Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

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

aerospace.org

Post reply on HN
Print view View original

41–50 of 111 posts

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

#41

Post by tehbeard »

gerad wrote: post #30
jsjohnst wrote: post #25

Earlier quoted context omitted.

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.

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.

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.

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

#42

Post by fwipsy »

holoduke wrote: post #27
Simon_O_Rourke wrote: post #2

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?

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.

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.

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

#43

Post by ghufran_syed »

fwipsy wrote: post #42
holoduke wrote: post #27

Earlier quoted context omitted.

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.

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.

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

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

#44

Post by xtian »

philwelch wrote: post #38
throwaway4good wrote: post #13

Earlier quoted context omitted.

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…

One of them hit Côte d’Ivoire.

Do you have a link to an official investigation/report on this?

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

#45

Post by numpad0 »

ch4s3 wrote: post #28
throwaway4good wrote: post #8

Earlier quoted context omitted.

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.

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.

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.

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

#46

Post by ch4s3 »

xtian wrote: post #40
ch4s3 wrote: post #37

Earlier quoted context omitted.

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.

> They already dropped one on a village. That sounds pretty serious. Was there any official investigation or just ambiguous pictures posted on social media?

It happened in May of 2020. The debris landed in Côte 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.

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

#47

Post by xtian »

ch4s3 wrote: post #46
xtian wrote: post #40

Earlier quoted context omitted.

> They already dropped one on a village. That sounds pretty serious. Was there any official investigation or just ambiguous pictures posted on social media?

It happened in May of 2020. The debris landed in Côte 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.

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?

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

#48

Post by philwelch »

xtian wrote: post #44
philwelch wrote: post #38

Earlier quoted context omitted.

One of them hit Côte d’Ivoire.

Do you have a link to an official investigation/report on this?

I don’t have a primary source handy but there’s tons of news reports. The Côte d’Ivoire crash was in May 2020.

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

#49

Post by xtian »

philwelch wrote: post #48
xtian wrote: post #44

Earlier quoted context omitted.

Do you have a link to an official investigation/report on this?

I don’t have a primary source handy but there’s tons of news reports. The Côte d’Ivoire crash was in May 2020.

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.

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

#50

Post by ch4s3 »

xtian wrote: post #47
ch4s3 wrote: post #46

Earlier quoted context omitted.

It happened in May of 2020. The debris landed in Côte 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.

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?

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...

Post reply on HN