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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."
Rockets are the most inefficient method of propulsion that's still in use, a better goal would be figuring out an entirely new propulsion system that could apply to everything. Speaking of which, what's the latest on Ginger?
And furthermore, who cares about "vertical drag racing"? Drag racing cars is fun because it's something everyone can relate to. Very, very few people can relate to racing rockets.
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.
Is it just me or does anyone else think that pushing the limits of rocket design technology at public airshows might not be in the best interests of public safty?
In conventional top fuel drag racing when things go wrong which they often do it can often result in part flying off 100's of meters into the air. Dragsters by their very nature are stressed to the limits of their durability, in order to get that little bit faster than the next guy.
I don't think we want distasters reminisant of the challenger disaster happening at airshows before we decide this is a bad idea.
can someone tell me why they're not interested in using balloons at all for reusable launch vehicles? It would make far too much sense to me since it's essentially free and lightweight, and a lot LESS expensive than dumping humungous feul tanks into the ocean after every launch. You can get up very high, ditch the balloon, then use attached rockets to fill you the rest of the way. You could even use reusable balloons with hot helium instead in case you need to lift too much weight for just hot air to raise.
If God gave us curiosity
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.
The first tourist in space got to stay on the ISS for a couple days and he was using a well tested reliable vehicle (Soyuz). The tourists of these sub-orbital rockets would get minutes (at most hours) in a cramped vehicle, is it worth the risk ? Although I agree with the concept of stimulating creativity for designing sub-orbital re-usable vehicles, keep in mind that these "tourists" would still be essentially strapped to a liquid oxygen bomb and that if "civils" start going into space what does that say about the gruelling Astronaut selection performed by NASA and all the space agencies that produce astronauts (Russia, ESA, CSA, NASDA,ISA etc.) These people (astronauts) give up a good part of their life to get a trip into space. Challenger was the first to fly a "tourist" on the crew and we know what happened. NASA then cancelled all civil/commercial endeavors using the shuttle ever since... In my opinion the risks are too great to let just anyone fly in these vehicles. (as payloads mind you) -I am tempted to use the cliche "Talk about the Wrong Stuff"
You have trouble with metric? Whats so hard about powers of ten?
Take temperature for example:
Imperial, freezing is at 32, boiling at 212
celcius, freezing at 0, boiling at 100
distance
12 inches to the foot, 3 feet to the yard, 5000 and change feet to the mile, anyone know how long a furlough is?
10 mm to the cm
100 cm to the meter
1000 meters to the kilometer
1000 ml to the liter
miligrams, grams, kilograms
its obvious what these are just from the name.
Imperial uses ounces for both wieght and volume!
Metric features a uniform system of naming:
mili - thousandth
centi - hundreth
kilo - thousand
etc...
Metric is MUCH simpler than imperial. The same obstinace that has the whole world speaking english is the only reason the USA hasn't switch to metric.
Anarchists never rule
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.
One other thing:
... negligable. These things are, by definition, aerodynamic. If you drop the plane straight down all you have to do is pull back on the yoke and pretty soon you'll be flying vertical again. The balloon has to do nothing more than just drop the rocket.
if you can get 16km up (which is pretty easy even with a large load) you've cut out a LARGE portion of the density of the atmosphere. For every 16km up you're down to 1/10th of the density. So 16km up is 0.1atm and 32km up is 0.01atm.
Needless to say 90% reduction in density leads to _significantly_ less air resistance. Now although air resistance is not a huge drag (no pun intended) it does play a part. Add to the equation now that you're 16km up without using any feul, and you have that much more potential energy to use to get up to speed.
And the risk of building that is
If God gave us curiosity
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.
Um, no, not really. First of all, high grade peroxide costs $0.50/lb for 70% grade in tankcar load quantities or larger, and $10/lb or so for 97% grade commercially concentrated (you can distill 90%+ yourself from 70%, but it requires significant processing equipment and has non-zero risk associated). LOX is cheaper than beer ($0.10/lb or less in large bulk quantities).
Second of all, handling liquid oxygen and nitrogen grade cryogenics is pretty easy. LOX is used in nearly all hospitals for their oxygen feeds; there's usually a LOX tank out in the parking lot somewhere. You have to avoid using organic materials in the piping, but it's handled by relatively low-trained truckers distributing it, in tanker truckload quantities, moved around cities with little hassle or hazmat risk, every day. It has risks, and must be properly respected, but is not a problem.
High-test peroxide is also subject to self-deomposition and detonation in extreme cases.
We have lively regular debates about the merits of various propellants in online forums like
sci.space.policy
and
sci.space.tech.
Talk to professional rocket engineers and nobody is even vaguely afraid of LOX. It's not everybody's first choice, but it's not a bad one.
Peroxide isn't the worst choice by far (FLOX, Liquid Fluorine, Nitrogen Tetroxide, Liquid Ozone, Chlorine PentaFluoride all are far farworse). But LOX is a really good choice.