Are you sure? that's a lotta rock - it's spread out a lot granted, but there's significant mass required to create a loop that wide, let alone that thick... Regardless, that's just a temporary stop off clearing up there on the way out to the Oort.

Chicken and the egg :D. We need to get up there to get the resources we need to build the machines to get the resources! That's why cheap launches are needed with a focus on micro robotics, self assembly and materials.

I always liked the launch rail idea too, but not cost effective. That's why there's interest in using planes to get as close to exit as possible. Think that's why a permanent balloon would work if payloads are small.

Anyone have the maths for highest possible attitude for a helium balloon? What if lifting a single digit kg load?

I just came up with a most unlikely sci-fi concept. If it were possible to contain a vacuum within a balloon without it collapsing, then you should be able go higher (I think). The problem is that the materials required to maintain a vacuum weigh so much that you would never leave the ground. Find an ultra lightweight method to contain a large enough vacuum, and float up and up and up. You would still need an extra kick once equilibrium has been reached due to the payload. No such method exists, but it does no harm to fantasize.

I don't think vacuum provides lift, I'd never considered this before - but I see the direction you approach from, the lack of mass therefore rising.

No such method exists, but that's only because no-one attempted to develop one yet. As you accurately identify, the materials involved commonly weigh too much and counteract any lift gained. The most obvious solution being to attempt to reduce the weight involved in the materials. You can print in ceramics now... it might be possible to design something that achieves lightweight by utilising an internal support structure that helps reduce total shell thickness. Also potential exists for what contains the vacuum to be inflatable, and use pressurised helium to hold it open.

As to the chicken and the egg comment, not quite. The golden egg(s) are certainly up there - but it is entirely possible to build the machines ourselves, and then crowdfund lifting the first one into orbit ready to eat LEO debris, and expand itself - clone itself, throw that over past Mars, midway to Jupiter to have the cycle repeat itself from mining that belt whilst throwing the proceeds back this way. At the current population levels, it'd take less than $70USD/head to have it lifted. If following my loose seed factory roadmap, then production of these ground based units will expand and refine themselves over time - print out clones of themselves for further distributions - and by offering their services to the general public render the construction and operation costless and meaning you only really pay for the lift. This can be brought down, possibly, by the likes of a baloon launch platform - things like the HAV304/Airlander 10 suggest payloads don't have to be small. Planes being used as a springboard is also another good idea - especially with advancments in electrical thrust in these fields. Rail launch is fraught with problems, like friction - and if attaining velocities to be useful, then also issues of G on the upsweep of the launch rail.

EyeR, the vacuum balloon idea just popped into my head after reading the other posts. I'm unsure about the theory. It's probably more Jules Verne than real science. I think it's always worth mentioning an idea anyway, if only to learn what is wrong with it. You never know who you might inspire, or for what purpose.

https://en.wikipedia.org/wiki/Vacuumairship https://en.wikipedia.org/wiki/Liftinggas

I think these might be useful, the second link having paragraphs related to not just vacuum but plasma as well (located half way down the page).

In regards to a vacuum, granted I don't know of any materials currently that fit the description of high strength/super low density, but could a honeycomb interior using an incredibly light material help solve the collapse issue? A way to possibly test lift potentials of a vacuum by starting with underwater tests, being that the density of water to air is roughly 1000/1, giving us an idea of any lift potential gained using heavier and more readily available materials before a large amount of time is spent trying to synthesize a material to fit the bill for low atmospheric pressures. If it has merit underwater, research continues, if no lift potential is seen, there is no time lost. An idea for the test could be either a sphere or pontoon frame, made from aircraft aluminum or alt., reinforced with internal struts and wrapped in layers of reinforced carbon fiber. Evacuate all pressure in it then weigh it at sea level on land, then submerse it and weigh it again.

Edit: I found a material that might prove promising, carbyne. It is still in its early infancy, but is showing higher strengths and stiffness than graphene and diamonds.

I'm happy that my idea sparked some interest. I agree that testing in water would be a good first plan. With new stronger materials being developed, the idea might have some merit in the future. I really don't know.

What about S.A.B.R.E. engines? A simple S.S.T.O. capable of runway landing and takeoff would mean it could become as commonplace as the jumbo-jet. Just a thought. but this would make orbital trips cheap, quick and available to the masses. 

https://en.wikipedia.org/wiki/SABRE_(rocket_engine)

For future reference, should you of enclosed that link with "< link >" (minus the spaces and qoutation marks) it should become clickable: https://asgardia.space/en/forum/forum/technology-104/topic/practical-and-cheap-way-to-get-into-orbit-1554/.

Hybrid rocket motors have been about for some time but I've not seen much practical developed and deployed for long term operations - been a few test flights. Bloodhound SFC uses a hybrid rocket motor, too, tho that isn't aiming for orbit. Overall, yes SSTO should be a goal, but multiphase right now is more probable. I don't think it matters much from how the lift is achieved, overall, the key requirement at the moment being driving down the cost to do so - hybrid rocket motor is a viable technology - but ultimately long term we should be seeking options that operate sans propellant - can go a lot further, and things can operate for a lot longer.

To ignore Blackstar, X-37B, XS-1 etc then the spaceplane scene is pretty thin. There's one with an operable test model, I can't seem to find it, of other things still in testing/design Virgin's imaginitively named SpaceShip2 is gearing up ready for actually punching out of atmos. They've tried this before, re-entry wasn't smooth. People died. Rel's Skylon system uses SABRE engines, I'm not aware of any test flights for that planned before 2025, It's still design phase, but shows promise.

http://commons.erau.edu/ijaaa/vol3/iss2/4/ looks interesting. I wouldn't want to be piloting when my craft suddenly counters a few tonnes+ of kinetic transfer from the "catapault", then suddenly gets a few tonnes lighter, in thin atmosphere. That sounds fun.

I think that humans should find that 'wings are for flying'. If they utilised this correctly, such as noting wingspan is practically the opposite of the current latitude measurements, with logic, they'd get up sooner. ET ships are flat and round!

And let's don't forget about "Orbital ring" concept.

the Yunitsky's model (known as GPV) is actively developing.

http://rsw-systems.com/news/yunitskiy-space-industrialization-prospects?lang=en&r=107491

As said there, for one flight the GPV is able to deliver about 10 mln tons of various cargo and 10 mln passengers. The system can perform up to 100 flights per year

Basically we are talking a type of space elevator here... or just a one-way launching system from Earth?

The image below is that of a saucer.

:https//i.stack.imgur.com/y5IfM.jpg

First, let us understand the concepts behind the saucer--flying speaker. When it enters an atmosphere, is uses the oscillation, like a speaker, to displace the air and cause a high pressure and low pressure system for lift. This oscillation can be obtained by applying a current to the material of a flying craft, e.g. an airplane's wings. Considering this displacement is made from an EMF, one must also apply the lift gained from the oscillation. As one leaves the atmosphere--leaving the Earth's magnetic shield--the intensity of the amount of natural light increases. This allows a craft to take full advantage of EMF, while negative the drag from air resistance. To say magnetic technology is expensive would be to say Our Earth's core does not contain high amounts of Iron.

The image below is that of a saucer.

:https//i.stack.imgur.com/y5IfM.jpg

First, let us understand the concepts behind the saucer--flying speaker. When it enters an atmosphere, is uses the oscillation, like a speaker, to displace the air and cause a high pressure and low pressure system for lift. This oscillation can be obtained by applying a current to the material of a flying craft, e.g. an airplane's wings. Considering this displacement is made from an EMF, one must also apply the lift gained from the oscillation. As one leaves the atmosphere--leaving the Earth's magnetic shield--the intensity of Universal electromagnetic forces increase. This allows a craft to take full advantage of EMF, while negating the drag from air resistance.