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Maverick Rocketeers Pursue Space Access
Mad.Scientist writes "This article at Space.com is about mavericks who are trying to lessen the cost of going into space. One of the companies, Armadillo Aerospace, is founded by John Carmack, who is also a founder of Id Software, and the brain behind games such as Doom or Quake. I just have to say, godspeed to all." Carmack is only one of the people mentioned in this story, but see our previous story for more on Carmack's rocketry habit.
Gerald Bull who shot to fame as the inventor of the Iraqi Super Gun did a lot of work on constant pressure launch systems - enormous cannons with explosives positioned along the barrel to keep the pressure behind the projectile constant for the full launch length.
Estimated cost to LEO? $1 per pound.
Because the shock was distributed along the acceleration, maximum G force on the load was 40G: fine for food and fuel and most construction supplies.
You can read more about his work at Federation of American Scientists Supergun pages, [2], and at NASA.
There really is more than one way to do it.
Hexayurt - open source refugee shelter,
If you really want a big gun then you want a Ram Accelerator. It will subject a projectile to about 25,000 G's of acceleration.
The beauty of it is its efficiency. The fuel (gas) is stored in the barrel. The projectile is fired to have it travel fast enough to cause its shock wave to ignite the gas in the tube and therefore propel it even more. Basically, it is just ahead of the detonation wave it creates.
The University of Washington has a good bit of info about them.
Cool stuff.
>Are you now using an inertial guidance system or is there a better alternative?
>I assume that GPS does not provide enough accuracy for low speed guidance
We are currently using a Crossbow inertial unit with fiber optic gyros for the fast attitude stabilization.
We have flown GPS on a couple flights, but the update rate is too slow for active control. I do feel that in the longer term, carrier wave interferometry GPS sensors will offer the most cost effective attitude sensors, but right now they are $15,000+ system. If I was doing this on a much tighter budget, I would consider trying to build a fast updating CW GPS system from available cheap GPS cores, but that is a project of significant complexity all by itself.
I have integrated a new laser altimeter with the electronics box, but we haven't flown it yet. I am looking forward to this, because it will allow us to begin working on auto-hover and auto-land control software.
John Carmack
Well, I am a rocket scientist and I couldn't agree with you more.
The "two guys from Ohio" were way, way ahead of their time. They were among the first to do actual experiment-based airfoil testing. They developed light-weight internal combustion engines. Their biggest breakthrough was realizing the importance of control: they developed twistable wings (the ailerons were invented later) to maneuver the airplane. It's not like major military powers were not trying to do the same thing; it's just that the two bicycle shop owners persisted and had the insight and ingenuity to do this.
Space travel has a much lower threshold today than air flight did for the Wrights: we know how to get there, we know how to survive, we know how to spread the risks. The difference is cost: it will take more than two dedicated hobbyists to build a space vehicle. And it will take a market demand to amortize the costs and make space travel possible; I think that's a bigger obstacle than technology or cost.