utilitas
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Post by utilitas on Jul 2, 2017 7:12:39 GMT
Neither methane snow nor meteor rain nor contraction heat nor solar flare nor gloom of tidally locked night stays these couriers from the swift completion of their appointed high density rounds.
We have the internet, we have radio transmission and we have plenty enough advanced cryptology to support it, yet we still use physical FIAT funds, require hand signature and every form in triplicate. Who said this'd be any different in the space age?
The idea is quite simple. What is the fastest, most reliable and most economically viable way of getting a standardized packet of high priority mail to and from the Moon? Other bodies would be a bigger nut to crack, so it's better to keep it simple and mostly three-body.
Would Lunar Post require specially designed containers/tugs for incoming parcels, or would they simply ship their mail along with passenger shuttles? Would it be faster to expedite high priority mail in dedicated containers launched on a free-return trajectory to be captured by either an orbital station or dropped into the ocean/mare? And how difficult would it be to ship from the largely equatorially inhabited Earth to one of the planned Moon habitats near its poles?
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Post by randommechanicumguy on Jul 2, 2017 15:37:05 GMT
here's an idea, have 3d printers on every conlony thats big enough to create anything useful. 'mail' will be sent by radio transmissions to other colonies, and any physical objects that need to be sent are sent through a .obj file that is then 3d printed
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Post by The Astronomer on Jul 2, 2017 15:47:38 GMT
here's an idea, have 3d printers on every conlony thats big enough to create anything useful. 'mail' will be sent by radio transmissions to other colonies, and any physical objects that need to be sent are sent through a .obj file that is then 3d printed Individual 3D printers are likely to become common in the next 20-30 years, so I guess it's going to be essential anywhere in the next century. No need to transfer delicate things, just materials required. Durandal |
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Post by Durandal on Jul 2, 2017 15:53:07 GMT
I see a few issues with that. Say that the receiver doesn't have the nessesary materials needed to print the object? Or what if said object is an old Earth relic made of wood or ivory or something that isn't readily accessible to our space age society? Think anybody thought to bring a good wine vintage up before Earth went to shit? *edit* Agreed Astro, but there would still have to be a way to send those materials that aren't standard building materials. And some things, like a 1990 vintage Cabernet Sauvignon bottle would still need to be physically moved. And I don't see Asteroid Colony Y2456t3 having a steady supply of ivory. (Using human bone as a stand in does not count.  ) |
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utilitas
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Post by utilitas on Jul 2, 2017 17:34:41 GMT
here's an idea, have 3d printers on every conlony thats big enough to create anything useful. 'mail' will be sent by radio transmissions to other colonies, and any physical objects that need to be sent are sent through a .obj file that is then 3d printed Imagine you're the guy operating a 3d printer that's currently printing a top secret federal communication confirming nuclear orders, only waiting for a stamp. Not happening. Besides, there's not just paper being printed - and paper is pretty complex by itself. There's all kinds of different inks, and any falsifiable document will have safeguards and chemical additives. 3d printing would work for normal pedestrian mail, but by that point, you might as well just send a text message. A postal service would be required by the bureaucracy, for the bureaucracy. |
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Post by Pttg on Jul 2, 2017 18:11:19 GMT
I'd go with planetary-scale railguns launching small cargoes at remarkable velocities. A small cosmic ray shield around a pressurized bubble and a layer of whipple, plus steering thrusters for aligning with a receiving railgun.
The speed and darkness of the projectile are the main defenses; if it's a couple hundred km/s, it's going to be hard to catch up with it and collect it, even with a missile or drone.
EDIT: But I guess you could maybe swing it if you have an interceptor in a second mail package fired within a small window after the previous package departs. It presumably burns a little, catches up with the target packet, bumps into it to send it in a new trajectory, and then you could send a larger, slower drone to catch it on its new orbit.
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Post by matterbeam on Jul 5, 2017 2:28:33 GMT
I think that physically storing data can be done in extremely lightweight payloads, even after radiation protection and redundancy is considered. Terabytes in a few hundred grams.
These are perfect packages for laser sail transport. Even just 100MW can accelerate a 100g laser sail at 13m/s^2, or about 1.35G. This will get across interplanetary distances in a matter of days.
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utilitas
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Post by utilitas on Jul 5, 2017 3:08:40 GMT
Yes, I thought that'd be the best way for very high-priority mail. Put the important mail into designed capsules with a very large surface area and beam them towards the other body either directly or on a convenient free-return trajectory. The journey would take a few days to even a few dozen hours if you pumped enough power - better than some mail services.
The main issue isn't in the journey itself. It's with the capture.
As we all know, Earth has plenty of air[citation needed] and the Moon has basically none. That makes for a great contrast between how you send and receive mail on either body.
On the Moon, you can have a shot at the Earth straight from the surface - there's no atmosphere to slow down the shot, so why not?
There is also no atmosphere to slow down the shot. Any mail sent from the Earth will either have to endure lithobraking at several score kilometers per second (kind of unlikely) or be captured in orbit or on the ground by specially designed stations. I don't think you can make a capsule like this accurate to even several meters without putting active guidance on it, adding more weight, more components of failure and therefore more power that needs to be pumped into it to be effective. That means you'll have to use huge nets:either passive, where you literally take a huge, strong net and slow the projectile down like a bungee, or active, where through magnetic (or even gravitational, if it's on a trans-stellar or trans-neptunian mail route) forces you slow it down with very little contact. That'll need either some good accuracy or some serious planning.
The Earth is a little more interesting. You can't fire from the surface, obviously - there's a bunch of that pesky nitrogen and oxygen and global warming juice in the way. So you'll have to lob the capsule from orbit. But when you have the atmosphere, there may be an opportunity for some of that aerobraking. An added ablative shield to break against the atmosphere.
The question is, is it worth it to add an ablative shield - all the mass and manufacturing hassle to have both an ablative shield and a laser reflector - when it may not even be very effective at such velocities and methods? Note that the capsule will be entering the atmosphere at either a very direct or a very shallow angle at several tens to a hundred kilometers per second. It might punch through the bulk of it without slowing down at all, and then it might be too late. Or it might melt to nothing but slag no matter what you do. And then it has to lands - which means, again, you have to aim well or pack along a parachute (again, more mass.) Then there's recovery which, if you don't aim for one of your facilities, can extend the delivery time by several hours. Wouldn't it be simpler and more efficient to capture it in orbit, then send it down through traditional means?
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Post by Durandal on Jul 5, 2017 3:08:52 GMT
I think that physically storing data can be done in extremely lightweight payloads, even after radiation protection and redundancy is considered. Terabytes in a few hundred grams. These are perfect packages for laser sail transport. Even just 100MW can accelerate a 100g laser sail at 13m/s^2, or about 1.35G. This will get across interplanetary distances in a matter of days. I assume this would be for data too secure to transmit? Couldn't anyone see the light sail and intercept it with an appropriate laser? Just how physically small could you build a tight-beam laser emitter to transmit terabytes worth of data? If you had a small enough laser on the railgun data brick projectile Pttg suggested it could transmit the data to the receiver after a specified time and then sail off into oblivion. That would prevent anyone with a spy sat from intercepting the data due to laser dispersion on interplanetary scales. |
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Post by vegemeister on Jul 5, 2017 5:20:08 GMT
I don't see the need for secure+fast transport of information. If you have secure+slow, you can send a one-time pad. Then you can transmit securely as fast as you like at the speed of light with ordinary radio.
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Post by apophys on Jul 5, 2017 5:26:38 GMT
If you're doing a laser sail, you should have a laser at the launch site and one on the receiving site. You'd accelerate as far as the launch laser can reach, turn around halfway, then decelerate with the receiving laser. That is, near-brachistochrone trajectories just like with in-game MPDs.
Launch can actually be from Earth's surface (or other planet with atmosphere) using a lightcraft, which then separates like a sabot upon reaching space and allows a laser sail to unfurl.
When Earth is the receiver, aerobraking doesn't have to be employed as the only method of braking. But it can certainly help improve overall time when it is used.
(Biological samples are one thing I can imagine still using regular mail.)
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Post by matterbeam on Jul 6, 2017 0:33:15 GMT
If you're doing a laser sail, you should have a laser at the launch site and one on the receiving site. You'd accelerate as far as the launch laser can reach, turn around halfway, then decelerate with the receiving laser. That is, near-brachistochrone trajectories just like with in-game MPDs. Launch can actually be from Earth's surface (or other planet with atmosphere) using a lightcraft, which then separates like a sabot upon reaching space and allows a laser sail to unfurl. When Earth is the receiver, aerobraking doesn't have to be employed as the only method of braking. But it can certainly help improve overall time when it is used. (Biological samples are one thing I can imagine still using regular mail.) If we move a kilogram at 10G, we can cross Earth-Mars in about 26 hours. A few hundred grams of data encoded as DNA could contain as much, at 215 petabyte per gram, as a hundred thousand petabytes. The data transfer rate is incredible, and this is how physical transport could compete with wireless beaming |
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utilitas
Junior Member
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Post by utilitas on Jul 6, 2017 8:42:17 GMT
Projectile data transfer would also be a more secure form of communication. Laser communication can be intercepted very simply just by parking a camera in its path, and if you don't have some form of encryption, you're basically hosed. But intercepting a tiny several kilogram projectile moving retrograde at several times you own velocity is a lot harder to rendezvous with, not to mention capture. You'd have to deflect its trajectory with a laser and land it somewhere else.
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Post by Rocket Witch on Jul 6, 2017 17:36:58 GMT
We have the internet, we have radio transmission and we have plenty enough advanced cryptology to support it, yet we still use physical FIAT funds, require hand signature and every form in triplicate. Who said this'd be any different in the space age? Most of what people own even in fiat isn't physical. If everyone attempted to withdraw even 10% of what they own the banks would be out of actual money to hand out, or so I once heard. As I understand, fiat is dying; Japan started accepting bitcoin as some sort of money this year, though I don't know if it's exactly legal tender you could buy a cup of coffee with. Things are shifting even without the decentralising influence of a new frontier in space. |
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utilitas
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Post by utilitas on Jul 6, 2017 18:34:44 GMT
Most of what people own even in fiat isn't physical. If everyone attempted to withdraw even 10% of what they own the banks would be out of actual money to hand out, or so I once heard. As I understand, fiat is dying; Japan started accepting bitcoin as some sort of money this year, though I don't know if it's exactly legal tender you could buy a cup of coffee with. Things are shifting even without the decentralising influence of a new frontier in space. That's obvious. They try to obscure it with thick terminology, but banks can basically create finance out of nothing. There's a base level of money they cannot re-lend to others out of every loan they accept. That is the minimum reserve. For the US, it's 10% and for the EU it's 1%. Effectively, if you depose $1000 to a bank, they have to keep $100 of that, but they can loan out $900 to someone else. If those $900 get deposed to another bank, they can do the same; keeping $90 and loaning out $810, ad infinitum. Even though there were originally only $1000 dollars and they still have those $1000, the bank now owes $2710. This is how Black Friday happened, and this is how the stock market crash happens - if anyone ever borrows more money than the bank can return, the entire system collapses. And the bitcoin doesn't solve that. As long as there are banks that can loan out money that isn't there, there will always be a measure of market instability. Gold-based finance was the best, anyway. Paper bills make for an inefficient railgun projectile. |
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