Reaction Engines plan Mach 5 Airliner 221
What is? writes "A British company has designed an eco-friendly airliner that could make a trip from London to Sydney in under five hours. Reaction
Engines has received funding from the
European
Space Agency to design the plane as part of the
Long-Term
Advanced Propulsion Concepts and Technologies project. The
A2
airliner would be capable of carrying 300 passengers at speeds of up to Mach
5."
Easy choice (Score:5, Funny)
Still it would make (Score:3, Funny)
Re: (Score:2)
Use Both Traditional and Ramjet (Score:3, Informative)
Behind the pre-cooler, the SABRE system consists of a number of different engine components, each tuned to a different portion of the flight. SABRE uses two "pure" rocket engines surrounded by a ring of smaller engines similar to ramjets.
It looks like this design is a combination of rocket engines and ramjets.
The performance section of this is most interesting though:
The designed thrust/weight ratio of SABRE ends up several times higher--up to 14, compared to about 5 for conventional jet engines, and just 2 for scramjets. This high performance is a combination of the cooled air being denser and hence requiring less compression, but more importantly, of the low air temperatures permitting lighter alloy to be used in much of the engine. Overall performance is much better than the RB545 engine or scramjets.
The engine gives good fuel efficiency peaking at about 2800 seconds within the atmosphere. Typical all-rocket systems are around 450 at best, and even "typical" nuclear powered engines only about 900 seconds.
The combination of high fuel efficiency and low mass engines means that a single stage to orbit approach for Skylon can be employed, with air breathing to mach 5.5+ at 26 km altitude, and with the vehicle reaching orbit with more payload mass per take-off mass than just about any non-nuclear launch vehicle ever proposed.
Like the RB545, the pre-cooler idea adds mass and complexity to the system, normally the antithesis of rocket design. The pre-cooler is also the most aggressive and difficult part of the whole SABRE design. The mass of this heat exchanger is an order of magnitude better than has been achieved previously; however, experimental work has proved that this can be achieved. The experimental heat exchanger has achieved heat exchange of almost 1 GW/m^3, believed to be a world record. Small sections of a real pre-cooler now exist.
The losses from carrying around a number of engines that will be turned off for some portion of the flight would appear to be heavy, yet the gains in overall efficiency more than make up for this. These losses are greatly offset by the different flight plan. Conventional launch vehicles such as the Space Shuttle usually start a launch by spending around a minute climbing almost vertically at relatively low speeds; this is inefficient, but optimal for pure-rocket vehicles. In contrast, the SABRE engine permits a much slower, shallower climb, air breathing and using wings to support the vehicle, giving far lower fuel usage before lighting the rockets to do the orbital insertion.
And there it is. That's why a vaporware tag might be applicable, this is still just a 'plan' and not actually in production right now. Still, it is massively safer to test prototypes of this th
Re:Use Both Traditional and Ramjet (Score:4, Informative)
Yeah, it's a dual-mode engine. If you do a little research on them, you'll probably find that aerospace designers discounted such designs a long time ago. The problem they ran into was that rocket craft spend so little time in the atmosphere that the extra weight and complexity incurred through dual-mode operation ends up gaining very little over a BDB. (Big Dumb Booster)
The only time they really make sense is for nuclear engines. In the case of nuclear, you can use anything that can be heated and exhausted as fuel. This leads to three options that can be used to power a Nuclear Thermal Rocket:
1. Pass air through the reactor, heating it up and using it as rocket exhaust. This is relatively low thrust and would only be useful in combination with another booster or to maintain velocity in the atmosphere.
2. Pass air through the reactor, heating it up and using it as rocket exhaust. As the air exits the engine, add hydrogen fuel for a second reaction. This greatly improves thrust at the cost of fuel efficiency. Perfect for initial takeoff.
3. Pass a stored, lightweight material like hydrogen through the reactor, heating it up and using it as rocket exhaust. Thrust is good in this mode, but not great. Depending on the design of the craft, this could be used 100% of the time or while in space.
Creating such "Tri-Mode" engines is reasonably straightforward and has been done. (e.g. The Triton Nuclear Engine [nuclearspace.com].) I'll leave it as an exercise to the reader to understand why they're not already in use.
Zubrin's Idea, using COTS tech: Black Colt (Score:2)
You could use such a vehicle as a 1st stage for cheap TSTO launch of small payloads. It can also be used for hypersonic intercontinental package delivery.
http://www.astronautix.com/lvs/blakcolt.htm [astronautix.com]
The idea also scales up. (To the point where the
Re: (Score:2, Interesting)
Re: (Score:2)
Just because something was discounted for a technical limitation doesn't mean that limitation will never be overcome.
Unless the technical limitation is "Violates the laws of the universe"
Re: (Score:2)
Why is it that people need things spelled out around here, else it's considered "wrong"? By saying "ZIP and BZ2 algorithms" I was referring to "some of the algorithms used in these formats for compression". LZ77 and Huffman are obviously used together in the DEFLATE algorithm for ZIP. BZ2 is more straightforward by first transforming the data into a more compressible form using BWT and move-to-front transforms before performing fa
Re: (Score:2)
Re: (Score:2)
Re:Use Both Traditional and Ramjet (Score:4, Interesting)
Over some 20 years, I met one, count 'em one candidate who correctly coded a Shell sort without blinking in an interview.
My question is basic, "Code a routine to sort a set of objects of any type of your chosing, based on a means of ordering them (comparison function). Use the language of your choice. The routine should be correct, and you be able to describe it's worst-case performance in O(n) notation. It need not be the most effective way of doing it."
Unfortunately, the candidate above made the fatal interview mistake of expounding on his personal school project "FTP server with dynamically loadable file-type handlers, based on requested file extensions" (to dynamically generate content based on extension), as a "servlet-supporting FTP server" to a different interviewer -- with a marketing backround -- who, for some reason, was trying to conduct a technical interview, when he should have been getting a feel for the candidates business sense.
This other interviewer dismissed the candidate as a fraud because "everyone knows" that web servers use servlets and ftp servers "don't".
Sadly, we had a policy where every interviewer had to "green light" a candidate for them to be hired.
And people wonder why so much software is crap.
Re: (Score:2)
You'd be surprised. Project Pluto, NERVA, and Timberwind were all supposed to be atmospheric-capable engines. (Though Pluto was a bit sadistic.) Triton is a modern Tri-Mode engine that's supposed to solve the graphite flaking problems by using tungsten cladding on the reactor to ensure that no "hot" materials escape the engine.
Actually, they want to [reactionengines.co.uk] "go to the moon" as you put it. It's just that they also want to go to sy [reactionengines.co.uk]
Re: (Score:2, Insightful)
Silly Mods... (Score:2, Informative)
I can't believe you guys gave this joke an "Informative" rating... of course, I fully expect to be modded down as a Troll for criticising the moderators, but here's some info for you clueless newbs...
Lempel-Ziv compression [wikipedia.org]
Huffman compression [flipcode.com]
As you can see, these are forms of data compression, not the compression of gasses, as would be used in a ramjet engine. Please, please have an idea of what you're reading about before marking something "informative". This may deserve a "Funny" mod, but it's not "In
Re: (Score:3, Funny)
CG is Cheap (Score:5, Insightful)
Is this going to be a real commercial jet, or just another cock tease?
Re: (Score:2)
Re: (Score:2)
Re: (Score:2)
That depends on if they are aiming this at a super luxury market or trying to make it a more mainstream product. There is a higher disparity in wealth distribution today than there was in the 70's and 80's. So if this is solely for wealthiest 0.5% then perhaps there is a way to make it cost effective. $100,000 ticket prices might make it work. But I agr
Re: (Score:2)
Re: (Score:2)
zing!
Code Name 'Blue Balls' (Score:2)
Re: (Score:2)
*_technically_ I suppose the linked image is supposed to be erotic, but if it's considered a NSFW image where you work then I truly pity you.
Re: (Score:3, Informative)
It might be classified as a sub-variant of that.
Or would Aeromechaphilia be a better word?
Re: (Score:2)
Is this going to be a real commercial jet, or just another cock tease?
Looking at the backgrounds of the company's key staff, I'd say this has a real chance of getting off the ground (pun intended).
Nothing New (Score:5, Interesting)
Don't hold your breath (Score:2)
Don't cancel your travel plans just yet.
Did you know you can travel from London to Sydney on a bus, only takes about 4 months.
riiiight (Score:2)
Scientist: No, Toby, and no more questions about whether this is a joke.
Re: (Score:2, Insightful)
Oh, won't somebody please think of the math (Score:5, Insightful)
Re:Oh, won't somebody please think of the math (Score:5, Interesting)
I just don't think there is a commercial viability for supersonic flight. The need to decrease flight times from 20 hours to 5 hours is just not enough of an incentive to cover all the associated investments and pitfalls of implementation.
Re: (Score:3, Funny)
Re: (Score:3, Interesting)
You joke, but I've often considered the idea of creating super-sonic mass-transit systems between cities. The idea that I visualize in my head is having a vacuum-sealed tube through which magnetically driven cars pass. Each mag-car would act as a ferry for one or more conventional vehicle. You'd drive your car into the station, drive onto the open mag-car platform, the mag-car would be sealed and pressurized, then moved into the launch queu
Re: (Score:2)
Re: (Score:2)
Dan East
Re: (Score:2)
NIMBY
That's the first goddamn thing that came to mind when I saw Mach 5. It sucks. We're stuck in the dark ages of sub-sonic flight because a vocal minority - mostly housewives with more time on their hands than brains - don't want their miserable little lives occasionally disrupted.
The need to decrease flight times from 20 hours to 5 hours is just not enough of an incentive to cover all the associated investments and pitfalls of implementation.
If you don't like using public restrooms, it is. :)
Sweet mother of Christ... what do people do in the bathroom that leave it such a mess?! WHAT ARE YOU PEOPLE DOING?!
Re: (Score:3, Insightful)
We're stuck in the dark ages of sub-sonic flight because a vocal minority - mostly housewives with more time on their hands than brains - don't want their miserable little lives occasionally disrupted.
On a day with the right weather conditions, I can see the remnants of dozens of contrails in the sky at any given time. I certainly don't want to be subjected to a dish-rattling sonic boom for each one of those.
Basically, you'd be annoying hundreds of thousands of people each time a few dozen passengers shave a couple of hours off of a flight (but still spend 4 hours in traffic jams, terminal waiting areas, baggage areas and security lines at the endpoints). Those "housewives" are 100% correct on this
Re: (Score:2)
Concorde was profitable. Its demise was met because nobody was willing to build new airframes, or maintain the existing ones, along with the fact that conventional First-Class flights were more profitable than supersonic ones.
If some actual competition were to occur, Supe
Re: (Score:3, Interesting)
I think the objective is to cruise in very rarified or no atmosphere while flights like the concorde cruised @ 18kms
this would be close to 70-80 kms or near the karman line. The dynamics would be vastly different.
the engines would have to be hybrid between a rocket engine and ram assisted engine rarified and atmospheric operation.
Although i can still see a problem in "reentry" hopefully they figure out a way to
Re: (Score:2)
There'd have to at least be some external cameras somewhere to give the pilots some view of their path and around their plane.
Choice of fuel (Score:3, Insightful)
They'd be using Hydrogen as a fuel, which when burning is about as "green" as they come. Hydrogen generation aside (can use solar, hydroelectric, etc for green generation) you don't have to worry about eco impacts on it like you do with the fuel-guzzlin' Concorde. You could reduce the drag by pushing the thing up to near space altitudes, 100k+ feet altitudes or even hi
Re: (Score:2)
Hydrogen PER KILOGRAM has 2 or 3 times the energy density of JetA. Liquified Hydrogen BY VOLUME has about 1/4 the energy density of JetA. Add in the weight overhead of of cryogenic storage + insulation and I question the legitimacy of their statement.
Re: (Score:2)
Re:Oh, won't somebody please think of the math (Score:5, Insightful)
Hydrogen is eco-friendly *at the point of use*, but unless someone can magically cause it to appear its production isn't environmentally sound at all. You just hide the costs and emissions somewhere that the public hopefully won't notice it. (Same with electric cars. Using electric doesn't pollute. Making it certainly does. Anyone telling you different wants your money or your vote.)
Re:Oh, won't somebody please think of the math (Score:5, Informative)
Hydrogen is normally produced [wikipedia.org] via steam reforming and related processes (water gas shift reaction, coal gassification, etc), not electrolysis. That is, the hydrogen and the energy to produce it both come from fossil fuels (mostly natural gas, but oil and coal can both be used -- though in the case of coal all the hydrogen is coming from the water).
And actually, there is currently a *huge* hydrogen production industry. It's just mostly used on site at large plants rather than shipped to consumers as energy storage. Ammonium nitrate fertilizer is a *gigantic* market, and it's made by combining atmospheric nitrogen and hydrogen into ammonia, and then converting some of that ammonia into nitric acid before combining the two to form AN.
The availability of hydrogen is actually only a minor detail in this design. The price and the awkwardness of handling the ultra light weight ultra cold liquid are much more relevant.
Re:Oh, won't somebody please think of the math (Score:5, Interesting)
Your point about electric cars I don't really get. Sure you have a longer tailpipe with an electric car, but if your thermal efficiency and CO2 or whatever pollutant you care about per mile is less, you are still winning. There are other technical challenges for electric cars, and a lot of people might not see that you have to look at the bigger picture, but even when you do EVs look pretty good.
reference on EVs here [evworld.com]
and yes I recognize that is an EV advocacy site, but their point is correct. IC engines have a thermal efficiency of about 15% or less. It's not hard to beat that with a stationary plant.
Now, about the present article - I'd like to see some analyses that say that you can actually fly a supersonic plane a good distance on hydrogen, and how the hell you think you can make that economical.
Re: (Score:2)
Mach 5 (Score:4, Funny)
Re: (Score:2)
Let me guess.. (Score:5, Funny)
300 passengers? (Score:5, Funny)
Toddler and Monkey (Score:3, Funny)
[OK, I was a young kid at the time I watched it...]
Re: (Score:2)
I'm just waiting for the day when airlines force you to stand because they realise they can fit twice as many people in that way.
Re: (Score:2)
noise & fuel costs (Score:5, Informative)
Second, I can't help but think that fuel costs will kill this idea. GIven rising energy prices (and no large-scale miracle hydrogen factories on the horizon), the fuel costs will tend to track oil and nat gas prices. Even "free" wind/solar power won't help because a hydrogen factory would need to pay a competitive price for energy, which will be tied to the rising cost of fossil fuels and the rising global demand for energy.
That said, I'd love to fly in this thing even though the artists sketch shows a lack of windows due to heat issues
Re: (Score:3, Informative)
Hydrogen sucks for aircraft. The energy density is better than gasoline, sure, but the mass density is horrid. Your tanks wind up being huge, which increases the vehicle size and drag, which increases the lift requirements and fuel requirements, which increase the propellant requirements
Re: (Score:2)
Even liquid?
Re: (Score:2)
According to British Airways, a 747-400 plane cruises at 927 km/h, burns 12,788 liters of fuel per hour and carries 409 passengers when full. 1 barrel of oil is 158.987296 liters. If the fuel were crude oil, it would burn 80.5 barrels an hour, at 87.25 a barrel, that's $7024 an hour. For a 6 hour flight that'
Re: (Score:2)
Re: (Score:2)
The wings look smaller than the Airbus 380 that they're comparing it to. You can't really tell the wing area from the pictures, but the aspect ratio is most definitely less. It is twice as long, and appears to have the same d
Mach 5 Airlines.... (Score:2)
With a name like that, the plane better have little buzz saws that extend out of the front to cut down... er, really tall trees, I guess. And should take off with the help of extending stilts from the bottom. Plus a lot of other cool, but ultimately useless, gadgets.
Oh, and a chimpanzee and a little kid in the trunk.
Then again, maybe I should have RTFA.
Re: (Score:2)
Re: (Score:2)
"Hey guys we made up this cool plane it's really fast! Yeah! Imagine going from London to Paris in INSERT_LOW_NUMBER minutes! Imagine it, bitch!
"This plane is longer than the A380. It's really freaking long! That's sweet!
"Did we mention that we play a lot of Mass Effect? Isn't it a cool game? Also our engines are called Scimitar engines! That's like, a shotgun in Mass Effect. Oh yeah, babe!
"This plane is FROM THE FUTURE motherf---er!"
Noise and price issues? (Score:5, Interesting)
The issues boiled down to two things that no amount of tech could alleviate: Noise issues (property owners near the airports got highly vocal about having to replace cracked windows from the occasional sonic booms), and price ($25k 1st class from NYC to Paris? And now you get to suffer the indignities of airport security too? Sounds like a masochist's dream come true...)
Unless/until they solve at least those two issues (in spite of public pronouncement, it doesn't look like they have IMHO - yet), they're going to have a hard time with it's initial public image, fuel economy be damned.
Sure the economics of volume may drop the price, and sure the noise problem can be solved through strict pilot discipline (e.g. no cracking the sound barrier until you're x miles away and at y altitude), but that won't change public perception that Concorde planted firmly in the public mind back during the 1970's).
OTOH, the tech is cool, and I can see a very solid use for it for trans-pacific passengers... Seattle to Tokyo in 3 hours instead of 12? Frickin' awesome...
Re:Noise and price issues? (Score:5, Informative)
Price will come down if fuel economy is reasonable and there are enough airplanes and flights to amortize development costs over. My impression (I've been following them for a while, and talked to people who should know) is that they're technically competent, and if they say they can get the price down, they can -- but that they're being overly optimistic about the market. Of course, if the government is paying for a low of the development, that helps a lot.
Noise is actually quite amenable to a technical solution. The first problem (noise near the airport) is a result of high-power, high exhaust velocity engines, combined with a need to get up to supersonic speeds quickly. If, as they claim, the airplane is efficient in the subsonic regime as well, then there is less pressure to accelerate rapidly. Efficient low-speed operation also inherently implies a lower exhaust speed (which they discuss briefly: variable high-bypass flow), which implies less noise -- for a given engine, noise power scales roughly (very roughly) linearly with exhaust velocity.
Noise from sonic booms is remarkably controllable, with sufficient work on the precise shape of the airframe. The technology to do that, high performance CFD, simply didn't exist when the Concorde was designed. They don't discuss it, but it's far too early in the design cycle for that to mean anything. Right now they're basically just trying to build the engine and convince people that a market exists at a price point they can reach. That requires design studies and concept art, but it's not yet time to be fine tuning the aerodynamics.
I'd say the technical problems, including noise, are amenable to solution if they manage to get the funding they need without too much interference. The market ones, less so. I'm sure one day we'll see supersonic airliners, but there are some *major* non-technical hurdles in the way of building anything the size of an A380.
Of course, it's wicked cool and I'd love to see it happen. Especially since the basic engine technology is also behind their Skylon SSTO spaceplane concept...
Re: (Score:3, Interesting)
Re: (Score:2)
I grew up less than ten miles from Dulles International Airport in Virginia, and when I was a kid, the highlight of my day was to see the Concorde flying overhead. It didn't matter where we were or what we were doing, if one of my family or I saw it flying overhead, we'd immediately stop what we were doing, and just gaze at it until it vanished from view.
I was hear
Barf Bags (Score:3, Funny)
Streamlining doesn't just apply to the aircraft... (Score:4, Insightful)
How droll. Soon, you will be able to travel from London to Sydney in less time than it takes to negotiate security at the airport. ^_^
Re: (Score:2)
Re:Streamlining doesn't just apply to the aircraft (Score:2)
There. Fixed that for you.
Better Option? (Score:2)
Long distance air travel sucks (Score:3, Insightful)
Why would this be a better option than a regular flight? Aside from being a relatively short trip...
You can stop right there. I'd HAPPILY pony up to cut a 12,000 mile trip time by 2/3. I've flown from the US to Japan, China, Thailand, and Singapore and several other similar routes multiple times. Not just for business either. One such flight should be enough to convince you that anything which makes the trip faster is worthwhile. Trust me that spending 12+ hours in the air (often with 24+ hour trips once layovers are considered) with 400 of your "closest friends" is just no fun at all. Flying first
Re: (Score:2)
Now imagine the same flight in something resembling an old fashioned pullman vagon. You do not have "close friends". You are alone in a cubicle or with 1 or 3 more people depending on the class you fly. It may be slower, but it is much more comfortable.
I would much rather fly in something like this even if it takes 2-3 times longer.
If we throw in connectivity options, a good restaurant and some in-flight entertainment and frankly there will be many people wil
I still don't get it (Score:4, Insightful)
Re: (Score:2)
Re: (Score:3, Informative)
They're claiming a price point comparable to current business class fares. There are enough business class fares sold currently to support a small fleet of such airplanes flying a few flights on the relevant long-haul routes. Anyone willing to pay for business class is certainly willing to pay a similar amount (or probably at least a moderate premium) to cut their flight time from 12+ hours to 2-4.
I can't speak to the details of this specific airplane, mostly because those details don't exist yet, but t
Re: (Score:2)
You can only go supersonic over the oceans whilst you are in the atmosphere
... always assuming they don't use some clever tech to reduce/eliminate the sonic boom too.
So, shoot up into (very!) low orbit over the Atlantic, zoom over the US, come down over the Pacific, land in Sydney. Do some shopping, have lunch at that excellent restaurant by the bridge, return home for tea.
Re: (Score:2)
Package Delivery (Score:2)
Re: (Score:2)
Eco-friendly???? (Score:2)
Haven't we seen this before? (Score:2)
Now the concorde is de-commissioned, we're told never to fly again. If the concorde allegedly couldn't turn a profit, even at something like 10x the ticket price of regular air carriers for the same route, how will these new ones be able to do it
Thunderbirds are go! (Score:4, Interesting)
No sonic boom answer = not serious proposal (Score:2)
Popular Science Article (Score:4, Informative)
Lapcat? (Score:2)
This may make it an inviting target, not for terrorists, but Dr. Evil... Bwuhaaa
The europeans better make sure they don't put frick'n laser beams on it...
The Mach 5 Plane? (Score:3, Funny)
Looks like it has ample cargo space [wikimedia.org].
proof of mach 5 fighters (Score:2)
Re: (Score:2)
Given the problems associated with the SR-71 as an operational aircraft, and the lack of significant, physics-defying advancements in heat-resistant skin materials, I'm quite comfotable with the fact that this will be as quick to market at Moller's car.
British Technology Never Flies (Score:5, Interesting)
The last major triumphs of British engineering to actually get built were Concorde and the Advanced Gas-cooled Reactors.
Ever since then the can't-do-won't-do attitude of Britain's "financial service economy" curtails any great technological projects. The only things that get built are science projects, with meager government funding.
Reaction Engines/Bristol Spaceplanes have some very interesting engine designs like SABRE. These are the people who designed the RB545 for Hotol (another great British triumph of procrastination over achievement).
Mark my words, this will sit firmly on the drawing board and will probably be reinvented in 20-30 years by the Chinese. The American's won't have it since they didn't invent it.
It sucks to be British unless you're in Banking or Insurance. Still, mustn't grumble. At least we're not French or German or foreign. Time for a nice cup of tea and a sit down.
British Aerospace Contributions... (Score:2)
qsst will happen LONG before reactions does (Score:2)
Mach 5 Cruiseliner! (Score:3, Funny)
What I want to see is a Mach 5 CRUISELINER! That would be worth building!
Has Designed? (Score:2)
From what I read on their website, "has designed" really ought to be "has been offered some money to think about how such a thing might be designed" - they're not designing yet, they're just getting EU money to do a few preliminary design studies, with design to start in a decade or so, maybe, possibly, depending on the EU's willingness to give them a heap more money sometime in the futur
Re: (Score:3, Informative)
Re: (Score:2)
Re: (Score:2)
Re:you haven't thought of all the uses of the new (Score:2)
you could use it to knock down bigger skyscrapers and the agencies won't have to explain why they did nothing - noone saw them comming!
Yeah, there's a fat chance an unqualified (terrorist) pilot could fly such a plane at such a speed (or even a third of that speed) at very low altitude into a sky-scraper.