After watching the last fiasco they called an election in the usa, yes, counting IS a difficult thing. It's so difficult, there was even one state that couldn't figure out how to do it, and instead waited for a supreme court decision to determine election results.
Multiple choice ballots are to confusing, and counting the results after the fact is to hard. The writing is on the wall, it'll only be a few more years before american elections are simplified even more. Ballots will have only one choice, that'll make all those pesky issues go away. That's what it's gonna take to 'dumb down' elections so they are not to challenging for the public, and it's coming soon to a ballot box near you.
Aluminum, particularly bulk aluminum is *not* combustible in LOX.
The british navy used to think this as well, so they built some ships from aluminum, and sent them down to the Falkland Islands to stem off an invasion. They discovered the hard way, if you heat a piece of aluminum to the correct temperature (achieved thru the ignition of an exocet missle) then the aluminum superstructure indeed will burn, and continue to burn, in a gas mix that's only 16% oxygen, with the rest relatively inert gasses (air).
It's used on the Space Shuttle main tank fer heavens sake!
There is an old saying in the aviation industry, 'Learn from the mistakes of others, you only get to make one yourself.' Aluminum + oxidizer + sufficient heat source = self sustaining combustion reaction. The rate of combustion will be controlled by the availability of oxidizer. LOX has a significantly greater percentage of oxidizer than air (a little more than 5 times as much, or one could say it's somewhat more pure).
I'll give nasa engineers enough credit that they probably understood this risk when designing the shuttle, but it was a tradeoff. The combustible nature of aluminum was considered an 'acceptable risk' when measured against the weight savings. The reality is, it wouldn't matter anyways, if the heat source is such that the aluminum was combusting, there would be plenty of liquid hydrogen in the general vicinity so as to make the combustible nature of the aluminum tank an insignificant variable in the overall disaster equation. Refer to the final challenger flight for empirical data thru observation to basically confirm this assumption.
The shuttle system is a great example of engineering compromise. Beginning with technology from the 70's, engineers began the balancing act of trading off function, weight, and safety in the process of coming up with a design that met the goal of re-useable launch vehicle. It can launch 40,000 pounds into low orbit, and do so on a fairly consistent schedule. With a mission failure rate on the order of 2%, it's pretty obvious that safety got the short end of the compromise in more cases than not. This is not necessarily a bad thing, just a fact of life. With the propulsion systems available, it's possible to meet the requirements for function and weight, just not possible to include a high safety margin into the same design. A series of compromises that resulted in an 'acceptable risk' at the time, which are today no longer considered acceptable.
The real enlightening part of that read, is to note how many of those nuclear incidents occurred in areas where the us military is specifically prohibited by treaty and/or local law from having nukes. Kind of demonstrates how the usa as a country honors, or more appropriately does NOT honor, the treaties it signs.
I thought that the explosion along the Siberian pipeline was the largest non-nuclear anyways
The destruction of ripple rock to clear a safe passage for shipping holds that title. 1375 tons of explosives going off about 10 feet underwater. It rattled windows 65 miles away. There's an article here .
The B2 and the F117A "Stealth Fighter" proved how well they work the first time we went to war with Iraq.
Sending 'stealth' planes into airspace that has no defending air force is not exactly a 'proof of the concept'. Coulda flown into iraq using a concorde, complete with it's huge sonic trail, would not have made any difference, there was no air force to defend anyways.
Stealth planes are not undetectable, they are just more difficult to detect than traditional aircraft. Countries with the will, and the technology, have long since built better detection systems, so flying into thier airspace with a 'stealth' machine will be no different than flying in with a traditional airplane. they are gonna see it coming well in advance, and the only surprise will be to the american taxpayer, those billion dollar airplanes are not nearly as sneaky as the military would have you believe.
Prepping a shuttle for launch takes months, using thousands of people. Each mission is planned out to the very last detail. You can call them a lot of things, but, routine is not one of them. A huge investment of time and effort on a 'per mission' basis in preparation is anything but routine.
On the safety side, the shuttle may have been around for a long time, but, 1 in 57 flights had catastrophic conclusions. A much higher percentage had other problems that folks came to accept as 'normal', little things like heat shield tiles falling off here and there. On at least half it's flights, shuttle returned to earth with missing/damaged tiles. Not exactly a big plus in the safety column, the most critical safety system on the vehicle was 'routinely' damaged during operations. Some folks may consider a failure rate of 1/57 acceptable risk, but nobody is going to pretend it's 'safe'.
For those that want to do pure calcs on the whole thing, its easy to break down into hard numbers. Shuttles fail on the order of 2% of flights. Minimum crew for a space station mission is 5, 2 shuttle crew, 3 station crew on rotation. 0.02 * 5 = 0.10. The cost of operating a shuttle mission is on the order of a half billion dollars, and 1/10 of one life. Running 4 missions a year, that works out to 2 billion dollars, and 4/10 of a life per annum, the cost of the program. The consensus is, the 4/10 life cost is to high, or the shuttles would still be flying, the monetary budget was already in place.
I find it ironic, a country willing to sacrifice an average of over 1 life a day in the conquest of oil, finds 0.4 lives a year to high a price for a program of exploration and scientific discovery. Guess it's all in the political spin, and what you can 'sell' to the public...
Our military has a legitimate purpose, whether you like our sitting president or not. That purpose is national defense.
History says otherwise. The us military has rarely been used in defense of american territory. On the other hand, it's been involved in various and sundry foreign invasions and occupations formally and informally on an almost non stop basis for the last 60 years.
The purpose of the us military is to project military force into other parts of the world. That's national offence, not defence. Defence would be defending ones own borders.
To each his own, but I think the 2 hours it takes to get a fully operational coLinux setup is a LOT LESS work that wiring up 4 machines, and I have no clue how I'd use 4 machines on an airplane. With coLinux I have windows and linux on the same machine, no need to reboot, and it 'just works'.
VMWare is to spendy, it's cheaper to buy another pc for the Windows stuff, than to use VMWare as an emulator, if you only need 2 environments.
Wine is the 'solution' that many hope will eventually work well one day, but, it's got it's share of problems. Politics and religion aside, if you want a solution that 'just works', Wine is not it, yet.
On the other hand, if you have a desire/need to have Windows and Linux on the same box, and want a solution that 'just works', coLinux is such a beast. On my notebook, I have Debian Sarge running as a service under Windows XP, and I can sit in the seat on an airplane, working on the Linux server end, and the Windows Client end of a large application, it all just works, no muss, no fuss. I have a full development system installed for both the Linux and the Windows systems, and with a judicious VNC setup, I can hotkey between the Linux and Windows desktops, all on the same machine, at the same time, self contained. It allows me to be fully productive during time that would otherwise be more or less wasted during long airplane rides and hotel stays, and I only have to pack around one notebook.
This is a solution that probably doesn't sit well with those that want to be puritans or zealots. But, for those of us that just want to get work done, it's worth the couple of hours it takes to install and figure out the coLinux environment.
I recognize your sarcasm, however reading the patent reveals that Microsoft lists GPS information repeatedly.
There is absolutely NOTHING new or innovative about sorting by either time or gps data. If you have been involved in the aerial photography at all for the last 20 years, then you've done this a LOT. Prior to the turn on of the GPS system, we used LORAN C systems to fly a track, taking photos. When gps came around, the military started using it for this purpose as soon as the system was turned on, industry followed suit as soon as the accuracy became available thru differential systems. I believe it was about 15 years ago when I first flew a camera platform that added time and location stamps to the photos as they were taken. Its at least 25 years ago since I saw one the first time. I strongly suspect the concept was patented back then, which means it would be expired by now..
Not only is the concept OBVIOUS, there are mature commercial products on the market that have been doing this kind of stuff for 20+ years, using many systems, prior to availability of GPS. I've seen both LORAN and interial nav systems used as location data sources for camera platforms, prior to the availability of gps.
I find it absolutely astounding that the USPTO will give out patents for concepts that have been in production for years. Do those idiots even read the applications anymore, or do they just collect the fees and issue patents for anything? this is one that I'm sure, the correct place to look for prior art is in the pile of EXPIRED patents issued by the USPTO.
hehe, ok, I'll grant you that. Dollar bills probably dont have the specific impulse required of rocket fuel either, but, you got the point. With hardware built, and the budget now in the 300K range, they'll have to squander a LOT of money real fast to not be on the order of 2 orders of magnitude less than the other guys.
I feel a lot better knowing Rutan's got several aircraft out there that he designed previously. Things that fly and don't kill people.
The well known ones dont fall out of the sky and kill people. Some of the not so well known ones did just that. A good start, read up on the accident reports during flight testing of the BD-10, one of his earlier attempts at a supersonic airframe. It had a tendancy to disintegrate as it approached transonic speeds, killed a few test pilots like that.
It's not as small a niche as you think. Picture a factory that's down at a cost of $1M/hour,
There's already a whole industry built around this. One of the mainstays of income for the air taxi business, is moving parts on a rush order because equipment is down in the field. I did a job a few weeks ago where we were delivering parts into the field, as they came out of the machine shop from fabrication. We would dispatch an airplane the moment the part arrived. Each piece weighed about 200 pounds. There's 4 flights a day by airline to the destination, it would have cost about 100 dollars each to ship on the airline. The private air taxi cost about $5000 per trip. Each delivery brought another machine back online, and the downtime estimate was on the order of $5000 a minute in cost (per machine). Nobody blinked at the price of the charters, they were only interested in 'how fast can we get it there'. Nobody was interested in holding the parts till the next scheduled airline departure to save 4800 on shipping costs.
These types of jobs are not at all unusual for air taxi operators.
I'm well aware of how the aerospace industry burns money, I've been involved in it for the last 28 years. The point is, it doesn't have to be that way.
If you take a look at the methodologies used by NASA and thier contractors, and present them with a requirement for a man rated design, from scratch, to exit the atmosphere, the project would have to be cut to the teeth to achieve flight hardware by the time they burned thru 2 billion dollars. Scaled composites did it for 20 million, that's 2 orders of magnitude less. Along comes Da Vinci, and they did it for another 2 orders of magnitude less, with the caveat it has not been flight tested yet. Even if they use 100 dollar bills for fuel on the flights, they'll still end up an order of magnitude cheaper than Scaled.
The real difference between scaled and da vinci is in methodology. Scaled is a group of professional engineers, working on a budget with a benefactor. It's a full time job, and everybody is collecting a salary. Da Vinci is driven by professional engineers, working in thier spare time, and collecting satisfaction for thier efforts. Has anybody seen this contrast in methodologies before ? It's kind of ironic that the 'big budget' x-prize vehicle is funded by Microsoft money, and the long shot contender is a volunteer collaborative effort.
The real point is, the aerospace industry as we know it is carrying a LOT of fat, mostly due to the fact it's driven by government contracts. the job can be done 2 orders of magnitude cheaper, Rutan and crowd have proven it. Collaboration and co-operation works, and it would be great to see the Da Vinci folks prove that too, in a field other than software.
At this point in time, scaled is the odds on favorite to grab the prize. Da Vinci has yet to fly hardware. that doesn't mean it's not gonna fly, or it's incapable of flying, it means it hasn't been tested in full flight configuration yet.
August could well be a very interesting month. If the Da Vinci folks can scrape up the cash they need to get thier hardware out to the launch site, and into the air, and get a couple good test results immediately, there may well be a race for the prize.
As an engineer, I have to have great respect for what the Scaled team has done, it's outstanding. As an individual, I still want to sit back and cheer for the 'back yard' guys. However small a chance they have, it would be great to see them succeed.
Check your history a little better. That's what happens right after the conservatives win an election. They lost. Wildfire is safe from the choppers on this go round.
Within the industry, diefenbaker will forever be known as the farmer from saskatchewan that killed an industry. I think it's rather ironic that wildfire will attempt to fly from his back yard.
The interesting thing comparing Da Vinci project to the effort at Scaled Composites. There's more than enough rumors within industry, and outside it, that peg the Spaceship One project price tag in the 20 million dollar range, one can probably assume there's some basis behind that number. There's another article on the Da Vinci stuff here that pegs numbers on the Da Vinci expenses. They are quoted at $337,000, doesn't specifically say cdn dollars, but every other number in the article is tagged as $us. It's a canadian paper, the figure is likely $cdn, which puts it around 1/4 million us dollars.
It's NOT a given that Spaceship One will walk away with the X-prize. A lot of folks seem to think it is, but, those same folks thought shuttle flights were routine, uneventful, and safe. Flying into space is HARD. SS1 has a good chance at it, but this craft will be ready to give it a shot.
It would certainly go with the spririt of the X-Prize to see this true 'backyard' effort pull it out of the blue, and beat SS1 to the X-Prize finish line. Nothing against Rutan and his team, but, X-Prize was meant to spark the real backyard innovation. Da Vinci project is just that. I think it would be great to see them scoop the prize out from under the noses of the foks that spent 20 million to achieve the same goal.
Re:No point "breathing air" at that temperature.
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Such vehicles might also be safer because you only have the fuel, which won't burn nearly as well without having an unnaturally high concentration of oxygen.
Not really. Any incident that involves an escape of the fuel from it's containment tanks, implies airframe failure. Airframe failures at subsonic speeds are normally catastrophic, but occaisionally surviveable . At hypersonic speeds there is no possibility of survival. If the airframe sustains enough damage to allow fuel to escape its tanks, the airflow may as well be a solid brick wall. There wont be much left but itsy bitsy pieces once the forces of mach 10 are thru with it.
Re:A Third of the Way There...
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You then attempt to start a fire in that supersonic airflow (imagine trying to light your zippo while holding it out a car window and multiply that difficulty by about a million).
This is a HUGE problem in some speed ranges, and it's _trivial_ in others. The neat thing about shock waves is, you get a rapid temperature rise during shock compression. One of the 'tricks' to the design of a scramjet, is to plan out the shock wave pattern in such a manner, the ambient temperature in the vicinity of your fuel injectors, is higher than the ignition point of your fuel. Then the only trick is, getting the system up to the velocities required for ignition to be spontaneous. Standard igniters just wont work in those velocity regimes.
As you suggested in the initial post, the problem of escaping atmosphere is huge for the orbital equation. Aerodynamic drag is 'inconsequential' whilst subsonic, but grows exponentially once you start playing with shock waves. 50% of the atmosphere (by mass) lives below 6,000 meters (18,000 feet) altitude. In the range of 80% lives below 13,000 meters (40,000 feet). The most efficient path out of the atmosphere is to utilize atmospheric lift at subsonic speed until well above these altitudes, to get past most of that sticky stuff called air. The messy problem of all that sticky air living below 40,000 feet really makes a single stage runway to orbit vehicle impractical. Efficient lift and reduced hypersonic drag are diametrically opposed concepts when designing the airframe. For the former, you want large smooth rounded surfaces, for the latter you want sharp edges and zero curves, as curves promote 'lotsa little shocks' and a 'shock fan', whereas an abrupt square corner still produces but a single shock wave.
If you look at modern heavy lift, long range airframes, they tend to all operate most efficiently between 32,000 and 40,000 feet. A 747 loaded to the max cannot climb above 32,000 till it's burned off a chunk of fuel (lower for older models), and then it MUST climb higer to be able to achieve it's maximum range, to take advantage of reduced fuel burns at 36 and 38 thousand. it's not really an accident that the transoceanic airways are 'busy' in the 32 to 38 thousand range, with virtually no traffic below or above those altitudes, except a few big ones in the early stages of step climbs as they burn off fuel. The combination of modern jet engines, and aerodymanic lifting bodies, this is the altitude range that is the 'sweet spot' for fuel efficiency. Aerodymanics prevent them from going higher (atmosphere gets to thin to generate the lift required), and engine efficiencies prevent them from operating lower. It's also not completely co-incidental that these are the tropopause altitudes, where you run into things like jet streams, which can give you a significant 'free ride' enroute. 80's and earlier vintage equipment operates 'at jet stream altitudes' eastbound, and 'just below them' westbound typically. Late 90's vintage equipment is slightly more efficient, so you operate above jet streams rather than below, when going westbound.
There have been many trillions of dollars spent on the engineering required for subsonic heavy lift above the majority of the atmosphere. We've got the point where it's efficient enough to be widely deployed. for a wide deployment of orbital transport, it doesn't make sense to NOT leverage this knowledge/technology base for the lower portion of the flight.
Scramjets are cool, but, they want to operate in the atmosphere, and at velocities that produce problems with the rest of the materials. In theory it's more efficient to not carry your oxidizer like a rocket does, but there's this little 'reality' problem with scramjets. We dont know how to build the tankage to carry the fuel for it, in a manner it wont melt from continued exposure to the hypersonic airstream that's presenting stagnation temperatures in the thousands of degrees (and at those high numbers, doesn't really matter if you are using C, K, or
This really boils down to a personal choice. What do you value higher, your paycheque, or your personal ethics? If you believe what the employer wants done is unethical, but are willing to do it anyways 'for the paycheque', well, that kind of answers the question.
It never ceases to amaze me how many people will 'talk the talk' over ethics, but when push gets to shove, they chose the paycheque, and wont 'walk the walk'. The age old cry of 'I was just following orders', or 'the boss told me to do it', its truely amazing how many folks will look to any excuse to try absolve themselves of responsibility for thier own actions.
Go to just about any airport in the usa, and take a good look around. The Bombardier CRJ is being purchased by most airlines, in quanties of hundreds. It's the aircraft of choice these days for short haul operations, that's why delta bought so many of them. The 90 passenger variant has become as ubiquitous at the airport as the DC-9 used to be.
Go count up all the different paitjobs on them, you'll find your Northwest and American, as well as Delta, United, America West, UsAirways, Eastern, Continental, and probably a few more. I know americans want to discount the company as 'not american, so it doesn't exist', but, Bombardier does produce more commerical jets than any other company today. This is what happens when you litigate an industry out of business with silly lawsuits. The ONLY reason Boeing is still manufacturing in the USA is because they got a special deal from the government which allows them to sell their planes thru a carribean subsidiary (Boeing aircraft sales corp), bypassing taxes and the huge product liability problems in the USA today.
As for Mcdonnel Douglas, they dont even exist anymore, except as a division of Boeing.
Just like the $300 coffee pot was for a C-130 full of troops,
Part of this is just silliness in the procurement procedure regarding specifications. I remember reading a detailed analysis of one such folly, the $80,000 coffee pot, it was a required reading in a class dealing with writing specifications (which i took more than 20 years ago).
The contract in question was a military contract to produce a long range aircraft. There were some allowances for crew comfort, and one of them was a small galley with a coffee pot. BUT, the overall preamble for the contract document stated, all systems in the aircraft must operate correctly in all flight regimes. The stated flight regimes were from negative 2 to positive 5 g forces. So, some dilligent engineer designed a coffee pot that would brew coffee, not spill coffee, and would properly dispense coffee while being subject to negative 2 g forces. The vast majority of the expense was the 'dispense properly' under that loading condition. Nobody stopped to ask, who's gonna be able to even stand there and try pour coffee in that condition?
It's easy to blame suppliers in a case like this, call it 'stupidity', but, if you are supplying to specification on a contract of that magnitude, you best meet all the specs. Blame the folks writing the spec in the first place for not putting some 'reality checks' in, and defining a difference between critical and anciliary systems. I can fully understand a coffee pot that doesnt spill in those conditions for an aircraft of that type, but I'm pretty sure it would be perfectly ok if it didn't brew or dispense the coffee until conditions returned to 'normal'.
Space habitats are only closed ecosystems if you build them to be closed. The shuttle as an example is NOT a closed system, it dumps junk overboard on a regular basis.
If you are going to build an industrial complex as a closed system, that means you are going to have to put all the processes in place to 'close the loop' and de-contaminate any pollutants produced, so things can all be recycled. If you are going to spend all the money on that kind of cleaning and re-cycling ability, no need to put it in orbit, it's perfectly good anywhere on the ground too, and sure saves a bundle on transportation costs. But, out here in the real world, the vast majority of industrial production becomes unprofitable if you add that kind of cleanup to the systems, that's why they dont do it.
The only reason closed systems are considered for use in space, is because it's cheaper to invest in the ability to recycle, than it is to transport up new raw materials. The same closed system used in space, could easily be operated in a residential neighborhood (assuming it's not relying on microgravity for it's process), be perfectly clean and safe in that location, and be a heck of a lot cheaper than putting it in orbit.
The ONLY reason to consider manufacturing in orbit, is to do something that cannot be done on the ground. Current modern thinking hedges this all around the free-fall (weightless) environment, or the requirement for hard vaccuum during the process. The sheer cost of lifting mass thru 100Km of atmoshphere, and accellerating it out of a 9.81 m/s^2 gravity well mean it'll always be cheaper to manufacture on the ground, even for products destined for consumption in orbit. Cheaper to lift the finished product.
This will change when 2 conditions that are currently false, hedge toward true. First, a source of raw material is required, to negate the need to lift mass. The second will be energy sources that can produce energy more economically than terrestrial sources currently. When raw material is available in orbit, it will become economical to manufacture stuff for use in orbit, on location. When energy becomes cheap up there, then it _may_ become viable to manufacture in orbit, for consumption on earth. Without both of these factors in place, it'll always be cheaper to lift finished product rather than raw materiels. The only exception, will be for manufacturing processes that REQUIRE an ambient condition (weightless or hard vaccuum) that cannot be achieved in a terrestrial location.
You don't need to worry at all about contaminating an atmosphere if you're in space
So what exactly is the difference between the pollutants being spewed UP from a chimney, or dropping DOWN from an orbital facility ? It still all ends up in the same atomosphere eventually.
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Multiple choice ballots are to confusing, and counting the results after the fact is to hard. The writing is on the wall, it'll only be a few more years before american elections are simplified even more. Ballots will have only one choice, that'll make all those pesky issues go away. That's what it's gonna take to 'dumb down' elections so they are not to challenging for the public, and it's coming soon to a ballot box near you.
The british navy used to think this as well, so they built some ships from aluminum, and sent them down to the Falkland Islands to stem off an invasion. They discovered the hard way, if you heat a piece of aluminum to the correct temperature (achieved thru the ignition of an exocet missle) then the aluminum superstructure indeed will burn, and continue to burn, in a gas mix that's only 16% oxygen, with the rest relatively inert gasses (air).
It's used on the Space Shuttle main tank fer heavens sake!
There is an old saying in the aviation industry, 'Learn from the mistakes of others, you only get to make one yourself.' Aluminum + oxidizer + sufficient heat source = self sustaining combustion reaction. The rate of combustion will be controlled by the availability of oxidizer. LOX has a significantly greater percentage of oxidizer than air (a little more than 5 times as much, or one could say it's somewhat more pure).
I'll give nasa engineers enough credit that they probably understood this risk when designing the shuttle, but it was a tradeoff. The combustible nature of aluminum was considered an 'acceptable risk' when measured against the weight savings. The reality is, it wouldn't matter anyways, if the heat source is such that the aluminum was combusting, there would be plenty of liquid hydrogen in the general vicinity so as to make the combustible nature of the aluminum tank an insignificant variable in the overall disaster equation. Refer to the final challenger flight for empirical data thru observation to basically confirm this assumption.
The shuttle system is a great example of engineering compromise. Beginning with technology from the 70's, engineers began the balancing act of trading off function, weight, and safety in the process of coming up with a design that met the goal of re-useable launch vehicle. It can launch 40,000 pounds into low orbit, and do so on a fairly consistent schedule. With a mission failure rate on the order of 2%, it's pretty obvious that safety got the short end of the compromise in more cases than not. This is not necessarily a bad thing, just a fact of life. With the propulsion systems available, it's possible to meet the requirements for function and weight, just not possible to include a high safety margin into the same design. A series of compromises that resulted in an 'acceptable risk' at the time, which are today no longer considered acceptable.
The real enlightening part of that read, is to note how many of those nuclear incidents occurred in areas where the us military is specifically prohibited by treaty and/or local law from having nukes. Kind of demonstrates how the usa as a country honors, or more appropriately does NOT honor, the treaties it signs.
The destruction of ripple rock to clear a safe passage for shipping holds that title. 1375 tons of explosives going off about 10 feet underwater. It rattled windows 65 miles away. There's an article here .
UBC had Thunderbirds long before Mozilla was even an inspiration in the original developers minds....
Sending 'stealth' planes into airspace that has no defending air force is not exactly a 'proof of the concept'. Coulda flown into iraq using a concorde, complete with it's huge sonic trail, would not have made any difference, there was no air force to defend anyways.
Stealth planes are not undetectable, they are just more difficult to detect than traditional aircraft. Countries with the will, and the technology, have long since built better detection systems, so flying into thier airspace with a 'stealth' machine will be no different than flying in with a traditional airplane. they are gonna see it coming well in advance, and the only surprise will be to the american taxpayer, those billion dollar airplanes are not nearly as sneaky as the military would have you believe.
On the safety side, the shuttle may have been around for a long time, but, 1 in 57 flights had catastrophic conclusions. A much higher percentage had other problems that folks came to accept as 'normal', little things like heat shield tiles falling off here and there. On at least half it's flights, shuttle returned to earth with missing/damaged tiles. Not exactly a big plus in the safety column, the most critical safety system on the vehicle was 'routinely' damaged during operations. Some folks may consider a failure rate of 1/57 acceptable risk, but nobody is going to pretend it's 'safe'.
For those that want to do pure calcs on the whole thing, its easy to break down into hard numbers. Shuttles fail on the order of 2% of flights. Minimum crew for a space station mission is 5, 2 shuttle crew, 3 station crew on rotation. 0.02 * 5 = 0.10. The cost of operating a shuttle mission is on the order of a half billion dollars, and 1/10 of one life. Running 4 missions a year, that works out to 2 billion dollars, and 4/10 of a life per annum, the cost of the program. The consensus is, the 4/10 life cost is to high, or the shuttles would still be flying, the monetary budget was already in place.
I find it ironic, a country willing to sacrifice an average of over 1 life a day in the conquest of oil, finds 0.4 lives a year to high a price for a program of exploration and scientific discovery. Guess it's all in the political spin, and what you can 'sell' to the public...
History says otherwise. The us military has rarely been used in defense of american territory. On the other hand, it's been involved in various and sundry foreign invasions and occupations formally and informally on an almost non stop basis for the last 60 years.
The purpose of the us military is to project military force into other parts of the world. That's national offence, not defence. Defence would be defending ones own borders.
To each his own, but I think the 2 hours it takes to get a fully operational coLinux setup is a LOT LESS work that wiring up 4 machines, and I have no clue how I'd use 4 machines on an airplane. With coLinux I have windows and linux on the same machine, no need to reboot, and it 'just works'.
Wine is the 'solution' that many hope will eventually work well one day, but, it's got it's share of problems. Politics and religion aside, if you want a solution that 'just works', Wine is not it, yet.
On the other hand, if you have a desire/need to have Windows and Linux on the same box, and want a solution that 'just works', coLinux is such a beast. On my notebook, I have Debian Sarge running as a service under Windows XP, and I can sit in the seat on an airplane, working on the Linux server end, and the Windows Client end of a large application, it all just works, no muss, no fuss. I have a full development system installed for both the Linux and the Windows systems, and with a judicious VNC setup, I can hotkey between the Linux and Windows desktops, all on the same machine, at the same time, self contained. It allows me to be fully productive during time that would otherwise be more or less wasted during long airplane rides and hotel stays, and I only have to pack around one notebook.
This is a solution that probably doesn't sit well with those that want to be puritans or zealots. But, for those of us that just want to get work done, it's worth the couple of hours it takes to install and figure out the coLinux environment.
There is absolutely NOTHING new or innovative about sorting by either time or gps data. If you have been involved in the aerial photography at all for the last 20 years, then you've done this a LOT. Prior to the turn on of the GPS system, we used LORAN C systems to fly a track, taking photos. When gps came around, the military started using it for this purpose as soon as the system was turned on, industry followed suit as soon as the accuracy became available thru differential systems. I believe it was about 15 years ago when I first flew a camera platform that added time and location stamps to the photos as they were taken. Its at least 25 years ago since I saw one the first time. I strongly suspect the concept was patented back then, which means it would be expired by now..
Not only is the concept OBVIOUS, there are mature commercial products on the market that have been doing this kind of stuff for 20+ years, using many systems, prior to availability of GPS. I've seen both LORAN and interial nav systems used as location data sources for camera platforms, prior to the availability of gps.
I find it absolutely astounding that the USPTO will give out patents for concepts that have been in production for years. Do those idiots even read the applications anymore, or do they just collect the fees and issue patents for anything? this is one that I'm sure, the correct place to look for prior art is in the pile of EXPIRED patents issued by the USPTO.
hehe, ok, I'll grant you that. Dollar bills probably dont have the specific impulse required of rocket fuel either, but, you got the point. With hardware built, and the budget now in the 300K range, they'll have to squander a LOT of money real fast to not be on the order of 2 orders of magnitude less than the other guys.
The well known ones dont fall out of the sky and kill people. Some of the not so well known ones did just that. A good start, read up on the accident reports during flight testing of the BD-10, one of his earlier attempts at a supersonic airframe. It had a tendancy to disintegrate as it approached transonic speeds, killed a few test pilots like that.
There's already a whole industry built around this. One of the mainstays of income for the air taxi business, is moving parts on a rush order because equipment is down in the field. I did a job a few weeks ago where we were delivering parts into the field, as they came out of the machine shop from fabrication. We would dispatch an airplane the moment the part arrived. Each piece weighed about 200 pounds. There's 4 flights a day by airline to the destination, it would have cost about 100 dollars each to ship on the airline. The private air taxi cost about $5000 per trip. Each delivery brought another machine back online, and the downtime estimate was on the order of $5000 a minute in cost (per machine). Nobody blinked at the price of the charters, they were only interested in 'how fast can we get it there'. Nobody was interested in holding the parts till the next scheduled airline departure to save 4800 on shipping costs.
These types of jobs are not at all unusual for air taxi operators.
If you take a look at the methodologies used by NASA and thier contractors, and present them with a requirement for a man rated design, from scratch, to exit the atmosphere, the project would have to be cut to the teeth to achieve flight hardware by the time they burned thru 2 billion dollars. Scaled composites did it for 20 million, that's 2 orders of magnitude less. Along comes Da Vinci, and they did it for another 2 orders of magnitude less, with the caveat it has not been flight tested yet. Even if they use 100 dollar bills for fuel on the flights, they'll still end up an order of magnitude cheaper than Scaled.
The real difference between scaled and da vinci is in methodology. Scaled is a group of professional engineers, working on a budget with a benefactor. It's a full time job, and everybody is collecting a salary. Da Vinci is driven by professional engineers, working in thier spare time, and collecting satisfaction for thier efforts. Has anybody seen this contrast in methodologies before ? It's kind of ironic that the 'big budget' x-prize vehicle is funded by Microsoft money, and the long shot contender is a volunteer collaborative effort.
The real point is, the aerospace industry as we know it is carrying a LOT of fat, mostly due to the fact it's driven by government contracts. the job can be done 2 orders of magnitude cheaper, Rutan and crowd have proven it. Collaboration and co-operation works, and it would be great to see the Da Vinci folks prove that too, in a field other than software.
At this point in time, scaled is the odds on favorite to grab the prize. Da Vinci has yet to fly hardware. that doesn't mean it's not gonna fly, or it's incapable of flying, it means it hasn't been tested in full flight configuration yet.
August could well be a very interesting month. If the Da Vinci folks can scrape up the cash they need to get thier hardware out to the launch site, and into the air, and get a couple good test results immediately, there may well be a race for the prize.
As an engineer, I have to have great respect for what the Scaled team has done, it's outstanding. As an individual, I still want to sit back and cheer for the 'back yard' guys. However small a chance they have, it would be great to see them succeed.
Within the industry, diefenbaker will forever be known as the farmer from saskatchewan that killed an industry. I think it's rather ironic that wildfire will attempt to fly from his back yard.
It's NOT a given that Spaceship One will walk away with the X-prize. A lot of folks seem to think it is, but, those same folks thought shuttle flights were routine, uneventful, and safe. Flying into space is HARD. SS1 has a good chance at it, but this craft will be ready to give it a shot.
It would certainly go with the spririt of the X-Prize to see this true 'backyard' effort pull it out of the blue, and beat SS1 to the X-Prize finish line. Nothing against Rutan and his team, but, X-Prize was meant to spark the real backyard innovation. Da Vinci project is just that. I think it would be great to see them scoop the prize out from under the noses of the foks that spent 20 million to achieve the same goal.
Not really. Any incident that involves an escape of the fuel from it's containment tanks, implies airframe failure. Airframe failures at subsonic speeds are normally catastrophic, but occaisionally surviveable . At hypersonic speeds there is no possibility of survival. If the airframe sustains enough damage to allow fuel to escape its tanks, the airflow may as well be a solid brick wall. There wont be much left but itsy bitsy pieces once the forces of mach 10 are thru with it.
This is a HUGE problem in some speed ranges, and it's _trivial_ in others. The neat thing about shock waves is, you get a rapid temperature rise during shock compression. One of the 'tricks' to the design of a scramjet, is to plan out the shock wave pattern in such a manner, the ambient temperature in the vicinity of your fuel injectors, is higher than the ignition point of your fuel. Then the only trick is, getting the system up to the velocities required for ignition to be spontaneous. Standard igniters just wont work in those velocity regimes.
As you suggested in the initial post, the problem of escaping atmosphere is huge for the orbital equation. Aerodynamic drag is 'inconsequential' whilst subsonic, but grows exponentially once you start playing with shock waves. 50% of the atmosphere (by mass) lives below 6,000 meters (18,000 feet) altitude. In the range of 80% lives below 13,000 meters (40,000 feet). The most efficient path out of the atmosphere is to utilize atmospheric lift at subsonic speed until well above these altitudes, to get past most of that sticky stuff called air. The messy problem of all that sticky air living below 40,000 feet really makes a single stage runway to orbit vehicle impractical. Efficient lift and reduced hypersonic drag are diametrically opposed concepts when designing the airframe. For the former, you want large smooth rounded surfaces, for the latter you want sharp edges and zero curves, as curves promote 'lotsa little shocks' and a 'shock fan', whereas an abrupt square corner still produces but a single shock wave.
If you look at modern heavy lift, long range airframes, they tend to all operate most efficiently between 32,000 and 40,000 feet. A 747 loaded to the max cannot climb above 32,000 till it's burned off a chunk of fuel (lower for older models), and then it MUST climb higer to be able to achieve it's maximum range, to take advantage of reduced fuel burns at 36 and 38 thousand. it's not really an accident that the transoceanic airways are 'busy' in the 32 to 38 thousand range, with virtually no traffic below or above those altitudes, except a few big ones in the early stages of step climbs as they burn off fuel. The combination of modern jet engines, and aerodymanic lifting bodies, this is the altitude range that is the 'sweet spot' for fuel efficiency. Aerodymanics prevent them from going higher (atmosphere gets to thin to generate the lift required), and engine efficiencies prevent them from operating lower. It's also not completely co-incidental that these are the tropopause altitudes, where you run into things like jet streams, which can give you a significant 'free ride' enroute. 80's and earlier vintage equipment operates 'at jet stream altitudes' eastbound, and 'just below them' westbound typically. Late 90's vintage equipment is slightly more efficient, so you operate above jet streams rather than below, when going westbound.
There have been many trillions of dollars spent on the engineering required for subsonic heavy lift above the majority of the atmosphere. We've got the point where it's efficient enough to be widely deployed. for a wide deployment of orbital transport, it doesn't make sense to NOT leverage this knowledge/technology base for the lower portion of the flight.
Scramjets are cool, but, they want to operate in the atmosphere, and at velocities that produce problems with the rest of the materials. In theory it's more efficient to not carry your oxidizer like a rocket does, but there's this little 'reality' problem with scramjets. We dont know how to build the tankage to carry the fuel for it, in a manner it wont melt from continued exposure to the hypersonic airstream that's presenting stagnation temperatures in the thousands of degrees (and at those high numbers, doesn't really matter if you are using C, K, or
This really boils down to a personal choice. What do you value higher, your paycheque, or your personal ethics? If you believe what the employer wants done is unethical, but are willing to do it anyways 'for the paycheque', well, that kind of answers the question.
It never ceases to amaze me how many people will 'talk the talk' over ethics, but when push gets to shove, they chose the paycheque, and wont 'walk the walk'. The age old cry of 'I was just following orders', or 'the boss told me to do it', its truely amazing how many folks will look to any excuse to try absolve themselves of responsibility for thier own actions.
Go count up all the different paitjobs on them, you'll find your Northwest and American, as well as Delta, United, America West, UsAirways, Eastern, Continental, and probably a few more. I know americans want to discount the company as 'not american, so it doesn't exist', but, Bombardier does produce more commerical jets than any other company today. This is what happens when you litigate an industry out of business with silly lawsuits. The ONLY reason Boeing is still manufacturing in the USA is because they got a special deal from the government which allows them to sell their planes thru a carribean subsidiary (Boeing aircraft sales corp), bypassing taxes and the huge product liability problems in the USA today.
As for Mcdonnel Douglas, they dont even exist anymore, except as a division of Boeing.
Part of this is just silliness in the procurement procedure regarding specifications. I remember reading a detailed analysis of one such folly, the $80,000 coffee pot, it was a required reading in a class dealing with writing specifications (which i took more than 20 years ago).
The contract in question was a military contract to produce a long range aircraft. There were some allowances for crew comfort, and one of them was a small galley with a coffee pot. BUT, the overall preamble for the contract document stated, all systems in the aircraft must operate correctly in all flight regimes. The stated flight regimes were from negative 2 to positive 5 g forces. So, some dilligent engineer designed a coffee pot that would brew coffee, not spill coffee, and would properly dispense coffee while being subject to negative 2 g forces. The vast majority of the expense was the 'dispense properly' under that loading condition. Nobody stopped to ask, who's gonna be able to even stand there and try pour coffee in that condition?
It's easy to blame suppliers in a case like this, call it 'stupidity', but, if you are supplying to specification on a contract of that magnitude, you best meet all the specs. Blame the folks writing the spec in the first place for not putting some 'reality checks' in, and defining a difference between critical and anciliary systems. I can fully understand a coffee pot that doesnt spill in those conditions for an aircraft of that type, but I'm pretty sure it would be perfectly ok if it didn't brew or dispense the coffee until conditions returned to 'normal'.
Space habitats are only closed ecosystems if you build them to be closed. The shuttle as an example is NOT a closed system, it dumps junk overboard on a regular basis.
If you are going to build an industrial complex as a closed system, that means you are going to have to put all the processes in place to 'close the loop' and de-contaminate any pollutants produced, so things can all be recycled. If you are going to spend all the money on that kind of cleaning and re-cycling ability, no need to put it in orbit, it's perfectly good anywhere on the ground too, and sure saves a bundle on transportation costs. But, out here in the real world, the vast majority of industrial production becomes unprofitable if you add that kind of cleanup to the systems, that's why they dont do it.
The only reason closed systems are considered for use in space, is because it's cheaper to invest in the ability to recycle, than it is to transport up new raw materials. The same closed system used in space, could easily be operated in a residential neighborhood (assuming it's not relying on microgravity for it's process), be perfectly clean and safe in that location, and be a heck of a lot cheaper than putting it in orbit.
The ONLY reason to consider manufacturing in orbit, is to do something that cannot be done on the ground. Current modern thinking hedges this all around the free-fall (weightless) environment, or the requirement for hard vaccuum during the process. The sheer cost of lifting mass thru 100Km of atmoshphere, and accellerating it out of a 9.81 m/s^2 gravity well mean it'll always be cheaper to manufacture on the ground, even for products destined for consumption in orbit. Cheaper to lift the finished product.
This will change when 2 conditions that are currently false, hedge toward true. First, a source of raw material is required, to negate the need to lift mass. The second will be energy sources that can produce energy more economically than terrestrial sources currently. When raw material is available in orbit, it will become economical to manufacture stuff for use in orbit, on location. When energy becomes cheap up there, then it _may_ become viable to manufacture in orbit, for consumption on earth. Without both of these factors in place, it'll always be cheaper to lift finished product rather than raw materiels. The only exception, will be for manufacturing processes that REQUIRE an ambient condition (weightless or hard vaccuum) that cannot be achieved in a terrestrial location.
So what exactly is the difference between the pollutants being spewed UP from a chimney, or dropping DOWN from an orbital facility ? It still all ends up in the same atomosphere eventually.
So if he meant airliner, it would still include the Antonov, Bombardier, and Embraer.