You can get out of a circular Earth orbit with a solar sail, if you want, by altering the albedo of different parts of the sail (this is how the Japanese sail steers itself). Air particles are a larger effect than light pressure below about 1000km altitude, so NanoSail-D could never do this.
Also, getting out of LEO this way is really, really slow, and results in you spending a long time in the van Allen belts. You can harden your electronics against this but you would avoid it if you can, hence why the Japanese deployed their sail after trans-Venus injection.
Its not pedantry, its a perfectly reasonable objection to the retarded way they name satellites.
1U cubesats, whos mass limit was 1kg, were picosatellites - until they got more generous and said a 1U could now weight up to something like 1.3kg. Now its a nanosatellite! Woo!
Software is a special case; its abnormally well documented on the Internet, and knowledge can be immediately and definitively checked on your computer. You find a piece of code on a website, it doesn't work, you find something else - fine. What happens if you read a fundamental misconception about particle physics? Are you going to verify it with your USB particle accelerator?
In my experience, an autodidact is someone whose making too much out of confirming their own beliefs.
Learning coding has *nothing* to do with looking stuff up online and *everything* to do with trying stuff out for yourself. Don't generalise from your ability to learn Python without thinking about this, or you will end up some sad loser on an Internet forum bleating on about tired light or reactionless space drives.
RTFA. The idea of it is, assuming the study comes out favourable, that costs will be reduced through the extra fuel saved. Whats the matter? Does reading longer than a paragraph make your brain hurt or something, fucktard?
Monopoly over railways is achieved by servicing the last mile that the rails don't cover. Monopoly over trucks is done by banning them from urban centres (politically not hard, its not like hauliers are the most popular group of society, and you can cite the emissions, road surface damage and safety).
First, I independently had a similar idea (although significantly differing in details, tbh I would trust the experts over me). Also, people have posted links to previous ideas above, and there is already the classic pneumatic canister system. The idea is as old as the hills, so we should judge it purely on the implementation, which sounds pretty smart.
However, I think they should take it much further...
Clearly, this would have to be implemented in along publicly owned routes i.e. roads. Its already pretty crowded down there, so they would have to go pretty deep I guess. However, you have just build a network designed to power vehicles and placed it under a road. If you wire it up to an induction system on the surface (presumably with some kind of wireless point of sale too) then as well as killing 92% of the carbon emissions of haulage, you've also just solved the range issue for electric cars in that same area.
If the goal is to get maximum quality of life for unit energy, such a scheme is going to pay for itself rapidly.
*some* engineers? I'm hard pressed thinking of an engineer who doesn't reckon they personally could automate the train system and save billions whilst cleaning up themselves. Hell, I know plenty of engineers who think that having pilotted civilian aircraft is retardedly expensive. In either case I don't think the problem is technical.
Unless you want a train station leading into every supermarket, retail park, and food court, then no. This system is designed for the last mile to the point of consumption, and likely a hell of a lot of the stuff that would use these tubes would've already traveled on trains at some point.
How do you think cargo containers were invented? A sudden need around the 1940s for the US to have a universal shipping system, and they weren't sending flowers over to Europe and Asia.
High altitude can compromise judgement and cause aggression. The aircrews serving drinks can exacerbate the problem, and air rage is bad enough without a sidearm.
Also, you are only taking into account someone trying to take the plane. What about a plain, old fashioned, bomb in the luggage?
They make an unreasonable request, you comply without thinking. They bark orders at you, you avoid eye contact and meekly take it. They are training you.
Sure, you can pick a new coordinate system in space; but your velocity vector won't magically align with it. Nor will it suddenly acquire the far, far greater magnitude needed to orbit compared to that needed to pop above the Karman line for a few minutes.
The worst thing is your combination of snarky arrogance with a complete unawareness of how vectors work. Betrand Russell was right I guess.
Skylon uses an air-breathing rocket engine. It isn't any kind of -jet at all. It doesn't work at as high speeds as a scramjet, but what it can do is switch to an internal oxygen supply at this speed, whereas with a scramjet you need a whole other engine, which is going to punish you quite severely in terms of mass fraction as you also require more plumbing and thrust structure.
No matter how much you scale up a hybrid, the mass fraction and specific impulse will always be too crappy for serious spaceflight. You haven't read much of 'the literature' if you don't know this.
You also show your lack of knowledge with the second question. Rockets accelerate to orbital velocity outside the Earths atmosphere and thus do not heat up in the process. Spacecraft have to heat up that much during re-entry because that is the amount of kinetic energy they need to dump in the atmosphere. If they didn't, they would have to lose kinetic energy with a retro-rocket about the same size as the one that launched them.
LOx/H2 can do SSTO but its a seriously tight margin. More likely technology is something that is partially airbreathing (i.e. Skylon or something based on the US scramjet research)
You can only use airbreathing for the lower altitudes and speeds, but it gets you a big boost because oxygen is such a large portion of the LOx/H2 mix.
However, this is a very difficult technology to master. Its almost certainly not going to provide access to space any cheaper than the big old nasty space agencies do.
Once you introduce staging, the costs go up because it works less like a plane and more like a conventional rocket. Also, due to the abysmal performance of hybrids, you would need a fuckton of staging to do it.
The maths isn't so much of a problem as engineering. Nobody has even attempted something so ambitious, and certainly a private space industry that is struggling sending very simple rockets to suborbital trajectories can't do it.
I don't have the maths with me, but I am fairly confident that won't work regardless of how many people on board.
Look at Skylon; a proposed design for an airbreathing rocket. The altitude at which it switches from atmospheric oxygen to on-board liquid oxygen is far lower than the altitude you could perform such a 'skip' maneouver at (which, by the way, decreases your velocity quite a bit. Most of the time, that is exactly why you do it)
There is a notion that if there is enough of a monetary prize out there, some magical process will allow entrepreneurs to find away around the collosal energy requirements of achieving orbit. This is fantasy I'm afraid.
Slashdot Mirror
Totally. Raven vs. mass Zergling can only end one way
You can get out of a circular Earth orbit with a solar sail, if you want, by altering the albedo of different parts of the sail (this is how the Japanese sail steers itself). Air particles are a larger effect than light pressure below about 1000km altitude, so NanoSail-D could never do this.
Also, getting out of LEO this way is really, really slow, and results in you spending a long time in the van Allen belts. You can harden your electronics against this but you would avoid it if you can, hence why the Japanese deployed their sail after trans-Venus injection.
Its not pedantry, its a perfectly reasonable objection to the retarded way they name satellites.
1U cubesats, whos mass limit was 1kg, were picosatellites - until they got more generous and said a 1U could now weight up to something like 1.3kg. Now its a nanosatellite! Woo!
Woah. You couldn't be much more ignorant about physics.
Software is a special case; its abnormally well documented on the Internet, and knowledge can be immediately and definitively checked on your computer. You find a piece of code on a website, it doesn't work, you find something else - fine. What happens if you read a fundamental misconception about particle physics? Are you going to verify it with your USB particle accelerator?
In my experience, an autodidact is someone whose making too much out of confirming their own beliefs.
Learning coding has *nothing* to do with looking stuff up online and *everything* to do with trying stuff out for yourself. Don't generalise from your ability to learn Python without thinking about this, or you will end up some sad loser on an Internet forum bleating on about tired light or reactionless space drives.
Idiot.
RTFA. The idea of it is, assuming the study comes out favourable, that costs will be reduced through the extra fuel saved. Whats the matter? Does reading longer than a paragraph make your brain hurt or something, fucktard?
Monopoly over railways is achieved by servicing the last mile that the rails don't cover. Monopoly over trucks is done by banning them from urban centres (politically not hard, its not like hauliers are the most popular group of society, and you can cite the emissions, road surface damage and safety).
True, as I posted elsewhere though, putting these things under roads could give you an opportunity to power electric and hybrid cars.
Go under roads, if you can find space under there. Surely there is scope for going down further, albeit with harder engineering problems.
Jesus, wtf are you thinking? What if someone in the TSA or equivalent is reading /.?
First, I independently had a similar idea (although significantly differing in details, tbh I would trust the experts over me). Also, people have posted links to previous ideas above, and there is already the classic pneumatic canister system. The idea is as old as the hills, so we should judge it purely on the implementation, which sounds pretty smart.
However, I think they should take it much further...
Clearly, this would have to be implemented in along publicly owned routes i.e. roads. Its already pretty crowded down there, so they would have to go pretty deep I guess. However, you have just build a network designed to power vehicles and placed it under a road. If you wire it up to an induction system on the surface (presumably with some kind of wireless point of sale too) then as well as killing 92% of the carbon emissions of haulage, you've also just solved the range issue for electric cars in that same area.
If the goal is to get maximum quality of life for unit energy, such a scheme is going to pay for itself rapidly.
*some* engineers? I'm hard pressed thinking of an engineer who doesn't reckon they personally could automate the train system and save billions whilst cleaning up themselves. Hell, I know plenty of engineers who think that having pilotted civilian aircraft is retardedly expensive. In either case I don't think the problem is technical.
Unless you want a train station leading into every supermarket, retail park, and food court, then no. This system is designed for the last mile to the point of consumption, and likely a hell of a lot of the stuff that would use these tubes would've already traveled on trains at some point.
Very different; Basically because airline passengers tend to be fairly opposed to containerization.
How do you think cargo containers were invented? A sudden need around the 1940s for the US to have a universal shipping system, and they weren't sending flowers over to Europe and Asia.
High altitude can compromise judgement and cause aggression. The aircrews serving drinks can exacerbate the problem, and air rage is bad enough without a sidearm.
Also, you are only taking into account someone trying to take the plane. What about a plain, old fashioned, bomb in the luggage?
You can just leg it past him though and get away. Sadly, though, that doesn't work well with airport security.
Oh, they are far from useless.
They make an unreasonable request, you comply without thinking. They bark orders at you, you avoid eye contact and meekly take it. They are training you.
LMAO Epic physics fail
Sure, you can pick a new coordinate system in space; but your velocity vector won't magically align with it. Nor will it suddenly acquire the far, far greater magnitude needed to orbit compared to that needed to pop above the Karman line for a few minutes.
The worst thing is your combination of snarky arrogance with a complete unawareness of how vectors work. Betrand Russell was right I guess.
Skylon uses an air-breathing rocket engine. It isn't any kind of -jet at all. It doesn't work at as high speeds as a scramjet, but what it can do is switch to an internal oxygen supply at this speed, whereas with a scramjet you need a whole other engine, which is going to punish you quite severely in terms of mass fraction as you also require more plumbing and thrust structure.
In both cases, its pretty speculative technology.
No matter how much you scale up a hybrid, the mass fraction and specific impulse will always be too crappy for serious spaceflight. You haven't read much of 'the literature' if you don't know this.
You also show your lack of knowledge with the second question. Rockets accelerate to orbital velocity outside the Earths atmosphere and thus do not heat up in the process. Spacecraft have to heat up that much during re-entry because that is the amount of kinetic energy they need to dump in the atmosphere. If they didn't, they would have to lose kinetic energy with a retro-rocket about the same size as the one that launched them.
LOx/H2 can do SSTO but its a seriously tight margin. More likely technology is something that is partially airbreathing (i.e. Skylon or something based on the US scramjet research)
You can only use airbreathing for the lower altitudes and speeds, but it gets you a big boost because oxygen is such a large portion of the LOx/H2 mix.
However, this is a very difficult technology to master. Its almost certainly not going to provide access to space any cheaper than the big old nasty space agencies do.
Once you introduce staging, the costs go up because it works less like a plane and more like a conventional rocket. Also, due to the abysmal performance of hybrids, you would need a fuckton of staging to do it.
The maths isn't so much of a problem as engineering. Nobody has even attempted something so ambitious, and certainly a private space industry that is struggling sending very simple rockets to suborbital trajectories can't do it.
I don't have the maths with me, but I am fairly confident that won't work regardless of how many people on board.
Look at Skylon; a proposed design for an airbreathing rocket. The altitude at which it switches from atmospheric oxygen to on-board liquid oxygen is far lower than the altitude you could perform such a 'skip' maneouver at (which, by the way, decreases your velocity quite a bit. Most of the time, that is exactly why you do it)
There is a notion that if there is enough of a monetary prize out there, some magical process will allow entrepreneurs to find away around the collosal energy requirements of achieving orbit. This is fantasy I'm afraid.