Was able to secure a sizeable amount to acquire a few 3D printers and will start playing with 3D components that can be reused and mass produced to create the vehicle.
A lot of elements will start to be proprietary and secret to a degree here so I will have to use generalities.
For example I created a proprietary trading software that I pushed to a hedge fund in exchange for the deal I got.
It is part of my out of the box thinking. I will also have to hire a few engineers and get some advanced advice in the practicality of some liquid H2 storage solutions.
At some point I will also need a decently sized workshop so as to move the building away from the loft I am staying. The health of my current relationship depends on it :)
And I don't think my significant other will appreciate the test firing noise of a minature hydrogen rocket engine either.
Sunday, February 27, 2011
Tuesday, January 25, 2011
3D printers
This is what I will need in my next stage...
http://www.desktopfactory.com/
Well that is one of many companies creating what is called 3D printers. The idea is create all the necessary pieces for the Firefly using straight 3D imaging to material methods.
I cannot afford the infrastructure of the Pentagon or Boeing... man intensive production units are not only elaborate and expensive but prone to countless delays and errors, like the 787 ordeal shows.
If something can be printed out of metal with a tolerance of a few microns, then all issues of fitting components to each other and creating extremely hardened structures using common raw materials is possible.
For the cylindrical tanks for example the constraints only go in one direction, so creating a vacuum separated layered tank with a bone like structure between the layers is a sure way to replicate titanium strength/lightness at a fraction of the costs.
3D modelling/simulation and 3D printers are the cornerstone of the project... they can be as instrumental as IM can be in reducing need for meetings and an overbearing management.
In a sense let Mind rule over Matter.
http://www.desktopfactory.com/
Well that is one of many companies creating what is called 3D printers. The idea is create all the necessary pieces for the Firefly using straight 3D imaging to material methods.
I cannot afford the infrastructure of the Pentagon or Boeing... man intensive production units are not only elaborate and expensive but prone to countless delays and errors, like the 787 ordeal shows.
If something can be printed out of metal with a tolerance of a few microns, then all issues of fitting components to each other and creating extremely hardened structures using common raw materials is possible.
For the cylindrical tanks for example the constraints only go in one direction, so creating a vacuum separated layered tank with a bone like structure between the layers is a sure way to replicate titanium strength/lightness at a fraction of the costs.
3D modelling/simulation and 3D printers are the cornerstone of the project... they can be as instrumental as IM can be in reducing need for meetings and an overbearing management.
In a sense let Mind rule over Matter.
Thursday, January 13, 2011
Finding the 3D models
Stumbled across a really interesting tool called SketchUp from google... and also found a Firefly model in 3D I can use as reference:
Thanks Abraham Katase for this very interesting rendering. It is actually very faithful to what I have in mind when I create the real deal.
I will use and experiment with SketchUp for a while until I have a good grip on the sizes and modifications also needed.
Next I will also try to see if it can find a skp to obj converter which could let me export the data into an engineering package.
The first rule of design which is to first see if someone else had done what you want to do had paid off!!!
Thanks Abraham Katase for this very interesting rendering. It is actually very faithful to what I have in mind when I create the real deal.
I will use and experiment with SketchUp for a while until I have a good grip on the sizes and modifications also needed.
Next I will also try to see if it can find a skp to obj converter which could let me export the data into an engineering package.
The first rule of design which is to first see if someone else had done what you want to do had paid off!!!
Saturday, January 8, 2011
First practical steps
Started looking for providers of the following: Screws, tubes, welding equipment and CNC machines. This will help me put together some cost estimates and also get a grip on the reality behind several challenges.
Abstract planning and work on theoretical model is cute, but it will always miss the 10% that will represent 90% of the difficulties.
Sometimes running out of a critical piece can ruin an entire project, just as a loose screw in a liquid hydrogen turbopump can blow up the engine, and at 100,000 rpm that puppy becomes a fragmentary grenade which will slice through the thin walls of the vessel with aplomb.
Russian designs are very good models for reliability and idiot-proofness. Most of their ICBM are made to be used by not exactly motivated 19 year old conscripts subjected to less than luxurious living conditions and poor maintenance.
The elements need to be lightweight but not suicidally so.
As far as permitting a spaceship goes... the FFA has pretty simple rules which I analyzed when trying to do the CATS project, which are that *anything* is allowed to fly granted it won't fly over population centers and it is equipped with something to blow it up would it veer off course.
That last part always itched astronauts. Ain't it fun to be disposable if your ship changes course?
The issue with my project here is also I can go for straight up HELICOPTER or VTOL vehicle licensing. After all the Firefly can takeoff vertically and although it is a spaceship it can also not be its primary goal given it can have an empty oxygen gas tank and just use Hydrogen to feed its air breathing engines and always stay in the athmopshere... in turn becoming a heavy lift vehicle matching the biggest and baddest helicopters out there.
Which gave me another incredible idea which can reinforce the practicality of the Firefly as the perfect transporter: How about I make the Oxygen and Hydrogen tanks... to the same specs, and able to transfer fluids to rebalance.
BAD IDEA if we have Liquid H2 and Liquid O2 in each... but perfect if I need to use the VTOL for straight up helicopter operations, in which case I will need to have an equal quantity of fuel in each tank to maintain my center of gravity.
So... in effect the 2 tanks can be the same, interchangeable, and use the same parts. Another coup for off the shelving and simplicity!!!
Abstract planning and work on theoretical model is cute, but it will always miss the 10% that will represent 90% of the difficulties.
Sometimes running out of a critical piece can ruin an entire project, just as a loose screw in a liquid hydrogen turbopump can blow up the engine, and at 100,000 rpm that puppy becomes a fragmentary grenade which will slice through the thin walls of the vessel with aplomb.
Russian designs are very good models for reliability and idiot-proofness. Most of their ICBM are made to be used by not exactly motivated 19 year old conscripts subjected to less than luxurious living conditions and poor maintenance.
The elements need to be lightweight but not suicidally so.
As far as permitting a spaceship goes... the FFA has pretty simple rules which I analyzed when trying to do the CATS project, which are that *anything* is allowed to fly granted it won't fly over population centers and it is equipped with something to blow it up would it veer off course.
That last part always itched astronauts. Ain't it fun to be disposable if your ship changes course?
The issue with my project here is also I can go for straight up HELICOPTER or VTOL vehicle licensing. After all the Firefly can takeoff vertically and although it is a spaceship it can also not be its primary goal given it can have an empty oxygen gas tank and just use Hydrogen to feed its air breathing engines and always stay in the athmopshere... in turn becoming a heavy lift vehicle matching the biggest and baddest helicopters out there.
Which gave me another incredible idea which can reinforce the practicality of the Firefly as the perfect transporter: How about I make the Oxygen and Hydrogen tanks... to the same specs, and able to transfer fluids to rebalance.
BAD IDEA if we have Liquid H2 and Liquid O2 in each... but perfect if I need to use the VTOL for straight up helicopter operations, in which case I will need to have an equal quantity of fuel in each tank to maintain my center of gravity.
So... in effect the 2 tanks can be the same, interchangeable, and use the same parts. Another coup for off the shelving and simplicity!!!
Thursday, January 6, 2011
Fault tree analysis and reliability
I will now get deeper into my project using a method which is probably unknown to the car or any major consumer industry: First see what can go wrong, assuming the product is finished.
Thankfully the nuclear and space domains used this way, and they had to. Or else the cost of even a small issue would annihilate the finished product, and its crew.
Nasa wasn't as diligent and Challenger/Columbia resulted... which gave the doomed shuttle a reliability on par with the Kamikaze planes used by the Japanese in WWII.
I exaggerate a bit since the later had a 100% pilot kill rate but 14 dead in less than 150 flight is not something to brag about.
Don't get me wrong, the Space shuttle is an awesome feat of engineering, that was put in the most plain looking shape ever for such means that were dispensed. It is a showcase of how to make human beings travel in a shaking nuclear bomb-sized potential energy accumulator.
Story Musgrave once said how much he grew scared at every missing that the thing would indeed blow up. His quote, hard to find online but which I read in a book about space once, expressed how flying something is supposed to inspire more and more confidence as you learn about it... not the damn reverse, which is what was happening in a vessel where everything was near its boiling/explosive/rupture point in one way or another.
It is once again the scourge of the custom and low volume. Separate elements which are made to order and unique will have reliabilities hard to judge. On the opposite scale using an element produced in huge quantities will garantee its specs are always the same and its reliability will be easy to estimate inside a more complex system.
My first operational decision is make the screws used to build the mesh of the spaceship the standard for everything that needs to be screwed. Another one is use metallic tubes of exactly the same size.
It will be easy to make a fault tree analysis on a small mesh subset and scale it up. Also I will be able to optimize the whole structure using linear programming.
Thankfully the nuclear and space domains used this way, and they had to. Or else the cost of even a small issue would annihilate the finished product, and its crew.
Nasa wasn't as diligent and Challenger/Columbia resulted... which gave the doomed shuttle a reliability on par with the Kamikaze planes used by the Japanese in WWII.
I exaggerate a bit since the later had a 100% pilot kill rate but 14 dead in less than 150 flight is not something to brag about.
Don't get me wrong, the Space shuttle is an awesome feat of engineering, that was put in the most plain looking shape ever for such means that were dispensed. It is a showcase of how to make human beings travel in a shaking nuclear bomb-sized potential energy accumulator.
Story Musgrave once said how much he grew scared at every missing that the thing would indeed blow up. His quote, hard to find online but which I read in a book about space once, expressed how flying something is supposed to inspire more and more confidence as you learn about it... not the damn reverse, which is what was happening in a vessel where everything was near its boiling/explosive/rupture point in one way or another.
It is once again the scourge of the custom and low volume. Separate elements which are made to order and unique will have reliabilities hard to judge. On the opposite scale using an element produced in huge quantities will garantee its specs are always the same and its reliability will be easy to estimate inside a more complex system.
My first operational decision is make the screws used to build the mesh of the spaceship the standard for everything that needs to be screwed. Another one is use metallic tubes of exactly the same size.
It will be easy to make a fault tree analysis on a small mesh subset and scale it up. Also I will be able to optimize the whole structure using linear programming.
Wednesday, January 5, 2011
Prototypes and refinement
My previous post forgot to mention the biggest off the shelf piece I took is in fact the Firefly model and its design. I reread today the Skytol specification and one major sentence struck me: The center of gravity will be where the engines are, when the ship is dry. Fuel is 80-90% of the mass too so we need to make sure that center of gravity doesn't shift much.
Subconsciously this is probably what struck me as most realistic when I saw Serenity.
I also realized I will need to carry more liquid H2 than the onboard O2 will burn. Simply because we will scoop the difference in the athmosphere.
What is at work here is already a process of refinement and the establishment of a workflow. Here of course only rough elements are tackled, but already I can say I base my development process on an evolutionary principle also inherited from software processes.
Prototyping is one major aspect of it. Rush to something operational using anything simple and already existing and mostly doing integration of 3rd party products. Then turning around and customizing and adapting incrementally.
Any complex project will fall under the 90-10 rule... 10% of it... mostly details, represent 90% of the effort. But if the 10% that provide 90% can be identified and done, things are way much easier.
For example most of the vessel will be 3 things: The engines and the 2 tanks. Yet it is all the rest that defines its functionality. First we will need fuel lines, then controls for the engines. Most of the elements that are then added are practical, need to be minimalistic, efficient. Then we can finally think of the paint and other NUMEROUS small details.
Things add up... soon we have a LOT of things to manage and put together. But the key is not be distracted.
This is where most projects again fail, where glorious abodes in the name of prefab-modern movement are exercise in vaporware (how do I know? I had grandiose plans when trying to rebuild my house destroyed by a wildfire... then I finally settling for the good old tried and true. Not the cute designs I kept seeing that required 10 X the monies just to get through the County's code, but I digress).
Why? because of lack of lucidity, of lack of concentrating on the 10% that matter the most and provide the cheapest way. Therein lies the talent and Art needed. But at the same time simple common sense can suffice.
Subconsciously this is probably what struck me as most realistic when I saw Serenity.
I also realized I will need to carry more liquid H2 than the onboard O2 will burn. Simply because we will scoop the difference in the athmosphere.
What is at work here is already a process of refinement and the establishment of a workflow. Here of course only rough elements are tackled, but already I can say I base my development process on an evolutionary principle also inherited from software processes.
Prototyping is one major aspect of it. Rush to something operational using anything simple and already existing and mostly doing integration of 3rd party products. Then turning around and customizing and adapting incrementally.
Any complex project will fall under the 90-10 rule... 10% of it... mostly details, represent 90% of the effort. But if the 10% that provide 90% can be identified and done, things are way much easier.
For example most of the vessel will be 3 things: The engines and the 2 tanks. Yet it is all the rest that defines its functionality. First we will need fuel lines, then controls for the engines. Most of the elements that are then added are practical, need to be minimalistic, efficient. Then we can finally think of the paint and other NUMEROUS small details.
Things add up... soon we have a LOT of things to manage and put together. But the key is not be distracted.
This is where most projects again fail, where glorious abodes in the name of prefab-modern movement are exercise in vaporware (how do I know? I had grandiose plans when trying to rebuild my house destroyed by a wildfire... then I finally settling for the good old tried and true. Not the cute designs I kept seeing that required 10 X the monies just to get through the County's code, but I digress).
Why? because of lack of lucidity, of lack of concentrating on the 10% that matter the most and provide the cheapest way. Therein lies the talent and Art needed. But at the same time simple common sense can suffice.
Monday, January 3, 2011
Off the shelf everything
I remember being fascinated once by an electric motorcycle project. The web site they had was called http://www.ecycle.com/
They offered grandiose plans for an electric and hybrid motorcycle back in 2001-2003. Boy I wish I took screenshots.
Today? They seem to manufacture electric engines. And their vehicular ambitions? well maybe digging up in the web site can tell of anything. I gave up trying years ago. I was enthusiastic, writing them emails and always checking their progress. And in the end pretty disappointed by empty promises.
For me eCycle became the poster child of this scourge of modern marketing called vaporware. Plain and simple. I asked them in 2001 about their motorcycle, and even asked why in the hell they needed to make the critical parts custom. Those critical parts where the battery bay and the electric engine/generator (from what I recall). Wouldn't one be able to find what they need for an effing motorcycle in any regular dealership, and simply modify/convert an existing design, and reuse the critical parts?
The reply I got was a staunch: "Because it needs to be so!".
In 2003 if I recall again they announced "trials" for the hybrid bike (the pure electric motorcycle was by then defunct). The conditions were so not customer friendly: Put down 6K, then pick up the puppy and play with it at your own risks, with no service, no warranty and no responsibility if it causes death and injury.
In the end they seem to have found a niche and finally product parts for the electric transportation industry. But it took a mere decade, almost.
Another vaporware example is the REEVU motorcycle helmet: Still waiting about 5 years for this glorious head contraption which is supposed to have a rear vision mirror built-in...
What sucks the most is I wasn't counting on some rear vision besides the regular side mirrors on my motorcycle, but hoping to have that helmet on when a cutie would ride behind me with an open shirt.
Damn!!!
Oh well they dashed my dreams of lowering my stress level and increasing my life expectancy while riding my favorite vehicle.
Their glorious site is here http://www.reevu.com/. Like bigfoot report to me if you see one of those rarities!!!
My whole point in those 2 examples? Sometimes one single solitary custom detail (either an engine or a mirror) can derail a promising project into vaporware territory. And those are not pie in the sky products. I believe the motorcycle has been around for more than a mere century now, and the motorcycle helmet for pretty much as long...
Scorn, frustration and laughing will ensue if a project becomes a vaporware. That is quite shameful...
So this is not what I want for this project!!! Therefore my first motto will be:
They offered grandiose plans for an electric and hybrid motorcycle back in 2001-2003. Boy I wish I took screenshots.
Today? They seem to manufacture electric engines. And their vehicular ambitions? well maybe digging up in the web site can tell of anything. I gave up trying years ago. I was enthusiastic, writing them emails and always checking their progress. And in the end pretty disappointed by empty promises.
For me eCycle became the poster child of this scourge of modern marketing called vaporware. Plain and simple. I asked them in 2001 about their motorcycle, and even asked why in the hell they needed to make the critical parts custom. Those critical parts where the battery bay and the electric engine/generator (from what I recall). Wouldn't one be able to find what they need for an effing motorcycle in any regular dealership, and simply modify/convert an existing design, and reuse the critical parts?
The reply I got was a staunch: "Because it needs to be so!".
In 2003 if I recall again they announced "trials" for the hybrid bike (the pure electric motorcycle was by then defunct). The conditions were so not customer friendly: Put down 6K, then pick up the puppy and play with it at your own risks, with no service, no warranty and no responsibility if it causes death and injury.
In the end they seem to have found a niche and finally product parts for the electric transportation industry. But it took a mere decade, almost.
Another vaporware example is the REEVU motorcycle helmet: Still waiting about 5 years for this glorious head contraption which is supposed to have a rear vision mirror built-in...
What sucks the most is I wasn't counting on some rear vision besides the regular side mirrors on my motorcycle, but hoping to have that helmet on when a cutie would ride behind me with an open shirt.
Damn!!!
Oh well they dashed my dreams of lowering my stress level and increasing my life expectancy while riding my favorite vehicle.
Their glorious site is here http://www.reevu.com/. Like bigfoot report to me if you see one of those rarities!!!
My whole point in those 2 examples? Sometimes one single solitary custom detail (either an engine or a mirror) can derail a promising project into vaporware territory. And those are not pie in the sky products. I believe the motorcycle has been around for more than a mere century now, and the motorcycle helmet for pretty much as long...
Scorn, frustration and laughing will ensue if a project becomes a vaporware. That is quite shameful...
So this is not what I want for this project!!! Therefore my first motto will be:
If trying to do something, first see if someone else already does it!!!
This is actually taken from a well known Computer Science mantra. Reuse, simplify, Refactor... and repeat endlessly until the complexity of what one tries to accomplish is manageable.
Yes I am a programmer and how I approach everything here will be influenced by my entire training in dealing with complex endeavors and somehow tackling them for a living.
Liquid hydrogen tanks? Maybe ask BMW
Liquid Oxygen tanks? countless vendors and providers, some of them for the aerospace industry
Mesh for the body? From India to China to the US there are a lot of them, some making tubes out of composites and offering services to weld them too.
Control panel, software etc...? Ditto...
One can look at our world of complex products and delivery routes not stretching thousands of miles and wonder why all this wouldn't be leveraged to accomplish something in fact simpler than a commercial jet.
This is why I believe I can find all I need off the shelf...
Sunday, January 2, 2011
Business philosophy
A lot of people will of course think this is an exercise in futility but I am also quite skilled in business projects as well as understand how the marketplace works...
It is clear the first most important factor for such a project like this to succeed is the cash flow. Basically enough money to get even more money. Focus is paramount as well as an agile business framework.
The tools, the material, even the rocket engines exist today. This is not about some pie in the sky endeavor but a mature reflection on how much a synthesis of today's available technology and marketing can be used to create something beyond inspiring. Something that can galvanize and move.
The cars and the planes defines our civilization, our world. How much more can a VTOL vehicle with tens of tons of lift capability and a performance envelope reaching into Space Shuttle territory do? Especially if it creates a passionate response and seems like the eerie transition of a sci-fi series that lasted 14 episodes and a feature movie into REALITY.
Well in a way it is a symbiosis between the world of ideas, the imaginary, and the hard knocks school of reality and the physical world. It just so happens that out of the hundreds of designs and bad sci-fi I saw so far in my lifetime something struck me as profoundly beautiful and achievable, as when Mal saw Serenity in that "out of gas" episode where the history of that imaginary vessel is chronicled somehow. I was looking for a shape, something more interesting than a tube and a rocket engine cone in the end. And I found it...
To achieve the goal I want to realize here the most important thing, besides cash flow and how to generate it, is also understand how (advanced high tech) projects fail, even in light of endless funding.
Constellation failed, the American SST failed in its craddle and later the Concorde also was nixed... the Space Shuttle itself is on the block after a murderous record of 14 dead in less than 120 missions at a cost each exceeding that of any 1960s era conventional manned rocket mission. How many other space-related projects also failed or ended up half baked and neither practical nor cost effective?
The lesson I have from such a richly populated graveyard is that small lightweight and agile business endeavor can see things to which there is a huge psychological block from large established ones.
IBM took 1 year to produce an empty box in 1981 so slow and heavy handed was its organization. Then came Microsoft... Toyota was created in a garage, as was Apple, at a time when computers filled an entire room.
The law of diminishing returns is a very harsh mistress indeed : You can't have one man dig a hole in 60 seconds, and expect 60 men to dig a hole in 1 sec. Yet most large corporations think that way.
The same applies here... but things are even easier and simpler today than for all those startups of old.
Meetings? just use IM... and you can talk to several people at once. Everything is so much easier and efficient in writing, leaving maybe 1% of the interaction in a team to be done in person.
Off the shelf one will find all they need to build a spaceship. Large capacity cryogenic tanks, composite material tubes to make meshes and tiles able to withtand the huge plasma cloud of reentry while being as lightweight as a sponge. Even liquid oxygen/hydrogen engines are on the free market somehow.
Using a vessel form taken from a defunct cult series with enough of a following to make a feature movie out of it 3 years later is also a good marketing move. Nobody among the people who can finance such a project will seriously dream of this at night:
But Serenity yes. People were exposed to its image for hours at a time. The producer of the series simply made it another member of the crew.
Passion and just glean what we already have around us, was always there. Then optimize and optimize and keep the focus on the goal and the simplest way to get there. Always strive to thwart the laws of diminishing returns and KISS.
Like a sculpture, a working version of a Firefly can be made by brushing away the excess and the psychological barriers people have in creating something so incredible.
It is clear the first most important factor for such a project like this to succeed is the cash flow. Basically enough money to get even more money. Focus is paramount as well as an agile business framework.
The tools, the material, even the rocket engines exist today. This is not about some pie in the sky endeavor but a mature reflection on how much a synthesis of today's available technology and marketing can be used to create something beyond inspiring. Something that can galvanize and move.
The cars and the planes defines our civilization, our world. How much more can a VTOL vehicle with tens of tons of lift capability and a performance envelope reaching into Space Shuttle territory do? Especially if it creates a passionate response and seems like the eerie transition of a sci-fi series that lasted 14 episodes and a feature movie into REALITY.
Well in a way it is a symbiosis between the world of ideas, the imaginary, and the hard knocks school of reality and the physical world. It just so happens that out of the hundreds of designs and bad sci-fi I saw so far in my lifetime something struck me as profoundly beautiful and achievable, as when Mal saw Serenity in that "out of gas" episode where the history of that imaginary vessel is chronicled somehow. I was looking for a shape, something more interesting than a tube and a rocket engine cone in the end. And I found it...
To achieve the goal I want to realize here the most important thing, besides cash flow and how to generate it, is also understand how (advanced high tech) projects fail, even in light of endless funding.
Constellation failed, the American SST failed in its craddle and later the Concorde also was nixed... the Space Shuttle itself is on the block after a murderous record of 14 dead in less than 120 missions at a cost each exceeding that of any 1960s era conventional manned rocket mission. How many other space-related projects also failed or ended up half baked and neither practical nor cost effective?
The lesson I have from such a richly populated graveyard is that small lightweight and agile business endeavor can see things to which there is a huge psychological block from large established ones.
IBM took 1 year to produce an empty box in 1981 so slow and heavy handed was its organization. Then came Microsoft... Toyota was created in a garage, as was Apple, at a time when computers filled an entire room.
The law of diminishing returns is a very harsh mistress indeed : You can't have one man dig a hole in 60 seconds, and expect 60 men to dig a hole in 1 sec. Yet most large corporations think that way.
The same applies here... but things are even easier and simpler today than for all those startups of old.
Meetings? just use IM... and you can talk to several people at once. Everything is so much easier and efficient in writing, leaving maybe 1% of the interaction in a team to be done in person.
Off the shelf one will find all they need to build a spaceship. Large capacity cryogenic tanks, composite material tubes to make meshes and tiles able to withtand the huge plasma cloud of reentry while being as lightweight as a sponge. Even liquid oxygen/hydrogen engines are on the free market somehow.
Using a vessel form taken from a defunct cult series with enough of a following to make a feature movie out of it 3 years later is also a good marketing move. Nobody among the people who can finance such a project will seriously dream of this at night:
But Serenity yes. People were exposed to its image for hours at a time. The producer of the series simply made it another member of the crew.
Passion and just glean what we already have around us, was always there. Then optimize and optimize and keep the focus on the goal and the simplest way to get there. Always strive to thwart the laws of diminishing returns and KISS.
Like a sculpture, a working version of a Firefly can be made by brushing away the excess and the psychological barriers people have in creating something so incredible.
Saturday, January 1, 2011
Where to put the tanks? And maybe the expected mass is too small?
This is the schematic where 2 tanks of the size we talked before would fit in the frame of the spaceship. The black lines between them are the fuel lines up to scale.
The tanks are small in respect to the frame of the ship, very hopelessly so... But keep in mind doubling the size of a tank multiplies by 8 its capacity (i.e 2^3) and we do not have the technology for hybrid air breathing jet-rocket engines that can push 1000+ tons of trust...
And we have a whopping 45 tons of dry mass, including the tanks themselves.
The hydrogen tank can be a scaled up version of the one BMW uses for their Series 7 hydrogen car:
BMW 7 hydrogen
"The hydrogen fuel is stored in a large, nearly 30-gallon (110 liters),[5] bi-layered and highly insulated tank that stores the fuel as liquid rather than as compressed gas, which BMW says offers 75% more energy per volume as a liquid than compressed gas at 700 bars of pressure.[6] The hydrogen tank’s insulation is under high vacuum in order to keep heat transfer to the hydrogen to a bare minimum, and is purportedly equivalent to a 55-foot (17 m) thick wall of polystyrene Styrofoam.[7]
To stay a liquid, hydrogen must be super-cooled and maintained at cryogenic temperatures of, at warmest, −253 °C (−423.4 °F). When not using fuel, the Hydrogen 7’s hydrogen tank starts to warm and the hydrogen starts to vaporize. Once the tank’s internal pressure reaches 87 PSi, at roughly 17 hours of non-use, the tank will safely vent the building pressure. Over 10-12 days, it will completely lose the contents of the tank because of this"
The space shuttle gives us an idea of how much this can be scaled up: The liquid hydrogen tank is 331 inches in diameter, 1160 inches long, and has a volume of 53518 cubic feet and a dry weight of 29000 pounds i.e 13 metric tons.
The space shuttle tank is equivalent to a 10 meter in diameter spherical tank. Our requirements call for a 30 % smaller tank (1.1^3).
If we use conservative good techniology I would think a 5 metric tons tank will fit the bill since we are also dealing with a spherical shape, which is way much more efficient.
We can use the same kind of storage materials for LO2 although it is easier to store the later. A 3 metric tons tank will fit the bill.
So we have:
8 tons for the 2 tanks, and they will store 225 tons of propellants.
As for the engine, let's allocate about 12 tons. Skylon's plans call for 10 tons for the engines and we can add an extra 2 for additional components and redundancy.
The engines are the single most critical component of the whole system.
That leaves us with 45 tons - 8 - 12 = 25 tons for the remaining frame etc...
Things are getting tight... I will now cross my fingers we can somehow fit the frame supporting the engines and tanks and the hull in that number, about the mass of an 18 wheeler that needs to expand and fill the size of a 90 meters long ship.
Gotta love extreme challenges in one's lifetime...
The tanks are small in respect to the frame of the ship, very hopelessly so... But keep in mind doubling the size of a tank multiplies by 8 its capacity (i.e 2^3) and we do not have the technology for hybrid air breathing jet-rocket engines that can push 1000+ tons of trust...
And we have a whopping 45 tons of dry mass, including the tanks themselves.
The hydrogen tank can be a scaled up version of the one BMW uses for their Series 7 hydrogen car:
BMW 7 hydrogen
"The hydrogen fuel is stored in a large, nearly 30-gallon (110 liters),[5] bi-layered and highly insulated tank that stores the fuel as liquid rather than as compressed gas, which BMW says offers 75% more energy per volume as a liquid than compressed gas at 700 bars of pressure.[6] The hydrogen tank’s insulation is under high vacuum in order to keep heat transfer to the hydrogen to a bare minimum, and is purportedly equivalent to a 55-foot (17 m) thick wall of polystyrene Styrofoam.[7]
To stay a liquid, hydrogen must be super-cooled and maintained at cryogenic temperatures of, at warmest, −253 °C (−423.4 °F). When not using fuel, the Hydrogen 7’s hydrogen tank starts to warm and the hydrogen starts to vaporize. Once the tank’s internal pressure reaches 87 PSi, at roughly 17 hours of non-use, the tank will safely vent the building pressure. Over 10-12 days, it will completely lose the contents of the tank because of this"
The space shuttle gives us an idea of how much this can be scaled up: The liquid hydrogen tank is 331 inches in diameter, 1160 inches long, and has a volume of 53518 cubic feet and a dry weight of 29000 pounds i.e 13 metric tons.
The space shuttle tank is equivalent to a 10 meter in diameter spherical tank. Our requirements call for a 30 % smaller tank (1.1^3).
If we use conservative good techniology I would think a 5 metric tons tank will fit the bill since we are also dealing with a spherical shape, which is way much more efficient.
We can use the same kind of storage materials for LO2 although it is easier to store the later. A 3 metric tons tank will fit the bill.
So we have:
8 tons for the 2 tanks, and they will store 225 tons of propellants.
As for the engine, let's allocate about 12 tons. Skylon's plans call for 10 tons for the engines and we can add an extra 2 for additional components and redundancy.
The engines are the single most critical component of the whole system.
That leaves us with 45 tons - 8 - 12 = 25 tons for the remaining frame etc...
Things are getting tight... I will now cross my fingers we can somehow fit the frame supporting the engines and tanks and the hull in that number, about the mass of an 18 wheeler that needs to expand and fill the size of a 90 meters long ship.
Gotta love extreme challenges in one's lifetime...
Some rough calculations
Happy New Year!
Well I decided to check out some data on info I gleaned online to refine my size calculation, namely infer how much fuel the 2 tanks would contain and by extension (say + 25%) how much we can have for the ship's dry mass.
From this:
From that deduction of how big the H2 tank is... we can now build the rest of the Firefly... first the O2 tank: Since we need a 2-1 ratio of H to O since we will nozzle out water vapor at speeds 4 X a bullet from a high powered rifle, that means we will need 8 units of mass of O2 to burn 1 unit of mass of H2 (H2= 1+1=2
O2= 16 + 16 = 32 and we have 2H2 + O2 = 2H2O).
One glorious liter of liquid H2 is about 70 grams (or 1/3 of a lb!!! i.e
Well I decided to check out some data on info I gleaned online to refine my size calculation, namely infer how much fuel the 2 tanks would contain and by extension (say + 25%) how much we can have for the ship's dry mass.
From this:
and assuming a total length of 90 meters (i.e 300 ft or so) we can deduct a 10 meters radius for the liquid hydrogen tank (20% of the total length in diameter, roughly) i.e 30 ft.
That gives us (thanks to http://www.thomas-jahnke.de/technik/umrechnungen/sphetank.htm) 4,188.800 m^3 of capacity (i.e 31334 gallons). Assuming liquid H2 filling 90% of it considering some losses we have about 4,000,000 liters of H2 (roughly 30,000 gallons).
Probably we could organize a BBQ for every single inhabitant of America for that kind of capacity... sadly Nature is a harsh mistress and this is barely good enough to propel a few tens of tons of payload (including the spaceship itself) to space and back.
Not like Spaceship 1, which is pretty much a joke i.e a simple ballistic flight to 60 miles up and back. Here we need not only to get where the air is thin enough to not be a problem plowing at 5 mi/sec through it (or 7.9 km/s) but also accelerate to said speed of mach 30+
All in about 10 minutes or so.
O2= 16 + 16 = 32 and we have 2H2 + O2 = 2H2O).
One glorious liter of liquid H2 is about 70 grams (or 1/3 of a lb!!! i.e
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