When and where will the Chinese rocket reenter Earth's atmosphere? The Chinese Long March 5B rocket is expected to enter Earth's atmosphere "around May 8," according to a statement from Defense Department spokesperson Mike Howard, who said the US Space Command is tracking the rocket's trajectory. The rocket's "exact entry point into the Earth's atmosphere" can't be pinpointed until within hours of reentry, Howard said, but the 18th Space Control Squadron will provide daily updates on the rocket's location through the Space Track website. McDowell explained that pinpointing where debris could be headed is almost impossible at this point because of the speed the rocket is traveling -- with even slight changes in circumstance drastically changing the trajectory. "We expect it to reenter sometime between the eighth and 10th of May. And in that two-day period, it goes around the world 30 times. The thing is traveling at like 18,000 miles an hour. And so if you're an hour out at guessing when it comes down, you're 18,000 miles out in saying where." Still, the ocean remains the safest bet for where the debris will land, he said, just because it takes up most of the Earth's surface.
找到一点点科普,总结一句话就是中国的火箭技术还是非常落后,50年代水平,懂得人评价一下 No. The Long March 5B is parallel staged. Most rockets are tandem staged, where you have a booster stage, and then other stages on top of that. Only the second or third stages make it to orbit, and they're much smaller. The Falcon 9 works like that, and the first stage lands, while the second continues to orbit and cannot be reused. But the Long March 5B uses parallel staging, which is an approach developed in the 50's, when engineers weren't quite sure they could reliably light engines in flight, and so instead light all the engines on the ground. These engines are attached to extra fuel tanks, or feed of the main fuel tank, and as the rocket burns fuel, and the atmospheric pressure drops until those engines aren't optimized to work well anymore, they fall off. The core stage, which is the height of the whole rocket, makes it to orbit as one big piece. The Space Shuttle was another parallel staged rocket, where the SRBs and SSMEs lit at t-6, and then the SRBs staged off while the EFT continued nearly to orbit. Now, with the shuttle, the external fuel tank didn't quite make it to orbit. The main engines would shut down just before orbit, leaving the fuel tank on a trajectory that would allow it to reenter, break apart, and splash down in the middle of the ocean, while the Shuttle would perform a small burn with the OMS to place itself into its final orbit. Likewise, other boosters which are tandem staged, with second and/or third stages that make it into orbit, will either do something like the shuttle did, relying on the payload to enter final orbit, or they'll detach the payload and light their engines to reenter at Point Nemo in the Pacific, or if that's not possible, somewhere else over the ocean. For payloads going to higher energy orbits (geostationary/geosynchronous, molniya, QZO, etc) the payload will separate, and then the booster will make another burn to place itself into an even higher energy orbit called a graveyard orbit, where it can remain for thousands to hundreds of thousands of years. The problem here is that the Long March 5B core stage is enormous, and it's currently uncontrolled. It will renter wherever the hell it reenters, which is really anyone's guess. Because it's parallel staged and thus the rocket body is so unusually large, big chunks will probably make it to the surface, which is unusual for spent rocket bodies, and it's certainly very unusual for that to happen anywhere other than a pretty specific spot in the pacific ocean which is literally as far away from everyone as it's geographically possible to be.
楼上有人问,其他国家呢?但rocket science就是rocket science,不会每个国家都具备发射能力的。现在的问题是,国际公约无法enforce,因为美国俄罗斯都不会出来说什么,因为保不准哪天他们也这样。之前看过一个视频,美国回收一个旧卫星还是什么的,nasa通知明天下午降落,give or take 14 hours,大约1/4的碎片会回到降落到地球,范围是北纬57度或南纬57度,然后下面一阵爆笑,主持人对着地球仪,手在上面360度转,然后说,大家,nasa通知你们的evaculation zone是这个。
但说中国故意的,有点想多了?我觉得中国没那么个胆子啊,真的也就是技术不行以及reckless Recklessness means the person knew (or should have known) that his or her action were likely to cause harm.
但说中国故意的,有点想多了?我觉得中国没那么个胆子啊,真的也就是技术不行以及reckless Recklessness means the person knew (or should have known) that his or her action were likely to cause harm.
https://www.mentalfloss.com/article/70708/nasas-unpaid-400-littering-ticket-skylab-debris-australia In 1973, NASA made its first attempt at an orbital space station with Skylab. The project, which had to eventually be abandoned before falling back to Earth, cost an estimated $2.2 billion, though one expense was left unpaid for over three decades: a $400 littering ticket issued by a park service official in Western Australia. 当年美国的skylab 一部分落到澳大利亚一个人烟稀少的地方,袋鼠国啥也没说,开了个400澳元的乱丢垃圾罚单,后来貌似好事民众捐款给交了。
Debris is recovered from a National Wildlife Refuge after uncrewed SpaceX Starship prototype rocket SN11 failed to land safely, in Boca Chica, Texas, U.S. March 31,2021. (Reuters)
🔥 最新回帖
都是在mitbbs, wenxuexity 混不下去的老将轮子。其实好多hardcore的老将轮子在huaren也混的不爽,搬去一个啥白菜网自high了。
这位是祥林嫂附身了?
🛋️ 沙发板凳
多谢。我follow 下这几天讨论的帖子 后知后觉了
设计成这样,就是故意的,因为没有更好的办法。 还要再射几次呢, 是不是感受到人类命运共同体的力量了?
去年发射就砸到科特迪瓦了,幸运的是没有死人,知乎有讨论: https://www.zhihu.com/question/394773977/answer/1223427766
那其他国家的呢?
明白了,太缺德了,中国官方科学家一个个都是Frankenstein~~
是点火那个吗
这要遭多少人恨呐
发射空间站核心仓看了半天,喷不动了 于是换个角度喷
不是说了么 5/8号落下来,有没有事,大家看着就好了2天而已
我赌这些骂街的人2天后又销声匿迹,as always 类似议题还有: 三峡大坝即将崩塌,长江水灾泛滥,中国缺粮要饿死人,川普要政变拿下老妖婆睡乔, 白宫是替身睡乔被锁地下室
想想,这些议题有没有自告奋勇follow up的?
5/09/2021 update - 残骸掉下来了, 无惊无险印度洋,没砸到人或陆地, 隔好远我都能闻到好多轮子ID失望的味道。 哎呀,土工真的是很邪恶, 一点面子都不给。。。让轮子白表演了,as always 长征残骸无险, 白宫睡乔真身,川粉政变被镇压,中国老百姓吃嘛嘛香,长江大水灾无踪,三峡大坝屹立不倒 事实和空想,始终它不一样!
无语了…没人管管吗?
真是受不了了,轮子造谣能不能专业一点,而且天天讲,月月讲,能不能有点专业精神,炮制点新的帖子?
No. The Long March 5B is parallel staged. Most rockets are tandem staged, where you have a booster stage, and then other stages on top of that. Only the second or third stages make it to orbit, and they're much smaller. The Falcon 9 works like that, and the first stage lands, while the second continues to orbit and cannot be reused. But the Long March 5B uses parallel staging, which is an approach developed in the 50's, when engineers weren't quite sure they could reliably light engines in flight, and so instead light all the engines on the ground. These engines are attached to extra fuel tanks, or feed of the main fuel tank, and as the rocket burns fuel, and the atmospheric pressure drops until those engines aren't optimized to work well anymore, they fall off. The core stage, which is the height of the whole rocket, makes it to orbit as one big piece. The Space Shuttle was another parallel staged rocket, where the SRBs and SSMEs lit at t-6, and then the SRBs staged off while the EFT continued nearly to orbit.
Now, with the shuttle, the external fuel tank didn't quite make it to orbit. The main engines would shut down just before orbit, leaving the fuel tank on a trajectory that would allow it to reenter, break apart, and splash down in the middle of the ocean, while the Shuttle would perform a small burn with the OMS to place itself into its final orbit. Likewise, other boosters which are tandem staged, with second and/or third stages that make it into orbit, will either do something like the shuttle did, relying on the payload to enter final orbit, or they'll detach the payload and light their engines to reenter at Point Nemo in the Pacific, or if that's not possible, somewhere else over the ocean. For payloads going to higher energy orbits (geostationary/geosynchronous, molniya, QZO, etc) the payload will separate, and then the booster will make another burn to place itself into an even higher energy orbit called a graveyard orbit, where it can remain for thousands to hundreds of thousands of years.
The problem here is that the Long March 5B core stage is enormous, and it's currently uncontrolled. It will renter wherever the hell it reenters, which is really anyone's guess. Because it's parallel staged and thus the rocket body is so unusually large, big chunks will probably make it to the surface, which is unusual for spent rocket bodies, and it's certainly very unusual for that to happen anywhere other than a pretty specific spot in the pacific ocean which is literally as far away from everyone as it's geographically possible to be.
楼上有人问,其他国家呢?但rocket science就是rocket science,不会每个国家都具备发射能力的。现在的问题是,国际公约无法enforce,因为美国俄罗斯都不会出来说什么,因为保不准哪天他们也这样。之前看过一个视频,美国回收一个旧卫星还是什么的,nasa通知明天下午降落,give or take 14 hours,大约1/4的碎片会回到降落到地球,范围是北纬57度或南纬57度,然后下面一阵爆笑,主持人对着地球仪,手在上面360度转,然后说,大家,nasa通知你们的evaculation zone是这个。
以前一级不直接入轨,发射完了直接就掉下来。弹道可控。靠上面级把载荷送入轨道。上面级比较小,一般在大气层里就烧光了。危害很小。
长征5号B(迄今为止就发了两次。上次掉到了科特迪瓦)的设计是一级直接入轨。这样就不需要上面级,可以装更大的载荷。但这样的结果是发射后一级要在轨道上停留好几天,何时返回,返回到哪里都不可控。而且一级的体积很大,很难在大气层里烧光。所以比较危险。
这是1990年以来,第一个超过10吨的物体非受控返回地球。
你们真的比美国爸爸还着急。
啊,非洲咋这倒霉!
那跟我上面贴的英文解释差不多
他说这是50年代的技术,
但是回落很大的可能性是落在海里
不是第一次了,上次命好没掉到人口稠密地区,这次谁知道会这么样,五角大楼要是敢打下来,估计要讨伐先动武器
反正就是自己瞎捣鼓一次次地实验吧,我觉得故意是不可能,最多就是reckless
碎片大小没那么大的话,到地球的时候,影响也不会很大。 这个是说的很大的物体,不是碎片吧。。。
拜托,卫星碎片,和这次辣么大个物体能相提并论么?
另外,你果然是大外宣啊~~
五角大楼要真的打的话
那就丑大了,
不过这年头啥事情都是有可能的
说落在海里可能性大,大约是因为海洋面积占地球面积的71%,但是要是某鲸鱼被砸到也蛮倒霉的。
对,不一样。大的砸下来还蛮严重的,好像墨西哥之前有次被落到了,我去搜一下。
摆脱,那个是笑话节目,你们这些人真是,没人保持中立吗?就是逢中必反才符合你心意??? 如果你把有色眼镜摘下来,或许你能看出我的意思是,这东西掉哪儿,没人知道啊。
???
大家担心的,可不就是“这东西掉哪儿,没人知道啊”~~
就跟高楼往下扔花盆一样,大概率是砸不到人的。
但说中国故意的,有点想多了?我觉得中国没那么个胆子啊,真的也就是技术不行以及reckless
Recklessness means the person knew (or should have known) that his or her action were likely to cause harm.
所以大家攻击的就是中国科学家毫无公德心, 如果是失控,那情有可原, 现在是明明知道技术不行却不考虑后果胡来。
没有良心的科学家,是世界最大的灾难。
有啥奇怪的,转基因婴儿都能搞出来的国家。
还能说啥?
水平能力就在那里
只能无语
那掉到睿大姐你们家比较合适,千万别推辞,推辞你也太不爱国了
同意每一个字。但是你说怎么办呢,中国技术是落后了,但你不能阻止他实验并且进步不是吗?每个国家都想争口气,尤其是现在这种被孤立的状况,更是想奋起直追,你瞧不起我,不让我弄,我非要弄个出来给你看,和当年先污染后治理差不多的意思?就看美国打算怎么吧,我觉得最后也不会怎样。
最后一句话简直太透彻了!没错!这种人的危害比普通的大无数倍啊。自从新冠以来,对科学家的认知也被刷新了。也是拿别人钱做事,很多东西不受控,加上原本就没什么高尚的品德和情操。加上我周围很多“科学家”们,他们领域的事情就不知道了,一定很牛。但做人的素质实在是一般。而且偏执起来完全不可理喻。
你周围科学家中国人美国人啊。。。
火箭有零件掉地上也不是一次两次了,美国spaceX发射火箭也有掉在印度尼西亚。你有那么激动吗?你有说,往我头上砸吗?
https://spaceflight101.com/falcon-9-jcsat-16/spacex-rocket-parts-rain-down-over-indonesia/
睿大妈你家人并排站,十二米管子能砸死几口人,你猜猜
中国人。IT领域的。
你这地洗得也是清奇,这就是我穷我有理,我穷我爱怎么撒泼使坏都有理?那你也千万别反对别人进你家抢劫,人家没有你有呀
长征5号B(迄今为止就发了两次。上次掉到了科特迪瓦)的设计是一级直接入轨。这样就不需要上面级,可以装更大的载荷。但这样的结果是发射后一级要在轨道上停留好几天,何时返回,返回到哪里都不可控。而且一级的体积很大,很难在大气层里烧光。所以比较危险。
这是1990年以来,第一个超过10吨的物体非受控返回地球。”
手动引用,貌似说的在理
我至少没像你这么洗地,所以你到底接不接受掉到你们家?别转移话题,砸到你孩子脑袋上你还会不会这么爱国?
我哪有洗地,说几十吨的砸地上是不可能啊,大多都烧掉不是事实吗?说事实和科学是洗地吗?
美国的你为啥不抱怨?起码我没有双标只抱怨一个。我两个都没有抱怨啊!
是不是要一年来一次这种刺激
exactly
的确这逻辑实在是简单粗暴。那不会开车的人在路上引发车祸也有理了,怎么办呢?人总得学会开车吧。拿别人的利益去做实验实在是无语
说得太好了!这帮没公德心的科学家,已经从天上往下扔垃圾几十年了!上世纪七十年代就往下扔了个七十几吨的大家伙,叫什么天空实验室的!太无耻了,太无耻了!!
是的,再往前更缺德,贩卖黑奴屠杀印第安人
当年美国的skylab 一部分落到澳大利亚一个人烟稀少的地方,袋鼠国啥也没说,开了个400澳元的乱丢垃圾罚单,后来貌似好事民众捐款给交了。
至理名言
这些轮子都没文化,他们哪儿知道几十吨的东西砸地面是什么盛况 信口就胡说八道
起码我个人没有双标,没有像你们那么恶心的表演。
https://english.alarabiya.net/News/world/2021/04/03/Piece-of-SpaceX-rocket-debris-lands-at-Washington-state-farm
https://spaceflight101.com/falcon-9-jcsat-16/spacex-rocket-parts-rain-down-over-indonesia/
应该说有危险的概率不是很大。不过因为随机性比较大,而且近三十年没人这么做过,所以争议比较大。
你开车是在中国驾校学的? 在美国,教练带着学员上路开车是常规操作吧?
嗯,中国历史上从来都是最和平,对各族人民一律平等的国家。但是在现在别人反思历史,改进火箭设计的时候,中国反其道而行,还把几十年,甚至几百年前的事拿出来当挡箭牌。嗯,俺们就是这么流氓 你能把我咋的?
对中国的任何成就一定要不择手段的喷。没有东西喷就制造角度喷
长征5b上次发射也被骂了一个月,明明残骸调到了大西洋,非要在非洲找了几个不明金属管子说是中国干的
SpaceX的2级火箭上个月刚刚掉到华盛顿的牧场里,巨大一个高压气罐砸下来。但是没人炒作。
https://www.theverge.com/2021/4/2/22364582/spacex-rocket-debris-falls-farm-washington
首先,那不是“别人”的利益,白纸黑字写着是common heritage of mankind,谁能谁上。中国不会停下来不做实验的,除非美国等国出来file claim,但美国不会,因为未来他可能也有这个需要,不过谁实力强谁说话算。我之前也贴了,之前asat弄了几千片太空垃圾,美国也就把iss挪了下躲了躲,没说啥,因为美国自己也在不停地干这事儿。
当然了,如果真的砸在哪个国家,中国是要负全责的。
觉得最好的方法还是开放合作,让美国专家去给中国科学家进行批评教育,真的要好好教育,为了美国自己,页不能让中国乱来啊不是吗。
哈哈哈哈,那个乱丢垃圾的罚单,还不交,后来民众捐款凑齐的!
spacex就上个月把华盛顿的农场都砸成那样了,这个你没看到吗?中国的还没掉呢!
起码我个人没有双标,没有像你们那么恶心的表演。
https://english.alarabiya.net/News/world/2021/04/03/Piece-of-SpaceX-rocket-debris-lands-at-Washington-state-farm
中国火箭助推器也经常砸到民房,但都没有引起大的关注。主要是助推器的弹道是可以预测的。
这次主要的关注点是弹道不可预测。如果掉到海里或者人眼稀少的地方当然最好,但如果掉到人口稠密的地方可能就是灾难了。
这可不是反道而行。。。这事儿中国不做,美国做,美国不做 ,俄罗斯做。
大妈不要造谣了, 照片是星箭SN11坠地后的残骸,地点是德州 Boca Chica
不要刻舟求剑。现在的道德标准和七十年代已经不一样了。
soaceX掉在印度尼西亚的也是没有预测到的。
这张图都被贴烂了,但是从来没有任何正规媒体报道/确认过,可信度几乎为零。这里有一偏帖子介绍具体的情况 火箭残骸全部落入大西洋。
https://spaceflightnow.com/2020/05/11/chinas-massive-long-march-5bs-rocket-falls-out-of-orbit-over-ocean/
哦,我没细看,原来space X还有更多砸到建筑物的例子啊!谢谢你提醒!
我更正一下。 下面是砸到National Wildlife Refuge的3月31号2021年的SN11,不是2天后space X砸到华盛顿farm的照片。spaceX砸的也太勤快了。太多例子,大妈我都给搞糊涂了。
Debris is recovered from a National Wildlife Refuge after uncrewed SpaceX Starship prototype rocket SN11 failed to land safely, in Boca Chica, Texas, U.S. March 31,2021. (Reuters)
2天后,华盛顿农场又迎接了space X的礼物。
SpaceX的二级火箭在轨道上飞几个月,回来砸到哪里也是不可预测的
事实上长征5号从来就没有任何残骸落到地面上过。上次所谓的非洲金属管,压根就没有证据证明和火箭有关系。
而SpaceX不仅有高压气罐砸到牧场里,而且现在每个月都有星链卫星失效掉下来。年初的时候就有几颗星链卫星在四川上空再入了
但是你 1. 不知道有这回事 2. 知道了也不觉额是什么大事,因为“新闻没有集体炒作肯定不是大事”
因为你每天关心什么事情,完完全全由新闻媒体给你灌输,替你决定
这就是话语权的威力
对呀,美国70年代做了啊。 所以中国有持无恐地在做啊。没想到偷了那么多技术,怎么还在用别人50年前的啊? 不怕丢脸吗?
Re
我挺好奇的,你这种前因后果都没搞明白的人,急匆匆出来洗地是图个啥
什么时候德州的英文叫做washington了?
https://www.theverge.com/2021/4/2/22364582/spacex-rocket-debris-falls-farm-washington
你这人这么这样啊,不厚道。千万别一人五毛全家死光这种恶毒的说法。
中国是落后的啊。。。。所以你让他赶紧进步点啊。
就现在SpaceX的2级还在往下掉,SpaceX的星链还在往下掉。同样是从轨道上再入,同样是无法预测落点
SpaceX一次星链任务就要打15.6吨卫星上低轨道,现在已经打了29次。低轨道上已经有了快500吨SpaceX卫星了
星链轨道的寿命只有3年。每年会有1/3的卫星再入。SpaceX号称自己的卫星能够受控离轨,但实际上用的是和长征5B一样的轨道钝化技术,大致瞄准一个数千公里的范围而已
更糟的是,其中大约1%的卫星会故障,完全无控再入
https://en.wikipedia.org/wiki/Starlink#Space_debris
但是只要媒体不炒作,不渲染,你根本就不知道有这回事。
没有哇,我看英文报道的。里面放的是那张图,我没有读图的description。我哪知道spaceX 3天内能砸那么多建筑物. 这个创历史记录了吧。啥叫洗,我是两边都没有谴责啊。
https://english.alarabiya.net/News/world/2021/04/03/Piece-of-SpaceX-rocket-debris-lands-at-Washington-state-farm
睿大妈自己都承认照片搞错了,你还硬凹个啥?
难道现在有国家有能力去改变轨道?
服了,出来秀无知还能这么理直气壮
SpaceX几天之内连着掉了一堆东西,砸了德州也砸了华盛顿州。。他贴错图了。我贴得是二级从轨道上掉下来砸到华盛顿牧场得图
新闻链接就放在上面。看来你真的不懂英文。
火箭砸民房也不是什么新闻。中国自己报道的也不少。
长五B的问题有两个。一个是太大,第二是完全不受控。你用二级火箭和卫星相比不太合适了。体积上根本没法比的。
是为了省钱?
向美国学习你都不乐意?
人总是会犯错吧,犯错了承认了就好了嘛。你还要别人怎样?那个新闻链接说的是华盛顿,里面放的图是另一个incident,也不能完全怪我啊,是misleading。理解万岁吧。纠正就好了啊。
我只看证据
长5b得设计就是尽可能烧完。主要部件都是为了在低温下工作 (燃料是液氢液氧)。箭体材料是铝镁合金,在大气层里很快就烧完了。
SpaceX的火箭里大量用到了碳纤维。这玩意儿耐高温,很难烧光。所以上面图片里掉到华盛顿牧场里的高压气瓶就是碳纤维做的
长征5号的残骸还没有被人捡到过。所谓非洲的金属管子完全是造谣附会。SpaceX的残骸倒是确实掉下来了,序列号都在
顺便提一下: 这是SpaceX的火箭第二次砸到有人区了
地球上有人口聚居的地区占地球总面积的1%不到。但是SpaceX100多次发射,居然有两次把残骸掉到了有人区。
然后SpaceX说自己的火箭是“受控再入”,道德上特别优越。
我看真正优越的是SpaceX的PR部门。
打掉,让它变成碎片,这个不能实现吗?