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Reaction Engines To Fly Reusable Spaceplane
Posted by
timothy
on Mon Jan 12, 2009 12:46 AM
from the let's-just-start-here-on-the-ground dept.
from the let's-just-start-here-on-the-ground dept.
RobGoldsmith writes "Reaction Engines have designed a 'reusable spaceplane' to provide inexpensive and reliable access to space. The Star Wars-looking 'Skylon' reusable spaceplane has already been designed and the team are well into engine testing. They have taken some time out from building spaceships to talk about their background, their goals, and their recent engine tests. This article shows new images of their STERN Engine, an experimental rocket motor which explores the flow in Expansion Deflection (ED) nozzles. They also discuss their Sabre air-breathing engine technology. View the Skylon Spaceplane concept, the STERN Engine and much more in this in-depth interview with the team."
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Dollars per kg? (Score:2, Interesting)
Re:Dollars per kg? (Score:5, Informative)
From http://www.reactionengines.co.uk/skylon_dev.html [reactionengines.co.uk] :
The total development program will cost about $10 billion.
Also... http://www.reactionengines.co.uk/skylon_vehicle.html [reactionengines.co.uk]
Skylon Statistics
Length: 82m
Fuselage Diameter: 6.25m
Wingspan: 25m
Unladen Mass: 41,000kg
Fuel Mass: 220,000kg
Maximum Payload Mass: 12,000kg
At the start of the take-off roll the vehicle weighs 275 tonnes, whilst maximum landing weight is 55 tonnes.
At take-off the vehicle carries approximately 66 tonnes of liquid hydrogen and approximately 150 tonnes of liquid oxygen for the ascent.
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Payload Capabilities
The Sklyon payload bay is 4.6m diameter and 12.3m long. It has been designed to be compatible with expendable launcher payloads but in addition to accept standard aero transport containers which are 8 foot square in cross section and 10, 20, 30 or 40 feet long.
It is anticipated that cargo containerisation will be an important step forward in space transport operations, enabling the "clean" payload bay to be dispensed with.
The vehicle can deliver 12 tonnes to a 300km equatorial orbit, 10.5 tonnes to a 460km equatorial spacestation or 9.5 tonnes to a 460km x 28.5 deg spacestation when operating from an equatorial site.
You do the per flight math.
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You also need to add in maintenance, staff (someone has to manage and test this thing), facilities (you're housing and launching it where?), fuel, insurance and other such costs.
Also there are only something like 20 commercial satellite launches a year and I think that includes geosynchronous orbit ones. Maybe you could double that if you add in government satellites but it's still not much.
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Yes, lot of stuff needs to be added. At a glance, it looks like they can use a convention runway (though it might need to be reinforced, apparently a loaded vehicle generates a lot of impact on landing). Insurance isn't much of a cost for the launch provider. Insurance against third party harm is rather low since US launch providers need to demonstrate a ridiculously low risk of harm before they can launch anyway. Insurance for the payload should be pretty good for an RLV with the kind of launch frequency t
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THe hard part is that we did this already; The shuttle had the same issue.
The Shuttle had serious issues aside from lack of demand (it would take the entire US launch market to achieve the design launch rate of 50 launches per year for the Shuttle). Particularly, the 1-2% failure rate and the monstrous overhead. These guys are hoping that they can get the operating costs down to a very cheap level, achieve a high reliability rate, *and* that the launch market will improve significantly to the point that by the time the vehicle flies, they can find enough demand for the vehicle.
Holy shit, it's a proto-Firefly! (Score:3, Funny)
SR-710? (Score:3, Insightful)
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I wish I could see any picture of it. Those sites have been Slashdotted :)
Did anyone else misread the title? (Score:5, Informative)
Reaction Engines is the name of the company. It's using conventional LOX/LH2 engines.
And for those who are calling this Shuttle 2.0, it's unmanned.
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From what I've read, they aren't conventional rocket engines. But if you know better, then please explain.
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They are anything but conventional. They run as an precooled jet engine [wikipedia.org] upto Mach 5.5 breathing air from the atmosphere and then close an inlet and run as a rocket using onboard liquid oxygen as an oxidizer.
http://en.wikipedia.org/wiki/Reaction_Engines_SABRE [wikipedia.org]
enough propellant? (Score:5, Interesting)
It doesn't seem to have enough propellant mass for the task. To get to LEO, it needs something like 7.5 km/s or more in delta v (ignoring very substantial gravity and air resistance losses). If it were purely a rocket, that would be roughly 7.2 km/s (rocket equation is delta v = -4420 m/s*log(53 tons/273 tons), where 4420 m/s is perfect exhaust velocity in vacuum for LOX/LH2 burning rockets). Even if we assume we can get to Mach 5 for free (which is 1.5 km/s roughly), that leaves no more than 1.2 km/s margin. A regular rocket picks up 1.5-2 km/s or so in gravity and air resistance losses. While gravity losses might be somewhat lower (due to lift), air resistance is definitely going to be higher than the 100-200 m/s a rocket of similar size would have. So we have gravity and air resistance losses. We also have probably an inefficient nozzle design with a tradeoff between greater bell size (and efficiency in vacuum) and lower air drag. Something like drop tanks would help a little, but there doesn't seem to be the space for a lot of extra mass there. Another possibility is to use denser fuel in place of LH2 for the early parts of the flight, but that weakens the isp a little.
Re:enough propellant? (Score:5, Interesting)
You can get slightly better Isp than that, actually. For example, I get 4664 m/s vacuum Isp for O:F of 6:1 and 3000 psi expanded to 1 psi. I don't know what pressure they run at, but for a wide altitude range I would imagine it's high. Furthermore, I believe they plan to still be using some outside air even at Mach 5 -- and at that altitude, they've also got some delta-v in the altitude itself, not just the velocity. Small effects, but they help... Anyway, I don't know the details of their flight plan, but I do know that the engineers behind it are decidedly competent, and do have a detailed trajectory plan that includes good estimates of air drag and such. If you can find trajectory details, though, I'd love to see them...
(Oh, to pick a few nits about your dv budget... 7.2 km/s is orbital velocity; don't forget nearly 500 m/s of Earth rotational velocity. So if you ignore air and gravity drag, it's actually slightly under 7 km/s total delta-v, though air and gravity drag will usually add more than 2 km/s to that.)
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(Oh, to pick a few nits about your dv budget... 7.2 km/s is orbital velocity; don't forget nearly 500 m/s of Earth rotational velocity. So if you ignore air and gravity drag, it's actually slightly under 7 km/s total delta-v, though air and gravity drag will usually add more than 2 km/s to that.)
7.5 km/s is orbital roughly. Still leaves up to 1.7 km/s which is pretty tight. OTOH, the payload could be a second stage, which gets you neatly around the problem.
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(Oh, to pick a few nits about your dv budget... 7.2 km/s is orbital velocity; don't forget nearly 500 m/s of Earth rotational velocity. So if you ignore air and gravity drag, it's actually slightly under 7 km/s total delta-v, though air and gravity drag will usually add more than 2 km/s to that.)
7.5 km/s is orbital roughly. Still leaves up to 1.7 km/s which is pretty tight. OTOH, the payload could be a second stage, which gets you neatly around the problem.
Yeah I think a spaceplane should never go into orbit. Instead it should make suborbital hops. Non-aerodynamic payloads could be exchanged during the ballistic part of the flight.
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You can get slightly better Isp than that, actually. For example, I get 4664 m/s vacuum Isp
DUDE!!! You must have a ton of warez!! Where can I sign up for Vacuum Isp?? My ISP suck0rs!! Im lucky if I get 3 Mb/s, but ur getting 4664!! NO FAIR!!!!1!
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Be careful what you ask for. No matter how bad your ISP is, it can't suck0rs as much as *vacuum* ISP.
Don't forget black-hole ISPs. They suck nearly as much as... hmm, what a choice...
Re:enough propellant? (Score:5, Interesting)
A friend of mine works on the heat exchange system for the SABRE engines that will power Skylon. The SABRE engines are air breathing i.e. they use air they pick up on the way as fuel, hence they need less fuel at launch.
From their website: "The Sabre engine is essentially a closed cycle rocket engine with an additional precooled turbo-compressor to provide a high pressure air supply to the combustion chamber. This allows operation from zero forward speed on the runway and up to Mach 5.5 in air breathing mode during ascent. As the air density falls with altitude the engine eventually switches to a pure rocket propelling Skylon to orbital velocity (around Mach 25)."
More info here: http://www.reactionengines.co.uk/sabre.html [reactionengines.co.uk]
The engine saves weight by using the same combustion chamber during both modes of operation and in air breathing mode it only cools the oxygen to it's vapour point (as opposed to full liquidization) which greatly simplifies the engine design.
At least that's my understanding, IANARS.
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Yes, that's pretty much what I gathered from looking at the design, especially the odd-shaped, untapered outlets for the Sabre engines and the fact no other nozzles appear anywhere on the ship.
The engine saves weight by using the same combustion chamber during both modes of operation and in air breathing mode it only cools the oxygen to it's vapour point (as opposed to full liquidization) which greatly simplifies the engine design.
This sounds like quite an effort. Would like to see if it works out. Recently, I was discussing a scramjet design [nasaspaceflight.com] with the internet:
tnphysics: The key to a gas-and-go SSTO RLV IMO is airbreathing engines-somewhat like the Forerunner V business jet proposed somewhere on the forum (afterburning ultra-high-bypass turbofan to Mach 8, then LNG scramjet to Mach 15, then switch to LH2 to Mach 20), with a small rocket added for EOI. A metallic TPS should be used.
At the time, I recommended reducing the complexity of the vehicle by eliminating the air-breathing turbofan at the start and using the rocket instead to get the vehicle up to scramjet spe
Sky-Lon? (Score:5, Funny)
Sounds like a Skynet-Cylon joint venture. Please don't be sinister-looking....
*Opens link*
Ah, crap.
does this add up ? (Score:4, Interesting)
- air intake in the order of hundreds of kg per second (400 kg/s to quote)
- passes through thousands of small tubes (resistance at that speed ?!?)
- in a few milliseconds
- cooled from + 1000degreesC to -150degreesC
Forgive me my ignorance, but are these materials physically possible ?
George Lucas copyright? (Score:3, Funny)
And later (from a galaxy far far away) the Empire will sue GL!
Still going? (Score:2)
Sad, really, as it's one of Europe's few contenders in the non-gov space race, and probably the most promising one, in ter
a 21st Century DC-3 (Score:3, Interesting)
If they can get the cost to orbit even remotely close to the $200/kg number the Space Power Satellite program proposed by NASA was based on, we could either build a full system or a large proof of concept orbital power array. We're a bit more desperate for power than we were when Bush defunded the SPS project. The launch capability is the hard part of SPS, the rest is just engineering we know how to do.
That could take up enough launches to provide the company a reasonable chance at profit.
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From what I saw at the company website, it looks like they're building the orbital equivalent of the first commercial airliner, the DC-3.
Cool. Now if we can just scale up to build space DC-8s, we can take all the scientologists to another planet and drop them in a volcano.
Whilst (Score:3, Informative)
Can I trust my payload and/or investment dollars to a company that uses "whilst" on their site? [reactionengines.co.uk]
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Do not want shuttle 2.1. Do want Space Elevator. Now get to work.
Are you personally picking up the tab for this space elevator? Even an RLV doesn't have much of a business case to be made. There simply isn't that much demand. A space elevator needs a lot more demand than has been demonstrated to exist. A reasonable plan is to build up the demand to the point that exotic launch systems make business sense. Not develope the exotic launch system and hope someone will use it.
Re:Space Elevator (Score:5, Insightful)
You know, the day Sputnik went up hardly anyone was thinking about a commercial use for space, and now look at us. Space has definitely become a "build it and they will come" scenario. If you make payload lifting even cheaper, there will be more customers because things that didn't make sense before suddenly start to.
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You know, the day Sputnik went up hardly anyone was thinking about a commercial use for space, and now look at us. Space has definitely become a "build it and they will come" scenario. If you make payload lifting even cheaper, there will be more customers because things that didn't make sense before suddenly start to.
There was around an eight year lag between Sputnik 1 and the first commercial satellite. My take is that there wasn't enough business to support a commercial launch provider till sometime in the late 70's or early 80's. So it seems odd to me to build a space elevator and then wait 20 years for the elevator to become economically viable. My take is a superior approach is to increase launch demand and reduce launch costs on current and near future vehicles. That will in turn drive demand for RLVs, space eleva
The Internet (Score:5, Insightful)
How many "2.0" Internet businesses exist only because of the unexpected consequences of humanity building the largest peer based computer network in existence?
Slashdot itself, and other newcomers like Netflix "on demand" only exist because of the Internet. Did we build the Internet so that we could stream "Superman" in real time, or argue politics with people from around the world?
No. but they all happened because we built the Internet!
So build it! Society will profit in ways we can't today imagine today any more than Bob Metcalfe imagined Slashdot when he co-invented Ethernet!
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And what pray tell does that have to do exactly with what the OP said, of "if you build it they will come"? No one said this stuff had to come immediately. The space shuttle is the first re-usable spacecraft the US created. Many of the first escort fighters (Allison-engined P-51 mustangs [wikipedia.org] didn't live up to expectations either, nor did the first assault rifle for the US (M-16 before they lined the barrel and chamber with chrome [wikipedia.org]).
First and early attempts rarely tend to their tasks as well as people hope or
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Sure, but guess what? I bet even current launch vehicles can do a lot better in cost per kg than they currently do. I figure the limit of expendable launch vehicles are somewhere around $500 per kg in very high launch volume (thousands of launches a year). RLV would drive that to somewhere around $100 per kg. At that point, you have the business to justify that next step to exotic technologies like space elevators, rail launch, etc. This is the point that I think is being missed. There's little reason to fu
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There isn't a demand because there isn't a supply. That's like the argument, "Which came first, the chicken or the egg?"
I used to live with a little jack terrier dog that would crap all over the place. If there was a space elevator I would have used it.
Re:Space Elevator (Score:5, Interesting)
I don't much like the idea of a space elevator, at least for short- or medium-term applications. (Long term, is 50 years from now, is different... but also not very relevant.) Why, you ask? Simple. Give me a space-elevator class building material, and I'll make rocket tankage out of it long before it's fully developed to space elevator performance levels. Those tanks will be so vastly superior in weight performance to current materials that I can give you a rocket that is not only single stage to orbit, but does it on *pressure fed* engines. Who needs turbopumps and all their associated machinery when you can just put enough pressure in the tanks (and run at a lower chamber pressure... which is more conducive to high reliability anyway)?
For a given payload rate, my pressure fed SSTO will use somewhere between 3 and 10 times the energy (depending on which kool-aid you drink when it comes to getting the power from the ground to the elevator car). It will have a *vastly* lower capital cost. It will be faster (no radiation worries for cargo that spends days passing through the van Allen belts). Perhaps more importantly, it will scale down better. It starts with a lower investment and lower flight rate to prove out demand, and then grows as more customers appear and more rockets get built.
Oh, reusability? It gets a lot easier when you don't have to jettison a stage a third of the way there -- and when your reentry vehicle is as light and fluffy as these building materials imply, it gets even easier. Engine reusability is pretty trivial when you don't have 60,000 rpm turbines wearing out all the time.
There are plenty of engineering problems to be overcome for a space elevator. They're not impossible, but they're far from trivial. But the real problem is the competition from rockets -- it makes zero sense to compare a space elevator built with magic nanotubes to a lithium-aluminum tankage rocket; it should be compared to a magic nanotube rocket. When you do that, you discover that for any unproven market (ie, where capital costs matter) the spaceship fleet is far, far cheaper.
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Re:Space Elevator (Score:4, Interesting)
Look into the Space Fountain instead... http://en.wikipedia.org/wiki/Space_fountain [wikipedia.org]
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Re:Space Elevator (Score:5, Interesting)
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Looks like an aircraft meant for hypersonic flight to me... Dunno why it needs to look like anything else.
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What the hell is an Aluminum Falcon?
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Re:Star Wars looking? (Score:5, Funny)
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The Brits and everybody else on the planet. ;)
Re:I see... (Score:4, Informative)
The precooler tests were run separate to the thrust tests. The thrust tests were related to the ED nozzle work.
As for the reliability, well when I wrote the test plan for the ED nozzle test engine, I can assure you, that reliability was very much part of the plan.
As for you not seeing any prototype being tested, note the photograph of a rocket shaped object with hot flame coming out of it in the News section?
I'm sorry the photograph isn't any better, but none of us were prepared to step outside the bunker during the hot firings. I'm working on improving the photos taken during test runs.
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