that? We can determine that using the concept of the "statistical value of a human life". For example, the NRC assigns a human life a statistical value of $9M when determining of the cost of some nuclear safety improvement is justified. This is similar to the value used for determining if traffic safety improvements are worthwhile or if medical procedures are justified.

Multiplying, this is saying that it's unacceptable that the cost of a reentry be as a little as $900. This seems quite unreasonable: the cost of avoiding uncontrolled entry should often be much higher than this. And indeed, if you look at what NASA actually does, it often gives wavers of this requirement. This tells me the requirement is of dubious legitimacy, existing more for PR purposes than because it's good policy.

I doubt the Chinese care about the political optics enough to waste their time avoiding such a low expected cost outcome. Nor should airlines cancel flights to avoid something like that either -- the cost far exceeds the expected benefit.

Re: New Long March 5B Uncontrolled Reentry Tracked by Aerospace's Experts

#102
post #91

Earlier quoted context omitted.

It may not say it directly but the implication is clear, in that uncontrolled re-entry is dangerous to anything that might cross its path, including people, infrastructure, planes, and pigeons if they’re really unlucky.

That's not a sufficient argument. Something can be dangerous without being sufficiently dangerous to warrant any personal action. In this case, I believe if you calculate you will find the chance of an aircraft being damaged was so extremely slight that it wasn't worth delaying any flight.

[deleted]

Re: New Long March 5B Uncontrolled Reentry Tracked by Aerospace's Experts

#103
post #99

Earlier quoted context omitted.

What? Ignoring my comment and instead writing an incoherent rant twice-in-a-row really is bizarre. If there isn't a substantive point, or a clarification, to add, then don't reply and save your credibility. Anyways, I will explain again: Local reporting is the only potential source of evidence that anything fell on land at all. Not just for this case, but for nearly all debris cases. Anyone not in the local area woul…

To clarify the things you are ignoring: 1. Multiple well known and respected experts like Dr.Marco Langbroek and Jonathan McDowell tracked the rocket heading at a low angle over the Atlantic towards Cote d'Ivoire 2. Multiple governments including the US released statements saying they believe it went down there 3. An infrasound station on the ground there picked up the debris traveling overhead[1]. What more do you r…

Okay this seems somewhat more substantive though still a tangent of my original point that The Verge linked to a clearly untrustworthy source, which impacts their credibility.

Re: New Long March 5B Uncontrolled Reentry Tracked by Aerospace's Experts

#104
post #54

This is deeply irresponsible by the CSNA and is a disaster just waiting to happen on the ground. Is it laziness on the part of their flight team or just crass disregard for others safety?

It's economically hardnosed of them. It's on average cheaper to just take the chance and pay off damages if someone is injured or killed. Remember, the highest chance of fatality will be in densely populated lower latitude countries where the monetary cost of killing someone is lower.

It's simple if you use the Foreign Death Conversion Chart.

Re: New Long March 5B Uncontrolled Reentry Tracked by Aerospace's Experts

#105
post #99

Earlier quoted context omitted.

To clarify the things you are ignoring: 1. Multiple well known and respected experts like Dr.Marco Langbroek and Jonathan McDowell tracked the rocket heading at a low angle over the Atlantic towards Cote d'Ivoire 2. Multiple governments including the US released statements saying they believe it went down there 3. An infrasound station on the ground there picked up the debris traveling overhead[1]. What more do you r…

Okay this seems somewhat more substantive though still a tangent of my original point that The Verge linked to a clearly untrustworthy source, which impacts their credibility.

It’s just some shitty local news outlet… I wouldn’t except most real papers to have a reporter who just knows a guy in that random little village.

If you speak French there are some other sources from larger regional papers, but I didn’t dig in too much, and my vocabulary doesn’t cover rocket words.

Re: New Long March 5B Uncontrolled Reentry Tracked by Aerospace's Experts

#106
post #19

Earlier quoted context omitted.

Neither. There just isn't that big a fraction of the earth's surface that's inhabited. You should regard this similarly to someone firing a gun into the air.

If you fired a gun into the air in the UK I'm pretty sure that a) You'd get in pretty serious trouble for it by itself and b) if you killed or injured someone that trouble would be significantly multiplied to the extent you'd end up in prison. I think it would be a manslaughter charge.

Right. Just as with the space debris, it should be illegal and prosecuted but it's quite unlikely to actually kill someone when only performed a few times. It's the habit you have to prevent.

Re: New Long March 5B Uncontrolled Reentry Tracked by Aerospace's Experts

#107
post #92

Earlier quoted context omitted.

There is a difference between the chance of debris hitting a person and the chance of it hitting any person. Regardless of the probability, there is a problem with choosing that risk for someone else without their consent.

> Regardless of the probability, there is a problem with choosing that risk for someone else without their consent. Every action we take imposes risks on other people. Economic models are one of our best tools to use in weighing these risks against each other and the costs of mitigating them. (OTOH: China's cost to mitigate most of these risks would be, generally, pretty small... It's a cost of being in the space gam…

There is an enormous gulf between most kinds of harm one can do to someone in a different country on the other side of the world and dropping part of a rocket on them.

Nobody agrees a priori to China’s assessment of their economic value.

Re: New Long March 5B Uncontrolled Reentry Tracked by Aerospace's Experts

#108
post #99

Earlier quoted context omitted.

What? Ignoring my comment and instead writing an incoherent rant twice-in-a-row really is bizarre. If there isn't a substantive point, or a clarification, to add, then don't reply and save your credibility. Anyways, I will explain again: Local reporting is the only potential source of evidence that anything fell on land at all. Not just for this case, but for nearly all debris cases. Anyone not in the local area woul…

To clarify the things you are ignoring: 1. Multiple well known and respected experts like Dr.Marco Langbroek and Jonathan McDowell tracked the rocket heading at a low angle over the Atlantic towards Cote d'Ivoire 2. Multiple governments including the US released statements saying they believe it went down there 3. An infrasound station on the ground there picked up the debris traveling overhead[1]. What more do you r…

You have accused myself and MichaelZuo of "taking the word of the Chinese government" and "carrying water for the CCP" respectively (based on nothing), and yet you continue to hold up the word of the US government and military as reliable and authoritative regarding their primary geopolitical rival.

Re: New Long March 5B Uncontrolled Reentry Tracked by Aerospace's Experts

#109
post #30

Earlier quoted context omitted.

That’s not how the stats work. There’s a 71% chance it lands in water this time (and every time). If you flip heads 3 times in a row, it doesn’t mean you’re more likely to flip tails next time.

My understanding is that this is more of the equivalent of making sure you land on heads all 3 times. In that case it’s a 1/8th on 3 coin flips, no?

> My understanding is that this is more of the equivalent of making sure you land on heads all 3 times

Yep!

Re: New Long March 5B Uncontrolled Reentry Tracked by Aerospace's Experts

#110
post #92

Earlier quoted context omitted.

> Regardless of the probability, there is a problem with choosing that risk for someone else without their consent. Every action we take imposes risks on other people. Economic models are one of our best tools to use in weighing these risks against each other and the costs of mitigating them. (OTOH: China's cost to mitigate most of these risks would be, generally, pretty small... It's a cost of being in the space gam…

There is an enormous gulf between most kinds of harm one can do to someone in a different country on the other side of the world and dropping part of a rocket on them. Nobody agrees a priori to China’s assessment of their economic value.

Even if you take the US assessment of the value of a person's life it probably doesn't make sense for China to do anything to control the entry of these stages.
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