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More SpaceShipTwo Details
Anonymous Coward from Manitoba writes "BBC news is reporting more details about Burt Rutan's proposed SpaceShipTwo. Apparently the new flyer will include five to eight passenger seats and have the 'same diameter crew cabin as a Gulfstream V business jet'. It will fly much higher than SpaceShip One - up to '135-140 km' that will permit an additional 90 seconds of microgravity. This will be important, since 'we want this roller coaster-type bar that you fold out of the way and you can float around'. They are also planning to 'have the option of landing in a different place from where they took off'. I can't wait until we can ride SpaceShipThree across the Atlantic in 20 minutes!"
I think a small increase in size and payload lift capacity results in a huge increase in the amount of fuel required. Fuel and the tank to hold it adds weight too. I think it's something insane like less than 5% of a rocket is payload.
They don't use oil based fuel.
Rocket fuel is usually liquid oxygen in one tank, and liquid hydrogen. There are several other fuels used, one of which is derived from kerosene and is not used often anymore.
Spaceshipone uses "hydroxy-terminated polybutadiene (HTPB), a common ingredient in tire rubber" as the fuel, and nitrous oxide (laughing gas) as the oxidizing agent.
Because they are common and not explosive in and of themselves, they are much easier to transport and use.
Oh, and they don't use much oil, AFAIK, either.
But, YMMV because IANARS.
Can you imagine how much more that baby behind you is going to cry when it starts floating around?
"A man is but the product of his thoughts what he thinks, he becomes." -Mahatma Gandhi
See also: Jules Verne
Yes it did. Initially it didn't but then someone had the bright idea of asking the regulat passengers how much they thought they were paying (these being the CEOs etc, not the pencil-pushers who booked the flights....) and they all mentioned amounts 2-3 times what they/their companies were being charged. So BA raised the cost of the flights by 2-3 times. They also started running gift flights which would go out over the Atlantic, go supersonic, pop champagne and then head home. This combination made the Concorde profitable.
Now it's probable that had BA etc had to shoulder the full cost of designing and building the thing, they'd never have made anything.....
In the late eighties there was a recession in the UK and this reduced the number of regular passengers and Concorde started becoming less viable. The combination of 9-11, the French Concorde explosion and general world angst finally killed it.
But in the Eighties it made BA and Air France lots of cash.
Troc.
Troc's dubious podcast and blog: http://www.trocnet.net
If you're talking about a tail-first reentry that relies on rocket thrust slowing down the craft to avoid overheating, I wouldn't think so... at least not with a hybrid engine. Maybe with cryogenic fuel.
Does the shuttlecock feather design work at high speeds? When it comes down from orbit and hits the atmosphere it'll be going like 17,000 mph. I wonder if the feather can slow it down fast enough to avoid sustained high temperatures.
In any event the orbiter will have to be made out of something more heat tolerant than epoxy composite.
On the other hand, the Discovery Channel program showed a brief glimpse of a Tier Two mockup on Burt's computer screen (a Mac)... it looked like a SS1 on a big stick, feather and all. I guess Burt's got it all figured out already.
Closer to 3%, at least for the SatV and recent Delta IV Heavy.
:)
A SatV weighs 3,038,500 kg, and can launch 118,000 kg to orbit. Lunar weight/payload ratios are even worse, at 47,000 kg to the moon, its about 1.5%.
I thought some of that might be for outdated technology (and some of it is, i'm sure, we could save structural weight now, not sure how much fuel requirements could change though) so I compared it against the Delta IV Heavy:
733,400 kg launcher.
25,800 kg payload to LEO.
3.5%
Don't whine about units, 'rocket science' generally uses metric, so thats what I found units in. I'm too lazy to convert them, use google calc and do it yourself.
They were worried about passing the heat tolerances of the SS1 materials at Mach 4. At near mach 25 it wouldn't stand a chance.
I'd like to see Rutan go orbital, but anyone who thinks it will be the small, light, inexpensive (for a space ship) craft it is today is fooling themselves.
The electrolyse is very inefficient, you have to put in more energy to create it then the hydrogen will provide. To create electricity there are multiple sources:
The first option is not used a lot at this time because is does not create enough energy to be profitable. Nuclear energy may be the real answer for the near future but as we all know there is a lot of international debate about it's safety. And then we get to the last one, our primary electricity sources of this time: oil and gas.
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They had to delay the launch to wait for needed parts. I havn't heard anything about them since, but I doubt they would drop out without saying anything.
Of course, there is always the chance that I missed it.
Again, spaceship one doesn't use hydrogen.
I'm sure petrolium products are used in the creation of the rubber ingredient used in the SS1/2 fuel, but it's no different than making a couple hundred thousand tires. Something that happens every hour of every day, anyway.
And to get slightly off topic, the only type of nuclear energy that looks to be truly safe is gravel-pit systems, which really aren't in use today (I think someone in china is developing them atm, or something)...
I'm actually happier that my electricity comes from nuclear power than anything else. Yeah, the stuff is going to be put into a pool under five miles of mountain somewhere out in the middle of nowhere. But at least there's no soot lining my house, no mercury in my water.. oh wait, there's a coal plant eighty miles upriver from me. There -is- mercury in my water.
Wow. Is that true? I find it interesting that U235 is 6 magnitudes beyond chemical fuels, while Antimater is only 3 orders of magnitude beyond that.
Well not exactly surprising. The fission of one U235 atom liberates approx 200 MeV which corresponds to roughly the mass of 1/5'th of a proton so the anihilation of one U235 Atom to pure energy would liberate roughly 1000 times more energy than fission..
Yours Yazeran
Plan: to go to Mars one day with a hammer.
TNT carries much less energy per kilogram than a simple candlestick. Its strength comes purely from reaction speed. The Russians fill up their rockets with ordinary Diesel fuel. Now that is what I call bang for the buck. I don't know how traditional dry fuels like AlCl3 compare though, anybody any figures on that?
10 ?"Hello World" life was simple then
the point is that a single jumbo actually WOULD transfer more people over the atlantic in a weeks time perioid than a cruiseliner ever would be able to.
But it will use disproportionately more fuel to do so.
I think you're wrong.
The Queen Mary 2, which is a modern and fuel-efficient cruise ship, moves 50 feet per gallon, which is about 0.01 miles per gallon. At 2,712 persons (which includes 921 crew, by the way), that's 25.8 person-miles per gallon. Source data.
A Boeing 747-400, which is a modern and fuel-efficient jumbo jet, moves 666 feet per gallon, which is about 0.13 miles per gallon. At 524 persons (not including crew), that's 66.3 person-miles per gallon. Source data.
That makes the jumbo-jet nearly three times more fuel-efficient than the cruise ship. I realize that they don't use the same types of fuel so a real efficiency comparison might require some additional correction factors, but I bet the jumbo jet still comes out way ahead. Especially if you didn't give the cruise ship the unfair advantage of counting the crew in the calculations.
If so, you may want to consider to book a parabolic flight with ZERO-G.
John Carmack has taken the ride and seems to have liked it a lot.
This book -- The Backroom Boys: The Secret Return of the British Boffin -- has a great section on Concorde. It explains the whole thing.
The Airbus A380, on the other hand, is of a more recent design, and its target mark is 81 person-miles per gallon.
"Oh, a lesson in not changing history from Mr I'm-my-own-Grandpa." - Dr Hubert Farnsworth
Fuel is one of the smallest costs associated with launching things into space.
If you use a Kerosene / LOX rocket to put things into orbit, when sitting on the pad, your rocket will be about 93% fuel, 4% rocket and 3% payload. That fuel will be about 7 parts oxygen to one part kerosene. LOX is one of the cheapest industrial chemicals available, at something like a penny per kilogram. If you can burn Jet-A fuel in your rocket, it runs something like $US0.40 / kilogram.
So, for each kilogram of payload for your orbital rocket, you need about 32kg of fuel, which will consist of about 4kg of kerosene at $1.60, and 28 kg of LOX at about $0.28 -- for a total fuel cost-to-orbit of less than $2/kg.
A ship can haul more tonnage per pound of fuel than an airliner. That is why things like grain, cars, and clothes tend to go by ship. The problem is when that tonnage is people you have to work time into that equation. When it takes days to travel you then need to provide food, entertainment, space to move, and medical services. All that takes fuel to move as well. For commercial grade travel a jumbo jet wins. Now if you got back to WWII the original Queen Mary once carried 10,000 troops. If the QM2 could do the same it would then beat the jumbo jet. However very few people would ever want to travel that way.
All in all a modern Airliner and yes while the 747 first flew over 30 years ago the -400 has many improvements and very state of the art engines are truly marvels of mass transit. Very fuel efficient, clean, and safe.
See my blog http://ilovecookes.blogspot.com/ for light hearted technical information.
This month's issue of Wired has a cover article on Richard Branson's Virgin Galactic, which will be using SpaceShipTwo to run a commercial spaceflight service.
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Some interesting quotes:
But look at the upside. The total price tag [of Virgin Galactic] is half the cost of a single Airbus A340-600 - and Virgin Atlantic ordered 26 of those last summer. In return, Branson gets bragging rights to one of the cooler breakthroughs of the early 21st century, with rocket-powered marketing opportunities that could fuel excitement - and sales - in his entire 200-company holding group.
SpaceShipOne's "shuttlecock" design adds an extra measure of safety. When the craft reaches its airless apogee, it hinges (feathers, in pilotspeak) into a broad V shape that automatically brakes the descent. "It lets you take an averagely competent pilot - like me - and throw anything you can think of at him, and still have everyone aboard get away safely," Tai explains. "The space shuttle does that with all sorts of fantastically complex systems. Burt's brilliance is that his ship uses smart design and the laws of physics. Which are, in fact, the only ways you can be truly drop-dead safe."
Why stop there? "I hope we'll get to the moon in my lifetime. The first baby born there - what country will it be a citizen of? Maybe we can put a Virgin bank in space, or maybe a Virgin tax haven. We could pay for all our people to go up there just by depositing their money." Now, that's adventure capitalism!
The simple fact is that going into space gives Branson a chance to do what a lot of massively successful guys wish they could do: grab the wheel of history and tug. Opening the final frontier to private citizens will ensure Branson's place in the human saga. And if that means fleets of Virgin spaceships soaring through the inky void, serving sip-packs of Virgin Cola on the way to the latest Virgin Clubhouse, so be it. "Space is virgin territory," Branson says, trying out a prospective marketing line and shooting another grin. "Is that 21st-century enough for you?"