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Can you describe your next-generation rocket?
Carmack: What we've got right now are the current quad vehicles, Pixel and Texel. They have four spherical propellant tanks and one engine in the center.
What we're going to be doing is reconfiguring the same basic systems, the same basic tank and engine, but making modules out of them. So you have two tanks and one engine as a discrete unit, and then you'll be able to bolt them together in any configuration you want, where you could start with four modules, which would look sort of like two quads stacked on top of each other with more engines on the bottom. That would be enough to take one person to 100 kilometers.
We'll mass-produce these modules and apply them in lots of different configurations. That's our focus in the coming year.
What business are you aiming Armadillo at?
Carmack: We're looking at some ways to commercially exploit the current generation of vehicles, like vertical drag racing and space diving. The space diving record was set in the '50s by an Air Force colonel from 105,000 feet, and he needed to be in a full-pressure space suit. All the records have been set by riding in a helium balloon, which would take a few hours, and it's extremely weather dependent. But if you were in a rocket, it would only take you two minutes to get there.
One of the great aspects of our development process is that we've been doing this so cheaply that a few stunts can make the company profitable and pay for the development.
But we think the first really significant business opportunity is with the suborbital space tourism market, taking people up to 100 kilometers on a rocket. Virgin Galactic has really proved that that market exists by taking in over $20 million of hard-cash deposits. But it is worth noting that they do not have any kind of an exclusive arrangement with Burt Rutan's development company and that if somebody else comes up with a vehicle (with) worthwhile capability, they'll be more than happy to work with other companies. So it's not out of the question that we might wind up flying some of the Virgin passengers at some point.
Why would Armadillo's vehicle be superior to Virgin's or others'?
Carmack: Well, SpaceShipOne and SpaceShipTwo are built from Burt Rutan's perspective as an aircraft designer, and he's probably the best person in the entire world to build a vehicle like that. But fundamentally, I'm from the camp that says that spaceships really shouldn't look very much like airplanes (because) they're going to be much more expensive to operate, have lower relative performance and probably cost more to fabricate.
We have some idea of their expenses per flight, based on their engine technology and their operational cost. And they could certainly turn a pretty good profit at $200,000 per passenger, but it's not likely that they could turn a good profit if the price pressure pushes it down to $50,000 or lower.
A good rocket, in my opinion, looks like a flying fuel tank. If you just fly it straight up and straight down, the operational cost is very, very low. It's essentially just the ground crew time and the consumables that you wind up burning on the way up, and there's no technical reason why a vehicle can't wind up being profitable with the ticket price of $10,000 per passenger.
Now that's not going to happen for a few generations (because) you'll have lots of experimental issues. But 10 years from now, if the market doesn't completely evaporate, you'd wind up with $10,000 ticket prices. And it would be for a vehicle that looks more like a vertical takeoff and landing, flying fuel tank, which is better operationally than a carrier-aircraft-based system.
Do you think that there is a big enough market for daredevil rocket diving? It seems like some new event for the X Games.
Carmack: There are probably a dozen people who are interested in one-upmanship: somebody wants to go to a 110,000-feet drop; the next person wants to go to 120,000 feet. It may be something that can be done more like a high-priced stunt, rather than a passenger thing, with a whole different level of informed consent because it would be on a very experimental vehicle and essentially a no-net stunt.
Would the rocket be like Pixel with an open-air chair?
Carmack: We were just going over this on Saturday and after a little bit of joking, the first thought was that (the seat) would be a saddle. That would be a very Texas and Armadillo. But then we decided that a racing motorcycle seat is probably the best thing on the current generation vehicle, mounted on a frame above the current computer.
We will probably wind up doing this for next year's X Prize Cup. Before that, we'll fly a dummy on the vehicle as our payload ballast.
How do you imagine it will work?
We'll probably have an "AeroShell" over (the rocket) just to reasonably streamline it with the person underneath. The rocket would go ahead and burn to--I don't have real simulation numbers on this--but the engine throttles down a little bit at maybe 70,000 feet and coasts up over your target altitude, so you wind up coming back down with the rocket and letting it pick up a little bit of air resistance. The air is very thin up there, but you get up to a few hundred miles per hour coming down. The person riding it would probably just toss off the AeroShell and let it flutter to the ground and then, while sitting on the rocket, open the parachute and get pulled away from (the rocket) rather than actually leaping off of it.
How does your work in software and games translate into what you're doing at Armadillo, if at all?
Carmack: The cornerstone from the very beginning at Armadillo was that we're going to attempt to take advantage of modern control systems. There are a few specific things that are much better today than they were in the '50s or '60s, when rocketry was originally starting. And foremost among those is computers. The computer in your cell phone is more powerful than everything that was in the Apollo program going to the moon. And you want to leverage this.
For the longest time, most of the people that were pursuing rocketry were more physics and plumbing guys--they want to make rocket engines, and they don't think about control systems. They are content to make something go really fast and maybe get it back, if the parachute happens to work. But from the very beginning, we want to leverage computers and use as much software for automating flight control, automating the landing, so that we can do double duty for all the systems, where you have one propulsion system that flies it up and takes it back down.
A lot of people in some of the rocket companies are mistrustful of computers because a lot of them come from aviation backgrounds, where there's still this kind of pilot clique. I firmly believe that while there are challenges and issues, there's just no way you will reach long-term goals of flying to orbit and the moon without embracing computers. So you might as well embrace them early on and leverage them as much as you can.