future space ships and stations

[epg20]

I think that at some time in the future space ships and stations as well as colonies and other outposts will be made out of steel and concrete, not just carbon fiber and aluminum, thanks to the discovery of some new concrete, that not only is strong, but is exceptional at protecting people and electronics from EMPs and radiation.;



EMP-proof-concrete.jpg



Structures made of or covered by this new type of concrete will have its electronics continue to function even after a powerful EMP pulse. Image University of Nebraska-Lincoln

EMP (electromagnetic pulse) is the bane of the modern way of life. A powerful enough burst can shut down anything powered by electricity. Thankfully a couple of engineers have developed a concrete mix that has ample anti-EMP shield.

The special concrete mix is cost-effective and is designed to shield against “intense pulses of electromagnetic energy,” thereby protecting any electronic device within its confines, reports


Its discovery was accidental as University of Nebraska engineers Christopher Tuan and Lum Nguyen were looking for a way to build safer bridges and roads. It was then that they realized their new concrete mix had electromagnetic energy-blocking properties.


The property comes from the magnetite that they included in the concrete mix. Magnetite is a type of iron ore with magnetic properties that allow it to soak up radiation. The concrete mix also has more carbon and metal elements than traditional concrete mixes for greater absorption.

Traditionally, a faraday cage or expensive metal enclosures are erected to protect agains EMP. Compared with these, the new concrete is easier and cheaper to deploy. The university even developed a spray-on “shotcrete” version as part of a licensing agreement with the American Business Continuity Group. This shotcrete version can be used on existing structures to retrofit them for EMP insulation. Alfred Bayle

[Annoyed]

We would need to see those materials with a higher strength to weight ratio than we do now, or / and a significant improvement in energy tech.; stronger engines to lift and move the additional weight. Weight is why Aluminum, carbon fiber and other low weight/high strength materials are used in aerospace.

[epg20]

We would need to see those materials with a higher strength to weight ratio than we do now, or / and a significant improvement in energy tech.; stronger engines to lift and move the additional weight. Weight is why Aluminum, carbon fiber and other low weight/high strength materials are used in aerospace.

yes that is true, BUT the durability is not equal, steel and concrete are the best, and by the time we are able to build these ships, we more than likely will have an orbital tether/elevator in to space, it will cut costs about ten times or more to carry things up in to orbit.

[thekillman]

yes that is true, BUT the durability is not equal, steel and concrete are the best, and by the time we are able to build these ships, we more than likely will have an orbital tether/elevator in to space, it will cut costs about ten times or more to carry things up in to orbit.

Nope. Orbital tether dreams got squashed. Carbon nanotubes are strong, but the slightest defect will massively reduce it's strength.

It'll be far cheaper and easier to get materials from asteroids (which can be rich in carbon, water, silicon, iron and nickel) and just build stuff that way. The biggest challenge with asteroid mining isn't even technology, it's convincing people to invest in stuff that may not pay off until 20-40 years later. (as finding, prospecting and redirecting an asteroid can take a while, plus mining it dry may take a while).

[Annoyed]

yes that is true, BUT the durability is not equal, steel and concrete are the best, and by the time we are able to build these ships, we more than likely will have an orbital tether/elevator in to space, it will cut costs about ten times or more to carry things up in to orbit.

Even giving you the "space elevator" concept, you still have to move the mass once in orbit; accelerate it out of Earth's gravity well, or whatever. And that takes energy, the more mass, the more energy required.
Granted, steel is far more durable than Aluminum and so forth, but it's much heavier. And that weight can't be ignored.

[epg20]

Nope. Orbital tether dreams got squashed. Carbon nanotubes are strong, but the slightest defect will massively reduce it's strength.

It'll be far cheaper and easier to get materials from asteroids (which can be rich in carbon, water, silicon, iron and nickel) and just build stuff that way. The biggest challenge with asteroid mining isn't even technology, it's convincing people to invest in stuff that may not pay off until 20-40 years later. (as finding, prospecting and redirecting an asteroid can take a while, plus mining it dry may take a while).

that is a common misconception, we don't need carbon nano tubes, though it would help, standard carbon fiber will do just fine, the cable for the "elevator" will be massive, but the starting position, doesn't need to be, in fact, the initial cable could be the thickness of your arm, then you continue to build the cable from the ground up, layering materials of differing substances one on top of another, the cable will need to deal with extreme cold and heat also high energy strikes, high winds and even micro meteor strikes as well as space junk, while carbon fiber will handle most of that fine, the lightning strikes will damage it severely, that is why there is a mesh of copper beneath the carbon fiber skin of air planes.

once the cable is established, you keep building on top of it, going further and further out, one inch at a time, each time you run a strand up to the top of the cable, you have a magnet attached to the end of it which will attach to a spot on top of the other one, north attracts south type of thing, with each strand you run up to the top you attach a magnet to the next, and so on, to the point the cable stretches all the way to the mid point between the earth and the moon, there you build a space station as a departure point to lunar orbit, there you might build the same thing there, or not, you could just use magnetic repulsion to have a soft landing, or some sort of a reverse rail gun thing, I haven't thought that out yet, though.

it would never be finished in our life times, or even our great grand kids time, but our great great grand kinds life time, ...eh maybe.

[thekillman]

It's not a common misconception when the alternatives are completely impractical:

https://www.researchgate.net/profile...13d02a198e.pdf



The breaking length of carbon fibre is around 250 km. The exponential graph is hard to read for this, but the taper factor is in the order of 1000 or more.

So a 1m thick cable at the anchor, would require a 1km thick cable at the top.

Practically, no existing material will do.

[epg20]

It's not a common misconception when the alternatives are completely impractical:

https://www.researchgate.net/profile...13d02a198e.pdf



The breaking length of carbon fibre is around 250 km. The exponential graph is hard to read for this, but the taper factor is in the order of 1000 or more.

So a 1m thick cable at the anchor, would require a 1km thick cable at the top.

Practically, no existing material will do.

what you have here is a tower, what I am talking about is a cable, the style and techniques I am suggesting is on a much smaller scale over a MUCH longer period of time, look at the construction of the golden gate bridge cables, that is the type of construction I am talking about, of course with MUCH different materials.

[Annoyed]

Regardless of how you achieve orbit, you're still ignoring the added mass that steel would have over aluminum. Unless it's a fixed orbit satellite that never moves, you STILL need more energy to change the velocity of steel spaceship vs a less massive exotic materials ship.

[epg20]

Regardless of how you achieve orbit, you're still ignoring the added mass that steel would have over aluminum. Unless it's a fixed orbit satellite that never moves, you STILL need more energy to change the velocity of steel spaceship vs a less massive exotic materials ship.

that is true, but it is also a better way to travel through space, once you overcome inertia, and that mass begins to move, momentum will help move the ship through space, the bigger the mass, the more momentum it has, the engines could be throttled back, once the ship begins to move, and as long as there is a constant acceleration, there is also artificial gravity, once you reach the mid way point, you turn the ship around and apply the same amount of thrust in the opposite direction, gravity will slowly dissipate and you will slow down over time, that is what ion engines are Really good for.

[Womble]

Nope. Orbital tether dreams got squashed. Carbon nanotubes are strong, but the slightest defect will massively reduce it's strength.

It'll be far cheaper and easier to get materials from asteroids (which can be rich in carbon, water, silicon, iron and nickel) and just build stuff that way. The biggest challenge with asteroid mining isn't even technology, it's convincing people to invest in stuff that may not pay off until 20-40 years later. (as finding, prospecting and redirecting an asteroid can take a while, plus mining it dry may take a while).

Not people, corporations. Some companies will invest into moonshots without an obvious path to profit the way Google, Facebook and Amazon often do. But 40 years is far too long for any investor, even state governments.

I suspect, however, that 40 years from now space travel may become more problematic. Earth orbit of all altitudes is accumulating so much space junk that, short of inventing force field shields, it'll be hard to keep space tech working. Given enough speed, every free-floating fleck of paint has the potential to do major damage to fragile antennae and solar panels of space stations and satellites.

[Annoyed]

that is true, but it is also a better way to travel through space, once you overcome inertia, and that mass begins to move, momentum will help move the ship through space, the bigger the mass, the more momentum it has, the engines could be throttled back, once the ship begins to move, and as long as there is a constant acceleration, there is also artificial gravity, once you reach the mid way point, you turn the ship around and apply the same amount of thrust in the opposite direction, gravity will slowly dissipate and you will slow down over time, that is what ion engines are Really good for.

Not quite. Yes, you turn around at midpoint and apply thrust in the opposite direction to decelerate. You lose gravity during the turnaround maneuver, but once you switch the engines back on to decelerate, you get the same gravity back; how ever many G's of thrust you are applying. Gravity doesn't dissipate.

And the extra mass of steel / etc. STILL incurs a penalty; your engines can only produce so much thrust; that same level of thrust will cause a higher level of acceleration on a lighter ship because there is less mass. So the lighter ship can achieve higher speeds for the same energy cost, shortening your travel time.

Mother nature ALWAYS balances her books. If you have more mass, it takes more energy to alter that mass's velocity. You can't escape that. As I say in many political discussions, "There is no free ride".

Sure, there are circumstances where you would willingly pay those penalties in exchange for sturdier construction, a combat ship or something else you suspect might get pounded on, but until energy is unlimited, overall, the lighter weight materials would make a better ship.

[thekillman]

what you have here is a tower, what I am talking about is a cable, the style and techniques I am suggesting is on a much smaller scale over a MUCH longer period of time, look at the construction of the golden gate bridge cables, that is the type of construction I am talking about, of course with MUCH different materials.

It doesn't work that way. I am talking about a cable. But that cable needs to be stable, you can't just make a 100km cable upwards as it would slam down due to orbital speed differences. It also can't be a tower since it would buckle. So what you do is you take a small asteroid and attach the cable to that. The cable will then be in tension, avoiding buckling. For stability it still needs to be very long (about to geosynchronous orbit).

So no, you do need a long cable made of materials stronger than what we have today. Sure carbon fiber may work on mars or the moon due to lower gravity, but on earth it doesn't work.

Sure, there are circumstances where you would willingly pay those penalties in exchange for sturdier construction, a combat ship or something else you suspect might get pounded on, but until energy is unlimited, overall, the lighter weight materials would make a better ship.

The main use for steel and concrete in space would be in stations and bases. For instance, a moon base or a proper orbital station to replace the ISS. Steel has some useful properties that titanium nor aluminium can match, mostly in it's fatigue resistance.

The biggest challenge to building stuff on mars for instance is that you can't really bring any stuff (especially since the launch window for a low-energy transfer is once every two years, and the travel time is in months), you'd have to make it on the spot. Mars is covered in iron oxide, so iron would be easy to acquire (it's also really common in asteroids compared to other metals).

For spaceships it may see some use, though that would probably be in situations where iron is accessible and replacements from earth are hard to get.