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Key Test For Skylon Spaceplane Engine Technology

Soulskill posted about 2 years ago | from the skylons-were-created-by-man dept.

Space 92

Ogi_UnixNut writes "The Skylon spaceplane is an ambitious project to develop a single-stage-to-orbit craft that can take off and land like a normal airplane. Part of this project requires an engine that can work both as a rocket engine and a normal air-breathing engine (a hybrid approach, essentially). This would reduce the amount of oxidizer required to send stuff into space, and thus greatly reduce the cost. Now, some key experimental parts of the engine have been built, and are to be tested in public at the Farnborough Air Show in the UK in July. The BBC has video of the cooling system being tested."

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92 comments

Finally! (1)

Anonymous Coward | about 2 years ago | (#39821699)

Gerry and Sylvia Anderson's visions will become true! Will they be flown by life-size marionettes with bushy eyebrows?

First post! (0)

Anonymous Coward | about 2 years ago | (#39821701)

To the moon alice!

Key Test... (1)

Anonymous Coward | about 2 years ago | (#39821771)

They should use one of those push-button ignition systems then they could skip the key test.

Reaction Engines Ltd, SABRE Engine (5, Informative)

xirtam_work (560625) | about 2 years ago | (#39821907)

I've been following the guys down at Reaction Engines and their SABRE engine concept for a few years. These are the same guys who came up with the HOTOL concept at Rolls Royce in the 1980's. No word on what they'd use for thermal protection on re-entry but they're a clever bunch and if I came into a billion pounds I'd shove a fair chunk of it at these guys to build me a fleet of spaceships to rule the world ;-)

If they could get government funding we could lead the world in launch capabilities. However, what would probably happen is that we'd end up handing it over the the USA as our leaders are too short sighted and too cheap to fund anything truly visionary or world beating.

Re:Reaction Engines Ltd, SABRE Engine (1)

schitso (2541028) | about 2 years ago | (#39822357)

However, what would probably happen is that we'd end up handing it over the the USA as our leaders are too short sighted and too cheap to fund anything truly visionary or world beating.

And USA leaders aren't?

Re:Reaction Engines Ltd, SABRE Engine (1)

LeadSongDog (1120683) | about 2 years ago | (#39822535)

Nah, it's not that USA leaders are short sighted. Just that they work in a different industry: shearing the sheep on Wall St.

Re:Reaction Engines Ltd, SABRE Engine (1)

gstoddart (321705) | about 2 years ago | (#39824865)

Just that they work in a different industry: shearing the sheep on Wall St.

I believe that would be "shearing the sheep for Wall St.".

Re:Reaction Engines Ltd, SABRE Engine (1, Insightful)

CanHasDIY (1672858) | about 2 years ago | (#39822403)

However, what would probably happen is that we'd end up handing it over the the USA as our leaders are too short sighted and too cheap to fund anything truly visionary or world beating.

At which point our leaders would promptly turn it over to venture capitalists, who would immediately strip the company of any and all value and sell what's left off for their own personal profit.

Re:Reaction Engines Ltd, SABRE Engine (2)

ScentCone (795499) | about 2 years ago | (#39822949)

At which point our leaders would promptly turn it over to venture capitalists, who would immediately strip the company of any and all value and sell what's left off for their own personal profit.

It's true. That's why promising companies started out by rich people venturing their capital have all been picked clean, and are now gone. I was so hoping that Space-X, Virgin, Orbital Sciences, and others would survive past their first couple of years, but the Eeeeevil Rich People just sold 'em off to buy gold plated spinning hubcaps for the Bentleys they use to drive over the poor people they use as speedbumps on the private estates where they hunt endangered cheetahs for sport.

Or maybe your meme is pure BS.

Re:Reaction Engines Ltd, SABRE Engine (1)

CanHasDIY (1672858) | about 2 years ago | (#39823913)

I believe the colloquialism is, 'par for the course.'

Or maybe your meme is pure BS.

I don't think that means what you think it means.

Re:Reaction Engines Ltd, SABRE Engine (2)

ScentCone (795499) | about 2 years ago | (#39824441)

What is par for the course? The dismantling of companies like Virgin by evil US investors?

The meme I'm referring to is that nice popular one, where venture investors don't build anything, don't see the money they risk ever put to good use, and that nothing good comes from them pushing small or dying companies into a healthy, viable condition. That's pure BS, on the face of it. But that image, that meme, is trotted around as if it were true - all because people who don't have money to invest and who don't understand how it works resent and villify those who do. The GP played that card in this scenario specifically to keep that false meme alive, to hope that it will keep rattling around in discussions as if it were an accurate portrayal of reality. Why? People have different reasons for wanting to lie about other people. Hard to say. Regardless of his motivation, it's worth calling him on it, and pointing out that it's false.

Re:Reaction Engines Ltd, SABRE Engine (2)

bigtone78 (943249) | about 2 years ago | (#39822553)

Not to worry I'm sure we'd bring you Brits along for the ride, just like we'd bring along the Cunucks, Aussies, etc. Ruling the world isn't any fun without a posse.

Re:Reaction Engines Ltd, SABRE Engine (1)

jklmuk (1383691) | about 2 years ago | (#39823103)

No word on what they'd use for thermal protection on re-entry

I did read somewhere (i thought it was on their website but can't find it now) that they wouldn't need ceramic tiles like the shuttle due to the high drag to weight ratio during re-entry. I assumed that this just meant they would be trying to slow down as much as possible before the heat built up too much. On the website it currently suggests the will use excess hydrogen to cool to the surfaces and dump in over board. If i find the source of the high drag to weight ratio i will post it here later

Re:Reaction Engines Ltd, SABRE Engine (0)

Anonymous Coward | about 2 years ago | (#39823427)

No word on what they'd use for thermal protection on re-entry

IOn the website it currently suggests the will use excess hydrogen to cool to the surfaces and dump in over board.

They hydrogen will at that point become superheated and immediately react with any oxygen in the rather thin air up there... At least this is what I hope would happen, because it would look awesome on re-entry.

Re:Reaction Engines Ltd, SABRE Engine (3, Funny)

nitehawk214 (222219) | about 2 years ago | (#39825187)

No word on what they'd use for thermal protection on re-entry

IOn the website it currently suggests the will use excess hydrogen to cool to the surfaces and dump in over board.

They hydrogen will at that point become superheated and immediately react with any oxygen in the rather thin air up there... At least this is what I hope would happen, because it would look awesome on re-entry.

So, what is your heat shield made of?

Fire.

Why isn't Richard Branson funding this? (1)

llZENll (545605) | about 2 years ago | (#39823163)

Why isn't Richard Branson funding this?

Re:Why isn't Richard Branson funding this? (0)

Richard_at_work (517087) | about 2 years ago | (#39825127)

Richard Branson puts his name on things that already work - Brawn F1, Virgin Galactic etc.

This is far too early for him to risk his brand on.

Re:Why isn't Richard Branson funding this? (1)

damburger (981828) | about 2 years ago | (#39827097)

He might be. Reaction Engines doesn't name its investors (or the ones who have pledged much larger sums of money, contingent on technology milestones like this precooler test being completed successfully

I agree, he won't put his brand on something this unready, but he might put his money into it.

Re:Reaction Engines Ltd, SABRE Engine (0)

Anonymous Coward | about 2 years ago | (#39823901)

"No word on what they'd use for thermal protection on re-entry"

As this is a large, low weight craft when empty it should not require too much of a reentry thermal protection system. Unlike the shuttle which is a brick with wings this craft would theoretically be able to use a much shallower glide slope, spreading the heat dissipation over a much longer time period. The shuttle and other typical spacecraft have to pile drive through the atmosphere. I would not think that heating on assent would be much of an issue either, as the craft would be filled with supercooled liquids, providing a natural self cooling. Though some type of circulation system may be necessary.

Re:Reaction Engines Ltd, SABRE Engine (1)

turgid (580780) | about 2 years ago | (#39824751)

or world beating.

Don't the biggest bankers' bonuses in the world count?

I'll get my coat...

Let's hope this works! (1)

jacknifetoaswan (2618987) | about 2 years ago | (#39821951)

Personally, I think SLS is only a stop-gap measure because NASA is too deeply engrained with...ahem...an older generation that won't move outside of a certain comfort zone, so I'm really happy to see something like this. I'm also hoping that they've got enough financial backing to make it a reality. Who knows? Maybe Peter Diamandis, James Cameron, Larry Page, and Eric Schmidt can use this technology to launch the second phase of Planetary Resources' mining operations!

Re:Let's hope this works! (1)

Coren22 (1625475) | about 2 years ago | (#39846617)

I think SLS is only a stop-gap measure because NASA is too deeply engrained with...ahem...an older generation that won't move outside of a certain comfort zone

So we should fire certain congressmen from Utah? They are the ones demanding SLS, not NASA who think it is a dumb idea.

Re:Let's hope this works! (1)

jacknifetoaswan (2618987) | about 2 years ago | (#39855487)

Heh...if you ask me, we should fire everyone in Congress and the Senate, and take the government, especially the Legislative branch, back to the way it was intended, eliminating career politicians No more Nancy Pelosi, no more John Boehner. We keep our eye on the prize, and we let no one, and I mean no one, get in our way. /jay

Skylons?! (0)

Anonymous Coward | about 2 years ago | (#39822013)

They look like us now!!!

Where's the warp drive? (1)

cpu6502 (1960974) | about 2 years ago | (#39822101)

I think we've got the Earth-to-space part well practiced... it needs a few tweaks like this spaceplane, but we're pretty good.

Now we just need a warp drive so we can fly to nearby planets & stars within a reasonable time. Hopefully before an asteroid hits us and kills-off the mammals. (Followed by the Age of Reptiles.)

Re:Where's the warp drive? (1)

Jeng (926980) | about 2 years ago | (#39822721)

I think to develop a warp drive we may need a laboratory that is no where near a gravity well. Otherwise it would be like trying to develop fan technology while in a category five hurricane.

Re:Where's the warp drive? (1)

osu-neko (2604) | about 2 years ago | (#39822839)

I think to develop a warp drive we may need a laboratory that is no where near a gravity well. Otherwise it would be like trying to develop fan technology while in a category five hurricane.

Since most engineering is done indoors, assuming the building is strong enough, this isn't really that difficult.

I'm impressed (4, Informative)

Baloroth (2370816) | about 2 years ago | (#39822111)

At high speeds, the Sabre engines must cope with 1,000-degree gases entering their intakes... Reaction Engines' breakthrough is a module containing arrays of extremely fine piping that can extract the heat and plunge the intake gases to minus 140C in just 1/100th of a second.

That is... impressive, to say the very least. It sounds from Wikipedia [wikipedia.org] like they are even using the heat energy to power the turbo compressor (wondering if it was possible to convert the heat to useful energy was one of my first thoughts). I'm curious how efficient the jet is at low speeds, though. Typically, most jet engines work well at either low or high speeds, not both.

These kinds of engines are definitely needed to make space travel cheaper. Much cheaper, potentially, than solid-state rockets.

Re:I'm impressed (1)

osu-neko (2604) | about 2 years ago | (#39823007)

I would guess they don't worry about efficiency at low speeds, since they don't plan to fly at low speeds for very long. As long as it's not so inefficient that it can't accelerate past the problem into its "comfort zone", of course...

Re:I'm impressed (1)

ArsonSmith (13997) | about 2 years ago | (#39824775)

the could always tack on a boaster that gets them up to speed then detaches and falls back to earth.

Re:I'm impressed (1)

Amouth (879122) | about 2 years ago | (#39825867)

the could always tack on a boaster that gets them up to speed then detaches and falls back to earth.

completely negating their selling point of not using consumable/trash rocket boosters???

Re:I'm impressed (1)

bruce_the_loon (856617) | about 2 years ago | (#39836603)

Doesn't have to be consumable, could be a self-landing and resuable jet-engine drone. But it does defeat their goal of single stage to orbit.

Re:I'm impressed (0)

Anonymous Coward | about 2 years ago | (#39823615)

"solid-state rockets"??? Can we PLEASE stop abusing that term?

I thought that was not the hard part.... (2)

Lumpy (12016) | about 2 years ago | (#39822171)

I though the hard part of making a space plane was that reentry is still a burn in problem. There is no way to slowly glide into the atmosphere without having to be fire and melt proof. and those requirements make it hard to build a plane that can take off enter space, re-enter and land.

I'm betting we can make one now that can take off and make it to orbit, it's the coming home part that is the problem.

Re:I thought that was not the hard part.... (1)

CanHasDIY (1672858) | about 2 years ago | (#39822451)

Re:I thought that was not the hard part.... (0)

Anonymous Coward | about 2 years ago | (#39823175)

Not in a terribly consistent fahsion:

http://en.wikipedia.org/wiki/Space_Shuttle_Columbia_disaster

Re:I thought that was not the hard part.... (5, Insightful)

bughunter (10093) | about 2 years ago | (#39823459)

STS didn't need to have air intakes that hang out in the breeze... that simple difference makes the engineering problems a whole lot more difficult.

I've worked in commercial and government space for nearly 30 years, and one thing I've learned is that most, nay almost every, new launch system idea that sounds promising and brilliant in the concept stage runs aground on shoals of engineering problems with the result of either grossly inflated cost and schedule, or catastrophic failure. Layman frequently underestimate how much of the technology space has been explored and found to be dead ends due to either unsurmountable technical difficulties or simple economics. Incremental materials improvements are the most common route to innovation, but they can only do so much to open up new avenues.

In other words, it's not always possible to identify technical risks early on. The history of launch systems is full of "oh, shits." The cliche "the devil is in the details" may very well have been coined by a rocket scientist.

That said, I wish them luck and good fortune. If there's a way that we haven't yet achieved of bumping up the payload fraction of conventional launch systems, this is it. Hybrid jet/rocket engine approaches are also one place where I believe the introduction of improved materials can be disruptive. REL may have found a new route to orbit, and I hope it works for them.

Re:I thought that was not the hard part.... (-1)

Anonymous Coward | about 2 years ago | (#39823689)

"Layman frequently underestimate how much of the technology space has been explored and found to be dead ends"

It's the basis of the Space Nutter religion. Underestimating the engineering challenges and overestimating the value of a total vacuum.

Re:I thought that was not the hard part.... (1)

CanHasDIY (1672858) | about 2 years ago | (#39824101)

Interesting stuff; it's nice to hear a voice that actually knows what it's talking about every once in a while.

Layman frequently underestimate how much of the technology space has been explored and found to be dead ends due to either unsurmountable technical difficulties or simple economics.

True, but as I recall, around the turn of the century we were experiencing similar issues with deep sea exploration, albeit regarding the intense pressures of the deep as opposed to the vacuum of space. In less than 100 years, we went from the Beebe and Barton observing jellyfish at nearly 1400 ft depth in their Bathysphere, to a movie director exploring the Challenger Deep (35,000+ ft below sea level) in a custom submersible.

I have utmost faith in the ability of mankind to overcome such engineering challenges.

Re:I thought that was not the hard part.... (-1)

Anonymous Coward | about 2 years ago | (#39824677)

Nice religion you have there. Hindsight is 20/20. How many technologies didn't make it past the first few years? It's all well and nice to cherry-pick engineering that DID work, ignore all the reasons it worked, then apply some kind of techno-religion to believe that we'll be able to engineer anything. Ask yourself why you have such a belief system. Hint: you are alive at the peak of our oil-powered journey.

Re:I thought that was not the hard part.... (1)

turgid (580780) | about 2 years ago | (#39826095)

STS didn't need to have air intakes that hang out in the breeze... that simple difference makes the engineering problems a whole lot more difficult

Couldn't they just have a pop-up umbrella to cover the air intakes on the way down? It'll keep the British weather out of the engines too.

Re:I thought that was not the hard part.... (1)

damburger (981828) | about 2 years ago | (#39827225)

The air intakes are closed on re-entry (and whenever else they aren't being used.) There is a cone shaped 'plug' at the front of each engine that can be used to vary the intake for different speeds/altitudes, or close it altogether.

Re:I thought that was not the hard part.... (1)

bughunter (10093) | about 2 years ago | (#39828363)

There is a cone shaped 'plug' at the front of each engine

In other words, a large articulated structure that must be insulated but still function perfectly over an extremely large range of temperatures, pressures, and airspeeds (including some combinations of which we've never made such a thing work - see the recent news about the HTV-2 failure board report). It must operate reliably within strict tolerances both before and after being subjected to the dynamic stresses of launch and the thermal stresses of re-entry, and it must be economically re-usable, re-workable, cleanable and inspectable. I can see the "oh, shits" already.

Those are some serious engineering challenges. I'm not saying they're insurmountable, but they're certainly not to be treated casually either.

There's an engineering definition of the word "risk," which includes factors like probability of failure and effects of failure. Right now, both of those factors are large. Clever and diligent engineering can reduce the probability of failure, but there's not much one can do to mitigate the effects of failure of the main engine on a manned spacecraft, especially when it's required for both liftoff and landing. The best you can do is add redundancy and backup systems... ... and there goes your improvement in payload fraction that gives you competitive advantage, right out the window. At some point it may still be technically feasible, but the economic reason for doing it becomes moot. You will not find any customers because a Soyuz or Proton is cheaper and more reliable, and their insurance companies will insist on the reliable part, that's for sure.

It sucks that it's that way. I am another "space nutter" who wants to see the human race develop better options than being confined to one gravity well.* But the technical and economic realities are harsh, and produce many victims. Any entrepreneur who is not aware of these realities is making a grave error.

(And the pessimists and nihilists who believe that it's a wasted effort are welcome to stay here at home, but we won't let you hold us back. We'll send home goodies, we promise...)

Re:I thought that was not the hard part.... (0)

Anonymous Coward | about 2 years ago | (#39826901)

Yes; but the example of X-33, failed due to SURMOUNTABLE engineering issues - followed by budgetary issues, which were really subtly-masked political issues, (little pork-piggies didn't want their money-suck stolen away).

Had the X-33 project continued, the team has actually shown that the technology can be made to work. There may come a time in the future where the concept is explored again. It was a sound and workable concept - the main hurdle was the fuel tank. Solved 10 years too late.

Re:I thought that was not the hard part.... (1)

damburger (981828) | about 2 years ago | (#39827331)

Bear in mind, this project is a descendent of HOTOL, and thus has about 30 years of work behind it. Contrary to what some people seem to think, its not an few cool rendered movies and an engineering drawing.

Consider, for instance, that part of the motiavtion for beginning Skylon was because HOTOL had insurmountable engineering problems (crappy payload fraction, and a centre of mass whose motion would make the rocket dangerously unstable as its tanks emptied.) This is essentially a iteration of the air-breathing rocket plane design,

Hopefully, decades of paper simulation have spotted enough of the pitfalls that the hardware development won't turn up any major impediments to this being realised. ESA felt this was the case when they reviewed the projects, and if they thought this it was a non starter they would not have been shy about saying so.

Re:I thought that was not the hard part.... (1)

EvolutionInAction (2623513) | about 2 years ago | (#39829961)

If I remember my readings about this system correctly, the thermal load is expected to be much smaller than the shuttle ever experienced. Since the SABER engines use liquid hydrogen, the tanks are absolutely massive - and on reentry, they're mostly empty. So it's much larger and much lighter than the shuttle. Light, massive objects slow down much, much faster on reentry.

Re:I thought that was not the hard part.... (4, Funny)

ColdWetDog (752185) | about 2 years ago | (#39822465)

it's the coming home part that is the problem.

Capt. Malcolm Reynolds: Just get us on the ground!
Hoban 'Wash' Washburn: That part'll happen pretty definitely.

Re:I thought that was not the hard part.... (1)

cheddarlump (834186) | about 2 years ago | (#39823135)

I'm not an engineer, but if the craft (like the one envisioned) is much lighter than the space shuttle, is the re-entry heat still such a huge obstacle? Just spitballing here, but say a low-orbit vehicle just starts 100% throttle at a vector that is 100% opposite to the direction it's travelling: if it's light, it can decelerate rapidly in space, then just fall to earth and use the wings to glide in when it's in thicker atmosphere, right? Maybe I'm way off here, just curious if that would work.

Re:I thought that was not the hard part.... (1)

Cold hard reality (1536175) | about 2 years ago | (#39824079)

Deccelerating something from orbital velocity is just as difficult as accelerating it to orbital velocity in the first place, except you've expended all your fuel already. Much easier to use the atmosphere.

Re:I thought that was not the hard part.... (0)

Anonymous Coward | about 2 years ago | (#39827081)

Right; you've got two options:
Aerobraking (descend to an altitude where there is enough air, create enough lift to stay there, deal with the heat on the airframe) or exoatmospheric thrusting (carry extra propellant up there, and blast it out quickly, before you lose so much orbital velocity that you find yourself down in the atmosphere, looking for aerodynamic lift, dealing with heat-issues, etc.)

Drogues are always an interesting solution for aerobraking, but you seldom end up with enough useable velocity afterwards, and you're basically ballistic, hanging in the air much the same way brick don't, to paraphrase Douglas Adams.

Re:I thought that was not the hard part.... (4, Interesting)

jacknifetoaswan (2618987) | about 2 years ago | (#39823159)

The issue isn't necessarily protecting the bulk of the spacecraft, it's protecting those parts that have openings to the outside world. It's easy to design an ablative thermal protection system, or a ceramic-based one, but the tough part is sealing the air inlets, docking ports, etc, etc, etc, such that superheated gasses can't melt the turbine blades or fuel nozzles within the engines. Yeah, you can have moveable doors that would swing open to block the ports, but you've got to make sure they're SEALED, and you've got to make sure that they can open again, reliably, after re-entry, so that you're able to start up your engines on the air cycle and make a safe landing.

Re:I thought that was not the hard part.... (0)

Anonymous Coward | about 2 years ago | (#39825481)

but you've got to make sure they're SEALED,

Quite true.

and you've got to make sure that they can open again, reliably, after re-entry, so that you're able to start up your engines on the air cycle and make a safe landing.

Unless your landing is as a glider (like the shuttle).

Re:I thought that was not the hard part.... (2)

osu-neko (2604) | about 2 years ago | (#39823213)

There is no way to slowly glide into the atmosphere without having to be fire and melt proof.

Your sentence is twice as long as it ought to be. If you could manage to slowly glide into the atmosphere, you wouldn't need to be fire and melt proof. The problem is, you simply can't slowly glide into the atmosphere to begin with. Among other things, until you enter the atmosphere, you can't glide at all, and you're likely to be coming in at near orbital velocity, and even if you did slow down before hitting the atmosphere, gravity will helpfully~ accelerate you back up to ludicrous speed.

In any case, that's a long solved problem. A single-stage to orbit craft has to solve much more difficult problems than surviving reentry. There's a reason that even the space shuttle still used an external launch rocket. Being able to get to orbit without the vast majority of your launch weight being devoted to getting into orbit is a far, far more difficult problem.

Re:I thought that was not the hard part.... (0)

Anonymous Coward | about 2 years ago | (#39827719)

Right.

Spaceship one "solved" this problem by 1. not going THAT fast (or TO orbit) in the first place, and 2. a VERY innovative configuration-altering technology to feather the flight surfaces to provide aerobraking - which worked okay at 80,000 ft at mach 1. Probably not so much at 200,000 ft at mach 17.

X-33 solved this problem (in theory, only) by storing fuel in a much less bulky internal tank, at very high pressure, and using an innovative high-efficiency engine called an aerospike. Unfortunately, the concept of the fuel tank didn't work on the experimental demonstrator - though they later proved that that problem could be solved years after the project was cancelled. "Gliding" back in was more of a ballistic thing, and at lower altitudes and speeds, it became a "lifting body" vehicle. (Obviously, I'm a big fan of the X-33 concept)

Re:I thought that was not the hard part.... (0)

Anonymous Coward | about 2 years ago | (#39823537)

Think of something like this. Your "engine" is actually three tightly packed adjacent engines with one common afterburner/exhaust port. Turbine engine for taking off and getting up to speed, a ramjet for really hauling ass, and then a rocket to orbit. When you're not using the turbine or ramjet, you just put a cover over the intake nacelle. Since the rocket stage still uses onboard LOX, there's no point for an intake to be used or open at that stage. During re-entry, that cover stays on there to protect the engine from superheated plasma. I'd also think the fancy cooling on the engine they show here is mostly for the turbine operating between mach 2.5 and mach 5 where the compressor blades would start to seriously heat up. (Even on engines that don't go that fast, the air in the compressor stage heats up. Bypass air is even used for things like de-icing on some aircraft.) After mach 5, that compression heating would be useful for the ramjet so you'd bypass the turbine somehow. Even when the turbine part is bypassed, you'll still need to cool that sucker down as it spools down with the hot intake gases of the adjacent ramjet are being piped around it. May as well do something with the useful with the waste heat, so have it run a coolant/fuel pump. (Besides, if you tried to do that job with an electric motor under those conditions, you'd still need some way to cool it.)

I may not be an engineer, but at least that's something that would still make sense to me while they leave the details out.

Re:I thought that was not the hard part.... (1)

Savantissimo (893682) | about 2 years ago | (#39824029)

"I'd also think the fancy cooling on the engine they show here is mostly for the turbine operating between mach 2.5 and mach 5 where the compressor blades would start to seriously heat up."

The idea is actually to liquify and store the air as they fly to provide oxidizer for the rocket phase of flight. I think they're freaking nuts, but if they can do it then they are truly gods among engineers.

Re:I thought that was not the hard part.... (1)

Ihmhi (1206036) | about 2 years ago | (#39823587)

This is largely due to my ignorance of how space travel actually works, but why can't you descend gradually (or more gradually than we already do)? Wouldn't that reduce the overall maximum heat that the craft is exposed to?

Re:I thought that was not the hard part.... (1)

i (8254) | about 2 years ago | (#39824013)

That cost fuel. (You have to thrust against the gravitation - at least.) And then we are back to the main problem.

Re:I thought that was not the hard part.... (2)

FSWKU (551325) | about 2 years ago | (#39824675)

This is largely due to my ignorance of how space travel actually works, but why can't you descend gradually (or more gradually than we already do)? Wouldn't that reduce the overall maximum heat that the craft is exposed to?

It all comes down to available fuel. Spacecraft burn most of their fuel getting into orbit, meaning that they usually have just enough left to drop their orbit into the atmosphere, where aerodynamic drag takes over. To descend gradually, you would need to have just as much (if not more) fuel as required to get into orbit in the first place, since you would have to slow down a LOT more than currently feasible. And after that you would need even more fuel to control your descent rate, since even if you stopped on a dime, gravity is going to accelerate you back to the point where thermal protection is required.

For reference, Joe Kittinger jumped from a balloon somewhere in the 100,000 foot (18.9 mile) range. The air is pretty thin up there, but he was into the thicker part before his velocity got too high. A spacecraft coming from, say, 190 miles has 10x farther to accelerate before the air becomes thick enough to act upon it. 190 miles is a long way, and even discounting the 19 miles from the balloon, that's still another 172 miles. By the time you get to where drag is a factor, you would be travelling upwards of 5,200mph (just under mach 16 at sea level). And that's just your vertical velocity assuming you managed to somehow bleed off ALL of your orbital velocity. So you would still need either thermal protection, or a lot more fuel to keep your descent rate below suicidal velocities.

Re:I thought that was not the hard part.... (1)

ArsonSmith (13997) | about 2 years ago | (#39824881)

A huge parachute in the thin atmosphere to slow down your orbital decent before you hit the thicker air?

Re:I thought that was not the hard part.... (1)

FSWKU (551325) | about 2 years ago | (#39829187)

A huge parachute in the thin atmosphere to slow down your orbital decent before you hit the thicker air?

Sounds like the trick they used in 2010. While I don't have any figures to spout off as to why it wouldn't work, it does still strike me as being a bad idea. But unfortunately I'm at a loss as to why I think that. My guess is that at the velocities involved, the stresses on the craft would be rather obscene.

Re:I thought that was not the hard part.... (1)

tgd (2822) | about 2 years ago | (#39823849)

I though the hard part of making a space plane was that reentry is still a burn in problem. There is no way to slowly glide into the atmosphere without having to be fire and melt proof.

Strictly speaking, that's not true. The heat happens because the atmosphere is used to slow the spacecraft down from orbital speeds. Its massively cheaper than carrying your own fuel to slow down. If you could slow from 17000mph to 0mph at the same rate you accelerated up from the ground, you'd have dropped most of your speed before the atmosphere got that thick and you'd just fall at terminal velocity.

Not that it helps with this scenario, but if the asteroid miners eventually get hydrogen and oxygen available in-orbit, it theoretically opens up more possibilities for how one de-orbits.

Re:I thought that was not the hard part.... (0)

Anonymous Coward | about 2 years ago | (#39831267)

Actually, that is completely wrong.

If you slow your craft down enough, you can literally waft back into the atmosphere like a feather with no more thermal protection than ... well ... a feather!

The PROBLEM is that doing so requires exactly as much delta-vee (blast you, Newton!) as it did to get to outer space in the first place ... whiiiiich requires just as much fuel/re-mass ... which we can't afford to carry with us (using present technology).

The need for a TPS (thermal protection system - not the sheets from Office Space) derives from the requirement to make a relatively quick re-entry using little fuel/re-mass, in other words, WITHOUT having to slow down very much.

Now ... back to the sensible discussion.

Re:I thought that was not the hard part.... (0)

Anonymous Coward | about 2 years ago | (#39853315)

Reentry is hot because we don't break wth rockets.

We don't break with rockets because heat shields weigh less than the amount of rocket fuel needed to get the job done.

Will, Holly! Skylons! (0)

Anonymous Coward | about 2 years ago | (#39822207)

Grumpy must have bitten another Pylon. Time to go shuffle some crystals on the matrix table. Watch out for sleestak.

Cylons?! (0)

Anonymous Coward | about 2 years ago | (#39822223)

Will this Skylon Spaceplane be able to land inside of a Skylon Base Ship, packed with Skylon Raiders?

Cylons? (2)

cstacy (534252) | about 2 years ago | (#39822567)

All this has happened before, and it will happen again... http://en.wikipedia.org/wiki/Rockwell_X-30 [wikipedia.org]

This will end well... (0)

Anonymous Coward | about 2 years ago | (#39823023)

Combining Skynet and Cylons? Brilliant!

Re:Cylons? (0)

Anonymous Coward | about 2 years ago | (#39823693)

No, the propulsion system is quite different. Skylon is not a waverider.

Re:Cylons? (1)

ThreeKelvin (2024342) | about 2 years ago | (#39823939)

Well, sort of. It's all engine research. And I hope that we'll continue doing research, even if we get a working space plane. There's allways more to learn, new discoveries to be made, system to optimize.

What makes the Skylon concept different is the engine. Instead of a SCRAM-jet air breathing engines they're going for a traditional rocket engine that is fed pressurized air, while in the atmosphere. This is advantageus to the SCRAM-jet and rocket approach, since only a single engine is needed for getting into orbit.

I'm not sure I believe in the Skylon space plane, but the SABRE engine is definitly interesting. If nothing else, researching the concept will teach us something about what is possible with our current technology.

Re:Cylons? (0)

Anonymous Coward | about 2 years ago | (#39824597)

The problem with the X-30 is that they never effectively eliminated side fumbling in their dingle arms.

Did anyone else read "Cylon" as in... (1)

gestalt_n_pepper (991155) | about 2 years ago | (#39826281)

"Key Test For Cylon Spaceplane?" I mean, "What the frak?"

Re:Did anyone else read "Cylon" as in... (0)

Anonymous Coward | about 2 years ago | (#39828823)

"Key Test For Cylon Spaceplane?" I mean, "What the fark?"

FTFY

Reducing cost (0)

Anonymous Coward | about 2 years ago | (#39827563)

The summary is incorrect on that cost reduction. The fuel and oxidizer costs are insignificant. Elon Musk has been very clear on this and he would know. What would reduce the cost is either an orders of magnitude cheaper to build expendable, or reusable with minimum cost to prep for the next flight. The shuttles failed miserably with regard to the latter. Perhaps Skylon would lead to such a thing but, it's very much to be determined. They certainly are advancing the state of the art and for that two thumbs up!

Altea Aerospace (0)

Anonymous Coward | about 2 years ago | (#39828315)

Maybe they should contact Altea Aerospace, they have some experience in this field. :)

Print the Legend .. (1)

dgharmon (2564621) | about 2 years ago | (#39828433)

"Some great inventions began in humble surroundings - think Bill Gates and Steve Jobs toiling in their garages [bbc.co.uk] - so I'm not being critical".

Steve Jobs yes, Bill Gates no, he toiled in the exclusive Lakeside School [wikipedia.org]. And Apple and Microsoft owe more to Steve Wozniak and Paul Allen than the former two mentioned.

More information on Skylon, TPS etc (1)

thaig (415462) | about 2 years ago | (#39830139)

If you're interested, there is a good lecture by Alan Bond here which addresses almost everything:

http://www.youtube.com/watch?v=2G-HPHNrrLQ?t=4m30s [youtube.com]

There is a lot of very informed and interesting discussion on the nasa spaceflight forums thread:

http://forum.nasaspaceflight.com/index.php?topic=24621.600 [nasaspaceflight.com]

There are many other sources of information but at least one collection is here:

https://www.facebook.com/pages/Reaction-Engines-Skylon-Spaceplane-Fans/105055779583747 [facebook.com]

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