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Private Rocketplane Test A Success
HobbySpacer writes: "XCOR
announced the success of the first phase of flight tests
for the EZ-Rocket. In the most recent flight, Dick Rutan fired both of its rocket engines to take off and reach a speed of 160knots and an altitude of 6200 feet. The vehicle is a Long-EZ kit plane modified to hold
twin 400 lb thrust rocket engines fueled by isopropyl
alcohol and liquid oxygen. The project is not aimed at a homebuilt EZ-Rocket but will demonstrate safe and reliable rocket propulsion.
The primary goal is development of reusable launch technology that leads next to a high altitude sub-orbital rocket vehicle for
space tourism,
rocket
racing (e.g. vertical drag racing at air shows) and the
X-Prize competition."
Think of how much money goes into car racing. Rocket racing would be an incredible spectacle.
This could easily lead to full funding for the transitional stage of private rocketry before the obvious profit potentials of orbital flight.
LOX eats through bad rocket elements (e.g. below spec piping and valves) much faster than H2O2, and the low temp makes valve sticking and thermal mismatch failures much more likely.
To get equivalent safety, working with LOX will cost 10 times as much.
Starting a grill with liquid oxygen.
The main reason is the FAA. If you want to be a high alt attempt, you need to file a lot of paperwork concerning your flight plan and risks to populated areas/foreign airspace. In theory, you could get approval for an orbital shot from two places in the USA (Black Rock and Alaska,) if you have a self-destruct device on board. Note that a self-destruct doesn't make the rocket vanish, it just puts the debris in a safe zone. Now, if you want to float to 120,000 feet before launch, your debris zone is about the size of the Pacific Ocean. You don't get approval, end of story.
On the other hand, it looks like the Rutan brothers are using something like Extreme Programming to build rockets... build up little by little, test daily, twice, three times a day, use existing airframes as testbeds (Dick Rutan could fly a LongEZ in his sleep, and probably has by now :) .... and you know damn good and well that when they get a reliable product they're gonna release it as a kit.
(drum roll please)
Open Source Aviation!
No, I'm serious... when you buy a kitplane, you get the source (plans, etc.), and you are perfectly free to hack'em, and post your results and sell the resulting product. (Kindof a BSDish license... 1/2 :) The original 2-seat pusher LongEZ became the 4-seat Velocity, the taildragger Quickie, and inspired the commercial LearStar and Beechcraft StarShip designs.
Yeah, aircraft design is kinda like doing something the size of Mozilla.. but once you've got something working (and the VariEze/LongEZ designs have been around for... well, the old VariViggen (the granddaddy of all homebuilt canards) the Museum of Flight was registered in 1972, so.... and once you've got something it's dead easy to do incremental improvement and even rapid prototyping.
They've been doing this on a shoestring budget (I know how the Rutan brothers work, that's how they built Voyager) for about two years now, and they've got a bird in the air alreddie... where the Zoche folks have been at this aerodiesel thing for six years now, and still don't have anything flying... which is a reflection of the design philosophy; Zoche is going for an FAR-23 certified engine up front, where XCOR is happy to get something off the ground in a safe manner... in much the same way as Netscape would write this huge thing ground-up and only release it when it was all done as opposed to Mozilla pumping out milestone after milestone as things gradually started working...
In short, real-world, non-code-geek example of why bazaar-style development works.
I hate to break this to the programming community, but you did not invent the philosophy of "open source" or the "bazaar vs. the cathedral."
Science has had an "open source" component for pretty much as long as there has been modern science. Everybody works on some little bit of the problem (figuring out how the universe works), and when they have something they think is reasonable they publish it for everyone else to critique. Such publications may not technically be free, because you have to subscribe to the journals, but in reality if you go to any science library you can get free access to them. Really, the philosophy of finding mistakes by releasing code as "open source" so that a lot of other people can look at it and tinker with it is the same old philosophy behind peer-review and publication of scientific papers. The "open source aircraft design movement" exists; it is called "Journal of Aircraft" and is delivered to my home every couple of months.
This may get me modded down, but I think that "open source" is just Computer Scientists figuring out something that the other branches of science have already known for a very long time. Getting new developments into the public domain and letting other researchers bang around on them will yield even newer and better developments. One team of people locked away in isolation is not nearly as likely to develop a workable product (which for science would pretty much be a model of everything in the universe.)
That said, I don't think the idea of developing aircraft the same way that you develop programs is a good idea, because they are NOT the same sort of things. I'm sure you all know the joke about if Airplane development went like Computer development then we'd already have hypersonic transport aircraft with world spanning range that the average person could afford to own and operate... and they would explode once every week or two killing everyone on board. Aircraft Theory and Aircraft Conceptual Design and Aerodynamic Behavior and other such things are generally done as public science and/or published in journals and presented at conferences (i.e. "open source"). When it gets time to actually design the aircraft, this is done with a relatively small, closed team of people. There is a good reason for this. Airplane and rocket crashes kill people. Pick up a copy of The Right Stuff and read the first chapter. Such things ARE tested regularly. They are tested methodically and often. In wind tunnels and CFD code and on the ground and finally in the air. They are tested with methods and in progressions that were proven to work with VERY costly (in dollars and lives) prior experience. You could call it "extreme programming" for aircraft. Aircraft design is also complex. Simply moving the battery from the front to the back of a plane this size can invalidate all previous flight test data, so it is with good reason that the development is done by people who know the whole picture intimately (a difficult thing for a hobbyist to do). And, many aircraft design groups don't want their detail designs and their "tricks of the trade" to be open source because they are proprietary or classified. Yes, other sciences have "Closed Source" projects, too; but unlike in computer science, they tend to usually be offshoots and niche developments with the bulk of science being "open source" (to use CS lingo). Even big, private company laboratories in other scientific fields publish a lot of "open source" scientific material. Not only do they realize the value of having it reviewed and verified by other scientists "for free," but they also understand the importance of such publication in maintaining their organization's prestige in their industry and in recruiting the best new talent.
Aerospace has had "open source" for almost 100 years now. Physics has had it since the days of Newton and Galileo. Computer scientists, welcome to the club. Just don't think the rest of us haven't known about this for a long time... and stop tacking the phrase "open source" on everything. Try terms like "peer review" and "in the public domain" on for size; maybe you'll sound less socialist and the public will take it more seriously.
Got any ideas? Once you're at the edge of the atmosphere, you're pretty much limited to using a self contained reaction motor.
Ground laser launching relies on superheating air, plus it's only been used to shove vehicles directly up, so it's basically a really cool but expensive way to replace July 4 bottle rockets. A more viable alternative is turning beamed EM into electricity then powering magnetohydrodynamic motors that superheat air, but you still have that pesky problem that you are relying on an atmosphere to get your speed.
You could accelerate the vehicle in a rail gun or rocket sled until it reaches orbital velocity while it's still on the ground. Ballpark figure, at a (barely) survivable 20g, you'd need a 150km track to reach the 7.73km/s orbital velocity of a typical shuttle mission, ignoring air resistance. Except you can't ignore air resistance, because at 7.73km/sec at 1 atmosphere, you'd burn the vehicle to a toasty crisp.
Even if you postulated antigrav, you still need to generate lateral acceleration to achieve orbital velocity, which again requires a self contained rocket, or an atmosphere.
A beanstalk (space elevator)? Heck, maybe we've already got the technology to do it, but we're not going to, not for a long, long time.
So, really, if you've got any ideas about what to use as an alternative to rocketry today, let's hear them. I'm fresh out.
If you were blocking sigs, you wouldn't have to read this.