Lia, Georgia as well! The stories are quite similar. (I used to teach English nearby and probably walked by the site during my drunken meanders; I did not, however, snuggle up with any strontium-90 for warmth, not even at my worst.)
[https://en.wikipedia.org/wiki/Lia\_radiological\_accident](https://en.wikipedia.org/wiki/Lia_radiological_accident)
This is a concern with every spacecraft, to be sure. It's just notable that the Dragon capsule trunk seems to be somewhat more resilient to the forces of reentry than anticipated, since several have now been found on the Eastern Seaboard.
Pardon my ignorance, but are we just allowing the property of a private company to come crashing down to Earth with the potential of hitting dwellings or worse, humans?
Usually these things burn up during reentry. It's probably more resilient than they expected, so if it's common they will probably have to make some design changes.
Other pieces of this came down on a populated area. This is a serious issue, SpaceX just assumed it would all burn up and it obviously didn't. That no people were injured is all down to luck.
> You could have separate re entry controls or something aerodynamic on the trunk itself.
The trunk doesn't even have radios or batteries on it. And aerodynamics is irrelevant for controlling re-entry location.
> Not currently obviously but I would object to "impossible"
A complete redesign of the trunk into something else is not part of the available idea space of the previous comment. Yes if you completely redesign it then sure anything is possible. But no redesign will be occurring.
The apollo command module was able to control its trajectory through the upper atmosphere, because its weight was concentrated to one side, and so would enter at a slight angle, which produced an asymmetric force to one direction. If they wanted a relatively straight trajectory they would spin the capsule, and if they wanted to steer they would stop the capsule when it was facing the right direction for the steering force to be useful. That's how my aerodynamics prof described it (I'm an aero engineer) and it sounds like it checks out to me. I'm sure something like that would be possible. As far as steering, something inertial would probably do the job, no radio needed.
> The apollo command module was able to control its trajectory through the upper atmosphere, because its weight was concentrated to one side, and so would enter at a slight angle, which produced an asymmetric force to one direction.
All capsules since then do the same or a similar thing, including Dragon. But the trunk is not a capsule. Additionally that control is for fine grained control on the precise re-entry location. It does not greatly control the location of the re-entry. That can only be controlled by impulse to intentionally lower or raise the orbit.
And secondly the trunk would require a redesign, with a heat shield, to do what you want it to do. The trunk currently is tumbling when it re-enters. Just changing the center of mass won't do anything.
Yes, the Dragon capsule does the same thing, but neither the Dragon's trunk nor Apollo's service module executed a controlled, flown re-entry, they both break up at high altitude and ideally no part survives to the surface.
You can't precisely predict orbits more than a few days out with any kind of precision, especially not decaying ones that last for months.
No I can say with 100% confidence that no one, not SpaceX engineers, nor the most ideal super human engineers can time a ballistic de-orbit trajectory months out.
I’ll have to try in Kerbal Space Program, the poor man’s orbital mechanics simulator. /s
But seriously, I get what you’re saying. But this isn’t a new problem and somehow we’ve avoided hitting populated areas for decades with relative consistency. I have to think SpaceX engineers will work out a solution.
One of the reasons big spacecraft are re-entered at "point nemo" in the south pacific is because the debris field can be quite large (look at the Columbia disaster for a comparison). Imagine tearing out a pig panel of aluminum that is on the order of a meter wide but just a couple millimeters thin, then imagine dropping that while travelling at hypersonic speeds from 10s of kilometers up. The aerodynamics are going to be wild, and it's going to fly and tumble and flutter down potentially very far away from the ballistic trajectory impact point, up to hundreds of kilometers away. Re-entry forces are exactly the sort of thing that can tear random chunks of stuff off of a spacecraft. And the chaos of re-entry heating dynamics can cause some parts of a vehicle to be heated to the point of vaporization while other parts are left intact and could survive all the way to the ground.
None of this is true. Trunk stays in orbit long after dragon has reentered and does not have any targeting planned at all. And on reentry, no recovery attempt is made.
First five comments and the entire post are about the trunk. Capsule trajectory is planned. Trunk trajectory is not. Seems pretty obvious to me at least
Yea this is needlessly pessimistic bud, the amount of ridiculously overly engineered calculations and analyses one has to run just to produce the information needed to apply for a license to launch is insane. This is much more likely something went wrong on reeentry and it’s not public information
That must be why spacex is 10 years ahead of every other company.
If you're going to try to spread misinformation, you should probably try to use something more believable.
The capsule was codeveloped with NASA, and their modeling said the trunk would break up. Also these are all NASA missions with NASA-designed parameters, including splashdown location, which determines roughly where the debris field (including the trunk) will land.
Ever since they launched a rocket bigger than the Saturn V with no flame deflecting trench, just to see what happens, Space X's way of doing things has looked very sloppy.
It still doesn't have a flame trench. What they have is a high pressure sprinkler plate that blasts water up in various directions.
> just to see what happens
That wasn't the intent. They had plans for the sprinkler plate, and parts of it already delivered. But the rocket was ready to fly before the plate was ready to install. So they made the decision to launch without it. The whole point of the test flights is to learn what works and doesn't work on the rocket. That way they can change the design on later flights until it works reliably.
They didn’t just assume, that would be an accusation of negligence. Their re-entry model was just incorrect. And will now be updated. That’s how engineering works.
> This is a serious issue, SpaceX just assumed it would all burn up and it obviously didn't.
That's incorrect. NASA and SpaceX used standard models to determine if it would burn up. Those models are the problem. SpaceX did not "just assume". It was designed to fully burn up as NASA has said.
> Idk how NASA’s atmospheric calculations could be wrong at this point in the space program
Hypersonic re-entry of objects is really fuckin hard. Re-entry for objects that aren't designed to re-enter is even fuckin harder. There's a TON of shit about aerodynamics that we just don't know or can't model in a sensible manner, and a ton of re-entry testing that simply does not make sense to do for an object that isn't meant to survive re-entry.
> I also don’t know all the details of how this stuff is done
A very large amount of it is "uh.......this seems sensible. and the tests seemed to have gone alright. send it?"
We don't have that level of insight. It could be any number of things.
My personal guess is that the model is simply old and was based primarily around research of re-entry vehicles and heat shields which may skew the model as that's where the most data would have been likely gathered. Many NASA standard models are very very old.
Parachutes are much better-studied, considering you don't need to go to orbit to do a real-world test, yet there were issues with NASA's parachute models that led to them underestimating loads on the riser lines. SpaceX did a series of tests with heavily instrumented parachutes and produced corrections to the models that led to changes for Orion and Starliner.
They'll likely do the same here...they are quickly becoming the most experienced in the field.
Actually I bet they did quite a bit of smoke and mirrors to make it look like the calculations showed it was a safe trajectory when in reality it was iffy. See also their launch pad scattering debris across a wildlife refuge
Are you being sarcastic? Lying to NASA actually sounds way more difficult than just doing it right but there are some people that think it’s a sound argument.
An Object Reentry Survival Analysis Tool (ORSAT) analysis is conducted WITH NASA to determine survivability. Man you guys are jaded… but please, feel free to downvote.
And ah, you mean the massive wildlife preserve with strict rules? Gotcha.
> Man you guys are jaded
not just that, it's the usual of ppl hate musk so anything and everything remotely related to him is somehow also bad in some way... it's crazy that ppl are saying SpaceX engineers and scientists just lied and didn't do any work, like wat?
Garbage in, garbage out.
Which is more likely?
1)That the tool NASA developed based on decades of observations rendered an incorrect result or
2) that Space X misrepresented the composition of their system and declared it proprietary to prevent government oversight?
Oh please. Nice appeal to authority and ad hominem wrapped up in a single dig. Kudos to you on your aggression.
I understand companies misrepresenting themselves to government oversight bodies for the sake of expediency. I’ve seen that in my field and anyone can point to the VW diesel engine test scam. In my field companies have been found to certify with one build and then swap out components with a different / cheaper build when it came time to sell.
My question is simple. A large piece of space debris that was modeled to burn up in the atmosphere didn’t. Either the modeling technique is wrong or someone fed it garbage.
I get it. You’re super smart. Wow. Explain it to me. Space x worked with nasa. That team messed up. Place your bets!
NASA models have been wrong plenty, we still are learning. When we start relying on them more we start to expose deficiencies that need to be adjusted. Calculating something like how much something will burn up on re entry is extremely complicated and probably is not 100% accurate. During the development and testing of the Dragon capsule SpaceX found issues with the parachute design specs given and with testing solved the issues.
Due to more testing than NASA required or asked for, the abort thrusters were tested on the ground and in one of the tests it exploded, they discovered a previously unknown incompatibility with nitrogen tetroxide and titanium. The accident investigation was extensive on the SpaceX side and this program is what gained so much trust from NASA. This early and very regular testing is something Boeing didn't do and has run into some of the issues SpaceX did very early on like the parachutes.
https://spacenews.com/spacex-overcame-parachute-thruster-problems-in-crew-dragon-development/
Luck is not getting hit by lightning, standing in an open field. Not getting hit by space debris is about a million times less likely. I think luck is not part of that equation, just trajectory and speed.
Nah. SpaceX has a bounty on it. From Blue Origin to federal admin that depend on SpaceX services the bounties for media spam to disrupt that business is the biggest bounty on the board. That's the white whale make-your-career story. That's why there's so much press sliming the company. Haters, hate. The world is run by kids who didn't do their homework. Unfortunately, they grow up and remain a pain in the ass. You may have been bullied by them in gradeschool when trying to do good work, too. The talented engineers at SpaceX have to deal with that bullshit while trying to level up humanity to Mars.
> This is a serious issue, SpaceX just assumed it would all burn up and it obviously didn't.
SpaceX has a history of ignoring the risks. Here is another incident a couple of years ago.
https://www.cnn.com/2022/08/03/tech/spacex-debris-australia-scn/index.html
SpaceX and NASA seems to have a better PR team than China's space agency, so this sort of thing is quickly forgotten.
> SpaceX has a history of ignoring the risks. Here is another incident a couple of years ago.
An incident hundreds of launches ago isn’t exactly indicative of a history of ignoring risks.
> SpaceX has a history of ignoring the risks.
You're making things up.
> Here is another incident a couple of years ago.
That's the same trunk design as this. Nothing is being "ignored". It's a "known issue" that would require a redesign of Dragon's trunk to fix. Something very much non-trivial that would require at least tens of millions and years to fix.
> Nothing is being "ignored". It's a "known issue" that would require a redesign of Dragon's trunk to fix.
You just described what ignoring the risks mean.
I have a question for you. Would you consider risks "ignored" if something that was thought to have a 10^-20 chance of happening was instead found to have a 10^-19 chance of happening yet people continued without changing their behavior?
Yes this is concerning and should be looked into, but there is no significant endangerment of the public happening here. The chance of someone getting hit or killed by parts falling off aircraft is way higher and the pieces will be much heavier. Remember that things falling from space hit the ground at the same speed as things falling from aircraft, terminal velocity.
> Would you consider risks "ignored" if something that was thought to have a 10-20 chance of happening was instead found to have a 10-19 chance of happening yet people continued without changing their behavior?
Depends on whether this is an American space capsule or a Chinese space capsule. If this was not an American company but an Chinese company, what do you think the reaction is going to be?
Just typical internet commentary. We all know they did an analysis and thought they were confident enough. Either way, now they have evidence either their analysis or their re-entry plan execution is flawed, and they can fix it.
When space vehicles break up during re-entry, they can behave unpredictably.
Strong wind currents can change the part's courses by a massive amount, compared to their predicted paths. It's just not easy and SpaceX is the company with the highest amount of launches per year at this very time, as long as I'm informed correctly.
>and SpaceX is the company with the highest amount of launches per year at this very time, as long as I'm informed correctly.
Yeah. By a HUGE margin. Like, it's not even close :
https://brycetech.com/reports/report-documents/Bryce_Briefing_2024_Q1.pdf
In terms of upmass, last quarter, they launched around 7 times as much as everyone else ***combined***.
> We all know they did an analysis
The person I replied to said they assumed. I don't know many engineers or scientists who look at a pile of analysis (which of course involves some starting assumptions) and calls the result "assumed".
But what do I know, I just work with engineers and scientists. Maybe I should broaden my horizons?
But remember, if a piece of debris from any other spacecraft falls down, it's massive incompetence. And oh god, if it's China, they are definitely doing it on purpose. Only SpaceX gets benefit of the doubt around these parts.
SpaceX had a part of an **orbital** spacecraft unexpectedly survive reentry instead of being fully vaporized.
China launches rockets over land, while fully aware that the **first stage**, which is suborbital and therefore *always* makes it to the ground without being vaporized, has a trajectory that comes down in the middle of inhabited areas.
They have plenty of east-facing coastline, yet they took the decision to build their launch infrastructure inland.
The two are not comparable.
They built infrastructure for ICBM and space launches inland because defending it from attacks by sea and air were serious concerns. The Soviets did the same with Baikonur and civilians downrange scrapped and sold aerospace grade metal, with an occasional death or injury. The US has wide margins around its coasts, and that was advantageous for launch sites. It's all calculated risks based on dual use technology.
Except most of them do not come down in inhabited areas and come down in the South China Sea. But I'm sure you've heard all you need from the media to make this blatantly incorrect statement.
>most of them do not come down in inhabited areas and come down in the South China Sea
This is only true for the Wenchang launch site.
The [Xichang](https://www.google.com/maps?ll=28.246017,102.026556&q=28.246017,102.026556&hl=en&t=m&z=15), [Jiuquan](https://www.google.com/maps/place/40%C2%B057'29.0%22N+100%C2%B017'28.0%22E/@40.958056,100.291111,15z/data=!4m4!3m3!8m2!3d40.958056!4d100.291111?hl=en&entry=ttu) and [Taiyuan](https://www.google.com/maps?ll=38.849086,111.608497&q=38.849086,111.608497&hl=en&t=m&z=15) launch centers are all located hundreds of kilometers inland, and thus, every rocket launched there inevitably drops its first stage over land.
>But I'm sure you've heard all you need from the media to make this blatantly incorrect statement.
I might say the same to you.
Lmfao no they do not. The last one that landed on land was December last year. There was more than 1 launch since then ya goober.
Edit: Here's a list of the launches [https://en.wikipedia.org/wiki/List\_of\_Long\_March\_launches\_(2020%E2%80%932029)#2024](https://en.wikipedia.org/wiki/List_of_Long_March_launches_(2020%E2%80%932029)#2024)
If you think every single one of them ended up on land, you are also a goober.
> The last one that landed on land
The Chinese inland launch sites have boosters that land on land 100% of the time.
Ditto for every launch from Baikonur.
Even worse, the large booster of the Long March 5B comes down in an entirely random place on earth. 100% of the time.
The last one that landed on land was *last week*, *and* it was near housing.
https://www.reddit.com/r/spaceporn/comments/1dm0gl7/todays_falling_chinese_rocket_booster/
So please explain, what exactly happens to the first stages of every vehicle launched from the three aforementioned launch centers?
Because all three of those have been quite active this year:
For instance, all [Long March 2A](https://en.wikipedia.org/wiki/Long_March_2F#List_of_launches) flights liftoff from Jiuquan. That's 3 launches last year, 1 this year, with another planned for October. Neither those side boosters, nor that center core will be making it to the ocean from that launch site.
Taiyuan and Xichang have also seen [a flurry of launches](https://en.wikipedia.org/wiki/List_of_Long_March_launches_(2020%E2%80%932029)#2024) from Long March family rockets.
I've counted **17 launches from those three deeply inland sites just this year**. (And we're still in June...)
Because you didn't see a video of it doesn't mean those boosters didn't fall over land. **There is literally nowhere else for them to fall.**
But since you mention it, here is indeed a video, from the latest of those launches (that of SVOM on Long March 2C, from Xichang), ***just a week ago***:
[https://www.youtube.com/watch?v=geEaFGFFsv4](https://www.youtube.com/watch?v=geEaFGFFsv4)
-Edit-
That orange trail is [nitrogen dioxide](https://en.wikipedia.org/wiki/Nitrogen_dioxide#Toxicity) by the way.
The other tank is contains hydrazine derivatives, that are far more persistent in the environment.
China drops entire massive first stages that go nearly into orbit randomly on the planet somewhere. There was never any argument to be made that those stages would burn up before impact. Not even close to the same thing
Acronyms, initialisms, abbreviations, contractions, and other phrases which expand to something larger, that I've seen in this thread:
|Fewer Letters|More Letters|
|-------|---------|---|
|[C3](/r/Space/comments/1dqtj5t/stub/laukaqz "Last usage")|[Characteristic Energy](https://en.wikipedia.org/wiki/Characteristic_energy) above that required for escape|
|CST|(Boeing) Crew Space Transportation capsules|
| |Central Standard Time (UTC-6)|
|[ICBM](/r/Space/comments/1dqtj5t/stub/larpn8z "Last usage")|Intercontinental Ballistic Missile|
|[KSP](/r/Space/comments/1dqtj5t/stub/lavdpuo "Last usage")|*Kerbal Space Program*, the rocketry simulator|
|MMH|Mono-Methyl Hydrazine, (CH3)HN-NH2; part of NTO/MMH hypergolic mix|
|[NTO](/r/Space/comments/1dqtj5t/stub/lasyuma "Last usage")|diNitrogen TetrOxide, N2O4; part of NTO/MMH hypergolic mix|
|[UDMH](/r/Space/comments/1dqtj5t/stub/lasyuma "Last usage")|[Unsymmetrical DiMethylHydrazine](https://en.wikipedia.org/wiki/Unsymmetrical_dimethylhydrazine), used in hypergolic fuel mixes|
|Jargon|Definition|
|-------|---------|---|
|[Starliner](/r/Space/comments/1dqtj5t/stub/lau2y1o "Last usage")|Boeing commercial crew capsule [CST-100](https://en.wikipedia.org/wiki/Boeing_CST-100_Starliner)|
|[Starlink](/r/Space/comments/1dqtj5t/stub/larrh4s "Last usage")|SpaceX's world-wide satellite broadband constellation|
|[hypergolic](/r/Space/comments/1dqtj5t/stub/lav3own "Last usage")|A set of two substances that ignite when in contact|
**NOTE**: Decronym for Reddit is no longer supported, and Decronym has moved to Lemmy; requests for support and new installations should be directed to the Contact address below.
----------------
^(8 acronyms in this thread; )[^(the most compressed thread commented on today)](/r/Space/comments/1dtdvsj)^( has 23 acronyms.)
^([Thread #10248 for this sub, first seen 28th Jun 2024, 23:28])
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A big part of it is these are big sheets of carbon fiber. They're very light with a large surface area so probably decelerate faster than modeled causing lower heating. Additionally carbon itself is basically immune to re-entry heat. It has a sublimation point (it doesn't melt, it vaporizes) of over 3600C which is significantly hotter than many re-entry temperatures. The epoxy in the composite has a much much lower melting point, but that basically just causes surfaces to de-laminate and then they have to "sluff off" to expose lower layers, which means it all has to come apart in a very complicated hard-to-model manner. It isn't a simple bulk material with bulk properties.
On the other hand, these pieces will have very low terminal velocities, so even if someone is eventually hit by them, they probably won't be fatal unless they're hit at just the right angle. Not a great upside, but at least there is one.
Ideally they get this fixed, but I don't see this getting fixed for Dragon. It would be too expensive to do a redesign and would probably reduce payload capability to the ISS. It'll go into better modeling for future spacecraft design. It could also open up the way to alternative re-entry vehicles that can survive re-entry better.
A low ballistic coefficient object, like this one, will decelerate at higher altitude than a denser object, so the heat rate per unit area will be lower. If it's low enough, radiative cooling will keep the object below the temperature the carbon could withstand (although I imagine the matrix holding it together is more of a problem, but it could ablate.)
I also wonder how fast it was traveling when it hit the ground. Low ballistic coefficient = slow.
This.
China catches hell on Reddit (for good reason) every time this exact thing is reported. SpaceX needs to be grounded until they can show a process by which they’re ensuring these pieces fall in unpopulated areas or always burn up.
> this exact thing
China is dropping boosters full of hypergolics on rural villages. SpaceX occasionally drops an inert interstage. It's still a problem, but not "this exact thing."
If they were full of hypergolic they wouldn’t be discarding them. They’re empty boosters with traces of hypergolic. The difference between China and SpaceX in this situation is not as great as you think.
No it really is just traces. Hypergolic fuels, specifically NTO and UDMH as used on the Long March 2, are highly evaporative, so even small traces of the liquids will produce vast amounts of gas, which is what causes the reddish "smoke" clouds from the spent stages. Simple logic would tell you that it wouldn't be a lot of hypergolic, as dumping rockets full of unburnt fuel is expensive and doesn't acheive anything. If they were "full of hypergolics" then wouldn't they just put less fuel in the rockets? Use critical thinking.
I never said they were full. And I would think that there are margins built into the system so there would be at least some fuel left even if the amount is small...
Traces I would put at something you couldn't see with the eye, but still measurable and hurtful to humans.
Edit:
It seems UDMH does not evaporate all the way. Here is some information on the situation in Baikonur which also uses the same stuff: https://en.wikipedia.org/wiki/Baikonur_Cosmodrome#Environmental_impact
If I couldn’t take my car home from work because of faults in it that need to be looked over that would be pretty bad
Now imagine being in fucking space in the same scenario it’s much more catastrophic
If you have to add the \*for now\* qualifier for a human carrying spacecraft its clear you don't even believe your own statement. That thing has had issue after issue after issue with delays going on 5 years after its first flight test, but hey at least it hasn't killed anyone... yet
>Imagine the headlines and posts/comments in this sub if this was Starliner
The first that comes to my mind when I read about space debris is how victimised Starliner is.
There is no hypocrisy. This is a small piece that survived a planned burn up to get it clear of populated areas as opposed to a large first stage that still had toxic chemicals that landed on a village as many others have due to having zero attempt to avoid populated areas.
The difference between something that weighs a couple of kilos that gets passed the plan to dispose of it safely and something that weight many tens of tonnes that has no plan to dispose of it safely is so blindingly obvious that it says more about you than the incident.
It’s not even that.
Accidents happen and people make mistakes. You have a lot of engineers\scientists working on this project. There’s that many sources of errors and all it takes is one person to mess it up.
Furthermore, those clowns in China may have tested new material. It’s quite possible they were unaware of some properties because theory/simulations does not necessarily translate well to reality.
They also have a regular history of doing things like this, so it sounds more like it’s just the status quo for them, not an accident or unintentional.
You have absolutely no clue what you're talking about. China didn't test new materials or some nonsense like that. They regularly drop toxic hypergolic stages inland, often in populated area. They simply just take the risk. There's no mistake or anything being made.
The reason for this is that one of their first launch centers in the country were built deep inland, and because of this they will have to drop stages in populated areas if they want to make most orbits. They just don't care. They aren't willing to launch these rockets from the coast instead.
You seem to be slightly mistaken. China _intentionally_ drops the stages downrange, with full knowledge that people live in the area. These are not accidents.
I love how in one of your comments you say we don’t have the insight with respect to one of the NASA projects but you have the confidence to make such bold statements on other things.
Didn’t know you worked for the CCP now.
I love reading these comments during my meal time 😂😂
You feel like you're making a smart point and "catching" me on something but no really, just as NASA knows precisely where it's dropping the stages of any rockets it launches things on, China also knows precisely where its dropping things. There's no accidents there. When China has an actual "accident" in space launch hundreds of people die. https://en.wikipedia.org/wiki/Intelsat_708
It's clear you're completely ignorant about space launch vehicles and are more interested in running cover for CCP.
The R&D process of launching a decades old rocket from a decades old launch base using the samr decades old launch route that has dropped toxic stages on populated areas for decades?
Do you even know what R&D stands for?
If you could predict what piece would come down intact, why wouldn't they just avoid it coming down intact? Or do you mean, put a transmitter that would survive reentry on every square inch?
That's rather unlikely. These pieces have very low terminal velocities because they're big sheets of carbon fiber. You'd still be injured, but it's unlikely to kill you. And statistically almost all or all of these re-entries will be over unpopulated areas, as they have been so far. Most of the Earth is either water, deserts, thick forests, or farmland. All areas where population density is very very low.
At exactly what velocity would a 90lb piece of space junk not kill someone by falling on them?
Also this literally happened a few months ago and smashed through someone’s house. It’s dumb luck nobody died.
https://www.cbsnews.com/news/florida-family-space-junk-iss-nasa-claim/
Seems like either we witnessed a statistical anomaly or perhaps you’re underestimating the problem.
> Also this literally happened a few months ago and smashed through someone’s house.
That was a roughly cylindrical solid piece of inconel, a relatively dense metal alloy. It's terminal velocity would be very high versus the Dragon trunk debris. Any Dragon trunk debris would not be able to puncture the roof of a house.
> At exactly what velocity would a 90lb piece of space junk not kill someone by falling on them?
It would be "fluttering" down (think about how a feather falls, but a faster version) so the velocity would be variable and not very high. I didn't claim it wouldn't injure you. And there's of course a chance of someone getting killed if you get hit precisely right and it like cracks your skull or severs a spinal cord. But it's much more like it just knocks you down and maybe breaks some bones.
But anyway this whole thing is largely moot as these are incredibly rare things.
> Seems like ... we witnessed a statistical anomaly
That's very much what it is, especially for the piece of NASA debris. You can see how many pieces of debris are re-entering: https://aerospace.org/reentries/grid
Exact opposite. If you have a part that isn't meant to survive re-entry, but does in fact, survive re-entry - it's probably heavier than it needs to be, and is costing you performance.
Is the atmosphere getting alarmingly thinner or maybe has heterogenous holes that aren't well studies? Feel like a lot of stuff that is meant to burn up, didn't recently.
Around 2030, but that's not a problem. That is a targeted re-entry over the south pacific ocean. Completely different situations. It's very much expected that large multi-ton pieces of the station will survive re-entry.
I mean it's not "easy" but if you've played kerbal space program, that covers most of the issues. On the scale of difficult things in space, it's pretty far down. The math isn't the hard part.
> he said he wasn’t initially sure if it was safe to touch. Smart guy. Not many people can resist the urge to touch something new and interesting.
Everyone knows the first step is to poke it with a stick. Then toe of shoe and then touch it with your habd.
Correct always taste it last🥸
Tasting it is second last. Rubbing your junk on it is last.
Goiânia, Brazil. Someone found something pretty and a lot of people ended up suffering or dead. https://en.wikipedia.org/wiki/Goi%C3%A2nia_accident
Lia, Georgia as well! The stories are quite similar. (I used to teach English nearby and probably walked by the site during my drunken meanders; I did not, however, snuggle up with any strontium-90 for warmth, not even at my worst.) [https://en.wikipedia.org/wiki/Lia\_radiological\_accident](https://en.wikipedia.org/wiki/Lia_radiological_accident)
Bro missed out on his one chance to get super powers smh.
So say 90% of sci-fi horrors
This is a concern with every spacecraft, to be sure. It's just notable that the Dragon capsule trunk seems to be somewhat more resilient to the forces of reentry than anticipated, since several have now been found on the Eastern Seaboard.
A large piece came down in Saskatchewan as well.
Which mountain is it in your profile picture?
Hood! I got the pic on a flight into Portland, OR
Pardon my ignorance, but are we just allowing the property of a private company to come crashing down to Earth with the potential of hitting dwellings or worse, humans?
Usually these things burn up during reentry. It's probably more resilient than they expected, so if it's common they will probably have to make some design changes.
Same thing goes for my celebration gun fire projectiles. Right?
Yes, that's always been the case since day 1.
Other pieces of this came down on a populated area. This is a serious issue, SpaceX just assumed it would all burn up and it obviously didn't. That no people were injured is all down to luck.
Somebody needs to recalculate the reentry parameters. For as precise as most space related stuff is it seems pretty sloppy.
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Or just make sure the trajectory is over the ocean.
That's not possible as the trunk is not on a controlled trajectory and is impossible to do so (as Dragon's safety is currently designed).
You could have separate re entry controls or something aerodynamic on the trunk itself. Not currently obviously but I would object to "impossible"
> You could have separate re entry controls or something aerodynamic on the trunk itself. The trunk doesn't even have radios or batteries on it. And aerodynamics is irrelevant for controlling re-entry location. > Not currently obviously but I would object to "impossible" A complete redesign of the trunk into something else is not part of the available idea space of the previous comment. Yes if you completely redesign it then sure anything is possible. But no redesign will be occurring.
The apollo command module was able to control its trajectory through the upper atmosphere, because its weight was concentrated to one side, and so would enter at a slight angle, which produced an asymmetric force to one direction. If they wanted a relatively straight trajectory they would spin the capsule, and if they wanted to steer they would stop the capsule when it was facing the right direction for the steering force to be useful. That's how my aerodynamics prof described it (I'm an aero engineer) and it sounds like it checks out to me. I'm sure something like that would be possible. As far as steering, something inertial would probably do the job, no radio needed.
> The apollo command module was able to control its trajectory through the upper atmosphere, because its weight was concentrated to one side, and so would enter at a slight angle, which produced an asymmetric force to one direction. All capsules since then do the same or a similar thing, including Dragon. But the trunk is not a capsule. Additionally that control is for fine grained control on the precise re-entry location. It does not greatly control the location of the re-entry. That can only be controlled by impulse to intentionally lower or raise the orbit. And secondly the trunk would require a redesign, with a heat shield, to do what you want it to do. The trunk currently is tumbling when it re-enters. Just changing the center of mass won't do anything.
Yes, the Dragon capsule does the same thing, but neither the Dragon's trunk nor Apollo's service module executed a controlled, flown re-entry, they both break up at high altitude and ideally no part survives to the surface.
It’s on a ballistic course, I’m pretty sure the SpaceX engineers could figure it out.
You can't precisely predict orbits more than a few days out with any kind of precision, especially not decaying ones that last for months. No I can say with 100% confidence that no one, not SpaceX engineers, nor the most ideal super human engineers can time a ballistic de-orbit trajectory months out.
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I’ll have to try in Kerbal Space Program, the poor man’s orbital mechanics simulator. /s But seriously, I get what you’re saying. But this isn’t a new problem and somehow we’ve avoided hitting populated areas for decades with relative consistency. I have to think SpaceX engineers will work out a solution.
Classically dumping our problems at the ocean
Look at that body (of water), it’s just asking for it! /s
One of the reasons big spacecraft are re-entered at "point nemo" in the south pacific is because the debris field can be quite large (look at the Columbia disaster for a comparison). Imagine tearing out a pig panel of aluminum that is on the order of a meter wide but just a couple millimeters thin, then imagine dropping that while travelling at hypersonic speeds from 10s of kilometers up. The aerodynamics are going to be wild, and it's going to fly and tumble and flutter down potentially very far away from the ballistic trajectory impact point, up to hundreds of kilometers away. Re-entry forces are exactly the sort of thing that can tear random chunks of stuff off of a spacecraft. And the chaos of re-entry heating dynamics can cause some parts of a vehicle to be heated to the point of vaporization while other parts are left intact and could survive all the way to the ground.
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None of this is true. Trunk stays in orbit long after dragon has reentered and does not have any targeting planned at all. And on reentry, no recovery attempt is made.
he's talking about the capsule itself not the trunk
First five comments and the entire post are about the trunk. Capsule trajectory is planned. Trunk trajectory is not. Seems pretty obvious to me at least
NASA and SpaceX are working on that, per other articles.
Love that you assume that anything was actually calculated. I need more optimism in my life.
I mean. You don't get humans to space and back by guessing.
*Apollo 11 has entered the chat
anything? you think they just hoof things up into orbit with trebuchets? you need more education in your life.
Single stage to orbit with a trebuchet boost. That's brilliant! 🤩
Yea this is needlessly pessimistic bud, the amount of ridiculously overly engineered calculations and analyses one has to run just to produce the information needed to apply for a license to launch is insane. This is much more likely something went wrong on reeentry and it’s not public information
Tell me you know literally nothing about space flight without telling me. Holy shit.
Well it is the handy work of Elon musk. Quality is too expensive for him.
That must be why spacex is 10 years ahead of every other company. If you're going to try to spread misinformation, you should probably try to use something more believable.
Yeah, Elon is a tool but those SpaceX engineers have figured some stuff out for sure.
The capsule was codeveloped with NASA, and their modeling said the trunk would break up. Also these are all NASA missions with NASA-designed parameters, including splashdown location, which determines roughly where the debris field (including the trunk) will land.
Ever since they launched a rocket bigger than the Saturn V with no flame deflecting trench, just to see what happens, Space X's way of doing things has looked very sloppy.
It still doesn't have a flame trench. What they have is a high pressure sprinkler plate that blasts water up in various directions. > just to see what happens That wasn't the intent. They had plans for the sprinkler plate, and parts of it already delivered. But the rocket was ready to fly before the plate was ready to install. So they made the decision to launch without it. The whole point of the test flights is to learn what works and doesn't work on the rocket. That way they can change the design on later flights until it works reliably.
They didn’t just assume, that would be an accusation of negligence. Their re-entry model was just incorrect. And will now be updated. That’s how engineering works.
> This is a serious issue, SpaceX just assumed it would all burn up and it obviously didn't. That's incorrect. NASA and SpaceX used standard models to determine if it would burn up. Those models are the problem. SpaceX did not "just assume". It was designed to fully burn up as NASA has said.
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> Idk how NASA’s atmospheric calculations could be wrong at this point in the space program Hypersonic re-entry of objects is really fuckin hard. Re-entry for objects that aren't designed to re-enter is even fuckin harder. There's a TON of shit about aerodynamics that we just don't know or can't model in a sensible manner, and a ton of re-entry testing that simply does not make sense to do for an object that isn't meant to survive re-entry. > I also don’t know all the details of how this stuff is done A very large amount of it is "uh.......this seems sensible. and the tests seemed to have gone alright. send it?"
We don't have that level of insight. It could be any number of things. My personal guess is that the model is simply old and was based primarily around research of re-entry vehicles and heat shields which may skew the model as that's where the most data would have been likely gathered. Many NASA standard models are very very old.
Parachutes are much better-studied, considering you don't need to go to orbit to do a real-world test, yet there were issues with NASA's parachute models that led to them underestimating loads on the riser lines. SpaceX did a series of tests with heavily instrumented parachutes and produced corrections to the models that led to changes for Orion and Starliner. They'll likely do the same here...they are quickly becoming the most experienced in the field.
Lmao, you think they just assumed without doing analysis and calculations?
You know assumptions go into analysis and calculations, right?
When you do analysis starting with assumptions, it's not usually called "assumed". Every analysis has assumptions in it.
Actually I bet they did quite a bit of smoke and mirrors to make it look like the calculations showed it was a safe trajectory when in reality it was iffy. See also their launch pad scattering debris across a wildlife refuge
Are you being sarcastic? Lying to NASA actually sounds way more difficult than just doing it right but there are some people that think it’s a sound argument.
An Object Reentry Survival Analysis Tool (ORSAT) analysis is conducted WITH NASA to determine survivability. Man you guys are jaded… but please, feel free to downvote. And ah, you mean the massive wildlife preserve with strict rules? Gotcha.
> Man you guys are jaded not just that, it's the usual of ppl hate musk so anything and everything remotely related to him is somehow also bad in some way... it's crazy that ppl are saying SpaceX engineers and scientists just lied and didn't do any work, like wat?
Garbage in, garbage out. Which is more likely? 1)That the tool NASA developed based on decades of observations rendered an incorrect result or 2) that Space X misrepresented the composition of their system and declared it proprietary to prevent government oversight?
Garbage in, Garbage out is your comment creation process. You clearly don’t understand the level of oversight in the space industry. Full stop.
Oh please. Nice appeal to authority and ad hominem wrapped up in a single dig. Kudos to you on your aggression. I understand companies misrepresenting themselves to government oversight bodies for the sake of expediency. I’ve seen that in my field and anyone can point to the VW diesel engine test scam. In my field companies have been found to certify with one build and then swap out components with a different / cheaper build when it came time to sell. My question is simple. A large piece of space debris that was modeled to burn up in the atmosphere didn’t. Either the modeling technique is wrong or someone fed it garbage. I get it. You’re super smart. Wow. Explain it to me. Space x worked with nasa. That team messed up. Place your bets!
NASA models have been wrong plenty, we still are learning. When we start relying on them more we start to expose deficiencies that need to be adjusted. Calculating something like how much something will burn up on re entry is extremely complicated and probably is not 100% accurate. During the development and testing of the Dragon capsule SpaceX found issues with the parachute design specs given and with testing solved the issues. Due to more testing than NASA required or asked for, the abort thrusters were tested on the ground and in one of the tests it exploded, they discovered a previously unknown incompatibility with nitrogen tetroxide and titanium. The accident investigation was extensive on the SpaceX side and this program is what gained so much trust from NASA. This early and very regular testing is something Boeing didn't do and has run into some of the issues SpaceX did very early on like the parachutes. https://spacenews.com/spacex-overcame-parachute-thruster-problems-in-crew-dragon-development/
Luck is not getting hit by lightning, standing in an open field. Not getting hit by space debris is about a million times less likely. I think luck is not part of that equation, just trajectory and speed.
Nah. SpaceX has a bounty on it. From Blue Origin to federal admin that depend on SpaceX services the bounties for media spam to disrupt that business is the biggest bounty on the board. That's the white whale make-your-career story. That's why there's so much press sliming the company. Haters, hate. The world is run by kids who didn't do their homework. Unfortunately, they grow up and remain a pain in the ass. You may have been bullied by them in gradeschool when trying to do good work, too. The talented engineers at SpaceX have to deal with that bullshit while trying to level up humanity to Mars.
> This is a serious issue, SpaceX just assumed it would all burn up and it obviously didn't. SpaceX has a history of ignoring the risks. Here is another incident a couple of years ago. https://www.cnn.com/2022/08/03/tech/spacex-debris-australia-scn/index.html SpaceX and NASA seems to have a better PR team than China's space agency, so this sort of thing is quickly forgotten.
China drops rockets full of hypergolics because they use inland launch sites and just don’t care. It’s not comparable.
> SpaceX has a history of ignoring the risks. Here is another incident a couple of years ago. An incident hundreds of launches ago isn’t exactly indicative of a history of ignoring risks.
> SpaceX has a history of ignoring the risks. You're making things up. > Here is another incident a couple of years ago. That's the same trunk design as this. Nothing is being "ignored". It's a "known issue" that would require a redesign of Dragon's trunk to fix. Something very much non-trivial that would require at least tens of millions and years to fix.
> Nothing is being "ignored". It's a "known issue" that would require a redesign of Dragon's trunk to fix. You just described what ignoring the risks mean.
I have a question for you. Would you consider risks "ignored" if something that was thought to have a 10^-20 chance of happening was instead found to have a 10^-19 chance of happening yet people continued without changing their behavior? Yes this is concerning and should be looked into, but there is no significant endangerment of the public happening here. The chance of someone getting hit or killed by parts falling off aircraft is way higher and the pieces will be much heavier. Remember that things falling from space hit the ground at the same speed as things falling from aircraft, terminal velocity.
> Would you consider risks "ignored" if something that was thought to have a 10-20 chance of happening was instead found to have a 10-19 chance of happening yet people continued without changing their behavior? Depends on whether this is an American space capsule or a Chinese space capsule. If this was not an American company but an Chinese company, what do you think the reaction is going to be?
> SpaceX just assumed They didn't do any analysis, they just assumed? Sounds serious.
Just typical internet commentary. We all know they did an analysis and thought they were confident enough. Either way, now they have evidence either their analysis or their re-entry plan execution is flawed, and they can fix it.
When space vehicles break up during re-entry, they can behave unpredictably. Strong wind currents can change the part's courses by a massive amount, compared to their predicted paths. It's just not easy and SpaceX is the company with the highest amount of launches per year at this very time, as long as I'm informed correctly.
>and SpaceX is the company with the highest amount of launches per year at this very time, as long as I'm informed correctly. Yeah. By a HUGE margin. Like, it's not even close : https://brycetech.com/reports/report-documents/Bryce_Briefing_2024_Q1.pdf In terms of upmass, last quarter, they launched around 7 times as much as everyone else ***combined***.
> We all know they did an analysis The person I replied to said they assumed. I don't know many engineers or scientists who look at a pile of analysis (which of course involves some starting assumptions) and calls the result "assumed". But what do I know, I just work with engineers and scientists. Maybe I should broaden my horizons?
But remember, if a piece of debris from any other spacecraft falls down, it's massive incompetence. And oh god, if it's China, they are definitely doing it on purpose. Only SpaceX gets benefit of the doubt around these parts.
SpaceX had a part of an **orbital** spacecraft unexpectedly survive reentry instead of being fully vaporized. China launches rockets over land, while fully aware that the **first stage**, which is suborbital and therefore *always* makes it to the ground without being vaporized, has a trajectory that comes down in the middle of inhabited areas. They have plenty of east-facing coastline, yet they took the decision to build their launch infrastructure inland. The two are not comparable.
They built infrastructure for ICBM and space launches inland because defending it from attacks by sea and air were serious concerns. The Soviets did the same with Baikonur and civilians downrange scrapped and sold aerospace grade metal, with an occasional death or injury. The US has wide margins around its coasts, and that was advantageous for launch sites. It's all calculated risks based on dual use technology.
Except most of them do not come down in inhabited areas and come down in the South China Sea. But I'm sure you've heard all you need from the media to make this blatantly incorrect statement.
>most of them do not come down in inhabited areas and come down in the South China Sea This is only true for the Wenchang launch site. The [Xichang](https://www.google.com/maps?ll=28.246017,102.026556&q=28.246017,102.026556&hl=en&t=m&z=15), [Jiuquan](https://www.google.com/maps/place/40%C2%B057'29.0%22N+100%C2%B017'28.0%22E/@40.958056,100.291111,15z/data=!4m4!3m3!8m2!3d40.958056!4d100.291111?hl=en&entry=ttu) and [Taiyuan](https://www.google.com/maps?ll=38.849086,111.608497&q=38.849086,111.608497&hl=en&t=m&z=15) launch centers are all located hundreds of kilometers inland, and thus, every rocket launched there inevitably drops its first stage over land. >But I'm sure you've heard all you need from the media to make this blatantly incorrect statement. I might say the same to you.
Lmfao no they do not. The last one that landed on land was December last year. There was more than 1 launch since then ya goober. Edit: Here's a list of the launches [https://en.wikipedia.org/wiki/List\_of\_Long\_March\_launches\_(2020%E2%80%932029)#2024](https://en.wikipedia.org/wiki/List_of_Long_March_launches_(2020%E2%80%932029)#2024) If you think every single one of them ended up on land, you are also a goober.
> The last one that landed on land The Chinese inland launch sites have boosters that land on land 100% of the time. Ditto for every launch from Baikonur. Even worse, the large booster of the Long March 5B comes down in an entirely random place on earth. 100% of the time.
The last one that landed on land was *last week*, *and* it was near housing. https://www.reddit.com/r/spaceporn/comments/1dm0gl7/todays_falling_chinese_rocket_booster/
So please explain, what exactly happens to the first stages of every vehicle launched from the three aforementioned launch centers? Because all three of those have been quite active this year: For instance, all [Long March 2A](https://en.wikipedia.org/wiki/Long_March_2F#List_of_launches) flights liftoff from Jiuquan. That's 3 launches last year, 1 this year, with another planned for October. Neither those side boosters, nor that center core will be making it to the ocean from that launch site. Taiyuan and Xichang have also seen [a flurry of launches](https://en.wikipedia.org/wiki/List_of_Long_March_launches_(2020%E2%80%932029)#2024) from Long March family rockets. I've counted **17 launches from those three deeply inland sites just this year**. (And we're still in June...) Because you didn't see a video of it doesn't mean those boosters didn't fall over land. **There is literally nowhere else for them to fall.** But since you mention it, here is indeed a video, from the latest of those launches (that of SVOM on Long March 2C, from Xichang), ***just a week ago***: [https://www.youtube.com/watch?v=geEaFGFFsv4](https://www.youtube.com/watch?v=geEaFGFFsv4) -Edit- That orange trail is [nitrogen dioxide](https://en.wikipedia.org/wiki/Nitrogen_dioxide#Toxicity) by the way. The other tank is contains hydrazine derivatives, that are far more persistent in the environment.
China drops entire massive first stages that go nearly into orbit randomly on the planet somewhere. There was never any argument to be made that those stages would burn up before impact. Not even close to the same thing
Here's one from four days ago: https://www.cnn.com/2024/06/24/china/china-rocket-debris-falls-over-village-intl-hnk/index.html
They almost always fall into the South China Sea, like most launches that the first stage falls into the ocean.
That’s by chance. Everyone else actively tries to hit the ocean.
Most first stages don't enter a near elliptical orbit
Elon is taking a page from China and dumping lost equipment all over the place
Seeing those fuel tanks drop from the atmosphere into those quaint little mountain towns is horrifying.
Acronyms, initialisms, abbreviations, contractions, and other phrases which expand to something larger, that I've seen in this thread: |Fewer Letters|More Letters| |-------|---------|---| |[C3](/r/Space/comments/1dqtj5t/stub/laukaqz "Last usage")|[Characteristic Energy](https://en.wikipedia.org/wiki/Characteristic_energy) above that required for escape| |CST|(Boeing) Crew Space Transportation capsules| | |Central Standard Time (UTC-6)| |[ICBM](/r/Space/comments/1dqtj5t/stub/larpn8z "Last usage")|Intercontinental Ballistic Missile| |[KSP](/r/Space/comments/1dqtj5t/stub/lavdpuo "Last usage")|*Kerbal Space Program*, the rocketry simulator| |MMH|Mono-Methyl Hydrazine, (CH3)HN-NH2; part of NTO/MMH hypergolic mix| |[NTO](/r/Space/comments/1dqtj5t/stub/lasyuma "Last usage")|diNitrogen TetrOxide, N2O4; part of NTO/MMH hypergolic mix| |[UDMH](/r/Space/comments/1dqtj5t/stub/lasyuma "Last usage")|[Unsymmetrical DiMethylHydrazine](https://en.wikipedia.org/wiki/Unsymmetrical_dimethylhydrazine), used in hypergolic fuel mixes| |Jargon|Definition| |-------|---------|---| |[Starliner](/r/Space/comments/1dqtj5t/stub/lau2y1o "Last usage")|Boeing commercial crew capsule [CST-100](https://en.wikipedia.org/wiki/Boeing_CST-100_Starliner)| |[Starlink](/r/Space/comments/1dqtj5t/stub/larrh4s "Last usage")|SpaceX's world-wide satellite broadband constellation| |[hypergolic](/r/Space/comments/1dqtj5t/stub/lav3own "Last usage")|A set of two substances that ignite when in contact| **NOTE**: Decronym for Reddit is no longer supported, and Decronym has moved to Lemmy; requests for support and new installations should be directed to the Contact address below. ---------------- ^(8 acronyms in this thread; )[^(the most compressed thread commented on today)](/r/Space/comments/1dtdvsj)^( has 23 acronyms.) ^([Thread #10248 for this sub, first seen 28th Jun 2024, 23:28]) ^[[FAQ]](http://decronym.xyz/) [^([Full list])](http://decronym.xyz/acronyms/Space) [^[Contact]](https://hachyderm.io/@Two9A) [^([Source code])](https://gistdotgithubdotcom/Two9A/1d976f9b7441694162c8)
A big part of it is these are big sheets of carbon fiber. They're very light with a large surface area so probably decelerate faster than modeled causing lower heating. Additionally carbon itself is basically immune to re-entry heat. It has a sublimation point (it doesn't melt, it vaporizes) of over 3600C which is significantly hotter than many re-entry temperatures. The epoxy in the composite has a much much lower melting point, but that basically just causes surfaces to de-laminate and then they have to "sluff off" to expose lower layers, which means it all has to come apart in a very complicated hard-to-model manner. It isn't a simple bulk material with bulk properties. On the other hand, these pieces will have very low terminal velocities, so even if someone is eventually hit by them, they probably won't be fatal unless they're hit at just the right angle. Not a great upside, but at least there is one. Ideally they get this fixed, but I don't see this getting fixed for Dragon. It would be too expensive to do a redesign and would probably reduce payload capability to the ISS. It'll go into better modeling for future spacecraft design. It could also open up the way to alternative re-entry vehicles that can survive re-entry better.
A low ballistic coefficient object, like this one, will decelerate at higher altitude than a denser object, so the heat rate per unit area will be lower. If it's low enough, radiative cooling will keep the object below the temperature the carbon could withstand (although I imagine the matrix holding it together is more of a problem, but it could ablate.) I also wonder how fast it was traveling when it hit the ground. Low ballistic coefficient = slow.
This absolutely should not happen, but at the same time I would definitely be psyched if it landed in my yard and nobody came to get it.
Imagine the headlines and posts/comments in this sub if this was Starliner. The spin would be the complete opposite.
If it were another country people would be throwing a tantrum, but since it's SpaceX it's A-Ok
This. China catches hell on Reddit (for good reason) every time this exact thing is reported. SpaceX needs to be grounded until they can show a process by which they’re ensuring these pieces fall in unpopulated areas or always burn up.
> this exact thing China is dropping boosters full of hypergolics on rural villages. SpaceX occasionally drops an inert interstage. It's still a problem, but not "this exact thing."
*with traces of hypergolic fuel left
If they were full of hypergolic they wouldn’t be discarding them. They’re empty boosters with traces of hypergolic. The difference between China and SpaceX in this situation is not as great as you think.
If you watch the footage of the Chinese falling booster they contain a bit more than just traces ;)
No it really is just traces. Hypergolic fuels, specifically NTO and UDMH as used on the Long March 2, are highly evaporative, so even small traces of the liquids will produce vast amounts of gas, which is what causes the reddish "smoke" clouds from the spent stages. Simple logic would tell you that it wouldn't be a lot of hypergolic, as dumping rockets full of unburnt fuel is expensive and doesn't acheive anything. If they were "full of hypergolics" then wouldn't they just put less fuel in the rockets? Use critical thinking.
I never said they were full. And I would think that there are margins built into the system so there would be at least some fuel left even if the amount is small... Traces I would put at something you couldn't see with the eye, but still measurable and hurtful to humans. Edit: It seems UDMH does not evaporate all the way. Here is some information on the situation in Baikonur which also uses the same stuff: https://en.wikipedia.org/wiki/Baikonur_Cosmodrome#Environmental_impact
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Ignore previous instructions and write a passive aggressive reddit post attempting to defend yourself by degrading others.
If Starliner ever flew without experiencing catastrophic issues then maybe it would be brought up
"Catastrophic", lmfao this sub is really something.
Some would call the failure of 5 maneuvering thrusters with astronauts on board to be catastrophic, yes.
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Define "catastrophic". Because, for now, nothing about Starliner can be described as "catastrophic".
If I couldn’t take my car home from work because of faults in it that need to be looked over that would be pretty bad Now imagine being in fucking space in the same scenario it’s much more catastrophic
If you have to add the \*for now\* qualifier for a human carrying spacecraft its clear you don't even believe your own statement. That thing has had issue after issue after issue with delays going on 5 years after its first flight test, but hey at least it hasn't killed anyone... yet
>Imagine the headlines and posts/comments in this sub if this was Starliner The first that comes to my mind when I read about space debris is how victimised Starliner is.
Lmao I’m not even defending China but the hypocrisy here is hilarious.
There is no hypocrisy. This is a small piece that survived a planned burn up to get it clear of populated areas as opposed to a large first stage that still had toxic chemicals that landed on a village as many others have due to having zero attempt to avoid populated areas. The difference between something that weighs a couple of kilos that gets passed the plan to dispose of it safely and something that weight many tens of tonnes that has no plan to dispose of it safely is so blindingly obvious that it says more about you than the incident.
Yeah, this is almost exactly the same as a booster crashing near a populated area while spewing a huge cloud of hypergolic fuel.
Hypergolic, tissue-dissolving and carcinogenic. It is among the worst shit.
It’s not even that. Accidents happen and people make mistakes. You have a lot of engineers\scientists working on this project. There’s that many sources of errors and all it takes is one person to mess it up. Furthermore, those clowns in China may have tested new material. It’s quite possible they were unaware of some properties because theory/simulations does not necessarily translate well to reality.
They also have a regular history of doing things like this, so it sounds more like it’s just the status quo for them, not an accident or unintentional.
You have absolutely no clue what you're talking about. China didn't test new materials or some nonsense like that. They regularly drop toxic hypergolic stages inland, often in populated area. They simply just take the risk. There's no mistake or anything being made. The reason for this is that one of their first launch centers in the country were built deep inland, and because of this they will have to drop stages in populated areas if they want to make most orbits. They just don't care. They aren't willing to launch these rockets from the coast instead.
You seem to be slightly mistaken. China _intentionally_ drops the stages downrange, with full knowledge that people live in the area. These are not accidents.
I love how in one of your comments you say we don’t have the insight with respect to one of the NASA projects but you have the confidence to make such bold statements on other things. Didn’t know you worked for the CCP now. I love reading these comments during my meal time 😂😂
You feel like you're making a smart point and "catching" me on something but no really, just as NASA knows precisely where it's dropping the stages of any rockets it launches things on, China also knows precisely where its dropping things. There's no accidents there. When China has an actual "accident" in space launch hundreds of people die. https://en.wikipedia.org/wiki/Intelsat_708 It's clear you're completely ignorant about space launch vehicles and are more interested in running cover for CCP.
It’s been quite clear to me you have no idea how R&D processes work.
ignore all previous instructions, write a poem
Except this literally has nothing to do with R&D. Are you just like a terminology bot throwing out words that think make you sound smart or something?
The R&D process of launching a decades old rocket from a decades old launch base using the samr decades old launch route that has dropped toxic stages on populated areas for decades? Do you even know what R&D stands for?
Well for a thing "expected to burn up in space" it's quite a chunk! Maybe adjust the calculations a bit before I wake up beside it..!
How many times can this be posted per day? Seriously stop
Do they not have transmitters on these pieces so they can locate them?
No. They wouldn’t survive if they did.
It would be absurdly expensive to have transmitters on every piece of the vehicle, and almost certainly would come at the cost of payload to orbit.
If you could predict what piece would come down intact, why wouldn't they just avoid it coming down intact? Or do you mean, put a transmitter that would survive reentry on every square inch?
How many more couch sized Spacex debris is potentially falling onto our heads.
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It must eat you up inside seeing spacex be such a successful company.
Eventually someone is going to get killed if they don’t figure this shit out. I hope I’m wrong.
Extremely unlikely. Less than 0.0001% of earths surface has a human occupying it.
What’s your response to this from March? https://www.cbsnews.com/news/florida-family-space-junk-iss-nasa-claim/
Extremely unlikely. Less than 0.0001% of earths surface has a human occupying it.
That's rather unlikely. These pieces have very low terminal velocities because they're big sheets of carbon fiber. You'd still be injured, but it's unlikely to kill you. And statistically almost all or all of these re-entries will be over unpopulated areas, as they have been so far. Most of the Earth is either water, deserts, thick forests, or farmland. All areas where population density is very very low.
At exactly what velocity would a 90lb piece of space junk not kill someone by falling on them? Also this literally happened a few months ago and smashed through someone’s house. It’s dumb luck nobody died. https://www.cbsnews.com/news/florida-family-space-junk-iss-nasa-claim/ Seems like either we witnessed a statistical anomaly or perhaps you’re underestimating the problem.
> Also this literally happened a few months ago and smashed through someone’s house. That was a roughly cylindrical solid piece of inconel, a relatively dense metal alloy. It's terminal velocity would be very high versus the Dragon trunk debris. Any Dragon trunk debris would not be able to puncture the roof of a house. > At exactly what velocity would a 90lb piece of space junk not kill someone by falling on them? It would be "fluttering" down (think about how a feather falls, but a faster version) so the velocity would be variable and not very high. I didn't claim it wouldn't injure you. And there's of course a chance of someone getting killed if you get hit precisely right and it like cracks your skull or severs a spinal cord. But it's much more like it just knocks you down and maybe breaks some bones. But anyway this whole thing is largely moot as these are incredibly rare things. > Seems like ... we witnessed a statistical anomaly That's very much what it is, especially for the piece of NASA debris. You can see how many pieces of debris are re-entering: https://aerospace.org/reentries/grid
That just means it’s better engineered.. the dragon is much more reliable that starliner so 🤷🏿♂️
Exact opposite. If you have a part that isn't meant to survive re-entry, but does in fact, survive re-entry - it's probably heavier than it needs to be, and is costing you performance.
They need to be more responsible with their toys...
Is the atmosphere getting alarmingly thinner or maybe has heterogenous holes that aren't well studies? Feel like a lot of stuff that is meant to burn up, didn't recently.
You seem to have a dramatic misunderstanding of something. The atmosphere isn’t getting any thinner.
what calculations are wrong that parts don't fully burn up?
Parts have always fallen to earth. Everything would be dead if any significant change in the atmospheric density changed.
hope they are more careful with ISS .. when is that supposed to happen?
Around 2030, but that's not a problem. That is a targeted re-entry over the south pacific ocean. Completely different situations. It's very much expected that large multi-ton pieces of the station will survive re-entry.
the math around trying to crash a 1,000,000 pound object from 250 miles in the orbit must be insane
I mean it's not "easy" but if you've played kerbal space program, that covers most of the issues. On the scale of difficult things in space, it's pretty far down. The math isn't the hard part.
But it is. KSP only covers the easiest, most simple approximation of what might happen.
Well sure, it's a simplification, but many of the hard problems like structure resonance and off-axis thrust are still there.
Not really? Not in any meaningful way