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ekuNNN posted:Ol' Musky is at it again: Zaran posted:Surprise! Let NASA themselves decide if it is safe (as safe a rocket full of angry chemistry can be).
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May 7, 2018 18:29
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And if anyone wasn't aware, the Washington Post shares an owner with aspiring SpaceX competitor Blue Origin.Ak Gara posted:I don't think cold RP-1 would be any more dangerous than liquid Hydrogen? I think the objection is that propellant being actively pumped around is more dangerous than propellant sitting in tanks.
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May 7, 2018 18:30
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both jeff bezos and elon musk are bad 
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May 7, 2018 18:34
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haveblue posted:And if anyone wasn't aware, the Washington Post shares an owner with aspiring SpaceX competitor Blue Origin. When they decided to redesign the Falcon 9 for sub-cooled propellants, they decided against redesigning the stages so they had more insulation to prevent boiloff. (This is why the Shuttle could sit on the pad for a few hours with fuel in its tank with all that insulation) Without the insulation, they must launch very quickly after fueling the rocket. (it honestly sounds like an unforeseen consequence of the sudden excited move to sub-cooled propellants) The AMOS-6 explosion was related to their attempts to fuel the rocket more quickly, but thankfully they've apparently backed off that level of loading for now. Their solution is to load the crew first, and then fuel the rocket and hope that if things go wrong the Launch Abort System will be able to save the crew from a fire or explosion. This last bit is considered sub-optimal since the LAS can exert a 3-4 G surprise load on the crew and really isn't considered a first-line safety item- its more of a "last resort". World War Mammories posted:both jeff bezos and elon musk are bad Also this.
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May 7, 2018 18:39
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Ak Gara posted:I don't think cold RP-1 would be any more dangerous than liquid Hydrogen? It's not about the RP-1, it's about the cryogenic oxygen. SpaceX uses superchilled oxygen because it's denser and you can fit more in the tank. But it will start to warm up, so if you fill the tanks and then board the crew, it sits there for a while warming up and venting and you lose most of the benefit of filling the tanks with superchilled O2 in the first place. So SpaceX wants to board the crew, and then fill the tanks while the crew's sitting there, so they can launch immediately afterwards. NASA's point is "It's not safe to have the crew on board while you're fueling." SpaceX's point is "There's a launch escape system, and this way there's never a point at which the crew is on the rocket while it's fueled and not strapped into their seats in case something goes wrong." Neither of these approaches can be said to be safer a priori than the other. Doing it SpaceX's way exposes the crew to a situation where the LES fails to get them away from an exploding rocket. Doing it NASA's way exposes the crew to a situation where a catastrophe happens while they're boarding the rocket. Dienes posted:There's a good summary for SpaceX here: https://www.huffingtonpost.com/entry/would-you-fly-in-a-spacex-rocket_us_58e514b7e4b02c1f7234591d NASA also fueled the rocket with the crew on board prior to Apollo 1. NASA's shuttle had no LES at all, due to the inherent limitations of the design, and you can't say "What was safe for the shuttle is safe for manned Falcon." It doesn't work that way, safety is something that needs to be evaluated at the *system* level, and a full risk matrix created and analysed. The breathless nature of the WaPo article is ridiculous for two reasons. One, again, there is absolutely *nothing* new in there, NASA's expressed concerns about having crew on board during fueling operations and everyone's known for a while that SpaceX needs to address those concerns in order to get a manned rating. Second, WaPo is the house organ of Jeff Bezos, who himself owns a competing rocket company. Ordinarily that wouldn't by itself be a matter for concern, without further evidence of bias on WaPo's part, but in in this case they have been cold-calling this article around to journalists to get them to pick up the drum beat. Edit: Someone already posted the twitter link. Okan170 posted:When they decided to redesign the Falcon 9 for sub-cooled propellants, they decided against redesigning the stages so they had more insulation to prevent boiloff. (This is why the Shuttle could sit on the pad for a few hours with fuel in its tank with all that insulation) Without the insulation, they must launch very quickly after fueling the rocket. (it honestly sounds like an unforeseen consequence of the sudden excited move to sub-cooled propellants) Note that the Shuttle sitting on the pad for a few hours with all the cold stuff in its tanks is what led to the accumulation of ice on the ET which is a thing that actually killed 7 people and destroyed a shuttle. That's not to say with sitting on the pad for a while with full tanks is inherently less safe than gas-and-go, but it is again to point out that the safety of a system needs to take the entire system into account. Bunni-kat posted:I feel many people think Bezos must be "the good one" just because Musk is so terrible. They both suck. Both of them would improve the world by dying and leaving all their money to the government.  Phanatic fucked around with this message at 18:54 on May 7, 2018 |
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May 7, 2018 18:45
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World War Mammories posted:both jeff bezos and elon musk are bad I feel many people think Bezos must be "the good one" just because Musk is so terrible. They both suck. Both of them would improve the world by dying and leaving all their money to the government.
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May 7, 2018 18:48
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Iirc almost every article on wapo about SpaceX mentions JeffyB owns it. As if they're trying to avoid litigation. 
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May 7, 2018 18:51
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Phanatic posted:Note that the Shuttle sitting on the pad for a few hours with all the cold stuff in its tanks is what led to the accumulation of ice on the ET which is a thing that actually killed 7 people and destroyed a shuttle. STS-107 was caused by a chunk of foam coming off the forward bipod ramp and hitting the wing, not ice. This is only a safety concern if you have something side-mounted on the tank, which nobody is doing anymore.
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May 7, 2018 18:53
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Ah, my bad, I wasn't aware of those things, thanks for clarifying. I just wanted to post because I hate Elon Musk for being a union-busting piece of poo poo. (ps all billionaires are poo poo)
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May 7, 2018 19:00
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Okan170 posted:STS-107 was caused by a chunk of foam coming off the forward bipod ramp and hitting the wing, not ice. This is only a safety concern if you have something side-mounted on the tank, which nobody is doing anymore. You're right, I misspoke. But the point remains. The foam was there in order to prevent the ice buildup you get from sticking a big tank full of cryogenic liquids out in the Florida humidity and letting it sit there for a few hours. Because big chunks of ice falling from the ET could damage the orbiter. But they replaced big chunks of ice falling from the ET with big chunks of foam falling from the ET. Which, still again, illustrates the need to evaluate safety at the system level, not just a subsystem level.
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May 7, 2018 19:06
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Phanatic posted:It's not about the RP-1, it's about the cryogenic oxygen. Cryogenic oxygen is some loving terrifying poo poo. If you gently caress up and set it off, it'll burn stainless steel tubing like it's det cord all the way back to a flange or bulkhead too large to flash-heat and burn. A match, a charcoal briquette, and a cup full of LOX is enough to commit a very  suicide, since the total energy of the charcoal is liberated as heat in like 20 milliseconds. An uncontrolled LOX/airframe fire would be brief, energetic, and very very loud.AirLiquide won't even sell it to random people without a safety signoff in a lot of areas, after too many people didn't take the 'degrease everything or die horribly' warnings seriously.
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May 7, 2018 19:28
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Methylethylaldehyde posted:Cryogenic oxygen is some loving terrifying poo poo. Anything you're going to launch a rocket into space with is some loving terrifying poo poo. Dimethylhydrazine? Red fuming nitric acid?
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May 7, 2018 19:38
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ok so "cryogenic" is just a fancy word for liquid oxygen which, of necessity, is cold at standard pressure. i was thinking there was some sort of turbo-version
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May 7, 2018 20:24
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Going to drag us back to Hawaii to ask: Does anyone remember the goon who was trying to set up a kind of hippy, living off the land project in Hawaii? And who invited other goons to come help make it? I'd be interested to know if they're anywhere near the eruptions, and if their project is even still ongoing. But really all I want to know is if they were in the way of the lava how did their mud and stick shacks hold up to it lol. Gunshow Poophole posted:ok so "cryogenic" is just a fancy word for liquid oxygen which, of necessity, is cold at standard pressure. i was thinking there was some sort of turbo-version By lowering the temperature you are effectively making turbo oxygen, the burning reaction is much more thermodynamically efficient and releases more energy with a larger temperature difference between reactants and products. Budgie fucked around with this message at 20:32 on May 7, 2018 |
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May 7, 2018 20:28
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Gunshow Poophole posted:ok so "cryogenic" is just a fancy word for liquid oxygen which, of necessity, is cold at standard pressure. i was thinking there was some sort of turbo-version Technically any kind of LOX is cryogenic, but the stuff SpaceX is using is a special kind of awful. You get it about 40K colder than the boiling point and it gets measurably denser, which is super great if you have a finite amount of space to cram it into. Less super great if that finite amount of space doesn't have a very robust bleedoff mechanism when large portions of it suddenly become 12-14% larger by volume, while still being an otherwise incompressible fluid. Phanatic posted:Anything you're going to launch a rocket into space with is some loving terrifying poo poo. Dimethylhydrazine? Red fuming nitric acid? Super high purity Peroxide is also an amazing nightmare inducing pile of horror. Nothing else in the panoply of fun chemicals rockets use is able to basically melt the poor bastard fueling the rocket into goo in 60 seconds or less. Methylethylaldehyde fucked around with this message at 20:42 on May 7, 2018 |
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May 7, 2018 20:34
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BlankIsBeautiful posted:A friend and myself were cutting up a huge, fallen, Beech tree with a massive 2 cylinder chainsaw that had handlebars on the tip side for the second guy. I think the bar length was 72 inches or something. Anyway, I was the guy on the handlebars, and as we cut down through the trunk, I began to get spattered with what I thought was chain oil, so I yelled to the guy running the engine side to cool it on the oil trigger. When we cut through the section, the tree was hollow, and inside there was a huge bee hive. I mean, combs of honey nearly 5 feet long. What I thought was chain oil was actually honey. It was cold that day, so the bees would fly out away from the hive for about 5 feet and then just drop. Yep, I did take a couple of the combs home with me, and yep, it was great honey -- as long as you could get past the bee parts in it.
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May 7, 2018 20:43
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Methylethylaldehyde posted:Technically any kind of LOX is cryogenic, but the stuff SpaceX is using is a special kind of awful. You get it about 40K colder than the boiling point and it gets measurably denser, which is super great if you have a finite amount of space to cram it into. Less super great if that finite amount of space doesn't have a very robust bleedoff mechanism when large portions of it suddenly become 12-14% larger by volume, while still being an otherwise incompressible fluid. huh, I wasn't aware of the density change that's fascinating. thanks for this explanation.
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May 7, 2018 21:07
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Methylethylaldehyde posted:Super high purity Peroxide is also an amazing nightmare inducing pile of horror. Nothing else in the panoply of fun chemicals rockets use is able to basically melt the poor bastard fueling the rocket into goo in 60 seconds or less. Chlorine Triflouride would like to have a word with you. It's outside, on the giant pile of burning asbestos.
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May 7, 2018 22:21
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EoRaptor posted:Chlorine Triflouride would like to have a word with you. It's outside, on the giant pile of burning asbestos. They quit trying to use that as an oxidizer a long time ago. Instead they use it to burn off whatever's stuck to the inside of the engine before reuse.
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May 7, 2018 22:36
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Budgie posted:Going to drag us back to Hawaii to ask: Does anyone remember the goon who was trying to set up a kind of hippy, living off the land project in Hawaii? And who invited other goons to come help make it? I'd be interested to know if they're anywhere near the eruptions, and if their project is even still ongoing. They're all dead and/or much poorer for it. And still out a stolen backhoe, or whatever. RE:musk he's the dude who doesn't like safety yellow and designated safe pedestrian paths and poo poo in his factories. What the gently caress makes you think spacex is remotely safe?
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May 7, 2018 22:36
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Memento posted:Edit: here's a new twist on the Leilani Estates eruptions I wasn't aware of until just now. There's a continuous deformation of the area south of the East Rift Zone called the Hilina Slump. A 20,000km³ section of the southern flank of the Kilauea Volcano that is slowly displacing to the south at about 10cm/year. This means it's a little loose in there. This means that continued uplift from the rising magma, combined with the seismic events associated with this new eruption could drop the whole thing into the Pacific Ocean in under a minute. Jesus. I can't believe I have never heard of this 'Sword of Damocles' before. Which lead me to the Nuuanu landslide, which lead me to the Tuscaloosa Seamount. quote:The largest of these is the great Nuuanu Debris Avalanche, which swept material more than 140 miles north of Oahu and Molokai. For the last 85 miles of its journey, the avalanche traveled uphill by about 1000 feet, leaving jumbled blocks -- once part of Oahu -- scattered over more than 9000 square miles of seafloor. A block, around 10 times the size of Mt Everest?? Mother, hold me. https://www.youtube.com/watch?v=RRsT77McdE8
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May 7, 2018 22:39
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Methylethylaldehyde posted:Super high purity Peroxide is also an amazing nightmare inducing pile of horror. Nothing else in the panoply of fun chemicals rockets use is able to basically melt the poor bastard fueling the rocket into goo in 60 seconds or less. I have a gallon of 50% H202 in my freezer, and can confirm that, even at its relatively low concentration, it will burn you just like any acid. I use it to clean metal parts of any organic matter. 90% H202, which is what's normally used as rocket oxidizer/fuel must be horrifying to work with.
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May 7, 2018 22:52
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May 7, 2018 23:30
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SpaceX should just skip to the real stuff and design an engine with big boy propellants like FOOF and an organomercury compound. Maybe a beryllium peroxide.
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May 7, 2018 23:40
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I'm sure Elon really wants to build a NERVA or something
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May 8, 2018 00:06
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Speaking of companies with autodrivers Report: Software bug led to death in Uber’s self-driving crash quote:According to two anonymous sources who talked to Efrati, Uber's sensors did, in fact, detect Herzberg as she crossed the street with her bicycle. Unfortunately, the software classified her as a "false positive" and decided it didn't need to stop for her. go fast make mistakes gently caress the pedestrians gotta make the ride as comfortable as possible
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May 8, 2018 00:16
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Methylethylaldehyde posted:AirLiquide won't even sell it to random people without a safety signoff in a lot of areas, after too many people didn't take the 'degrease everything or die horribly' warnings seriously. What if my degreasing procedure is to hose stuff down with LOX?
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May 8, 2018 00:22
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https://www.youtube.com/watch?v=Q9sIT6P_05I
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May 8, 2018 00:24
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May 8, 2018 00:57
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"I got another film for ya" (maniacal laughter) (Also, turn it off before 5:30, you're welcome.) ChesterJT fucked around with this message at 01:12 on May 8, 2018 |
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May 8, 2018 01:09
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ChesterJT posted:(Also, turn it off before 5:30, you're welcome.) I really wish I read this...
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May 8, 2018 03:12
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Sticks in the mind, doesn't it? (which is rather the point)
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May 8, 2018 03:13
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Writeup for the safety party I helped throw: http://gothamist.com/2018/05/07/safety_fest_photos_2018.php#photo-1
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May 8, 2018 04:03
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https://i.imgur.com/oe1Af2Q.mp4
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May 8, 2018 04:26
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TWIST ENDING DRACULA
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May 8, 2018 04:40
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My first thought was that the vehicle was going to tip. Then I saw the wires and thought that it would touch them. Then I decided that was misdirection and it was actually going to tip.
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May 8, 2018 04:41
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Potential BFF posted:SpaceX should just skip to the real stuff and design an engine with big boy propellants like FOOF and an organomercury compound. Maybe a beryllium peroxide. Just once in my life I want to see what a nuclear salt rocket would look like in real life. You know, 2 subcritical liquid radioactive salt tanks pumped into a single chamber, causing a continuous sustained nuclear explosion.
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May 8, 2018 04:54
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I assume you'd probably die if you were close enough to watch a NSWR liftoff.
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May 8, 2018 05:01
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Pretty sure it would look a lot like that one scene in Shin Godzilla.
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May 8, 2018 05:02
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wdarkk posted:Shin Godzilla.
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