SSTO....any ideas?

[SWPIGWANG]

Come on, you people must have some ideas for single stage to orbit launch vechicles....

[The Dark]

Highly aerodynamic vehicle with high-efficiency jet engine and scramjet, similar to the X-15 but on a larger scale (and replacing the rocket with a scramjet). Don't know if it's feasible, I'm no engineer, but it could just work.

[The Duchess of Zeon]

Come on, you people must have some ideas for single stage to orbit launch vechicles....

Single stage is inefficient. Why carry along the extra weight into orbit? Want you want is something which can carry the maximum payload with the available technology, for the minimum cost, into orbit. Then you want to mass-produce them. Re-usability is not a requirement, though if you can make stages re-useable without increasing cost to lift each pound into orbit, that's a pleasant addition.

To paraphrase: someone on another board I frequent: "The physics of chemical rocketry allow for, at most, 10% of the launch weight being payload. Only about 1% of the launch weight of the space shuttle is payload. At most, with the space shuttle, we put 124 tons into orbit and bring back 100 tons of it. Think of what we could do if we'd been putting 100 tons into orbit and leaving it there with each launch."

Space planes are a stupid idea. What we need at this stage in our development are vehicles that can put lots of stuff into orbit cheaply to build up an orbital infrastructure and provide support for additional exploration which can be launched from that infrastructure.

[Enlightenment]

Highly aerodynamic vehicle with high-efficiency jet engine and scramjet, similar to the X-15 but on a larger scale (and replacing the rocket with a scramjet). Don't know if it's feasible, I'm no engineer, but it could just work.

Scramjets don't work in vacuum. Orbital vehicles must have rockets or some other means of propulsion that doesn't require outside air.


What space access needs now is not specifically SSTO or Big Dumb Boosters. What space access needs is economical lift to orbit on the order of $1,000/kg rather than the $100,000/kg cost of the Shuttle or the $10,000/kg cost of Western ELVs. How costs are brought down by several orders of magnitude is much more a matter of careful design and competent management (i.e. management and design conducted by someone other than the US government/defense industry) rather than a matter of using any one specific technology.

Reusable vehicles--be they SSTO or TSTO--have considerable potential for reducing LEO access costs as each launch doesn't expend millions of dollars of equipment. Since the vehicle can be reused it's possible to amortize consruction costs over the productive life of the vehicle. This cannot be done with ELVs as they are by definition used only once.

Big Dumb Boosters have their own benefits but in order to be economic they much rely on economies of mass production on a scale that is far in excess of the existing or predicted space access market. If a large space access market develops, BDBs may very well be cheaper than RLVs but in the short term, RLVs seem to be better suited to handling the low launch rates of the forseeable future.

[Crossover_Maniac]

One with a nuclear engine or uses microwave beam power. Chemical propulsion doesn't have a specific impulse high enough to make it a single stage rocket. The ship would have to 90% fuel, at least. That only 10% of the mass for structure, recovery system (parachute, wings, extra fuel, or whatever you're going to use), and payload. You have two realistic choices

1). Go with a TSTO-RLV

2). Wait for advance propulsion technology.

1). we can do right now and don't have to wait for the technology of SSTO to come into being.

[Darth Wong]

Really big trampoline.

[Sea Skimmer]

Really big trampoline.

Moving back onto feasible ideas, I wonder how much a 5000mm supergun would cost? Iraq managed to buy the parts for a 1000mm model without much of anyone noticing so it can't be that high, though the mounting probably cost a damn lot.

[TrailerParkJawa]

Moving back onto feasible ideas, I wonder how much a 5000mm supergun would cost? Iraq managed to buy the parts for a 1000mm model without much of anyone noticing so it can't be that high, though the mounting probably cost a damn lot.

What kind of payload could such a gun put up into orbit. What kind of acceleration would the payload have to endure. I cant imagine it would to too expensive.

[Darth Wong]

To blast something into orbit, you would need a hypervelocity gun. Escape velocity is 11.2 km/s, and air friction would eat away a substantial portion of that velocity, so you realistically need more.

A muzzle velocity of, say, 15 km/s would be extremely difficult to achieve. The acceleration force is tremendous, and the payload is likely to be crushed in the process. Moreover, the projectile would create lots of unpleasant interactions as it moves through the air, such as a radiative plasma wake that can blind anyone with a line of sight.

[Durandal]

To blast something into orbit, you would need a hypervelocity gun. Escape velocity is 11.2 km/s, and air friction would eat away a substantial portion of that velocity, so you realistically need more.

A muzzle velocity of, say, 15 km/s would be extremely difficult to achieve. The acceleration force is tremendous, and the payload is likely to be crushed in the process. Moreover, the projectile would create lots of unpleasant interactions as it moves through the air, such as a radiative plasma wake that can blind anyone with a line of sight.

Depends on the length of the barrel, but I don't know how long we could make a giant tube pointing straight up with modern engineering techniques.

[Crossover_Maniac]

To blast something into orbit, you would need a hypervelocity gun. Escape velocity is 11.2 km/s, and air friction would eat away a substantial portion of that velocity, so you realistically need more.

A muzzle velocity of, say, 15 km/s would be extremely difficult to achieve. The acceleration force is tremendous, and the payload is likely to be crushed in the process. Moreover, the projectile would create lots of unpleasant interactions as it moves through the air, such as a radiative plasma wake that can blind anyone with a line of sight.

All of the plans to use artillery to launch payloads into space is only for deliveries to LEO. Even after your losses, that's a delta-V of 10 km/s. Secondly, the gun is only a first stage. The Iraqi supergun design would launch a 2000 lb projectile. The projectile was a solid-rocket with a 600 lb satellite designed to survive tens of thousands of g's. Not a bad idea if you were just delivering material to LEO and collecting it.

[SWPIGWANG]

This makes me remeber the idea to build a gas gun using a thousand+ km long tunnel under antartic ice.....

[TrailerParkJawa]

What do you guys think of this idea? I dont know enough about this stuff to make an evaluation.

http://www.g2mil.com/SRT.htm

[Asst. Asst. Lt. Cmdr. Smi]

What do you guys think of this idea? I dont know enough about this stuff to make an evaluation.

http://www.g2mil.com/SRT.htm

As long as it works, I'm fine with it. Still, you would need fuel to power the sled, and there's probably other problems too.

[Seggybop]

This is information for the giant cannon.
http://www.fas.org/nuke/guide/iraq/other/supergun.htm

[Uraniun235]

To blast something into orbit, you would need a hypervelocity gun. Escape velocity is 11.2 km/s, and air friction would eat away a substantial portion of that velocity, so you realistically need more.

A muzzle velocity of, say, 15 km/s would be extremely difficult to achieve. The acceleration force is tremendous, and the payload is likely to be crushed in the process. Moreover, the projectile would create lots of unpleasant interactions as it moves through the air, such as a radiative plasma wake that can blind anyone with a line of sight.

Goddamn but that just sounds really cool.

[Knife]

We can stick we standard chemical rockets but need to keep working on efficency. The Areospike engine that would have gone on the Venturestar was more efficient than normal because it adjusted the flow of thrust to maximize its profficency. New light weight materials would lower the weight of the vessel and alow more cargo.

Ontop of these, the idea of inflight refueling for a RLV has been raised aswell. Some sort of jet/rocket plane that takes off with its rockets empty and gets to altitude with regular or whatever jet engines. Here its rockets get fueled by a tanker, then it lights its rockets and continues up threw the atmoshpere burning up most if not all of its fuel (keeping enough to slow its orbit for reentry). Then using the remaining fuel in the jet engines, lands like an ordinary plane. Of coarse its rudimentry, but has some possibilities.