[robomartin]

The MAGLEV Launcher.

http://en.wikipedia.org/wiki/Rocket_sled_launch

http://www.reallyrocketscience.com/node/2393

Using MAGLEV as a launch assist technology to offset the amount of energy derived from burning tons and tons of fuel. Some of the articles estimate a potential to increase payload by 80% compared to a conventionally launched rocket.

If you want to get a little deeper into it, this is a good read:

http://upload.wikimedia.org/wikipedia/commons/5/58/Maglifter...

Some fun data points:

    Power for large scale system: 10GW for 20 seconds. 
    Thermal Management system capable of dissipating 40GJ.

What's the probability of this ever being built? In the US, my guess is zero. I could see the Chinese throwing money behind such a crazy project if the numbers make any sense at all. If a system like this can significantly reduce cost to orbit it could represent a huge competitive advantage.

[schiffern]

The payoff would be immense though. At datacenter electricity prices, the fundamental energy cost to LEO is about 50¢/kg.

[stcredzero]

Fuel (energy) cost is less than 1% of the cost to launch. The big costs are manpower, maintenance, and refurbishment.

[ChuckMcM]

That was the interesting takeaway from the Elon Musk talk about how cheap the fuel was compared to everything else. Having the Skylon be reusable then shifts some of the operational costs back to fuel.

Of course a plane that can fly a Mach 5 and 100,000' has other uses, the most obvious one being the SR-71 replacement. Nothing like a bit of high speed aerial surveillance "right now" to help folks on the ground make better decisions. I'm sure someone would pony up the $400M they need.

[stcredzero]

Yes, but having anything be reusable does that. If you can make up what you would have gained with Skylon by making the fuel tank 5% larger, then the opportunity cost of developing a radically new engine isn't worth it. Mach 5 does have other uses, though.

[robomartin]

I don't know the first thing about orbital-scale rocket economics, so, please, regard this as complete and utter speculative nonsense.

My thinking is that, if there's a future where we might have regular launches to orbit all of those costs will have to drop. At that point fuel might just start to become far more significant.

Let's imagine weekly "Orbit The Earth Adventure"(TM) launches in 25 or 50 years. The spacecraft, crews and maintenance would have to be optimized in order to enable the business model. I think it could very well be in that context that a MAGLEV launch-assist vehicle might make sense.

Again, I don't know what I am talking about and don't really have the time to research the subject and learn about the economics of low-earth-orbit manned space flight. I'll just have to leave it at that.

[stcredzero]

> My thinking is that, if there's a future where we might have regular launches to orbit all of those costs will have to drop.

http://news.ycombinator.com/item?id=4844581

> I think it could very well be in that context that a MAGLEV launch-assist vehicle might make sense.

Maglev would indeed allow smaller, less complex vehicles built with less stringent margins to be launched.

[geori]

Elon might build it for the Hyperloop, if you believe the speculation on the hyperloop blog posts last week.