Oh yeah
Rutan said: “Fatigue is not an issue at all.”
I bet someone said that about the Comet before they started disintegrating and falling out of the sky.
As expected, British billionaire Sir Richard Branson and American aerospace engineer Burt Rutan unveiled the WhiteKnightTwo mothership yesterday that will be used for his project to launch tourists into space. The mothership itself is not designed to leave the atmosphere, but will air launch the yet-to-be-finished SpaceShipTwo …
"Maybe, just maybe the more people - especially those with money, power etc - who get to see our beautiful, little, blue-green planet from the splendour of the stratosphere - the more people will realise quite how important it is that we don't trash it."
Hmmm... I wonder how much fuel, and therefore carbon emissions, it takes to get that thing up and passengers in to space?
"Yes? Hello? I'd like an insurance quote. Can you 'Quote Me Happy?'. Yes. I'm going to be launching a bunch of world-famous billionaires into space on a fibreglass rocket ships that is air launched from a newly-designed plastic airplane. Yes, very similar to the introductory footage for the '$6 Million Dollar Man' TV series. Yes. No. But... Ah... But... Hello? Hello? Hello?..."
"Maybe, just maybe the more people - especially those with money, power etc - who get to see our beautiful, little, blue-green planet from the splendour of the stratosphere - the more people will realise quite how important it is that we don't trash it. Of course, this is purely speculation."
- it might have an effect but how much of the worlds resources would it have taken to get them there in the first place? It makes Virgin Atlantic look like Greenpeace!
"I bet someone said that about the Comet before they started disintegrating and falling out of the sky."
There's always at least one blithing idiot. No-one knew anything about metal fatigue before the Comet started falling out of the air. It took a lot of time and effort to find out what was happening, and for reasons beyond comprehension the resulting data was given by the British to the Americans for free.
These days fatigue is well understood, to the point that engineers can predict to a fair degree of certanty when a component will fail. Rutan will have done this math, and also worked out that he's only going to fly the aircraft to altitude a couple of times per week (unlike civil airliners that cycle multiple times per day).
There are old pilots and there are bold pilots, but there are no old, bold pilots. -- old pilot's saying.
If I understand the "80%" comment, Rutan is leaving out a lot of design work. Do Airbus and Boeing slap parts together and call the result an aircraft? Bold, indeed!
The "crash & burn" icon for good measure.
You can't say that "fatigue is not an issue". The FAA will disagree in a big way with this statement. Fatigue of flight components is always an issue because an airframe isn't completely rigid (ever watched out of your window on take-off and seen the wingtips of your 737 moving up and down in relation to the rest of the plane?) and those components that move around will start to suffer fatigue.
This is why all major aircraft components have a fatigue limit, and why they are replaced well before they reach that limit so as to avert a fatigue-induced airframe failure. I think what Mr Rutan is trying to say is that the designed-in fatigue limit is nice and high.
Incidentally fatigue limit (particularly on the engines) is the other factor, other than money, that will limit the amount of display flying that the recently returned to flight Vulcan will be able to undertake before it is permanently grounded.
Fatigue is definitely an issue. I'm fatigued by armchair engineers !
There are a multitude of materials available which are IMMUNE to fatigue. That is, their properties do not change through repeated load cycles below their yield level. Rutan may choose to use them.
Conventional aluminium alloy is prone to fatigue but Rutan is a composites expert. Any limits may even be beyond the service life of the craft !
Furthermore, aircraft components do not necessarily have a fatigue life. They range from "indefinite lifespan" through "regular inspection required" to "replacement at pre-defined flight hours."
Modelling performance on computer is only 20 years old. Computer aided design only 30 years old. Performance & failure prediction calculations are still phenomenally expensive and not for one-offs. The Spitfire was designed with a pencil, drawing board and slide rule. I think they did ok there.
Just so you know. I have qualified as a mechanical engineer, commercial pilot and flying instructor.
So obviously there will be the typical fatigue issues with engines and things, but that isn't really an issue on current airplanes, since you can replace bits and keep an eye on them. I imagine that the non-replaceable bits of the airplane are what he was talking about, since fatigue there would give you a heap of scrap.
And composites don't fatigue like metals at all, and you really can design out any of that kind of problems. In fact you sort of need to design them out, since composite fatigue is frequently difficult to detect, and it can lead to some pretty impressively fast and catastrophic failures.
And in case anyone is wondering, I've got both a degree in Mechanical Engineering and a massive hangover, and I have been working with high modulus carbon fiber composites lately.
'However, amid claims that fatigue would be a problem for its all-composite fuselage and wing design, Rutan said: “Fatigue is not an issue at all.”'
The whole point of using composites is to avoid fatigue - using composites for applications where fatigue is not a critical design consideration is usually pointless* - for the vast majority of cases, metals, particularly steels & aluminium alloys, are better and cheaper.
It's only for applications with massive variations in stress (e.g WK2) or large numbers of cyles (wind turbine blades) do composities become a cost-effective option.
*BOCTAOE
Please try not to treat press releases like technical documents.
When he says that fatigue is not an issue, it doesn't mean fatigue doesn't happen. It just means it's not a problem; it won't come out of nowhere and surprise people with a sudden breakup. It's understood, they can retire it at the right time and they have a handle on it.
If he went into the technical aspects, the media would pounce all over it and jump to conclusions and take quotes out of context.
You have to be very careful what you say about topics that nobody else understands. People go nuts.
Case in point, all the armchair engineers here equating it to the Titanic.
It could be much worse, it could be backed by Virgins Indian call centre for tech support.
Cust> HELP, THE PLANE HAS JUST CUT OUT AND WE ARE FALLING...
Tech> Ah sir, that is because you have gone over your daily thrust allowance, and you are not being throttled back to 20% of your capacity.
I'm suffering from sufficient Branson fatigue already without El Reg giving his harebrained get-rich-even-quicker schemes publicity.
It's NOT space travel - it's merely a flight in the upper atmosphere a third faster than Concorde. It's a con. What a surprise.
I met Branson when he was shyster-ing his 'Student' magazine long before he became very rich (which he did initially by sharp-dealing musicians and record stores - I've yet to meet a musician who has a good word for him and I've met a LOT of musoes!). He was a money-grubbing misfit when I met him and he's still a misfit now.
True, he once leant his name to a half-decent airline but he then blew those brownie points by lending it to probably the worst train company in the world.
Wealth or not, Branson is an egregious puerile show-off (and one with as little sense of decorum as Victoria Beckham).
Bah! humbug!
Paris because even she'd see through the Branson hype.
great so we the taxpayer have to pony up £100K to send that blithering idiot beatrice windsor into low orbit.....I refuse to use the term "princess". She is just another in-bred muppet (I use that term as most so called "royals" are, thats why haemophilia is so prevalent amongst them among other diseases). Hopefully there is a "fatigue incident" that results in her landing in the ocean at 13000 mph.....
Hmmm shame cromwell didnt manage to eradicate the lot of them and then someone eradicate him and his religious insanity. Might have a country that hasnt went to the dogs totally.
OTOH if you correlate the average "bloke in the pub with a GnT"'s estimate of rate of british caninewards acceleration with the power of the monarchy you broadly get an inverse relationship...
AIUI 18th Century political theorists believed that constitutional monarchy was superior to republican/presidential systems because it provided a balance between the limit of politicians power and head of states power...
Do the recent incumbents of both UK PM and American President really give you complete confidence that the system of giving all the power to the person who is most competent at elbowing everyone else out of the way is definitely the best in all possible circumstances?
"Business jets and private planes are the only other all-composite fuselage aircraft that fly on a regular basis."
You're forgetting gliders, all of which are made of carbon fibre/fireglass these days. Admittedly while 50,000 ft isn't a normal operating altitude it has been done (http://en.wikipedia.org/wiki/Flight_altitude_record#Gliders), and half that height is pretty straight forward if you're in the right place. No special modifications needed to the airframe even for world altitude flights...
Mike asks: "Do the recent incumbents of both UK PM and American President really give you complete confidence that the system of giving all the power to the person who is most competent at elbowing everyone else out of the way is definitely the best in all possible circumstances?"
Easy question; easy answer. No.
That's one of the only advantages of the monarchy - it stops people like Blair or Thatcher becoming head of state.
What is being smoked here?
I gleaned the following from the right-on eco cheerleaders such as the BBC and Guardian about this PR stunt, with not a peep about what comes out as it goes up:
Guardian - 'Among the first to fly will be the physicist Stephen Hawking, the environmentalist James Lovelock and former Dallas actress Victoria Principal.' I guess the paper will be selling tickets. Business is business. Maybe not on the eco page when they rail against 4x4s or plastic bottles, though.
Then BBC - Branson unveils space tourism jet - Ahh... now I get why: '... It has enormous weight capability, so if there were a [humanitarian] crisis in Africa it could carry enormous loads [for aid]'
I am obviously missing something here as this effort is getting a heck of a pass compared to some others of 'confused' e-value. I think it's a potentially awesome technological leap, but having it under such a banner seems hard to wash as green.
SpaceShipTwo will fire its rockets and take six very wealthy passengers on a 2½ hour ride into the Earth's thermosphere.
Really? TWO AND A HALF HOURS, From a Rocket Engine?
And theres me thinking 3 minutes of Rocket Boost and 5 minutes freefall, and a sharp descent to the hard stuff (The space ship is only a stubby winged glider!)
The quoted 2.5 Hours is mainly spent climbing to 50kFeet under the White Knight! and NOT AFTER IT IS RELEASED!
After a 2 hour ascent by White Knight 2, SpaceShipTwo will be released and fire its rockets and take six very wealthy passengers on a 10 Minute ride through the Earth's thermosphere, followed by a 20 minute steep glide back to terra firma.