[HN Gopher] New Long March 5B Uncontrolled Reentry Tracked by Ae...
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New Long March 5B Uncontrolled Reentry Tracked by Aerospace's
Experts
Author : graderjs
Score : 63 points
Date : 2022-11-06 10:44 UTC (12 hours ago)
(HTM) web link (aerospace.org)
(TXT) w3m dump (aerospace.org)
| throwaway4good wrote:
| The remains of the rocket have landed somewhere in the pacific
| ocean.
| dvt wrote:
| My flight from the Canary Islands to Portugal was delayed for ~2
| hours because of this. Everyone was a bit on edge and it seems
| extremely irresponsible, dangerous, and wasteful.
| [deleted]
| pfdietz wrote:
| That's a major overreaction.
| speedylight wrote:
| Better be safe than sorry. Uncontrollable entry is actually
| uncontrollable and anything could happen.
| pfdietz wrote:
| 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.
| elteto wrote:
| 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.
| Denvercoder9 wrote:
| Those agencies tracking reentry also are of the opinion
| that the risk to any individual is negligble: see e.g.
| https://twitter.com/jeff_foust/status/1587858672373403654
| cfraenkel wrote:
| Duh - it's going to come down in one place. The odds of
| "any" one individual being in that exact place is
| negligible. On the other hand, where it comes down is
| under it's flight path, which is a predictable series of
| points on a line, ordered in time. If you (or your
| airplane) happen to be in one of those points at the same
| time, your odds go way way up (for a few minutes). The
| flight in question was no doubt going to be under the
| boosters flight path. You know this ahead of time, and
| you can obviously delay with minimal consequence (minimal
| compared to an airliner being hit with falling debris,
| anyway.) In that situation, it'd be negligent to say
| 'screw it, the odds are in our favor, lets just ignore
| it.'
| dvt wrote:
| Not according to the ESA[1], NASA[1], Portugese airspace
| authorities, or our captain. Or my dad, for that matter, who
| works for NASA (some of his projects specifically involve
| space debris cleanup). But thanks for your input, random
| internet stranger.
|
| [1] https://www.space.com/nasa-esa-space-chiefs-condemn-
| china-ro...
| pfdietz wrote:
| Nowhere in that rather bombastic report did I see any
| argument justifying altering any airline flight due to the
| reentry.
| speedylight wrote:
| 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.
| pfdietz wrote:
| 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.
| LatteLazy wrote:
| fnordpiglet wrote:
| I like how you squeezed a crazy conspiracy theory that's been
| largely dismissed in at the end. Slick.
| LatteLazy wrote:
| I don't actually think COVID was leaked from the lab. I just
| think that Chinas refusal to do basic food hygiene, despite
| multiple zoonotic diseases already arriving makes it equally
| criminal...
| tostonescon wrote:
| Genuinely curious - why is China doing uncontrolled reentry any
| different? As far as I understand it the vast majority of rockets
| have uncontrolled re-entry, save for spaceplanes, falcon 9, and
| more recently electron.
| mrweasel wrote:
| > As far as I understand it the vast majority of rockets have
| uncontrolled
|
| I don't think that's true anymore. There's a Danish radio
| program[1] that talked about this and apparently China is the
| only country/operator that still have uncontrolled reentry
| rocket stages. Everyone else have committed to controlled
| reentry.
|
| Looking that the possible places where the rocket can hit
| populated areas. It looks like they went out of their way to
| ensure maximum coverage of Africa. Reentry a little earlier and
| they would have been almost ensured that it would hit the
| Atlantic Ocean.
|
| [1]: https://www.radio4.dk/program/den-nye-
| rumalder/?gid=43389&ti...
| tostonescon wrote:
| https://www.nature.com/articles/s41550-022-01718-8
|
| >In 2020, over 60% of launches to low Earth orbit resulted in
| a rocket body being abandoned in orbit
|
| >In the USA, the Orbital Debris Mitigation Standard Practices
| (ODMSPs) apply to all launches and require that the risk of a
| casualty from a reentering rocket body is below a 1-in-10,000
| threshold4. However, the US Air Force waived the ODMSP
| requirements for 37 of the 66 launches conducted for it
| between 2011 and 2018, on the basis that it would be too
| expensive to replace non-compliant rockets with compliant
| ones
|
| I do think China's space program is more irresponsible than
| USA/EU launches based on some of the debris fall, but blaming
| uncontrolled re-entry seems like the wrong thing here
| mlyle wrote:
| It's that it's uncontrolled re-entry of a giant first
| stage. No one does anything like that except China.
| tkanarsky wrote:
| Several nuances:
|
| "Controlled reentry" isn't necessarily synonymous with "booster
| recovery". Most rockets have a way to deorbit the upper stage
| once its job is done, either by firing the main engine
| retrograde, or using a small dedicated deorbit motor. By firing
| the motor about half an orbit before the projected reentry
| point, you can control exactly when and where the stage will
| reenter the atmosphere, hence controlled reentry.
|
| Second, the Long March 5B is somewhat unique among rockets in
| that its large main stage stays with the payload all the way
| until orbital insertion. Most other rockets drop a large
| majority of their bulk long before it has enough energy to stay
| in orbit for any appreciable amount of time. Probably the
| closest comparison in this category is the space shuttle's big
| orange external tank, as it provides fuel for the main engines
| until just a hair below orbital velocity, but it's subsequently
| jettisoned and the orbit is completed using the shuttle's
| onboard thrusters.
|
| So you have a combination of (no deorbit capability) and (big
| tank floating in orbit) that results in (big tank crashing down
| at an arbitrary location whenever it feels like coming down to
| earth).
| Simon_O_Rourke wrote:
| 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?
| holoduke wrote:
| This is China in a nutshell. They don't give a fuck about
| what's happening around them. Unless it Harms their economic
| interest. Other than that they do not have any compassion for
| safety, environment etc. It might change in the future, but
| with this crazy regime I doubt people ever gonna care about it.
| fwipsy wrote:
| Let's not make generalizations about a country of 1b+ people
| based on one aspect of their space program. You could easily
| draw an equally unflattering image of the US or any other
| nation if you're willing to extrapolate from a single
| datapoint like that.
| ghufran_syed wrote:
| charitable interpretation: "china" = "chinese government"
| in the statement you are responding to.
|
| I try to use the latter form myself when talking about
| nation state actions to aid people who have trouble
| translating from one to the other, but it doesn't seem
| _that_ hard to figure out in this case. otoh e.g. "the
| chinese value education highly" is a bit more ambiguous
| since the statement is true for both the chinese people
| _and_ the chinese goverment
| fwipsy wrote:
| This interpretation is a little better, but I think my
| objections still apply.
| tgsovlerkhgsel wrote:
| There are plenty of other data points that line up with
| this one though.
| [deleted]
| [deleted]
| MonkeyMalarky wrote:
| I'd chock it up under crass disregard for others safety. They
| drop boosters on their own people and don't care:
| https://arstechnica.com/science/2019/11/china-keeps-dropping...
|
| >China's defiance of this norm has resulted in some horrific
| scenes as its boosters have periodically crashed into villages.
| dangle1 wrote:
| And possibly a fairing half dropped onto a populated area
| from a different launch yesterday:
|
| https://twitter.com/cnspaceflight/status/1589289240776839168
| tgsovlerkhgsel wrote:
| "It's fine, we did tell everyone to evacuate" - I wonder
| how many actually evacuate / can afford to evacuate every
| time.
| pfdietz wrote:
| 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.
| supertrope wrote:
| Two thirds of the planet is water. Most land is uninhabited.
| Population and property is concentrated in cities. The chance
| of debris hitting you is less than a lightning strike.
| mcculley wrote:
| 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.
| mlyle wrote:
| > 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 game, IMO.)
| elteto wrote:
| The won't even pay for any damages. They would never allow
| one of these to reenter over US airspace or other large,
| powerful countries. But if it falls in the middle of some
| small country, tough luck getting paid for damages.
| pfdietz wrote:
| They are signatory to a treaty that requires them to pay
| for damages. And they had no control over where this
| booster came down (except that it would come down between
| 41S/41N, roughly), so your "they would never allow" is
| incorrect.
| supertrope wrote:
| China signed the Outer Space Treaty. Your rocket your
| damage your bill.
| chihuahua wrote:
| But how is anyone going to collect on the bill, if China
| doesn't want to pay?
| tgsovlerkhgsel wrote:
| Just quickly and quietly paying is likely cheaper than
| the international incident, the "China refuses to comply
| with treaty" headlines, and likely resulting souring of
| international relations.
| graderjs wrote:
| I agree. I'm all for China achieving things but this seems
| really inconsiderate and irresponsible. Dropping debris on
| populations is unacceptable as nearly happened over the last
| few years according to this story. Clashes with their
| environmental stance and desire to be responsible global power.
| Why?
| zasdffaa wrote:
| I can't answer your question but be aware that you are
| looking through a very western lens, and probably US-centric
| lens particularly, and other cultures can see things in very
| different way, starting with assumptions (or simply unthought
| practices) that you have nothing to compare with.
| cycrutchfield wrote:
| Yes
| throwaway4good wrote:
| It is a calculated risk; perhaps similar to what have been done
| by the US and Russia when their space ambitions were at their
| highest.
| iwillbenice wrote:
| cycrutchfield wrote:
| Ah, the good old "whatabout the US did it 50 years ago
| therefore we can do it today". Also used to justify all sorts
| of atrocities, imperialism, IP theft, etc.
| FpUser wrote:
| >"the US did it 50 years ago therefore we can do it today"
|
| The US / or other countries for that matter "did it XXX
| years ago" to advance their goals and get more prosperous
| at the expense of the others. If you want to punish
| countries for doing similar things now it is totally ok, as
| long as you punish the same crimes committed earlier. The
| crime must be paid for. This of course will never happen so
| when you are trying to tell other countries that they
| should not be doing things that you've done yourself and
| got away with the only reasonable answer you can expect is
| fuck you very much.
| cycrutchfield wrote:
| If you punish every country retroactively for crimes
| committed ages ago, every country would cease to exist.
| There is no country without blood on its hands,
| historically. This is like saying that you should go to
| jail because your grandfather jaywalked 80 years ago,
| which was not a crime back then but is now.
| FpUser wrote:
| Starting with the people who are still alive would be a
| good idea. I think you can find plenty of people
| responsible for modern wars/other crimes against humanity
| after WWII. The end of WWII also marks the "official"
| punishment as in Nuremberg trials.
|
| This is not "your grandfather jaywalked" case but pretty
| rational I think. But you know where it will end up when
| for example our "leader" the US had declared that it does
| not recognize ICC, and will take any measures starting
| with sanctions and including force if it ever gets
| prosecuted. The other countries take it as an example.
| Cant blame them for not buying into that do as I say
| bullshit.
| throwaway4good wrote:
| I also think there is a somewhat hyperbolic anti-China
| sentiment in the commentary on all of this. Plus a perhaps
| frustration at the US Space authorities on the lack of
| communication from their Chinese counterpart, something of
| course they themselves are entirely to blame for.
|
| Anyway; the Chinese have done a few of these "uncontrolled
| reentries" now. All crashing into the ocean; so they are
| either very lucky or it is not so uncontrolled after all.
| throwaway4good wrote:
| Chances of not hitting land after n completely random
| reentriees is (71%)^n. That drops fairly fast.
| jsjohnst wrote:
| You're down into single digit percentage by the time n
| hits 7 in that case. What are we at, 4th re-entry? So 25%
| chance it lands in water given your formula. Given
| Chinese superstitions around the number 4, let's hope
| this one has a safe and wet splashdown.
| gerad wrote:
| 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.
| tehbeard wrote:
| That's a five year-olds uninformed take because you
| assume it could land anywhere on earth, hence 71%
| water....
|
| Orbital mechanics does not work that way (except for a
| polar orbit). It's covering a particular band of the
| surface that it could land on if uncontrolled.
| anomaloustho wrote:
| 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?
| tannedNerd wrote:
| That is just a bold faced lie that 2 seconds of googling
| would prove you wrong.
|
| https://arstechnica.com/science/2019/11/china-keeps-
| dropping...
|
| https://www.newsweek.com/photos-show-rocket-debris-india-
| chi...
|
| Anyway; I don't know if you are an Astro turfing troll or
| just that brainwashed.
| k_paleologos wrote:
| Reports suggest that they require only 3 launches in this
| configuration LM5B where the core stage falls back, for
| the construction of their station. They might have made
| the assumption that chances of damage due to debris is
| very low considering that only 3 launches are to happen
| with this configuration.
|
| In case even if there is damage on the ground, there are
| treaties that govern the liabilities in case.
|
| It would be interesting to know why they technically
| chose this particular way of doing it, but the discussion
| seems too hyperbolic for that.
| sp332 wrote:
| Now that the design has been proved out, they're not
| going to stop doing it.
| vasco wrote:
| > In case even if there is damage on the ground, there
| are treaties that govern the liabilities in case.
|
| If it fell on your house with you sleeping inside I'm
| sure the liabilities treaties would make your family be
| totally ok with it.
| FpUser wrote:
| When governments, including your own make these kinds of
| decisions they do not give a flying fuck about your
| particular family. They only car if it will cost them
| election, loosing giant lawsuit etc.
| justinclift wrote:
| Kind of wonder how it'd go, if the rocket accidentally
| took out the head of a mafia family or some equally
| dangerous group. ;)
| signatoremo wrote:
| Regardless of the sentiments of the criticism, the fact
| is it's irresponsible on the China part. You seem to
| downplay that fact. If you want to be balanced that's the
| first thing you'd need to acknowledge. And no, it is
| uncontrolled. No questions about it.
|
| No matter how small the risk, countries have to make
| plan, allocate resources, keeping track of the rocket's
| path, in case it does happen. They can't just pray. Spain
| briefly closed part of their airspace, delaying 300
| flights. Who is responsible for that?
|
| https://www.reuters.com/lifestyle/science/spain-briefly-
| clos...
| philwelch wrote:
| One of them hit Cote d'Ivoire.
| xtian wrote:
| Do you have a link to an official investigation/report on
| this?
| philwelch wrote:
| I don't have a primary source handy but there's tons of
| news reports. The Cote d'Ivoire crash was in May 2020.
| xtian wrote:
| I've looked at the news reports and as far as I've seen
| they only reference social media posts which seem to be
| inconclusive.
| [deleted]
| causality0 wrote:
| 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.
| wlll wrote:
| 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.
| lsllc wrote:
| In most areas of the US recklessly discharging a firearm
| into the air would also get you in serious trouble (even
| in rural areas) along with a (lesser) murder charge if
| you killed someone.
|
| FWIW, according to a study published by the National
| Library of Medicine, "celebratory gunfire" accounts for
| 4.6% of all stray bullet-related deaths and injuries:
|
| https://pubmed.ncbi.nlm.nih.gov/22743389/
| mozman wrote:
| Is there anything wrong with being anti PRC?
| fnordpiglet wrote:
| PRC != China or Chinese
| xenadu02 wrote:
| As if two wrongs somehow make it right!
|
| Uncontrolled re-entry of any debris likely to reach the
| ground without burning up is a bad idea. So is blowing
| anything up in orbit (creating huge hazards for other
| spacecraft).
|
| These are bad ideas no matter who does them and the fact
| that anyone did so in the past is not an excuse for
| continuing the bad behavior.
| lizardactivist wrote:
| I think pulling the whataboutism card may have worked in
| the past, but today people realize it's just a really bad
| defense for when you have nothing sensible to reply with,
| after facts, inconvenient truths, and plain hypocrisy has
| been pointed out.
|
| It's simply not the ace up the sleeve people think it is.
| ch4s3 wrote:
| The US and Russia didn't do this. Both space programs either
| used upper stages to boost into orbit or were small enough to
| burn up on reentry. The Long March 5B has a giant rocket 20
| metric ton that is too big to burn up and falls to Earth in
| an uncontrolled fashion.
| numpad0 wrote:
| 20 metric ton is roughly the same as Falcon Heavy center
| core(unloaded), for visual reference. It's not a random
| stage 2 left in orbit, it's the F9S1 coming down.
| throwaway4good wrote:
| I was referring to them taking calculated risks; not doing
| exactly the same thing.
| ch4s3 wrote:
| Dumping 20 tons of metal from orbit isn't a "calculated
| risk" its sloppy and dangerous. They could have built the
| rocket using 50 years of experience knowing this could be
| an issue, instead they just lie and say it will burn up.
| They already dropped one on a village.
| ghufran_syed wrote:
| the real issue is "what is the probability of human
| injury or death?" Is it 1% per launch? 0.01% 0.000001%
|
| The area of the earth's surface occupied by humans (not
| their stuff, but the people themselves) is around 8000
| km^2 (1m^2 per person) out of a total Earth surface area
| of 510 million km^2. so the probability is around 1.6E-5
| or 0.0016% per launch. This obviously doesn't account for
| the specific trajectory or population distribution, but
| gives us a rough order of magnitude.
|
| I would prefer they didn't do it also, and it definitely
| loses them international good will - but it's a pretty
| low (but non-zero) risk.
|
| [typo corrected]
| ch4s3 wrote:
| It's just a known issue that could be trivially avoided
| in the design phase. Even building for controlled reentry
| could have allowed them to accurately dump it in the
| ocean 100% of the time. It just super dick-ish to not do
| that and lie about every time you launch. The lie that
| the whole thing burns up on reentry is also super shitty
| and indefensible when these huge hunks of metal are
| trivially tracked by scientists and governments world
| wide.
| xtian wrote:
| > They already dropped one on a village.
|
| That sounds pretty serious. Was there any official
| investigation or just ambiguous pictures posted on social
| media?
| ch4s3 wrote:
| It happened in May of 2020. The debris landed in Cote
| d'Ivoire and the debris was spotted in it's way down by a
| local infrasound station. The debris was tracked in the
| atmosphere by multiple governments and there are photos.
| Google it for yourself.
| xtian wrote:
| I tried Googling for an official report or investigation
| but I couldn't find one. Do you know if any of these
| multiple governments issued one?
| ch4s3 wrote:
| Astro physicist Johnathan McDowell[1] was tracking it. I
| doubt the Cotes d'Ivoire did an official investigation
| due to their general lack of funds, and China denies that
| the Long March can even reenter the atmosphere so they
| didn't go check it out. Here's another story that
| references local reports[2]. An article from Ars quoting
| the US Space Force confirming entry over the Atlantic
| headed toward Cotes d'Ivoire[3].
|
| What more do you want?
|
| [1]
| https://twitter.com/planet4589/status/1260222397350887425
|
| [2] https://www.theverge.com/2020/5/13/21256484/china-
| rocket-deb...
|
| [3] https://arstechnica.com/science/2020/05/large-chunks-
| of-a-ch...
| xtian wrote:
| Just anything more conclusive than social media posts. An
| actual investigation into these reports and purported
| debris fragments.
|
| According to Wikipedia, Cotes d'Ivoire is one of the
| largest economies in West Africa, representing 40% of the
| total GDP of the Economic Community of West African
| States.
| ch4s3 wrote:
| There are numerous scientists and government agencies on
| the record making official press releases claiming to
| have tracked the rocket debris to an area of Cotes
| d'Ivoire. There are photos in Cotes d'Ivoire of wreckage
| consistent with the rocket. Why do you need an "official
| investigation"? Who would you trust to do that? Why are
| you taking the word of the Chinese government?
| MichaelZuo wrote:
| The Verge article links to a 'local news site'
| afriksoir.net that looks really shady, similar to
| clickbait spam sites.
|
| Registered on April 9th, 2019 with GoDaddy according to
| WHOIS.
|
| It's top story today is just commenting on some Ivorian
| politican's Twitter feed https://afriksoir.net/lobognon-
| junte-goita-integrite-mali-jo...
|
| And it's not linked to any established West African news
| organization.
|
| This took me about 10 minutes of digging to uncover. So
| if Verge thinks this is a credible source that really
| speaks volumes.
| ch4s3 wrote:
| Oh please, numerous scientists and governments tracked
| the Rocket debris going down over Cotes d'Ivoire. It
| landed somewhere there for sure. Analysts think the photo
| is credible. The preponderance of evidence points in a
| clear direction, we're not trying to convict someone of
| murder here.
|
| What do you think fell in Cotes d'Ivoire? What level of
| proof would be sufficient? Why are you so willing to
| believe the CCO line here? How have they demonstrated
| evidence to the contrary? If it burned up in reentry
| surely they have proof no? Where's there investigation?
| MichaelZuo wrote:
| You seemed to have entirely ignored my comment?
|
| The fact is that this shady site was linked as a source,
| and it's in fact the first external link in a decently
| long article.
| ch4s3 wrote:
| I hardly matters that the local reporting from the
| village isn't very good. The rocket is KNOWN to have gone
| down in that part of Cote d'Ivoire which you are
| willfully ignoring. What is more likely, that part of the
| rocket did land on the edge of that village in line with
| it's known ballistic trajectory or that it's fake and a
| bunch of scientists, governments, and groups watching
| objects in orbit are all part of a conspiracy?
|
| You're engaged in gish gallop jumping form one unrelated
| small critique to the next while ignoring that we know
| the rocket didn't burn up and a hunk of it did land in
| Cote d'Ivoire. We know China lied about it burning up on
| reentry.
|
| Why are you ignoring all of that? Why are you carrying
| water for the CCP on this?
| MichaelZuo wrote:
| What? Ignoring my comment and going into some tangential
| rant twice really undermines credibility.
|
| If you don't have a substantive point to add or a
| clarification to the original point then you can just not
| reply.
|
| If you genuinely believe local reporting can be easily
| dismissed 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.
|
| How else would anyone, not in the immediate vicinity,
| know if anything actually hit the ground?
| graderjs wrote:
| Maybe; but the optics are terrible.
| tjpnz wrote:
| You really should learn more about the history of the US
| program before making such ill informed statements.
| fnordpiglet wrote:
| nkrisc wrote:
| It was wrong then and is wrong now.
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