Jan 4, 17 / Aqu 04, 01 12:10 UTC

Practical and cheap way to get into orbit  

Hi Guys,

thought Id float one of my more mad ideas out here and see how it might go,

I think mankind's most pressing and expensive problem is space launching, as there is no existing cheap and efficient way to get into orbit from ground level safely, even for non humans.

I mean it currently costs over $22,000 to send 1KG of anything into orbit, due to their not being a simple and efficient propulsion system

I propose we develop a maglev track with rocket sled capable of achieving LEO. I mean its off the shelf,cheap, as it just needs electricity and high powered magnets, and reliable, as these have been used for years...

in order to fund it, it can be used to cart loads up into orbit that nobody wants on earth in the first place.... nuclear waste comes to mind, toxic chemicals and other nasties that nobody wants to bury in a mine someplace.

as its currently so expensive to store such noxious and dangerous loads, this would be a perfect solution, where it cannot harm or pollute anymore.

just an idea, sure they will be better ones soon enough.

Jan 4, 17 / Aqu 04, 01 17:19 UTC

It's a good idea, sometime ago I heard of similar ideas and I think there are also papers exploring this kind of launch systems. It'd be good to launch payloads with minimal cost; for people it would need to keep the acceleration at 5-6 Gs maximum or it could cause serious damage to the passenger. The only problem I see in this idea is that, unless we collaborate with other nations, we will need to buy a place where to build the launch facility and all ancillary structures.

Jan 5, 17 / Aqu 05, 01 00:03 UTC

If it was built within about 10 degrees of the equator it could use the spin of the earth to help. An artificial island would do the job. The sea between the top of Australia and Papua New Guinea/Indonesian is not very deep if I remember correctly.

The launch direction would be towards the east and it is not much land mass or population in that direction so it could be aimed to launch out over the open sea just in case things do go wrong. (There are probably better locations but I just can not think of them at the moment)

The biggest problem with this location is that it is near the pacific ring of fire.

eg2505 have you done any rough calculations as to how long/wide and tall the launch system would have to be to be able to launch a payload into space with a max g-force of 5 to 6 G's?

Jan 5, 17 / Aqu 05, 01 08:26 UTC

We can use higher g-force if the people are under water and breathing a liquid thing, for example PFC.



Jan 5, 17 / Aqu 05, 01 16:48 UTC

The problem with practical Mag Lev systems launching from Earth is both size and air resistance I once came across a SciFi story of the more practical hard SF kind where some thought had gone into the practical and political problems of building a real world working version its by Mike Combs and freely available on the net link below


I found it and interesting read as a plausible way of doing the job technically whether it could be done politically and financially is another matter.

Jan 6, 17 / Aqu 06, 01 04:11 UTC

Definitely rail-launch systems are not the most viable - or they wouldn't of stopped development or such uses not long after WWII. They can certainly add some momentum, but in the overall scheme of things it's just easier to do away with.

The cheapest I can wrangle is to construct a platform that floats on a series of helium baloons. Helium can be pumped from baloon to ballast tanks to raise/lower as desired, and a cheap and cilivised low-G ascent can begin up to upper atmos. At this point a low orbit facility can winch down a platform to just above the atmosphere - vastly reducing the amount of propellant based propulsion required to utilise. Once winched up, centrafugal launchers can throw payloads out further... Such a system(designed correctly) could be re-used indefinitely, and be able to be deployed in parallel operation.

Transporting things like nuclear waste isn't entirely clever, and even less so without a plan of how to deal with it. I would personally suggest to centrafuge it into the nearest star, in this case, Sol. It'll incinerate a long time before it actually gets there, and done right ends a problem.

Jan 14, 17 / Aqu 14, 01 03:32 UTC

Regarding the use of helium for an upper atmosphere launch, I looked up some general values to help put it in perspective. The Space Shuttle weighed 4,398,100 lbs, that is the shuttle itself, fuel, but doesn't include any payload or people. Helium has a relative lift potential of 65.82 lbs per 1000 cubic feet (weight of helium itself subtracted from the weight of the surrounding air). It would take in the ball park of 66,820,115.47 cubic feet of helium to lift the shuttle alone, not taking into account weight of the balloons, weight of the launch platform, any mechanisms for recapturing the helium to cut down on lost lift potentials, and mechanics to hold the platform in a stationary position during launch (probably other things can be taken into account as well). A single spherical lifting balloon would be 500ft across (not accounting for distortion). The most recent price for helium I could find per 1000 cubic feet is $85, putting the cost of helium around $5,612,889. Again, this is before cost of the platform, the ship, fuel, and other essential components for launch. Granted it would be cheaper in the long run, barring any lost materials or catastrophic failure, esspecially if it were to be used for rapid successive launches.

Jan 15, 17 / Aqu 15, 01 12:18 UTC

I don't know about rapid succession, I was under the impression it'd take several hours to ascend to launch height.

I was loosely operating on the HAV 304/airlander10 being able to lift ten tonnes(payload) to about 6.5Km - which it can do on 1,300,000 cu ft of helium - To assume a similar weight to the airlander structure(ten tonnes), then scraping 5 tonnes from it's payload could provide extra reinforcements to the "baloon" in order to get near the stratopause(about ½ way to Kármán line) and for launch capacity, still leaving 5 tonnes carried - which could easily be tonne n ½ of fuel, tonne of rocket and leave two tonnes for payload, ½tonne safety margin.

A single spherical baloon wouldn't be optimum for this, IMHO, a single toroid could be made to work easily, as could four in corners. To assume toroid model, then the rocket can be dropped through the hole in order to keep center of gravity low and provide stability in the lift. If as the rocket fired, and took it's weight from the platform the helium dumps back into the ballast tanks, then as the rocket ascends, the platform can rapidly descend - meaning it'll require lesser blast shielding as it can clear itself of the danger zone rapidly, before damages occur.

  Updated  on Jan 15, 17 / Aqu 15, 01 19:03 UTC, Total number of edits: 1 time
Reason: typo

Jan 16, 17 / Aqu 16, 01 00:33 UTC

I thought about how to get into orbit cheaply and with a minimum of explosion riding a lot over the better half of the last year (yep even before asgardia came around) and i believe the most optimal option to be a vehicle fixed to a maglev sled accelerating inside a (near) vacuum tube to orbital velocities (over a length of about 5300 km if you accelerate with 4g to 7500 m/s). Of course this vehicle has to eventually be released into the atmosphere (preferably at a high mountain top because you could evade a lot of dense air in lower regions that way), therefore it should be geometrically very optimized for supersonic flight and be also equipped with a heat shield (though not an ablative one like we're used to use for slowing down it has to be something more like the shuttle's isolation tiles). also because the vehicle will bleed of a certain amount of speed inside the atmosphere it has to leave the tube at a higher velocity than the one required for orbit.

i already thought up a few types of how to get the required acceleration inside such a tube and also wanted to build a small prototype to confirm my ideas but unfortunately the Neodymium magnets i wanted to order are only shipped to the US.... -.- and i'm still searching for substitutes.

The idea of using a balloon torus (or balloon lifted platform in general) has also crossed my mind a number of times but a big problem i see with it is the still present need of large scale chemical propulsion (eg. huge explosions) inside of the atmosphere and that if you want a sturdy balloon it's going to be heavy, plus the (way smaller but still big) rocket and all it's "ground" equipment lets say all in all about 500 tons... that would probably mean a balloon torus of about 1.5 km assuming a 10 m hole in the middle (i did the math for that a few months back that's just what i vaguely remember). That's quite the large volume to fill with helium, additionally i suspect the device will only last so much de- and reinflations, landings and launches until it gets leaky.

Of course once any vehicle is in orbit you have to rely on chemical propulsion but the forces needed up there are way smaller and so the engines needed are way less prone to create catastrophic failures.

Jan 16, 17 / Aqu 16, 01 03:16 UTC

By rapid successive launches, I had meant multiple launches in a short period of time. The single balloon I had mentioned wasn't an idea pitch, but an example of how large an area that much helium would take up. If a platform were to be designed in this manner, I would think 6-8 balloons in a hexagon or octagon would allow for more stability, especially under launch conditions. Regarding lift weight, even with getting necessary components into orbit, we still need a way to manipulate, move, and assemble them into place, hence the added wait for a ship. I like the toroidal concept and the helium ballasts. This would still end up being a floating super structure. Any idea what size the initial exhaust plume from launch is?

Jan 16, 17 / Aqu 16, 01 13:41 UTC

I've been thinking about this for a lot longer than a year... lot longer than a decade... Did you ever stop to question why rail-launch technology petered out just after WWII?

Lets pretend you can get it up to 7.5Km/s in gravity, hitting the curve(I assume you'll start flat, and leave pointed at sky) at even ½ that speed will kill anyone on board, or require about thirty miles of slowly increasing incline to avoid anything not designed to withstand a serious impact from smashing. Lets assume you've scrubbed all atmosphere out of the launch site to actually have some hope of hitting such a velocity(and somehow, are able to exit) - when you enter atmos at the end of the track it's going to be like slamming into a brick wall. Even if you can build the craft to withstand that, it's unlikely anything in it will survive, as that'll still be doing the same speed the craft isn't anymore. It'll instantly burst into flames due to the air friction, minimally... Here is where I'd predict the rapid unplanned disassembly. Then, assuming that can be mitigated, the air resistence is going to seriously rob you of momentum, and so will gravity. You need applied thrust. Leaving the top of a mountain isn't going to save you that much, that's still "gained" a kilometer, kilometer n ½ at best. All of 0.13 seconds of your journey. Only another 99Km to go. By the time you're 30 klicks up I'd expect you to of lost at least 50% of your velocity... and another 50% of that by time you hit the mesopause. Even with "good aerodynamics". You should fire up KSP and attempt to build such a device...

As for the "baloon platform" - I'd also think a hex/oct arrangement superior to quad, but prefer the toroid. Intent was to highlight a single baloon above would be a problem. I don't know about "superstructure" but it would be quite large - but no reason it should be larger than the HAV304/Airlander 10. The initial plume would depend entirely on the fuel, bootser design etc. This could take place much below the actual vessel it's riding, however, and can be generally directed away - the only issue would be as it's moving past the hole in the toroid - but if that's moving down as the rocket moves up, then it can take place before it burns through the sheilding or causes any other issues - ½ a second or so of exposure. You could also build the inner of the toroid intentionally wide to further reduce possibilities. For assembling bits up there - Three or six little units powered by Q-Thruster/EM-drive could collectively tow things..

Jan 19, 17 / Aqu 19, 01 11:22 UTC

I'd argue that starting small would make the most sense.

Any kind of launch platform that is designed to launch micro-sat sized objects or similar would be much cheaper and simpler. Larger constructs could then be auto-assembled from the smaller ones once in orbit.

If you forget about trying to get humans into space, and focus on trying to get manufactured material into space over a longer period (rather than single launch), then the the balloon platform is perfect. I'm a programmer/roboticist, so I'm not too knowledge about velocities needed to break earth orbit etc., but obviously only a minimal launch platform would be needed on the balloon to break orbit if we're talking low mass payloads. The reason it costs $20,000+ to launch 1kg isn't because 1kg is hard to get into orbit, it's because the rockets are designed for maximum payload, hence larger rocket, hence more weight, hence more fuel, and we're in a chicken and the egg scenario of fuel and wight.

Jan 23, 17 / Aqu 23, 01 22:38 UTC

First off sorry, i failed to mention, I'm not a professional in any way (yet), just a mere 18 year old guy trying to realize childhood dreams one day ^^, and I'm happy about any critics.

Also I'm not saying that this is the easiest way to get into orbit, just the optimal way, because in order to accelerate you have to push against something, and what better to push against then the very thing you want to get away from. Of course there are major hurdles to eliminate in order to get such a thing working, but i believe it can be done and once it is built it is the most efficient way to get up there.

And just because people fifty years ago weren't able to get it done, doesn't mean its not even worth looking into with all the new technology we have come up with since then.

Jan 24, 17 / Aqu 24, 01 10:38 UTC

Manufactured material is a waste of energy - that needs constraining to a minimum amount of lifts. For anything significant to be constructed up there then it's seriously going to require harvesting materials from up there, and using them to build manufacturing facilities.... Look between Mars and Jupiter, almost every element in the periodic in them rocks, and squish them together there's a mass of about double Earth - before we're even ½ way through harvesting that we can be shipping material back from out in the Oort. There's really more than we can use, even accounting for exponential expansion, lifting it from the floor is just... restrictive.

Yes, smaller is "easier" to launch. That's the point of moving about ½ way up before launching, requiring a lot less fuel. You can do that with a much much smaller rocket and then still carry similar payloads - the 2.5Tonnes I'd guessed at payload capacity is actually quite tiny. I wasn't thinking of breaking orbit, but yes, the same design with less payload would easily. And no-one really launches 1KG, it's mathed like that because more weight needs more fuel - but the fuel isn't the major part of that cost, it's the fact that 90% or so of the rocket is disposable, it's taken a lot of man-hours and commonly with high grade materials machined to high tollerances... By cutting off the lower stages of the rocket - which is where most of the fuel is wasted - you should be able to drive costs down significantly.

As to the rail launch system... Not a lot has changed in 50 years with physics, all the rules are still the same. Lets assume you've no magical way to do this in vacuum that also allows to exit at rediculous velocities. The principle "fail" is going to be wind resistence. 7.5Km/s in atmosphere isn't happening, most likely. To take something like the Bugatti Veyron, that's fine up to about 150MPH, or only a dawdling 67.056 m/s but after that the exponential increase in wind resistence is what eats up all the engine power, charicterised by a noticiable drop in the steepness of the accelleration curve, it becomes flat compared to say, 30MPH-90MPH. Lets ignore that you'll create friction enough to become a fireball well before 1800m/s, taking it past 2000m/s will take significant energy even with "perfect" aerodynamics. To avoid getting lift at this stage, either removing from the track or providing friction against, it'll also be useless for controlled re-entry. Once you get up past 20,000 meter the air is maybe thin enough to think about hitting those sorts of speeds. It'll still flame 2000m/s+. Then, somehow, if you do manage to acheive these speeds then the curve as you move from horizontal to vertical for launch would generate unacceptable G. The only mitigation being to reduce the incline, and increase space giving you about thirty miles of gradual increase in elevation, and even if you can build that big, you'll of lost most energy before you'd left the end of the rail. Fire up KSP and try to build such a system, I've not managed to kill any with G so that's not going to be a factor. Space might be an issue, building a multiKM rail might be out of the question but doctoring the physics on an electrical motor might allow to hit velocities before edge of runway - which could be remodelled into the curve... Would allow you to at least see what I mean with air resistence and gravity stealing all your momentum before ½ way, and the temperatures generated in the attempt.

  Updated  on Jan 24, 17 / Aqu 24, 01 10:40 UTC, Total number of edits: 1 time
Reason: typo

Jan 24, 17 / Aqu 24, 01 10:59 UTC

The total mass of the asteroid belt is just about 4% of the Moon. But yes, that is a lot, enough for everything.