Drive systems

I realize that this subject has been hammered on ad nauseam- but there is still a need for our kind to develop these, as chemical drive systems, with the exception of ground to orbit, do not seem to be practical.So, I'd like to open the door to discussions on things like photon drives, light sails, mag drives, et.al. Ground to orbit systems, such as laser launchers and orbital elevators would seem to be the first step, but current infrastructure looks to be what we're limited to.

Having worked in the plastic film industry I am aware of how multilayer technology could be a first step to sustainable system wide access, along with how polymer technology could provide 'slingshot' type cargo movers. I am interested in what thoughts you folks might have on this subject.

anyone interested?

Caliban wrote:I realize that this subject has been hammered on ad nauseam- but there is still a need for our kind to develop these, as chemical drive systems, with the exception of ground to orbit, do not seem to be practical.So, I'd like to open the door to discussions on things like photon drives, light sails, mag drives, et.al. Ground to orbit systems, such as laser launchers and orbital elevators would seem to be the first step, but current infrastructure looks to be what we're limited to.

Having worked in the plastic film industry I am aware of how multilayer technology could be a first step to sustainable system wide access, along with how polymer technology could provide 'slingshot' type cargo movers. I am interested in what thoughts you folks might have on this subject.

anyone interested?

If you’re looking for just orbital access, you could convert a retired ICBM silo. Strip out all the equipment, line the walls with high powered (cut a car in half) lasers hooked to a dedicated power plant. Add reflecting mirrors to bounce each beam horizontally around the plane. Plug the hole with the payload/space craft. Fill with water & “Fire the lasers!” The water would superheat, turn to steam & POP – like a champagne cork, into orbit. Hmmm. Launching spacecraft on coal power - lol

MAD-4A wrote:The water would superheat, turn to steam & POP – like a champagne cork, into orbit. Hmmm. Launching spacecraft on coal power - lol

My guess is you won't come close to orbital velocities with that approach for the same reasons steam rockets are rarely used for space launches: evaporation takes time even when the water is superheated. Also, lasers have a high power and energy density at the target but for heating something on a bulk scale, they are rather inefficient.

Currently, maglev launchers like the StarTram 1 or 1.5 concepts seem the most workable concept with current technology.

I like the space fountain and orbital ring concepts for getting to orbit, but I do have one problem with them:
How the hell do you deploy one?

Even if you get a space fountain up to orbit, as soon as you launch from it you'd start falling. As XKCD puts it, Orbit isn't an altitude, its speed. So while you could build one from the ground up, then what?

Launching from an orbital ring isn't so tricky. The tricky part would be deploying one in the first place!
I know a lot of folk on these forums are smarter than me. What do you think?

aairfccha wrote: evaporation takes time even when the water is superheated. Also, lasers have a high power and energy density at the target but for heating something on a bulk scale, they are rather inefficient…

I specified "high powered (cut a car in half) lasers" current lasers (even anti-missile lasers) would be underpowered but with enough power the water will superheat and blow (it’s been done – accidentally – with an underground nuke test – the hole was filled with water, plugged with a large metal plug and a nuke set off at the bottom of the hole – the water was instantly super-heated to steam and pop! - plug in orbit) you would just have to find a laser (or perhaps plasma ejector) or other substitute for the Nuke to be reusable and not destroy the silo in the launch.

What you develop depends upon what the intended cargo is. Something that is going to be putting nonliving cargo into orbit like supplies and fuel/air and such can use launching methods that generate a lot of g-force: something like a magnetic launcher/giant railgun/cannon methods. But if humans and/or animals are going to be the cargo, then the g-force has to be kept down to a more tolerable speed. Which means for now, chemical rocket engines. Unless/when we can build a space elevator, I think we'll be limited to the rockets (whether powered by hydrogen,m fusion or whatever as a fuel source) until someone comes up with anti-gravity/gravity plates and energy reactionless drives.

I think a Space elevator would be a good Idea. I have read that a Penn State Professor has come up with a benzene process that is harder than a Diamond. http://www.extremetech.com/extreme/1906 ... e-elevator
If you turned this benzene process into a cable like they do with suspension bridges (wind them into a large cable) I believe that would make a great elevator cable. The Cable could be wrapped around a type of benzene tube it would contain Liquid oxygen Or water that could be split into its basic components (hydrogen and Oxygen) use the Oxygen for the facility at a Geo-sync orbit. Store the Hydrogen for use as fuel for the ship.

Build a orbital assembly plant for ship design/ launching. The type of ship that could be built in space would be less restricted than having to have it launch from earth. One would not have to take Launch stresses into account when designing the ship.

Ok here is my idea for the space elevator car use a maglev or a antigrav system to launch it into space. The outside of the car could be coated with the same Benzine proces.

If the facility at the top of the elevator was large enough one could rent out space to a chip maker(IE computer chips) the type of computer chip that could be built in low/no gravity could be a great benefit to the spaceships constructed in the OAP (orbital assembly plant).

Next step would be to have a cable for transferring power back to earth from Solar panels set on the outside of the structure that is at the top of the elevator.

To see this happen is my dream. I doubt it will happen in my life time.

Caliban wrote:So, I'd like to open the door to discussions on things like photon drives, light sails, mag drives, et.al. Ground to orbit systems, such as laser launchers and orbital elevators would seem to be the first step, but current infrastructure looks to be what we're limited to.

O.K., I'm not a rocket scientist, but in principle it all comes down to energy density. Those nice ideas like photon drives or light sails have one major issue: how do you brake? Light sails, specifically, would probably not survive hits by microparticles at high delta-v. And there's a lot of dirt in the inner solar system.
Based on current technology and physics, I'd see nuclear fission reactors as viable energy sources for drive systems. And for intra-system astrogation there are ion thruster drives. They maximize mass efficiency of the drive, which you need for everything farther off than the moon. Combined with the energy output of a fission reactor that could give you the mass-efficiency and accelaration (and de-accelaration) you'd need. If you complement that with chemical propellant drives for maneuvering, you get a working combination.
But you won't land something like that on anything heavier than a country-sized asteroid...

MAD-4A wrote:

Caliban wrote:I realize that this subject has been hammered on ad nauseam- but there is still a need for our kind to develop these, as chemical drive systems, with the exception of ground to orbit, do not seem to be practical.So, I'd like to open the door to discussions on things like photon drives, light sails, mag drives, et.al. Ground to orbit systems, such as laser launchers and orbital elevators would seem to be the first step, but current infrastructure looks to be what we're limited to.

Having worked in the plastic film industry I am aware of how multilayer technology could be a first step to sustainable system wide access, along with how polymer technology could provide 'slingshot' type cargo movers. I am interested in what thoughts you folks might have on this subject.

anyone interested?

If you’re looking for just orbital access, you could convert a retired ICBM silo. Strip out all the equipment, line the walls with high powered (cut a car in half) lasers hooked to a dedicated power plant. Add reflecting mirrors to bounce each beam horizontally around the plane. Plug the hole with the payload/space craft. Fill with water & “Fire the lasers!” The water would superheat, turn to steam & POP – like a champagne cork, into orbit. Hmmm. Launching spacecraft on coal power - lol

Read Pournelle;s "High Justice." and following stories.

DDHv wrote:

Caliban wrote:I realize that this subject has been hammered on ad nauseam- but there is still a need for our kind to develop these, as chemical drive systems, with the exception of ground to orbit, do not seem to be practical.So, I'd like to open the door to discussions on things like photon drives, light sails, mag drives, et.al. Ground to orbit systems, such as laser launchers and orbital elevators would seem to be the first step, but current infrastructure looks to be what we're limited to.

Having worked in the plastic film industry I am aware of how multilayer technology could be a first step to sustainable system wide access, along with how polymer technology could provide 'slingshot' type cargo movers. I am interested in what thoughts you folks might have on this subject.

anyone interested?

MAD-4A wrote:If you’re looking for just orbital access, you could convert a retired ICBM silo. Strip out all the equipment, line the walls with high powered (cut a car in half) lasers hooked to a dedicated power plant. Add reflecting mirrors to bounce each beam horizontally around the plane. Plug the hole with the payload/space craft. Fill with water & “Fire the lasers!” The water would superheat, turn to steam & POP – like a champagne cork, into orbit. Hmmm. Launching spacecraft on coal power - lol

Read Pournelle;s "High Justice." and following stories.

Which was based on actual work being done at Aerojet (I believe). I don't know why nothing came of it.