Exactly- the possibility of in-situ generation is a potentially important advantage. This assumes, almost certainly incorrectly, that you will ever be able to get to Mars in the first place using such an arrangement. Someone might try to weigh 31 Raptor engines and comparing that to the weight of the extra tank needed for methane over kerosene.
There is *nothing new* here, all of this stuff was studied extensively over half a century ago, it's well-known what the optimum parameters are, every idea, crackpot and otherwise, has long been studied from both a standpoint of performance and of practicality. Including the original Space Buff himself, Werner Von Braun.
Only the enthusiast community seems to be enthralled with these "new" developments, and only because they haven't bothered (like Musk) to study the existing literature enough to know that.
So, yes, you can build a booster using supercooled liquid methane and LOX, it can be made to do useful work, that has been known since the 30s. It's not going to be quite as good or as practical as other well-known solutions, but swell, nobody is stopping them from trying.
In an unthinakbly rare mistake, particularly given the laser-accurate reporting on Musk's antics in the space buff community, there is a mistake in the summary.
Supercooling the methane don't increase the ISP, it increases the density, making the tanks slightly smaller for a given volume, slightly reducing the weight of the tanks. Technically, it increases the mass ratio (ratio of fueled to dry mass) very slightly. That's still good, as good as if it had increased the ISP, but the effect (which, as all things Musk "invents", has been used for about 60 years or more) is not to change the ISP.
Once you start burning it, you need exactly the same amount per unit oxygen and use the same mass of it per unit impulse you would have had anyway.
The rest of the concept is marginal, Methane is only slightly better than RP-1 (refined kerosene) in terms of ISP in an ideal situation for both, and even supercooled methane is still less dense than RP-1. So the effect is that the effect you are creating with supercooling is more effective if you went to RP-1 - still smaller tanks for a given amount of energy.
The same effect is why hydrogen makes a bad fuel, particularly for a first stage (or even worse, an airplane). Giant tanks for a given energy and the difficulty of handling outweigh the very large increase in ISP aside from special cases like upper stages.
The Russians have been doing that for a long time, there's always a big green streak in the exhaust. How that works with a 'reusable" engine while it is oxidizing the combustion chamber, well, we'll see.
What evidence do you have of that last bit? All I hear from liberals is how they are going to ban speech they don't like, steal money from people and give it to others, and create an all-pervasive central government. They have to, in order to force people who have different ideas to go along by force of law.
The biggest problem with bitcoin is that there is no consideration as to the cost to the environment. Those that are dishonest can better exploit bitcoin than those that are honest.
The first is ridiculous, the second is correct. Correct to the point that you have to wonder if it wasn't designed that way intentionally. Already it has been shown to be vulnerable to the most obvious and blatant "pump and dump" schemes imaginable. Either the people who came up with it knew that and built it that way so they could rip a bunch of people off, or, they were so incredibly naive that it never occurred to them. Based on the comments here (basically, the target audience for pretend money, the Dungeons and Dragons crowd), I think it is probably the latter.
Why is it in anyway relevant that they are "rich kids"" It's unfair, because "poor kids" cannot also cheat? What about taking them all away, so no one can cheat?
I actually don't care even a little bit what happens "over the pond". And calling it a "girls game" as an insult is particularly ridiculous coming from a soccer fan. Here, soccer is a game for 8-year-olds and their moms, until they get old enough to play a real sport.
Your premise about rugby would make more sense if playing football didn't result in severe long-term head trauma and CTE - even with the protective gear. If you played rugby with the typical fast, mobile, 300-lb NFL linemen, people would *die*.
The only soccer people involved in the NFL are the kickers, who kick the ball and usually run to the sidelines as fast as their little legs can carry them, to keep from getting killed.
It's at least imaginable that women could play at a high level in baseball - fast-pitch softball, which is played almost exclusively by girls/women - is ridiculously difficult, and fast pitch pitchers VS big-league hitters usually results in embarrassment from the hitters .
If any girls want to try to play either, I am sure the NFL and MLB will be falling all over them to make it possible.
Yes, it's all the rage among the neckbeard crowd to be enamored of all things European. The best one-size-too-small Fedoras come from there, you know. Of course, they will never go there - United charges them for two seats due to their, uh, "glandular condition". Thus saving some trapped normal from a 7-hour discussion of how Star Wars technology would curbstomp the Federation.
Of course, they prefer "futbol" AKA "kicking the ball and pretending to be hurt" over real football - despite never having played either.
Right, people are tempted to do illegal things to make more money. The same forces have been working for 10,000 years or so, and its not going to change.
Why does having terabytes of data, virtually of which is mundane and completely off-topic, so important to learn that lesson? Even if you wanted to study it, how do you sort out the relevant parts? How would you even start? Every Ken Lay email? The prosecutors did that for you already, at least to the extent practical, read the transcripts (which are entirely different public records and presumably available from the court).
Carbon fiber/epoxy would be a terrible choice for the tankage for exactly the reason you suggest - it would just shatter like glass from shock at cyrogenic temperatures and you couldn't insulate it well enough. Stainless, use conventionally, is a very good choice from all aspects, and as the Atlas experience showed, it can make for a very high performance system. The Atlas stage and a half system had one of higher stage mass ratios ever fielded, the entire missile would go into orbit, it's as close to SSTO as you are ever likely to get for a practical payload fraction. The problem is that at a practical weight, it has to be so thin that it must be pressurized all the time or collapse.
Young internet space buffs tend to grossly underestimate the state of the art and the knowledge and wisdom of the past, this entire article and the original "Popular Mechanics" (for goodness sake, it's still around?) being sterling examples. 50's and 60's engineering was of an exceptional standard, and nothing much has changed about space technology, at least as regards to the important and difficult part of boosters, since then.
It also illustrates why SSTO is a fundamentally ridiculous idea, you have to build something that is quite difficult to deal with to achieve a tiny payload fraction - meaning the rocket itself tends to be huge, multplying the cost enormously. Welding up a SS balloon tank rocket stage large enough to do more than loft a Mercury capsule, say 3x-5x the size of an Atlas, can certainly be done. However, the same payload can be lofted by a much smaller staged rocket because of the mass ratio advantages.
What difference does it make at this point? The case is closed, the company is gone, people have gone to jail. It's completely irrelevant today. There are also plenty of public records of the trials if anyone wants to know the details.
They built something like 500 balloon-tank Atlas missiles at Atlas II and they were extremely successful, every single one of them was stainless steel. They launched the last one in the early 2000's , and the Atlas II has a perfect success record. Hardly "ill-fated attempts one the Atlas program in the late 50's".
Musk, of course, is not using the stainless in an ideal manner, mostly for show. That's because he is more PT Barnum than Werner Von Braun.
OOOH, you guys are so busted, the EU internet cops are going to be on you like Hans Brinker on a silver skate! You're getting a boot up the ass - a wooden boot, of course.
Sociopaths, we call them, and there seem to be a lot of them about recently. Of course, they are also idiots if they think a single politician can somehow destroy the most adaptive species every to arise. That also has a name, Trump Derangement Syndrome.
Of course. In 1977, Star Wars was a stunning breakthrough, with "2001"-level special effects and a moderately entertaining (and utterly predictable and unoriginal) story. The stories are still numbingly predictable, and the effects are no better than you can get on TV for free every night. And you can never been the memories of a bunch of middle-aged men who saw Star Wars when they were 12.
Here's an observation - from a story standpoint, the prequels, and particularly Clone Wars and Revenge of the Sith, were *far superior*, even knowing how the protagonist was going to end up. And the acting, aside from the poorly-cast leads, was a lot better than freaking Mark Hamill ever managed. These movies were excoriated by the 12-years-old in 45-year-old bodies.
There is *nothing* you can do to replace the wonder they felt right from the first scene of Star Wars. When that ship came flying over your heads getting wider and wider, George Lucas was a multi-millionaire, no matter what happened afterwards. Nothing like that is even possible now, it's all old hat.
Literally nothing they could have done would have made these films any more successful than they were, it had to run out of gas eventually, because the basic stories (repeated over and over) are just not that good.
That's all true - but there was also tremendous opposition to some of the routes existing at all. Which meant that the road was rerouted out of town, cutting off what would otherwise have been much better local access. That they ended up doing in some cases was cutting off their nose to spite their face.
You have a point, but It takes 2000 years to grow to full height. I don't think it's that much of a risk compared to rabbits or cane toads. Plus, it's probably not going to work in any case, they evolved to work in a very specific, rare (bordering on unique), habitat, and most of Australia is *utterly* incompatible. I don't see much danger of being overrun.
If it was paleozoic glossopteris, then it would be more of a concern. They are about at close to managing that as they are T. Rex. or trilobites.
Slashdot Mirror
Exactly- the possibility of in-situ generation is a potentially important advantage. This assumes, almost certainly incorrectly, that you will ever be able to get to Mars in the first place using such an arrangement. Someone might try to weigh 31 Raptor engines and comparing that to the weight of the extra tank needed for methane over kerosene.
There is *nothing new* here, all of this stuff was studied extensively over half a century ago, it's well-known what the optimum parameters are, every idea, crackpot and otherwise, has long been studied from both a standpoint of performance and of practicality. Including the original Space Buff himself, Werner Von Braun.
Only the enthusiast community seems to be enthralled with these "new" developments, and only because they haven't bothered (like Musk) to study the existing literature enough to know that.
So, yes, you can build a booster using supercooled liquid methane and LOX, it can be made to do useful work, that has been known since the 30s. It's not going to be quite as good or as practical as other well-known solutions, but swell, nobody is stopping them from trying.
In an unthinakbly rare mistake, particularly given the laser-accurate reporting on Musk's antics in the space buff community, there is a mistake in the summary.
Supercooling the methane don't increase the ISP, it increases the density, making the tanks slightly smaller for a given volume, slightly reducing the weight of the tanks. Technically, it increases the mass ratio (ratio of fueled to dry mass) very slightly. That's still good, as good as if it had increased the ISP, but the effect (which, as all things Musk "invents", has been used for about 60 years or more) is not to change the ISP.
Once you start burning it, you need exactly the same amount per unit oxygen and use the same mass of it per unit impulse you would have had anyway.
The rest of the concept is marginal, Methane is only slightly better than RP-1 (refined kerosene) in terms of ISP in an ideal situation for both, and even supercooled methane is still less dense than RP-1. So the effect is that the effect you are creating with supercooling is more effective if you went to RP-1 - still smaller tanks for a given amount of energy.
The same effect is why hydrogen makes a bad fuel, particularly for a first stage (or even worse, an airplane). Giant tanks for a given energy and the difficulty of handling outweigh the very large increase in ISP aside from special cases like upper stages.
The Russians have been doing that for a long time, there's always a big green streak in the exhaust. How that works with a 'reusable" engine while it is oxidizing the combustion chamber, well, we'll see.
A "solution" being more akin to the "Final Solution" than what most people might mean, perhaps.
The violence will end when everybody currently being ethnically cleansed is dead. Peace in our time!
Most trusted world authorities - the UN?! The same UN that puts Sudan on the "Human Rights Committee"?
What evidence do you have of that last bit? All I hear from liberals is how they are going to ban speech they don't like, steal money from people and give it to others, and create an all-pervasive central government. They have to, in order to force people who have different ideas to go along by force of law.
The first is ridiculous, the second is correct. Correct to the point that you have to wonder if it wasn't designed that way intentionally. Already it has been shown to be vulnerable to the most obvious and blatant "pump and dump" schemes imaginable. Either the people who came up with it knew that and built it that way so they could rip a bunch of people off, or, they were so incredibly naive that it never occurred to them. Based on the comments here (basically, the target audience for pretend money, the Dungeons and Dragons crowd), I think it is probably the latter.
Why is it in anyway relevant that they are "rich kids"" It's unfair, because "poor kids" cannot also cheat? What about taking them all away, so no one can cheat?
I actually don't care even a little bit what happens "over the pond". And calling it a "girls game" as an insult is particularly ridiculous coming from a soccer fan. Here, soccer is a game for 8-year-olds and their moms, until they get old enough to play a real sport.
Your premise about rugby would make more sense if playing football didn't result in severe long-term head trauma and CTE - even with the protective gear. If you played rugby with the typical fast, mobile, 300-lb NFL linemen, people would *die*.
The only soccer people involved in the NFL are the kickers, who kick the ball and usually run to the sidelines as fast as their little legs can carry them, to keep from getting killed.
It's at least imaginable that women could play at a high level in baseball - fast-pitch softball, which is played almost exclusively by girls/women - is ridiculously difficult, and fast pitch pitchers VS big-league hitters usually results in embarrassment from the hitters .
If any girls want to try to play either, I am sure the NFL and MLB will be falling all over them to make it possible.
Yes, it's all the rage among the neckbeard crowd to be enamored of all things European. The best one-size-too-small Fedoras come from there, you know. Of course, they will never go there - United charges them for two seats due to their, uh, "glandular condition". Thus saving some trapped normal from a 7-hour discussion of how Star Wars technology would curbstomp the Federation.
Of course, they prefer "futbol" AKA "kicking the ball and pretending to be hurt" over real football - despite never having played either.
Right, people are tempted to do illegal things to make more money. The same forces have been working for 10,000 years or so, and its not going to change.
Why does having terabytes of data, virtually of which is mundane and completely off-topic, so important to learn that lesson? Even if you wanted to study it, how do you sort out the relevant parts? How would you even start? Every Ken Lay email? The prosecutors did that for you already, at least to the extent practical, read the transcripts (which are entirely different public records and presumably available from the court).
Butthurt fanboi alert!
Carbon fiber/epoxy would be a terrible choice for the tankage for exactly the reason you suggest - it would just shatter like glass from shock at cyrogenic temperatures and you couldn't insulate it well enough. Stainless, use conventionally, is a very good choice from all aspects, and as the Atlas experience showed, it can make for a very high performance system. The Atlas stage and a half system had one of higher stage mass ratios ever fielded, the entire missile would go into orbit, it's as close to SSTO as you are ever likely to get for a practical payload fraction. The problem is that at a practical weight, it has to be so thin that it must be pressurized all the time or collapse.
Young internet space buffs tend to grossly underestimate the state of the art and the knowledge and wisdom of the past, this entire article and the original "Popular Mechanics" (for goodness sake, it's still around?) being sterling examples. 50's and 60's engineering was of an exceptional standard, and nothing much has changed about space technology, at least as regards to the important and difficult part of boosters, since then.
It also illustrates why SSTO is a fundamentally ridiculous idea, you have to build something that is quite difficult to deal with to achieve a tiny payload fraction - meaning the rocket itself tends to be huge, multplying the cost enormously. Welding up a SS balloon tank rocket stage large enough to do more than loft a Mercury capsule, say 3x-5x the size of an Atlas, can certainly be done. However, the same payload can be lofted by a much smaller staged rocket because of the mass ratio advantages.
What difference does it make at this point? The case is closed, the company is gone, people have gone to jail. It's completely irrelevant today. There are also plenty of public records of the trials if anyone wants to know the details.
They built something like 500 balloon-tank Atlas missiles at Atlas II and they were extremely successful, every single one of them was stainless steel. They launched the last one in the early 2000's , and the Atlas II has a perfect success record. Hardly "ill-fated attempts one the Atlas program in the late 50's".
Musk, of course, is not using the stainless in an ideal manner, mostly for show. That's because he is more PT Barnum than Werner Von Braun.
The UN goal is to advance globalism.
I suggest you identify as a robot instead.
The Fringe:
http://www.sealiesoftware.com/...
I got bored at level 348 with 30+ extra guys left
OOOH, you guys are so busted, the EU internet cops are going to be on you like Hans Brinker on a silver skate! You're getting a boot up the ass - a wooden boot, of course.
Sociopaths, we call them, and there seem to be a lot of them about recently. Of course, they are also idiots if they think a single politician can somehow destroy the most adaptive species every to arise. That also has a name, Trump Derangement Syndrome.
Of course. In 1977, Star Wars was a stunning breakthrough, with "2001"-level special effects and a moderately entertaining (and utterly predictable and unoriginal) story. The stories are still numbingly predictable, and the effects are no better than you can get on TV for free every night. And you can never been the memories of a bunch of middle-aged men who saw Star Wars when they were 12.
Here's an observation - from a story standpoint, the prequels, and particularly Clone Wars and Revenge of the Sith, were *far superior*, even knowing how the protagonist was going to end up. And the acting, aside from the poorly-cast leads, was a lot better than freaking Mark Hamill ever managed. These movies were excoriated by the 12-years-old in 45-year-old bodies.
There is *nothing* you can do to replace the wonder they felt right from the first scene of Star Wars. When that ship came flying over your heads getting wider and wider, George Lucas was a multi-millionaire, no matter what happened afterwards. Nothing like that is even possible now, it's all old hat.
Literally nothing they could have done would have made these films any more successful than they were, it had to run out of gas eventually, because the basic stories (repeated over and over) are just not that good.
That's why it is generally a good idea not to *break the law*.
That's all true - but there was also tremendous opposition to some of the routes existing at all. Which meant that the road was rerouted out of town, cutting off what would otherwise have been much better local access. That they ended up doing in some cases was cutting off their nose to spite their face.
Well, actually, even if it kills *you*. They'll be OK.
You have a point, but It takes 2000 years to grow to full height. I don't think it's that much of a risk compared to rabbits or cane toads. Plus, it's probably not going to work in any case, they evolved to work in a very specific, rare (bordering on unique), habitat, and most of Australia is *utterly* incompatible. I don't see much danger of being overrun.
If it was paleozoic glossopteris, then it would be more of a concern. They are about at close to managing that as they are T. Rex. or trilobites.