There's a huge field of reflectors surrounding such a tower. The only way it would fall over and crush a school would be if the school were for some strange reason built in the field of reflectors.
NASA couldn't even make the Aerospike work either, and that was supposed to revolutionize space travel in the mid-80's.
The X-33 failed because NASA couldn't get their composite fuel tanks to work, and with the additional weight needed for traditional metal tanks, they wouldn't be able to achieve SSTO. As I understand it, the aerospike itself worked great.
The flaw of the aerospike is the very thing that makes it work. It uses aerodynamic forces from the atmosphere to produce a continuously variable expansion ratio, and while it's not optimally efficient at any given altitude, it's pretty good at all altitudes. Because of this, it needs direct access to the atmosphere, and thus must be located on the exterior of a vehicle. For a toroidal aerospike, that means you can only have a single rocket motor. For a linear aerospike, you have to gang multiple in a row, which leads to a wide, flat, 'spaceplane' shape.
Single engine launch vehicles are fairly rare, with most modern launch vehicles involving multiple common cores, or a large core with multiple smaller boosters. Redesigning a launch vehicle to use a single engine would be a significant undertaking, and since most of the cost of a launch vehicle lines in the development and manufacturing, rather than the fuel, the only way it would be worth it to invest in an expensive new engine would be if it were recoverable and reusable for multiple launches.
Assuming you could pull it off, a reusable space plane would be a great way to accomplish the above. It would have to be far more robust than the shuttle, meaning you cannot require the engines be torn down, re-machined, and rebuilt from scratch after each run, and the thermal protection system would need to be something more traditional than the carbon carbon and ceramic tiles on that readily fall off and get damaged. Again, since aerospikes need to be in the airflow, you would not be able to put boosters or fuel tanks on the top and bottom. The angled side of a delta shaped object is not conducive to strapping things on either. All your fuel must be carried internally, which falls back to why that composite fuel tank was so crucial to the design of the X-33. The best you could hope for is you might be able to get away with some form of conformal drop tanks like you see on high performance fighters.
Again, your sense of scale is orders of magnitude off. 2.5MW is roughly a gallon of gasoline per minute. Commercial diesel generators are capable of that. Turboprop aircraft and small business jets are capable of several times that. The APU on a 747 uses about that much fuel, and that's for wholly auxiliary purposes, shore power and main engine startup.
The acronym 'NAP' isn't coming up with anything useful. Perhaps you could provide a link to some information?
As for the heat exchanger, it's not that hard to do and there's no need for several-megawatt class or larger reactor just to heat air and reaction mass. They had everything they needed to build aircraft with NTR and NAP sixty years ago but scrapped the project because ICBMs were cheaper and more effective than developing a nuclear bomber.
You misread me. I didn't say several megawatt. I said several hundred megawatt. Take the SR-71 as an example of the closest we have to a similar craft. It burned through fuel at around 5.3kg/s, for a power output of some 230MW. For a space plane, you're looking at a substantially larger craft, running at 2-4x the speed. You could conceivably need power output in the gigawatt range. The open core power-plant that would have been made part of the supersonic nuclear ramjet was a 500MW class reactor. The closed loop reactor intended for the nuclear turbojet was only rated for some 50MW, but it was only intended for a subsonic bomber. As you surely know, power requirements scale with the square of velocity.
On a related note, should you get your nuclear scramjet into space, how do you intend to radiate all that heat being put off by fuel decay after you shut down the reactor and have no airflow through the engines to cool it? You generally estimate about 5-10% the thermal output of the reactor at full power.
No fuel required? What prey tell would run the nuclear reactor, if not fuel?
So lets say you build this hypothetical fission powered scramjet. How are you going to exchange the heat into the supersonic flow. Either you open the core to the flow, dumping massive amounts of radiation into your exhaust, or you have an equally massive closed loop heat exchanger. I would absolutely love to see the heat exchanger with a high enough surface area to operate in the several hundred megawatt range, while still managing to maintain supersonic flow.
Once you've started into nuclear powered engines, why even bother with a linear motor launch? Use a combined cycle engine like the J-58. Use a standard turbojet engine with the combustion chamber replaced by your magical heat exchanger for take off. Once you get up to supersonic speeds, close bypass doors to the turbine and compressor, and operate as a ramjet. As you approach hypersonic speeds, lower the engine further down into the flow, and adjust your inlet geometry to produce a series of oblique shocks, rather than a single normal one, allowing supersonic flow into the heat exchanger.
Have you actually studied any of this, or are you just making up shit as you read things on wikipedia?
While I would normally agree with you, I've found that widescreen on more reasonably sized laptops (17" monsters need not apply) allows for a full sized keyboard. I've got big hands, and a larger keyboard is always welcome.
Yes. And at those speeds, it takes a long way to do that without incurring excessive g-forces, all the while in the dense, low atmosphere, building heat and sucking down fuel.
You can't just make a slight upward curve at towards the end. That curve is going to have to be miles long, and thousands of feet high to get any significant inclination in the flight path. That curve constitutes an acceleration, and as explained, if you try to do it too quickly, you're going to flatten your passengers.
I suspect that the underlying error is failing to recognize that the top of a space elevator is in geosynchronous orbit. Moving at orbital velocity, at an altitude of 22,000 miles.
If I'm going to be corrected, I'm going to get pedantic. The center of mass (not the top) of a space elevator is in geostationary orbit. Geosynchronous is a type of orbit, but geostationary is one specific geosynchronous orbit. The difference is important here.
All that is needed to launch another satellite from there into a low Earth orbit of 300 to 1500 miles is a short burn to put the bird into an orbit that grazes the atmosphere, some heat shielding, and some atmospheric control surfaces. And a good computer program that will handle multiple dips into the atmosphere to both shed excess velocity and use the control surfaces to alter direction.
That would be foolish. Forget the initial transfer burn. Just detach at some point below geostationary, where your periapsis grazes the atmosphere.
At an orbit of 22,000 miles altitude, there is more than enough potential energy to move a bird into any LEO. The general problem is one of shedding excess energy in a very controlled way.
You're completely missing the whole point I was trying to make. Changing altitude is trivial. Even without your aerobraking maneuver, there's only a couple km/s difference between LEO and GEO. That's not the hard part. The hard part are the plane changes. Back to my point that a space elevator would be geostationary, that means it's over the equator. The vast majority of LEO satellites are at a high orbit inclination, to allow them to pass over the bulk of Earth's surface. Even using a lifting body during your braking maneuver, you're not likely to get more than a couple degrees deflection off equatorial. As mentioned, in two-body mechanics, your only remaining option is to carry the fuel necessary to perform the change. Somewhere around 70 inclination, you reach parity with just launching from the surface.
That is in traditional two-body mechanics. The only way around that would be to introduce a third body into the equation, the Moon. You use the space elevator (that still exists well out past geostationary) to launch you around the Moon, and back towards Earth on a polar orbit. Now when you do this, the factor of difficulty goes up by a shitton. The sheer distances involved means you're going to have to be far more accurate on your orbital calculations. Due to differences between the Moon's orbital inclination, and the Earth's axial tilt, there are only going to be a couple times a year where you can hit the proper launch angle for the free return and proper insertion. That means each time one of these launch windows opens, there will be a small flotilla of satellites all staged out on the end of this elevator, and launched in rapid succession. Flying that many satellites over that distance in such close proximity is extremely difficult.
Simply put, there's a whole lot more to solve than just getting the thing up there. A functional space elevator would be great, and the promise of cheap access to space would enable a whole new field of possibilities. But space is big, and it's not always easy to get from one place to the next. Depending on where you want to go, getting out of a gravity well and into one orbit does not necessarily mean you're any closer to your destination.
Where did you learn your orbital mechanics? No one in their right mind would even consider doing that directly unless time was very very precious, and fuel delivered to orbit was $3.899/gallon.
By using the elevator we've been talking about for a decade or more to get to a lunar circumnavigation launch when the cable is released, that 90 degree plane change can be done with only enough delta-V to take you above or below the moon, and enough to fiddle it to perfect your polar orbit once you have used the moon for a slingshot.
Your best bet might be to travel well out past geostationary, using the elevator as a whip to launch you into a lunar transfer orbit, and then using the Moon to facilitate the plane transfer, combined with a heat shield and aerocapture to dump you into the desired orbit.
You don't understand. It's not like an airplane that you can deflect off the atmosphere. In two-body mechanics, the only way to change plane is direct thrusting with the engines. Gravity potential and aerodynamic losses of a LEO launch are only going to cost about 15% of the total delta-v budget. The rest is going to go into achieving orbital velocity. During a 90 plane change, your budget will be roughly 1.4 times your orbital velocity. Thus, a 90 plane change will be roughly 20% more expensive than getting to the same orbit from the ground. Note that is expense rated in delta-v, and actual fuel costs will be measured exponentially from that. Add into that your not-insignificant insertion burn coming off the elevator, and there's simply no purpose to it.
Yes. 50 miles or more in what direction? Our deepest mines only go a few miles down, and even if you build up the side of a mountain, and down well below it, you're going to run into increasing temperature and eventually break through the mantle. As I mentioned, it must be an inclined track, because if you try to launch horizontally, you're just going to end up wasting gobs of energy in huge aerodynamic losses over the hundred or so miles it takes to pull up out of the atmosphere. You would be lucky to break even.
You mean the direction that smart phones should have gone in the first place? Leave the phone itself as a fairly dumb device. Stuff it into a headset, with a big battery, voice command, and little power hungry processing power. Remove all long range communications from the big clunky handheld device, making it simply one of many tablet devices that tethers to the phone over bluetooth. Take it for multimedia and texting purposes, and as an axillary keypad if you don't want to use voice control. Or leave it and just use the relatively cheap handset that can stay on your ear, or easily fit in a pocket, and isn't a big loss if it gets swiped.
The space elevator has merit for getting into equatorial and escape orbits. While that would be a boon for the large communications and observation satellites in geostationary, LEO satellites are largely at high inclinations. It would cost more in delta-v to take a satellite up on a space elevator and attempt a plane transfer into polar orbit, than it would be to simply launch directly from Earth. Your best bet might be to travel well out past geostationary, using the elevator as a whip to launch you into a lunar transfer orbit, and then using the Moon to facilitate the plane transfer, combined with a heat shield and aerocapture to dump you into the desired orbit.
It would be a great stepping stone for getting to the rest of the solar system, but it's certainly not a one size fits all solution to all of spaceflights woes.
Technically, that would be two-stage to orbit, with the first stage being the 'jettisoned' launch rail. You can't just 'pull back' once you hit the end of the rail. At hypersonic speeds, you would spend tens of seconds in low, dense atmosphere doing so, and would bleed off much of your initial launch energy. If you instead use a vertical rail, you would need depths of tens of miles in order to achieve the speeds needed for a a scramjet to operate without imposing too high acceleration on the crew.
Mass driver/scramjet launches are a possibility for cargo loads, but unless we come up with some form of artificial gravity, they could never be used for manned launches.
Actually, it comes from Intel, and is the former LightPeak they've been showing off for the past few years. Apple is simply the first OEM to pick it up in their hardware.
It's the entire 800MHz or so of digital cable spectrum, and whatever content they are broadcasting in the roughly 5Gbps of bandwidth it provides. VOD channels are the exception, and they actually are IPTV streams, while on traditional cable they are simply a spare channel that is broadcast to everyone.
Well, you're back to a the rented cable box, or any other valid CableCard supporting device. There are a handful of TVs, DVRs, and PC tuner cards that support it.
fiber-based "triple play" internet/quasi-cableTV/telephone being rolled out by the telcos generally split the available downsteam bandwidth between the real, user-visible, internet bandwidth used for the internet connection part of things, and the non-user-visible bandwidth dedicated to sending digital media streams down the wire that are sold as "cable" rather than "internet streaming".
Actually, the way Verizon FiOS is set up, you have one light carrier dedicated specifically for video broadcasting. It runs through an optical transducer, which outputs a real QAM modulated digital cable signal, directly usable by any TV or PC tuner card that supports QAM.
Oh come on. If you were ripping your own disk and storing them on your own server, you wouldn't give a fuck what the 'de-facto standard' was, and would instead use whatever format your hardware supported. Get a clue and stop trying to defend someone bragging about illegal acts any second grader could pull off. It's like people taking pictures of their guns and drugs, and posting it on facebook.
The fact that the attempts are being made means that Linux servers are a viable target, and they are being compromised by this method. Botnet operators wouldn't bother fishing as such if there were never any results.
And just the same, there's a crapflood of compromised Linux servers out on the internet. Those hundreds of brute force SSH attacks you get daily are proof of that.
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There's a huge field of reflectors surrounding such a tower. The only way it would fall over and crush a school would be if the school were for some strange reason built in the field of reflectors.
NASA couldn't even make the Aerospike work either, and that was supposed to revolutionize space travel in the mid-80's.
The X-33 failed because NASA couldn't get their composite fuel tanks to work, and with the additional weight needed for traditional metal tanks, they wouldn't be able to achieve SSTO. As I understand it, the aerospike itself worked great.
The flaw of the aerospike is the very thing that makes it work. It uses aerodynamic forces from the atmosphere to produce a continuously variable expansion ratio, and while it's not optimally efficient at any given altitude, it's pretty good at all altitudes. Because of this, it needs direct access to the atmosphere, and thus must be located on the exterior of a vehicle. For a toroidal aerospike, that means you can only have a single rocket motor. For a linear aerospike, you have to gang multiple in a row, which leads to a wide, flat, 'spaceplane' shape.
Single engine launch vehicles are fairly rare, with most modern launch vehicles involving multiple common cores, or a large core with multiple smaller boosters. Redesigning a launch vehicle to use a single engine would be a significant undertaking, and since most of the cost of a launch vehicle lines in the development and manufacturing, rather than the fuel, the only way it would be worth it to invest in an expensive new engine would be if it were recoverable and reusable for multiple launches.
Assuming you could pull it off, a reusable space plane would be a great way to accomplish the above. It would have to be far more robust than the shuttle, meaning you cannot require the engines be torn down, re-machined, and rebuilt from scratch after each run, and the thermal protection system would need to be something more traditional than the carbon carbon and ceramic tiles on that readily fall off and get damaged. Again, since aerospikes need to be in the airflow, you would not be able to put boosters or fuel tanks on the top and bottom. The angled side of a delta shaped object is not conducive to strapping things on either. All your fuel must be carried internally, which falls back to why that composite fuel tank was so crucial to the design of the X-33. The best you could hope for is you might be able to get away with some form of conformal drop tanks like you see on high performance fighters.
Again, your sense of scale is orders of magnitude off. 2.5MW is roughly a gallon of gasoline per minute. Commercial diesel generators are capable of that. Turboprop aircraft and small business jets are capable of several times that. The APU on a 747 uses about that much fuel, and that's for wholly auxiliary purposes, shore power and main engine startup.
The acronym 'NAP' isn't coming up with anything useful. Perhaps you could provide a link to some information?
As for the heat exchanger, it's not that hard to do and there's no need for several-megawatt class or larger reactor just to heat air and reaction mass. They had everything they needed to build aircraft with NTR and NAP sixty years ago but scrapped the project because ICBMs were cheaper and more effective than developing a nuclear bomber.
You misread me. I didn't say several megawatt. I said several hundred megawatt. Take the SR-71 as an example of the closest we have to a similar craft. It burned through fuel at around 5.3kg/s, for a power output of some 230MW. For a space plane, you're looking at a substantially larger craft, running at 2-4x the speed. You could conceivably need power output in the gigawatt range. The open core power-plant that would have been made part of the supersonic nuclear ramjet was a 500MW class reactor. The closed loop reactor intended for the nuclear turbojet was only rated for some 50MW, but it was only intended for a subsonic bomber. As you surely know, power requirements scale with the square of velocity.
On a related note, should you get your nuclear scramjet into space, how do you intend to radiate all that heat being put off by fuel decay after you shut down the reactor and have no airflow through the engines to cool it? You generally estimate about 5-10% the thermal output of the reactor at full power.
No fuel required? What prey tell would run the nuclear reactor, if not fuel?
So lets say you build this hypothetical fission powered scramjet. How are you going to exchange the heat into the supersonic flow. Either you open the core to the flow, dumping massive amounts of radiation into your exhaust, or you have an equally massive closed loop heat exchanger. I would absolutely love to see the heat exchanger with a high enough surface area to operate in the several hundred megawatt range, while still managing to maintain supersonic flow.
Once you've started into nuclear powered engines, why even bother with a linear motor launch? Use a combined cycle engine like the J-58. Use a standard turbojet engine with the combustion chamber replaced by your magical heat exchanger for take off. Once you get up to supersonic speeds, close bypass doors to the turbine and compressor, and operate as a ramjet. As you approach hypersonic speeds, lower the engine further down into the flow, and adjust your inlet geometry to produce a series of oblique shocks, rather than a single normal one, allowing supersonic flow into the heat exchanger.
Have you actually studied any of this, or are you just making up shit as you read things on wikipedia?
While I would normally agree with you, I've found that widescreen on more reasonably sized laptops (17" monsters need not apply) allows for a full sized keyboard. I've got big hands, and a larger keyboard is always welcome.
Yes. And at those speeds, it takes a long way to do that without incurring excessive g-forces, all the while in the dense, low atmosphere, building heat and sucking down fuel.
You can't just make a slight upward curve at towards the end. That curve is going to have to be miles long, and thousands of feet high to get any significant inclination in the flight path. That curve constitutes an acceleration, and as explained, if you try to do it too quickly, you're going to flatten your passengers.
I suspect that the underlying error is failing to recognize that the top of a space elevator is in geosynchronous orbit. Moving at orbital velocity, at an altitude of 22,000 miles.
If I'm going to be corrected, I'm going to get pedantic. The center of mass (not the top) of a space elevator is in geostationary orbit. Geosynchronous is a type of orbit, but geostationary is one specific geosynchronous orbit. The difference is important here.
All that is needed to launch another satellite from there into a low Earth orbit of 300 to 1500 miles is a short burn to put the bird into an orbit that grazes the atmosphere, some heat shielding, and some atmospheric control surfaces. And a good computer program that will handle multiple dips into the atmosphere to both shed excess velocity and use the control surfaces to alter direction.
That would be foolish. Forget the initial transfer burn. Just detach at some point below geostationary, where your periapsis grazes the atmosphere.
At an orbit of 22,000 miles altitude, there is more than enough potential energy to move a bird into any LEO. The general problem is one of shedding excess energy in a very controlled way.
You're completely missing the whole point I was trying to make. Changing altitude is trivial. Even without your aerobraking maneuver, there's only a couple km/s difference between LEO and GEO. That's not the hard part. The hard part are the plane changes. Back to my point that a space elevator would be geostationary, that means it's over the equator. The vast majority of LEO satellites are at a high orbit inclination, to allow them to pass over the bulk of Earth's surface. Even using a lifting body during your braking maneuver, you're not likely to get more than a couple degrees deflection off equatorial. As mentioned, in two-body mechanics, your only remaining option is to carry the fuel necessary to perform the change. Somewhere around 70 inclination, you reach parity with just launching from the surface.
That is in traditional two-body mechanics. The only way around that would be to introduce a third body into the equation, the Moon. You use the space elevator (that still exists well out past geostationary) to launch you around the Moon, and back towards Earth on a polar orbit. Now when you do this, the factor of difficulty goes up by a shitton. The sheer distances involved means you're going to have to be far more accurate on your orbital calculations. Due to differences between the Moon's orbital inclination, and the Earth's axial tilt, there are only going to be a couple times a year where you can hit the proper launch angle for the free return and proper insertion. That means each time one of these launch windows opens, there will be a small flotilla of satellites all staged out on the end of this elevator, and launched in rapid succession. Flying that many satellites over that distance in such close proximity is extremely difficult.
Simply put, there's a whole lot more to solve than just getting the thing up there. A functional space elevator would be great, and the promise of cheap access to space would enable a whole new field of possibilities. But space is big, and it's not always easy to get from one place to the next. Depending on where you want to go, getting out of a gravity well and into one orbit does not necessarily mean you're any closer to your destination.
Where did you learn your orbital mechanics? No one in their right mind would even consider doing that directly unless time was very very precious, and fuel delivered to orbit was $3.899/gallon. By using the elevator we've been talking about for a decade or more to get to a lunar circumnavigation launch when the cable is released, that 90 degree plane change can be done with only enough delta-V to take you above or below the moon, and enough to fiddle it to perfect your polar orbit once you have used the moon for a slingshot.
I did mention that as a possibility up here
Your best bet might be to travel well out past geostationary, using the elevator as a whip to launch you into a lunar transfer orbit, and then using the Moon to facilitate the plane transfer, combined with a heat shield and aerocapture to dump you into the desired orbit.
You don't understand. It's not like an airplane that you can deflect off the atmosphere. In two-body mechanics, the only way to change plane is direct thrusting with the engines. Gravity potential and aerodynamic losses of a LEO launch are only going to cost about 15% of the total delta-v budget. The rest is going to go into achieving orbital velocity. During a 90 plane change, your budget will be roughly 1.4 times your orbital velocity. Thus, a 90 plane change will be roughly 20% more expensive than getting to the same orbit from the ground. Note that is expense rated in delta-v, and actual fuel costs will be measured exponentially from that. Add into that your not-insignificant insertion burn coming off the elevator, and there's simply no purpose to it.
Yes. 50 miles or more in what direction? Our deepest mines only go a few miles down, and even if you build up the side of a mountain, and down well below it, you're going to run into increasing temperature and eventually break through the mantle. As I mentioned, it must be an inclined track, because if you try to launch horizontally, you're just going to end up wasting gobs of energy in huge aerodynamic losses over the hundred or so miles it takes to pull up out of the atmosphere. You would be lucky to break even.
PETA? People who are going to attack you and try to eat all those tasty animals you caught?
You mean the direction that smart phones should have gone in the first place? Leave the phone itself as a fairly dumb device. Stuff it into a headset, with a big battery, voice command, and little power hungry processing power. Remove all long range communications from the big clunky handheld device, making it simply one of many tablet devices that tethers to the phone over bluetooth. Take it for multimedia and texting purposes, and as an axillary keypad if you don't want to use voice control. Or leave it and just use the relatively cheap handset that can stay on your ear, or easily fit in a pocket, and isn't a big loss if it gets swiped.
The space elevator has merit for getting into equatorial and escape orbits. While that would be a boon for the large communications and observation satellites in geostationary, LEO satellites are largely at high inclinations. It would cost more in delta-v to take a satellite up on a space elevator and attempt a plane transfer into polar orbit, than it would be to simply launch directly from Earth. Your best bet might be to travel well out past geostationary, using the elevator as a whip to launch you into a lunar transfer orbit, and then using the Moon to facilitate the plane transfer, combined with a heat shield and aerocapture to dump you into the desired orbit.
It would be a great stepping stone for getting to the rest of the solar system, but it's certainly not a one size fits all solution to all of spaceflights woes.
Technically, that would be two-stage to orbit, with the first stage being the 'jettisoned' launch rail. You can't just 'pull back' once you hit the end of the rail. At hypersonic speeds, you would spend tens of seconds in low, dense atmosphere doing so, and would bleed off much of your initial launch energy. If you instead use a vertical rail, you would need depths of tens of miles in order to achieve the speeds needed for a a scramjet to operate without imposing too high acceleration on the crew.
Mass driver/scramjet launches are a possibility for cargo loads, but unless we come up with some form of artificial gravity, they could never be used for manned launches.
But this is Intel tech, not Apple.
Actually, it comes from Intel, and is the former LightPeak they've been showing off for the past few years. Apple is simply the first OEM to pick it up in their hardware.
It's the entire 800MHz or so of digital cable spectrum, and whatever content they are broadcasting in the roughly 5Gbps of bandwidth it provides. VOD channels are the exception, and they actually are IPTV streams, while on traditional cable they are simply a spare channel that is broadcast to everyone.
Well, you're back to a the rented cable box, or any other valid CableCard supporting device. There are a handful of TVs, DVRs, and PC tuner cards that support it.
fiber-based "triple play" internet/quasi-cableTV/telephone being rolled out by the telcos generally split the available downsteam bandwidth between the real, user-visible, internet bandwidth used for the internet connection part of things, and the non-user-visible bandwidth dedicated to sending digital media streams down the wire that are sold as "cable" rather than "internet streaming".
Actually, the way Verizon FiOS is set up, you have one light carrier dedicated specifically for video broadcasting. It runs through an optical transducer, which outputs a real QAM modulated digital cable signal, directly usable by any TV or PC tuner card that supports QAM.
Oh come on. If you were ripping your own disk and storing them on your own server, you wouldn't give a fuck what the 'de-facto standard' was, and would instead use whatever format your hardware supported. Get a clue and stop trying to defend someone bragging about illegal acts any second grader could pull off. It's like people taking pictures of their guns and drugs, and posting it on facebook.
Or do you mean the fact that botnets and such are _trying_ to compromise Linux servers, that indicates a large number of compromised linux servers?
Yes. The fact that they're bothering to try gives evidence that it works.
The fact that the attempts are being made means that Linux servers are a viable target, and they are being compromised by this method. Botnet operators wouldn't bother fishing as such if there were never any results.
And just the same, there's a crapflood of compromised Linux servers out on the internet. Those hundreds of brute force SSH attacks you get daily are proof of that.