This is completely different from what Branson is doing which is tourism for rich people. The proposal here is to launch large planes to the edge of atmosphere for rapid transportation.
If you bother reading the article you’ll see that the motivation here is to save fuel. It’s a lot cheaper to use an electromagnetic launcher to launch the plane.
@yogthos@goatsarah Thing is: This idea is not new. People have thought about it for a long time. And in the end they all came to the same conclusion: it isn't worth it.
yogthos@lemmy.ml
on 15 Mar 2024 15:45
nextcollapse
Thing is that the west stopped making any ambitious engineering projects. The idea isn’t new, but the will to put these kinds of things in practice doesn’t exist outside of China.
@yogthos Physics is the same all over the world. Your goal is to reach orbital velocity, otherwise you don't stay in the orbit. You cannot achieve this on the ground level, since the air resistance would melt your device. Also the drag would slow the system down massively. This means that you would had to carry fuel with you, to be able to accelerate, once you reached the upper atmospheres.
Also the article claims that people should be carried with that device as well. This limits the acceleration to around 4g.
Physics states that this type of travel is perfectly possible. The question is whether people want to invest into making this sort of tech or not. I’m familiar with the arguments for and against this tech already. What I’m trying to explain to you is that serious people are working on this project, and it’s absurd to assume that they don’t understand basic things you learned from a short youtube video.
@yogthos I don't need that video for that. I'm interested in that topic for many years, means that I know enough physics to understand the problems behind that. I'm able to use the appropriate formulas for stuff like acceleration. Also I know how to perform proper research. And with this I don't mean "Youtube".
@yogthos I'm a space nerd, so I'm always happy to see advancements in this area. I'm no "the west is the best" guy. I'm also a fan of the Indian space program. They achieve great stuff with an astonishing low budget. And I really hope that they will launch people into space in a not so distant future.
Also I think that it is a real shame, that there is this aggressive competition in space. I would love to see all the nations cooperate in a common space program, like it had already been done, when the ISS had been built.
China is launching a lot of rockets into space. They only should stop their launches from Jiuquan, Xichang or Taiyuan, since from there they have to drop their first stages onto land in areas where people live.
@yogthos@goatsarah You would had to enter hypersonic regime at ground level to even have got the possibility to reach the edge of space. Just imagine the sonic boom from that ... Also think about the thermal protection that would be needed for your device to withstand the air friction.
Again, I’m sure actual engineers designing this stuff have in fact thought about these things.
heluecht@pirati.ca
on 15 Mar 2024 15:32
nextcollapse
@yogthos Sadly the article is behind a paywall, so I have to make some educated guesses. This idea has got multiple problems. First thing is that especially when you want to transport people (like said in the article), the g-load is really limited. This means that your rail gun would had to be incredibly long to speed up the plane to a significant speed. Remember that you need to travel at 25,000 km/h to stay in orbit.
But even when you sped up to such a speed, you would experience a ton of drag because of the air resistance. It is only feasible to really speed up in higher regions (> 70-80km). So you would need some kind of first stage that had to carry some kind of a second stage to that region, so that it could accelerate from there. But this is exactly the concept that is used by rockets like the Falcon9/Falcon Heavy or Rocket Labs Electron, who all perform a stage separation in that region and perform a RTLS or controlled splash down to recover the first stage.
Also you would had only a single possible orbit here. But in reality there are a bunch of different interesting orbits out there.
Then just think about the costs. Just calculate how much launches with systems like the F9 or the upcoming Neutron you would have to perform, to even reach the break even point.
yogthos@lemmy.ml
on 15 Mar 2024 16:19
nextcollapse
since it works for me, here’s the text from it
People could soon be launched into space using a type of hypersonic rail gun, as Chinese scientists and engineers combine the significant advances made in recent years in both electromagnetic launch and hypersonic flight.
Essentially the goal is this: to use a giant electromagnetic launch track to accelerate a hypersonic aircraft to Mach 1.6. The aircraft would then separate from the track, ignite its engine and enter near space at seven times the speed of sound.
This space plane, a behemoth weighing 50 tonnes and measuring longer than a Boeing 737, is part of the “Tengyun project” unveiled in 2016.
Relying on the plane’s own power for lift-off would require a huge amount of fuel. And to ensure safety during a low-speed take-off, scientists and engineers have had to make compromises in aerodynamic design and engine layout that affect high-speed flight efficiency.
But, while in the past such projects did not get past the discussion phase, this time it is different. China is putting words into action.
And scientists working on the project are confident the various issues can be solved.
“Electromagnetic launch technology provides a promising solution to overcome these challenges and has emerged as a strategic frontier technology being pursued by the world’s leading nations,” the team, led by scientist Li Shaowei with the magnetoelectric general department of China Aerospace Science and Industry Corporation’s (CASIC) Flight Vehicle Technology Research Institute, wrote in a peer-reviewed paper published in the Chinese academic journal Acta Aeronautica on February 6.
Putting theory to the test
To test the theory, CASIC, one of China’s foremost aerospace and defence contractors, has constructed a 2km (1.2 mile) low-vacuum track high-speed maglev test facility in the industrial heartland of Datong, Shanxi province.
This facility can propel a heavy object to speeds approaching 1,000km/h (620mph)– close to the speed of sound. In the coming years, the length of the test line will be extended to achieve a maximum operating speed of 5,000km/h.
This is the most ambitious electromagnetic propulsion facility on the planet, poised to support the development of next-generation high-speed railways and gather vital scientific and engineering data for the space electromagnetic launch project.
Meanwhile in Jinan, capital of the eastern Shandong province, another giant maglev track to support ultra high-speed electromagnetic sled experiments is also up and running, under the supervision of the Chinese Academy of Sciences (CAS).
Nasa’s failure to launch
China is not the first country to propose an electromagnetic space launch system. Such concepts have been floating around since the Cold War era.
In the 1990s, Nasa tried to bring this idea from paper to reality, with the first step being the construction of a mini test line measuring 15 metres (49 feet).
However, due to insufficient funding and technical difficulties, the actual length of the completed track was less than 10 metres. Eventually, the project was scrapped, and government and military leaders redirected resources towards the development of low-speed electromagnetic catapult technology for aircraft carriers instead.
But the USS Ford, the first aircraft carrier to be fitted out with this new technology, has been plagued with issues. During Donald Trump’s presidency, he complained that the actual performance of the electromagnetic catapults was far inferior to that of their traditional steam counterparts.
The US Navy has also publicly acknowledged that the excessively high failure rate of the Ford’s electromagnetic catapult system has resulted in reduced combat capability for the entire carrier strike group.
Due to significant setbacks in electromagnetic launch technology, the US military has abandoned the development of some related projects, such as rail guns, and shifted the saved funding to hypersonic missiles.
Now, China has picked up the relay baton handed off by America. Nonetheless, Li and his colleagues are being cautious.
Computer simulations, wind tunnel tests
In the early stages of their research, they uncovered a startling omission by Nasa: no wind tunnel tests were ever conducted to ascertain the viability of detaching the space plane from its track.
Nasa’s original idea was that accelerating the space shuttle to just 700km/h would be enough to eliminate the need for a first-stage rocket, but Chinese scientists believe this speed is too low.
However as the speed increases, the airflow between the aircraft, the electromagnetic sled carrying it and the ground track becomes very intense and complex. So one of the first things the project team must confirm is that the aircraft will be able to safely separate from the track.
To this end, Li’s team has conducted extensive computer simulations and wind tunnel tests. Their findings have revealed that a
@yogthos So the system just accelerates to Mach 1.6, then the system had to use its own fuel to speed up to just Mach 7. But Mach 7 is just a fraction of the needed velocity to get into orbit. Mach 7 is around 8,500 km/h. But you need 25,000 km/h to stay in orbit. So you need an additional stage to accelerate to that speed. And that stage would had to be expendable, otherwise you couldn't carry enough payload.
Still you can only reach a single orbit. To reach another orbital plane, you then would had to use a lot of additional propellant to perform a dogleg maneuver to switch to a different plane.
BTW: This whole idea reminds me of SpinLaunch. Prototypes are already built by the U.S. based company with the same name. They want to accelerate small launchers in a vacuum chamber, so that in the end they can carry up to 300kg in a low earth orbit.
But the goal isn’t to stay in orbit. The goal is to push the plane to upper atmosphere where there is low air resistance, and then it mostly glides to where it needs to go. The article very clearly explains that the goal is to create an alternative to long range flights instead of doing space launches. I’m also familiar with SpinLaunch, and it’s a completely different purpose where they want to launch small satellites into low Earth orbit.
@yogthos The articles ends in "While SpaceX’s reusable rockets have slashed satellite launch costs to US$3,000/kg, some scientists have estimated that an electromagnetic space launch system could drive those costs down to a mere US$60/kg."
This tech can be used for both purposes, but most of the article discusses transportation. Once China puts this tech in production, I’m sure it will be used for orbital launches as well.
@yogthos I now had more time to look into the article. The whole article is focused solely on the electromagnet technology. From here it refers to some other technology that uses electromagnet acceleration like Musk's fever dream "Hyperloop" and sea carrier catapults while in the end making a reference to orbital launch costs.
Thing is: It simply doesn't make sense. Neither in point-to-point transportation nor in space launch activities this would work out, since you could reach only a single orbital plane or flight direction. To reach more than one point or orbit, you would need to have a lot of these systems, which then would result in really high operational costs.
However, this technology is fine for a highly improved land based transportation method, especially for China, which is the forth biggest country (behind Russia, Canada and the USA).
This is literally what people said about high speed rail. The argument was that this is simply not cost effective and that’s why it can’t be built. Yet, China covered the whole country with HSR in a decade. Short term cost effectiveness isn’t really an issue when you have a state directed economy. And costs for any new technology come down over time. Maybe China will start using it for ground based transportation first, and then start using it for other applications. We’ll just wait and see.
@yogthos Which people said that about high speed rail? The country I'm living in has got high speed rail since the 90s. See also Japan or France (and some other countries).
The original point was that arguments about cost efficiency have been made regarding HSR. Every new technology is expensive when it’s initially developed, and it requires significant investment. One way to look at that is to say that it’s not worth spending the effort on, another way to look at it is that spending the effort creates jobs, spurs innovation, and brings long term benefits to society. It’s pretty clear to me that China tends to take the long view on such things, and hence I think it’s very probable that they will try building such launch systems.
@yogthos Well, I've got the opinion, that infrastructure shouldn't be operated for profit, so I've got no problem with investing a lot of money in advance. My points are meant from a technical standpoint. And when I refer to the costs, then I mean this in a way that I've got the opinion that the money should be invested in other stuff as well.
I don’t think anybody is arguing this sort of stuff should be funded at the expense of other stuff though, and based on how quickly the standard of living is improving in China, seems that they are doing a pretty good job funding the other stuff.
Trudge@lemmygrad.ml
on 15 Mar 2024 16:40
nextcollapse
Essentially the goal is this: to use a giant electromagnetic launch track to accelerate a hypersonic aircraft to Mach 1.6. The aircraft would then separate from the track, ignite its engine and enter near space at seven times the speed of sound.
Does no one read the article anymore before commenting? I’m not responding to all the comments here since it’s clearly a waste of my time, but every single one of the concerns that people mention in this thread so far has been acknowledged in the article already.
cmnybo@discuss.tchncs.de
on 15 Mar 2024 18:51
nextcollapse
Sure, that will be for “planes” and definitely not for long range hypersonic cruise missiles.
electricprism@lemmy.ml
on 16 Mar 2024 01:34
collapse
threaded - newest
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This is completely different from what Branson is doing which is tourism for rich people. The proposal here is to launch large planes to the edge of atmosphere for rapid transportation.
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If you bother reading the article you’ll see that the motivation here is to save fuel. It’s a lot cheaper to use an electromagnetic launcher to launch the plane.
.
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I love how you think you know more about the subject than the actual engineers building this stuff. 😂
@yogthos @goatsarah Thing is: This idea is not new. People have thought about it for a long time. And in the end they all came to the same conclusion: it isn't worth it.
Thing is that the west stopped making any ambitious engineering projects. The idea isn’t new, but the will to put these kinds of things in practice doesn’t exist outside of China.
@yogthos Physics is the same all over the world. Your goal is to reach orbital velocity, otherwise you don't stay in the orbit. You cannot achieve this on the ground level, since the air resistance would melt your device. Also the drag would slow the system down massively. This means that you would had to carry fuel with you, to be able to accelerate, once you reached the upper atmospheres.
Also the article claims that people should be carried with that device as well. This limits the acceleration to around 4g.
I recommend to watch the following video, where someone calculated all the values: https://www.youtube.com/watch?v=hQCTTvkh7gw
Here is an alternative Piped link(s):
https://www.piped.video/watch?v=hQCTTvkh7gw
Piped is a privacy-respecting open-source alternative frontend to YouTube.
I’m open-source; check me out at GitHub.
Physics states that this type of travel is perfectly possible. The question is whether people want to invest into making this sort of tech or not. I’m familiar with the arguments for and against this tech already. What I’m trying to explain to you is that serious people are working on this project, and it’s absurd to assume that they don’t understand basic things you learned from a short youtube video.
@yogthos I don't need that video for that. I'm interested in that topic for many years, means that I know enough physics to understand the problems behind that. I'm able to use the appropriate formulas for stuff like acceleration. Also I know how to perform proper research. And with this I don't mean "Youtube".
Again, are you suggesting that people working on this stuff lack the understanding that you have, and aren’t able to understand these problems?
@yogthos Well, this whole article sounds like a lot of propaganda without any real facts to me.
I guess we’ll see won’t we.
@yogthos I'm a space nerd, so I'm always happy to see advancements in this area. I'm no "the west is the best" guy. I'm also a fan of the Indian space program. They achieve great stuff with an astonishing low budget. And I really hope that they will launch people into space in a not so distant future.
Also I think that it is a real shame, that there is this aggressive competition in space. I would love to see all the nations cooperate in a common space program, like it had already been done, when the ISS had been built.
China is launching a lot of rockets into space. They only should stop their launches from Jiuquan, Xichang or Taiyuan, since from there they have to drop their first stages onto land in areas where people live.
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@goatsarah BTW: This sounds like a super sized "Spinlaunch" in my ears - which also has got a lot of technical difficulties.
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@yogthos @goatsarah You would had to enter hypersonic regime at ground level to even have got the possibility to reach the edge of space. Just imagine the sonic boom from that ... Also think about the thermal protection that would be needed for your device to withstand the air friction.
Again, I’m sure actual engineers designing this stuff have in fact thought about these things.
@yogthos Sadly the article is behind a paywall, so I have to make some educated guesses. This idea has got multiple problems. First thing is that especially when you want to transport people (like said in the article), the g-load is really limited. This means that your rail gun would had to be incredibly long to speed up the plane to a significant speed. Remember that you need to travel at 25,000 km/h to stay in orbit.
But even when you sped up to such a speed, you would experience a ton of drag because of the air resistance. It is only feasible to really speed up in higher regions (> 70-80km). So you would need some kind of first stage that had to carry some kind of a second stage to that region, so that it could accelerate from there. But this is exactly the concept that is used by rockets like the Falcon9/Falcon Heavy or Rocket Labs Electron, who all perform a stage separation in that region and perform a RTLS or controlled splash down to recover the first stage.
Also you would had only a single possible orbit here. But in reality there are a bunch of different interesting orbits out there.
Then just think about the costs. Just calculate how much launches with systems like the F9 or the upcoming Neutron you would have to perform, to even reach the break even point.
here’s a full article so you don’t have to speculate archive.ph/KbL8c
@yogthos The link sadly doesn't work.
since it works for me, here’s the text from it
People could soon be launched into space using a type of hypersonic rail gun, as Chinese scientists and engineers combine the significant advances made in recent years in both electromagnetic launch and hypersonic flight. Essentially the goal is this: to use a giant electromagnetic launch track to accelerate a hypersonic aircraft to Mach 1.6. The aircraft would then separate from the track, ignite its engine and enter near space at seven times the speed of sound. This space plane, a behemoth weighing 50 tonnes and measuring longer than a Boeing 737, is part of the “Tengyun project” unveiled in 2016. Relying on the plane’s own power for lift-off would require a huge amount of fuel. And to ensure safety during a low-speed take-off, scientists and engineers have had to make compromises in aerodynamic design and engine layout that affect high-speed flight efficiency. But, while in the past such projects did not get past the discussion phase, this time it is different. China is putting words into action. And scientists working on the project are confident the various issues can be solved.
“Electromagnetic launch technology provides a promising solution to overcome these challenges and has emerged as a strategic frontier technology being pursued by the world’s leading nations,” the team, led by scientist Li Shaowei with the magnetoelectric general department of China Aerospace Science and Industry Corporation’s (CASIC) Flight Vehicle Technology Research Institute, wrote in a peer-reviewed paper published in the Chinese academic journal Acta Aeronautica on February 6. Putting theory to the test To test the theory, CASIC, one of China’s foremost aerospace and defence contractors, has constructed a 2km (1.2 mile) low-vacuum track high-speed maglev test facility in the industrial heartland of Datong, Shanxi province.
This facility can propel a heavy object to speeds approaching 1,000km/h (620mph)– close to the speed of sound. In the coming years, the length of the test line will be extended to achieve a maximum operating speed of 5,000km/h. This is the most ambitious electromagnetic propulsion facility on the planet, poised to support the development of next-generation high-speed railways and gather vital scientific and engineering data for the space electromagnetic launch project. Meanwhile in Jinan, capital of the eastern Shandong province, another giant maglev track to support ultra high-speed electromagnetic sled experiments is also up and running, under the supervision of the Chinese Academy of Sciences (CAS).
Nasa’s failure to launch China is not the first country to propose an electromagnetic space launch system. Such concepts have been floating around since the Cold War era. In the 1990s, Nasa tried to bring this idea from paper to reality, with the first step being the construction of a mini test line measuring 15 metres (49 feet). However, due to insufficient funding and technical difficulties, the actual length of the completed track was less than 10 metres. Eventually, the project was scrapped, and government and military leaders redirected resources towards the development of low-speed electromagnetic catapult technology for aircraft carriers instead. But the USS Ford, the first aircraft carrier to be fitted out with this new technology, has been plagued with issues. During Donald Trump’s presidency, he complained that the actual performance of the electromagnetic catapults was far inferior to that of their traditional steam counterparts. The US Navy has also publicly acknowledged that the excessively high failure rate of the Ford’s electromagnetic catapult system has resulted in reduced combat capability for the entire carrier strike group. Due to significant setbacks in electromagnetic launch technology, the US military has abandoned the development of some related projects, such as rail guns, and shifted the saved funding to hypersonic missiles. Now, China has picked up the relay baton handed off by America. Nonetheless, Li and his colleagues are being cautious.
Computer simulations, wind tunnel tests In the early stages of their research, they uncovered a startling omission by Nasa: no wind tunnel tests were ever conducted to ascertain the viability of detaching the space plane from its track. Nasa’s original idea was that accelerating the space shuttle to just 700km/h would be enough to eliminate the need for a first-stage rocket, but Chinese scientists believe this speed is too low. However as the speed increases, the airflow between the aircraft, the electromagnetic sled carrying it and the ground track becomes very intense and complex. So one of the first things the project team must confirm is that the aircraft will be able to safely separate from the track. To this end, Li’s team has conducted extensive computer simulations and wind tunnel tests. Their findings have revealed that a
.
@yogthos So the system just accelerates to Mach 1.6, then the system had to use its own fuel to speed up to just Mach 7. But Mach 7 is just a fraction of the needed velocity to get into orbit. Mach 7 is around 8,500 km/h. But you need 25,000 km/h to stay in orbit. So you need an additional stage to accelerate to that speed. And that stage would had to be expendable, otherwise you couldn't carry enough payload.
Still you can only reach a single orbit. To reach another orbital plane, you then would had to use a lot of additional propellant to perform a dogleg maneuver to switch to a different plane.
BTW: This whole idea reminds me of SpinLaunch. Prototypes are already built by the U.S. based company with the same name. They want to accelerate small launchers in a vacuum chamber, so that in the end they can carry up to 300kg in a low earth orbit.
But the goal isn’t to stay in orbit. The goal is to push the plane to upper atmosphere where there is low air resistance, and then it mostly glides to where it needs to go. The article very clearly explains that the goal is to create an alternative to long range flights instead of doing space launches. I’m also familiar with SpinLaunch, and it’s a completely different purpose where they want to launch small satellites into low Earth orbit.
@yogthos The articles ends in "While SpaceX’s reusable rockets have slashed satellite launch costs to US$3,000/kg, some scientists have estimated that an electromagnetic space launch system could drive those costs down to a mere US$60/kg."
This is a comparison to a launch into an orbit.
This tech can be used for both purposes, but most of the article discusses transportation. Once China puts this tech in production, I’m sure it will be used for orbital launches as well.
@yogthos I now had more time to look into the article. The whole article is focused solely on the electromagnet technology. From here it refers to some other technology that uses electromagnet acceleration like Musk's fever dream "Hyperloop" and sea carrier catapults while in the end making a reference to orbital launch costs.
Thing is: It simply doesn't make sense. Neither in point-to-point transportation nor in space launch activities this would work out, since you could reach only a single orbital plane or flight direction. To reach more than one point or orbit, you would need to have a lot of these systems, which then would result in really high operational costs.
However, this technology is fine for a highly improved land based transportation method, especially for China, which is the forth biggest country (behind Russia, Canada and the USA).
This is literally what people said about high speed rail. The argument was that this is simply not cost effective and that’s why it can’t be built. Yet, China covered the whole country with HSR in a decade. Short term cost effectiveness isn’t really an issue when you have a state directed economy. And costs for any new technology come down over time. Maybe China will start using it for ground based transportation first, and then start using it for other applications. We’ll just wait and see.
@yogthos Which people said that about high speed rail? The country I'm living in has got high speed rail since the 90s. See also Japan or France (and some other countries).
This is a common narrative in US and Canada, meanwhile countries like France or Japan are dismissed as being small. Here’s an example for you scientificamerican.com/…/why-high-speed-bullet-tr…
@yogthos I'm not living in the US, neither I'm a fan of most of their politics. So I definitely won't defend them.
The original point was that arguments about cost efficiency have been made regarding HSR. Every new technology is expensive when it’s initially developed, and it requires significant investment. One way to look at that is to say that it’s not worth spending the effort on, another way to look at it is that spending the effort creates jobs, spurs innovation, and brings long term benefits to society. It’s pretty clear to me that China tends to take the long view on such things, and hence I think it’s very probable that they will try building such launch systems.
@yogthos Well, I've got the opinion, that infrastructure shouldn't be operated for profit, so I've got no problem with investing a lot of money in advance. My points are meant from a technical standpoint. And when I refer to the costs, then I mean this in a way that I've got the opinion that the money should be invested in other stuff as well.
I don’t think anybody is arguing this sort of stuff should be funded at the expense of other stuff though, and based on how quickly the standard of living is improving in China, seems that they are doing a pretty good job funding the other stuff.
Works for me
Does no one read the article anymore before commenting? I’m not responding to all the comments here since it’s clearly a waste of my time, but every single one of the concerns that people mention in this thread so far has been acknowledged in the article already.
Sure, that will be for “planes” and definitely not for long range hypersonic cruise missiles.
Just Like Evergrand