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Repost from LJ: 28440000 joules per pound January 30, 2006

Posted by electricaloratory in Technology.

It costs 28440000 joules of energy to move a pound of matter into space. (Unit discrepancy, I know. Bite me.) That will never change. It is the number written on the toll booth that is our gravity well. We sit on one side of this invisible barrier, built by the very laws of physics. It is this number that keeps us from finding the stars.

We can’t change that number, so all we can try to do is find better ways to apply that much energy to the stuff we want to send into space. It’s a lot of energy. The best way we can figure out to defeat this number is to strap a very tiny amount of matter on top of a giant explosion and cross our fingers. To our credit, we’ve gotten pretty damn good at it. From this layman’s perspective our rocketry skills are fairly spiffy. But that’s still what we’re doing.

When that tiny amount of matter is an instrumentation package or a satellite, we pretty much own the show. But when it’s a human – a smart, brave, fragile human body – it all still seems so far away. Air. Heat. Food. G-forces. These are things we either need, or need to avoid. Solving every one of those problems adds weight. More energy. Bigger explosion. Harder problem.

There is this wonderful, young, hopeful part of me that says that we should be going into space as fast as humanly possible. Human footprints on the dirt of Syria Planum. Human eyes watching the sun rise from Europa. Space stations glowing from the reflected beauty of Saturn. It’s part of what we do, part of who we are. It requires smarts, and determination, and bravery, and I refuse to believe that any of these are in short supply amongst the human race.

But I’m not entirely that person anymore. I’ve gotten older and more cynical. I have (if nothing else) an elementary knowledge of economics that only really serves to depress me. What is on the moon that warrants a permanent human settlement? Why are we even trying to go Mars while the moon is such a tremendous hurdle? Why why why? Everything I wrote in the previous paragraph seems hollow in the face of the realities of it. Money. 1 billion for NASA? Drop in the bucket. A real functioning moonbase, not some proof-of-concept bullshit that can’t do anything useful, may require a trillion.

What warrants that expenditure? Nothing yet. The optimist can say that we don’t know what’s there until we go. We’ll never know unless man lives on the moon and can experiment. But as long as the tickets are so expensive few can go. And experimentation will not flourish unless it is cheap. Lower the barriers to entry and human creativity will explode. It’s been seen time and time again. If there is a reason to be on the moon, we’ll find it. But we have to be there, many of us, first. Some will die. More will fail. So many lives must cross into the frontier before we will understand even a hint of its wonders. And it’s so expensive. The only way this works is if it gets cheaper.

The optimist, then, responds by saying that it *will* get cheaper. If we keep at it. We’ll solve the problem. Then I think about the Space Shuttle. The promises of which have gone utterly unrealized. It never got cheaper to operate, never was the revolving door through which man would routinely enter orbit. A launch a month? Please. Not even close. And how many billions were poured into that project? Why should I feel any confidence in this next multibillion speculative venture?

Depressed, again. The optimist takes one last swing at things. The problems are solvable. We have the creativity and the will. But NASA can’t do it. They’re hidebound, bureaucratic. Not suited for the 21st century. The answers are there, we just have to change for how we look at them. In which case, Bush should be ripping our entire space program apart. Start from scratch. Move in several different directions, all of them new, and see what works. We’re 5 years away from even having an organization that could oversee this massive endeavor. More from going back to the moon. Easily more than a decade from going to Mars.

None of these things are happening. A tiny amount of money, for a dubious venture, to an unreliable organization. Why should I have hope? Why should I cling to dreams that have been dead for so long? The Well looms overhead, and it has never seemed taller or more daunting.

28440000 joules per pound. That’s what it takes.



1. Mike S. - January 31, 2006

Though energy per se isn’t the problem– 28440000 joules is 7.9 kilowatt-hours, so if we could just convert electricity at 100% efficiency and disregard reaction mass, we could launch on wall current for less than 80 cents a pound. Even with the Shuttle, fuel costs are a tiny part of the budget– something in the dozens of dollars per pound to orbit, and potentially reduceable. The cost is in the human labor and specialized hardware.

That doesn’t make it easy, and it doesn’t necessarily bring us closer. But it’s engineering rather than physics that stands between us and cheaper launches, which is at least a reason for hope. And the fact that the X-Prize competitors are doing what only the two most powerful governments in the world could manage in 1960 is likewise at least a gleam. Ultimately, it comes down to engineering and economics– the less a launch costs per pound, the more that it’s practical and attractive to do in space, and there’s plenty of room for improvement.

That said, I agree that NASA as it stands is very unlikely to contribute much to that other than some basic science; it doesn’t seem to be institutionally capable of bringing down launch costs. They’re the only ones who’ve ever sent people past LEO, but if it ever happens again I doubt that they’ll be the ones to do it.

2. Mike S. - January 31, 2006

Damn, I’m predictable. I went back to your original posting of this to discover that I said more or less the same thing then, including converting the joules to kwh.

3. Electrical Oratory - January 31, 2006

I thought you had deliberately just cross-posted the comment, didn’t go back to see that it wasn’t an exactly copy. Heh.

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