Skylon Spaceplane

BULLER

https://www.youtube.com/watch?v=LYos3J_8D5Q

Well worth a watch! Aiming to make spaceflight boring while propelling Europe into world leaders in spaceflight.
The technology is genius and will revolutionise everything.

They're currently finishing the crucial pre-cooler tests that will make this thing happen. Once thats done the ESA have said they found no major obsticles. Investors are already queueing up.
Was recently on BBC aswell http://www.bbc.co.uk/news/science-environment-17864782

Doc Ruby

No mention of costs or price per kilo. My guess is weak compared to the Star Tram, at 40 bucks a kilo its hard to go wrong.

Calibos

Doc Ruby wrote: »

No mention of costs or price per kilo. My guess is weak compared to the Star Tram, at 40 bucks a kilo its hard to go wrong.

In fairness, I think a 1000 mile long vacuum tube with a 12 mile high kink on the end can have a lot of things go wrong!!

Between the two my vote is on Skylon and I hope they can do it. If they can pull it off it will be a case of Rule Britannia, Britannia rules Outer Space.... and I'd say fair fcuks to them The boost it would give to science and science funding over there and getting the public interested in science/engineering careers again etc could have them back on top technology wise within a generation or two. ie. it could have seriously beneficial knock on effects on the British economy.

BULLER

Doc Ruby wrote: »

No mention of costs or price per kilo. My guess is weak compared to the Star Tram, at 40 bucks a kilo its hard to go wrong.

:eek: Are you serious? Star tram?! Thats sorta fantasy land. Space elevators are many decades away!!
Skylon is an almost a certainty with the engine at this stage of development. Investors from all over the world have been contacting them. Hopefully we manage to keep this technology in Europe though; would be incredible for us to be world leaders in spaceflight through genius!

I'd imagine the reason for no "cost per kilo" is because its incredibly hard to estimate. Look at the space shuttle, for example. The key difference is that this throws away no elements on the way to orbit. Everything is returned to Earth. Turn-a-round time is less than a week. So VERY cheap cost per kilo I'd guess, which is the whole point!

Doc Ruby

This nerdfight is on! Yeah I'm into the Star Tram.

I've been reading through their forum and they have a lot more information than is on the main site.

Calibos wrote: »

In fairness, I think a 1000 mile long vacuum tube with a 12 mile high kink on the end can have a lot of things go wrong!!

About as much as can go wrong with a major airline, so an accident once every 2800 years. Its safer to take the train than strap a bombload of volatile chemicals to your bottom and set fire to it.

Calibos wrote: »

Between the two my vote is on Skylon and I hope they can do it. If they can pull it off it will be a case of Rule Britannia, Britannia rules Outer Space.... and I'd say fair fcuks to them The boost it would give to science and science funding over there and getting the public interested in science/engineering careers again etc could have them back on top technology wise within a generation or two. ie. it could have seriously beneficial knock on effects on the British economy.

Well lets not wrap things in flags here instead lets talk about real benefits and drawbacks.

BULLER wrote: »

:eek: Are you serious? Star tram?! Thats sorta fantasy land. Space elevators are many decades away!!

Its not a space elevator its a space train. And it needs no new technology.

BULLER wrote: »

Skylon is an almost a certainty with the engine at this stage of development. Investors from all over the world have been contacting them. Hopefully we manage to keep this technology in Europe though; would be incredible for us to be world leaders in spaceflight through genius!

You see here's the problem with skylons and rocket systems in general. They are a submarine trying to lift the ocean along with them. Thats literally what they are trying to do.

Star Tram is instead sailing in the ocean, not bringing along its fuel source with it, and so will always have the advantage in terms of cost and cargo capacity.

Looking at the Skylon's more informative wikipedia page

In paper studies, the costs per kilogram of payload are hoped to be lowered from the current £15,000/kg to £650/kg (as of 2011)

This information alone puts Skylon in a distant second stringer place, since its costs to orbit are twenty times higher than Star Tram. Twenty times!

Further their payload is less than half that of the Star Tram, which further reduces the useability of the program. And to be honest I don't think they really get what happens when you try to go mach 25 in an atmosphere - the Americans went mach 20 recently and lasted almost three minutes.

I support every effort to get into space, and applause to those doing their part, but the stram knocks them all into a cocked hat.

jumpjack

I didn't get when the tests will be performed.

BULLER

jumpjack wrote: »

I didn't get when the tests will be performed.

Tests on the pre-cooler are underway, as that BBC news article link I posted shows. The first test config was a compelete success. Stage 3 after this testing will involve building the whole engine, this should be done by 2013. Really exciting!

Star trains and space elevators are fantastic idea's but if we're being realistic, I know where my money would be.

You shouldn't be comparing Skylon to "sky trams" anyway, the benefits of economics over current rockets are in order of magnitude greater. It has the ability to transform space and make spaceflight routine. I dont think airliners can be called unsafe...

the costs per kilogram of payload are hoped to be lowered from the current £15,000/kg to £650/kg (as of 2011)

And this isn't enough, no? It's revolutionary!!

And to be honest I don't think they really get what happens when you try to go mach 25 in an atmosphere - the Americans went mach 20 recently and lasted almost three minutes.

Get your facts straight before you post. There's a full ESA report on skylon done by loads of engineers on how theres no obsticles bar the precooler; want a copy? The max skylon will be going in the atmosphere is roughly mach 5, its into space from there.

The US Air Force were using an entirely different technology. Using scramjets which have a tendency to melt and only work in a range of mach 3.5 to maybe 10... certainly not mach 20! They dont have great potential because they've to be accelerated up to high speeds before working.

Doc Ruby

BULLER wrote: »

Star trains and space elevators are fantastic idea's but if we're being realistic, I know where my money would be.

Star Tram and the Space Elevator are two completely different things. The SE needs some nonexistium to happen, although graphene is showing promise, the ST needs no new technology.

BULLER wrote: »

And this isn't enough, no? It's revolutionary!!

No, its not enough, when the same job could be done for a twentieth the cost. And cost is what its all about. If-and its a big if-they can get their show on the road I for one will be stading up and cheering with everyone else. All I'm saying is that it is made redundant by the Star Tram, along with the fine efforts being made by Burt Rutan, Elon Musk and the rest of them.

We're at a technological stage similar to where we were at with the first airplanes, all manner of wacky constructions and far out ideas, some ending in spectacular crashes, some never getting off the ground before the final shape of successful airplanes was settled on.

Star Tram is that final shape. The next stage after that would be the space elevator, if that's possible, its the only way to make earth to orbit any cheaper.

BULLER wrote: »

Get your facts straight before you post. There's a full ESA report on skylon done by loads of engineers on how theres no obsticles bar the precooler; want a copy? The max skylon will be going in the atmosphere is roughly mach 5, its into space from there.

In order to go mach 5 using air breathing engines it needs to be actually in pretty dense atmosphere. It can't zip from that into space instantly.

And besides, I'm sure the DARPA engineers were fairly sure their effort wasn't going to blow up in transit.

BULLER wrote: »

The US Air Force were using an entirely different technology. Using scramjets which have a tendency to melt and only work in a range of mach 3.5 to maybe 10... certainly not mach 20! They dont have great potential because they've to be accelerated up to high speeds before working.

https://www.youtube.com/watch?v=O75PQHF8Y1s

BULLER

Sorry I was refering to the Boeing X-51, got mixed up with DARPA's effort. That kinda helps my point though. Skylon wont be going mach 20 in the atmosphere. The max it'll go in any sort of dense atmosphere would be mach 5. At that speed, it points up and switches to rocket mode. There's no chance of melting seen at higher mach speeds...

Sky Tram: Estimates suggest that building a passenger-capable Startram would require at least 20 years and a construction budget (ignoring inflation and overoptimism) of about $60 billion. They currently have noone willing to fund that.
Its a pipe dream.

Skylon will be built 7 years from now with a fraction of that development cost. (providing everything continues to go as planned)

Doc Ruby

BULLER wrote: »

Sorry I was refering to the Boeing X-51, got mixed up with DARPA's effort. That kinda helps my point though. Skylon wont be going mach 20 in the atmosphere. The max it'll go in any sort of dense atmosphere would be mach 5. At that speed, it points up and switches to rocket mode. There's no chance of melting seen at higher mach speeds...

The point is that there's a lot that can go wrong, especially dealing with those extreme velocities and energies. DARPA and the USAF have vastly more experience and a much higher budget than the Skylon guys, if they can't get it right you can assume the learning curve is almost vertical.

BULLER wrote: »

Sky Tram: Estimates suggest that building a passenger-capable Startram would require at least 20 years and a construction budget (ignoring inflation and overoptimism) of about $60 billion.

Its a pipe dream.

It cost three times as much to build the space shuttle. Twice as much to build the ISS. And of course you are referring to generation 2. Generation 1 would cost $20 billion and could be done by 2020, and would change the game completely. I appreciate you're invested in Skylon, but its already surplus to requirements.

If I compared the numbers and genuinely thought Skylon was a better bet, I'd be right behind you, but it simply is not.

BULLER wrote: »

Skylon will be built 7 years from now with a fraction of that development cost. (providing everything continues to go as planned)

A pretty big fraction! A pretty big provision!

Calibos

Natural disaster cuts power to the superconducting cables. 12 mile high section of tube falls to earth.. Billions and years needed to rebuild????????

I see the $40/Kg figure seems to be tied to 300,000 tonnes to orbit, ie economies of scale. Is there a market for 300x 1000 tonne craft/satellites, or 3000x 100 tonne, or 30000 x 10 tonne sats/craft etc?

As cool as the idea is I see the money going to the more conventional looking tech in the Skylon, even if technically speaking, the intercooler problem was harder to solve than levitating a vacuum tube 12 miles high.

Skylon is also more likely to get the investment because of the spinoff of commercial airliner travel to the other side of the planet in 4 hours.

I think if anything, Skylon needs to happen before Skytram has a hope of getting the investment. When space becomes boring, when getting to orbit becomes so routine, when people realise the amazing things you could do if you could put 300,000 tonnes up there which aren't possible with the likes of Skylon. Well then investors will say to themselves that the 20 billion investment in Skylon paid off for them and be more trusting that the 60 billion for Sky Tram could pay off even more.

Doc Ruby

Calibos wrote: »

Natural disaster cuts power to the superconducting cables. 12 mile high section of tube falls to earth.. Billions and years needed to rebuild????????

That's generation 2. There are proposals to offset the issue in that gen, and gen1 has no such difficulties. So no, I don't see that as being a problem.

Calibos wrote: »

I see the $40/Kg figure seems to be tied to 300,000 tonnes to orbit, ie economies of scale. Is there a market for 300x 1000 tonne craft/satellites, or 3000x 100 tonne, or 30000 x 10 tonne sats/craft etc?

Also not a problem.

Calibos wrote: »

As cool as the idea is I see the money going to the more conventional looking tech in the Skylon, even if technically speaking, the intercooler problem was harder to solve than levitating a vacuum tube 12 miles high.

Skylon is also more likely to get the investment because of the spinoff of commercial airliner travel to the other side of the planet in 4 hours.

I think if anything, Skylon needs to happen before Skytram has a hope of getting the investment. When space becomes boring, when getting to orbit becomes so routine, when people realise the amazing things you could do if you could put 300,000 tonnes up there which aren't possible with the likes of Skylon. Well then investors will say to themselves that the 20 billion investment in Skylon paid off for them and be more trusting that the 60 billion for Sky Tram could pay off even more.

Skylon was a dinosaur before it ever got built, if it ever gets built. A dead end, a cul de sac.

I have nothing but respect for the people behind it, however make no mistake, Star Tram is a disruptive technology, lots of people are going to be put out by it, but just look up. Look up! Its all right there for the taking, a universe of possibilities. Skylon doesn't open that door. The open source non profit lunatics at Star Tram do.

mike65

Some of us are old enough to remember HOTOL when that was first proposed in the late 70s

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

BULLER

mike65 wrote: »

Some of us are old enough to remember HOTOL when that was first proposed in the late 70s

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

Yep it's all in the video interview. Think development of that idea actually started in 1986. They've come a long way since then but thhe original concept is the same.

Doc Ruby

BULLER wrote: »

Yep it's all in the video interview. Think development of that idea actually started in 1986. They've come a long way since then but thhe original concept is the same.

Old and busted.

nokia69

sky tram will never get built

skylon is being worked on now so there is a chance they can get it to work

also keep an eye on space X if they can make their falcon 9 reuseable, then they will send people to mars

for me the best hope is spaceX, some time next year they will fly the falcon heavy, which will have twice the payload of the shuttle for a fraction of the cost thats when thing will start to get interesting

Doc Ruby

nokia69 wrote: »

sky tram will never get built

I wonder did the Wright brothers have similar commentary passed at them.

Yes, I'm fairly sure they did.

And yet here we are.

nokia69

Doc Ruby wrote: »

I wonder did the Wright brothers have similar commentary passed at them.

Yes, I'm fairly sure they did.

And yet here we are.

well who is going to pay for sky tram ?

without money its just a nice idea

the wright brothers did not need billions from governments to get off the ground

give us a call when they start building sky tram

Doc Ruby

nokia69 wrote: »

the wright brothers did not need billions from governments to get off the ground

Probably because they could do their thing with a stretch of canvas, a few bits of plywood, and a lawnmower engine. And for the record, ST isn't looking for the government dollar, unlike Skylon, who have their hands deep in the taxpayers' pockets. You want to talk about profit, how much money will the silk road of space, the Hong Kong of high orbit, the gate to the stars make?

Quite a lot, would be my estimation.

nokia69 wrote: »

tgive us a call when they start building sky tram

Its Star Tram. Before giving a cutting critique of the project, a critique which clearly surpasses the skill and ability of the engineers at Sandia National Laboratories, try to master the name first eh.

nokia69

it won't make any money if its never built

the only way it gets built is if a government puts up the money, and I can't see that happening

I'm not against the idea, in fact I would love to see it built ASAP with private or government money, but I don't think it has a hope

I'm just realistic

the best hope right now is space X

Doc Ruby

nokia69 wrote: »

it won't make any money if its never built

the only way it gets built is if a government puts up the money, and I can't see that happening

I'm not against the idea, in fact I would love to see it built ASAP with private or government money, but I don't think it has a hope

I'm just realistic

the best hope right now is space X

If you say so.

BULLER

Doc Ruby wrote: »

Old and busted.

Trams are a pretty old idea aswell...

You've pretty much hi-jacked this thread and turned it into a Skylon vs Star Tram debate. I just wanted to give people an update on the Skylons Sabre engine progress.
Can you keep that star tram stuff to its own thread?!

For the record I agree with nokia69; I think the best chances of us ever going to Mars are going to come from either SpaceX's reusable Falcon 9 or this Skylon.

Doc Ruby

BULLER wrote: »

For the record I agree with nokia69; I think the best chances of us ever going to Mars are going to come from either SpaceX's reusable Falcon 9 or this Skylon.

In the face of overwhelming evidence to the contrary?

nokia69

Doc Ruby wrote: »

If you say so.

I like their plans, but do they have any launchers of their own ?

they will have their hardware launched by some one else

the whole point is cost of putting payload in orbit, nothing else matters

the best way to do this is with a reuseable launcher, who ever does this first will own the launch market, for a while, until their tech gets copied

even if space X fail to make the falcon 9 reuseable they will still have the lowest launch costs

nokia69

Doc Ruby wrote: »

In the face of overwhelming evidence to the contrary?

space X have launched their dragon capule into orbit and returned it

large countries have tried less in space and failed

if they can send a 3rd stage into orbit and return it, then IMO its possible for them to do the same with the 1st and 2nd stage

the problem is can they do it without adding too much weight to the rocket, very hard, but not impossible

baalthor

Doc Ruby wrote: »

nokia69 wrote: »

the wright brothers did not need billions from governments to get off the ground

Probably because they could do their thing with a stretch of canvas, a few bits of plywood, and a lawnmower engine. And for the record, ST isn't looking for the government dollar, unlike Skylon, who have their hands deep in the taxpayers' pockets. You want to talk about profit, how much money will the silk road of space, the Hong Kong of high orbit, the gate to the stars make?

Quite a lot, would be my estimation.

nokia69 wrote: »

tgive us a call when they start building sky tram

Its Star Tram. Before giving a cutting critique of the project, a critique which clearly surpasses the skill and ability of the engineers at Sandia National Laboratories, try to master the name first eh.

Doc, you might convince more people with a catchy song and dance routine for the sky rail ...

Doc Ruby

nokia69 wrote: »

the whole point is cost of putting payload in orbit, nothing else matters

Exactly. And it doesn't get cheaper than Star Tram. Planetary Resources have no business plan. They are backed by billionaires and geniuses, but they can't make a profit without the stram. Its just not possible.

nokia69 wrote: »

space X have launched their dragon capule into orbit and returned it

large countries have tried less in space and failed

if they can send a 3rd stage into orbit and return it, then IMO its possible for them to do the same with the 1st and 2nd stage

the problem is can they do it without adding too much weight to the rocket, very hard, but not impossible

Have you mentally edited out every comment I've made so far? It is OVER. The quest for space, its done. We have the tools, we have the tech, we have the plans. Lets make it happen.

Doc Ruby

baalthor wrote: »

Doc, you might convince more people with a catchy song and dance routine for the sky rail ...

I fear my Moulin Rouge garters in space set might be a bit too risque for the general public just yet.

BULLER

Doc Ruby wrote: »

Exactly. And it doesn't get cheaper than Star Tram. Planetary Resources have no business plan. They are backed by billionaires and geniuses, but they can't make a profit without the stram. Its just not possible.


Have you mentally edited out every comment I've made so far? It is OVER. The quest for space, its done. We have the tools, we have the tech, we have the plans. Lets make it happen.

So they have the funding with these billionaires?

When does construction start?

Why are you still talking about this in a thread about Skylon?

Doc Ruby

BULLER wrote: »

So they have the funding with these billionaires?

When does construction start?

Why are you still talking about this in a thread about Skylon?

Why are you still talking about Skylon? Its a waste of time. STG1, thats where its at.

nokia69

Doc Ruby wrote: »

Exactly. And it doesn't get cheaper than Star Tram. Planetary Resources have no business plan. They are backed by billionaires and geniuses, but they can't make a profit without the stram. Its just not possible.


Have you mentally edited out every comment I've made so far? It is OVER. The quest for space, its done. We have the tools, we have the tech, we have the plans. Lets make it happen.

but we don't have the tools or the tech, star tram won't get built

planetary resources do have a business plan, you may not agree with it, but they do have a plan, and unlike star tram they are backed by people with money

the first step for planetry resources is to look for target asteroids to mine, this will take them years to complete, they can do this while they wait for launch costs to fall

I think it you who are mentally editing out comments you don't like

Doc Ruby

nokia69 wrote: »

but we don't have the tools or the tech, star tram won't get built

Again, you just aren't bothering to read the facts. Yes we do have both the tools and the tech. Its easy. It will just take a little time and money.

nokia69 wrote: »

planetary resources do have a business plan

Really, you might want to tell them that.

"I asked Lewicki specifically about how this will make money. Some asteroids may be rich in precious metals — some may hold tens or even hundreds of billions of dollars in platinum-group metals — but it will cost billions and take many years, most likely, to mine them before any samples can be returned. Why not just do it here on Earth? In other words, what’s the incentive for profit for the investors? This is probably the idea over which most people are skeptical, including several people I know active in the asteroid science community.

I have to admit, Lewicki’s answer surprised me. “The investors aren’t making decisions based on a business plan or a return on investment,” he told me. “They’re basing their decisions on our vision.”

Now unless you have something constructive to add to the discussion, I'll take it that you've counted yourself out.

Rubecula

Sorry Doc Ruby but I must disagree with you on this.

The Space Tram is a serious "cock-a-snoot" at reality plan. We can not build it, and I am pretty certain if we could we wouldn't. It is an idea but a sci-fi idea that will not see the light of day in our lifetimes. I would put it happening on a scale of 5 if 6 was a Dyson sphere.

Skylon may not happen either, but at least it has a real founding in reality.

Mind you I once said HOTOL would happen too. So I admit I can be wrong at times.

Doc Ruby

Rubecula wrote: »

Sorry Doc Ruby but I must disagree with you on this.

The Space Tram is a serious "cock-a-snoot" at reality plan. We can not build it, and I am pretty certain if we could we wouldn't. It is an idea but a sci-fi idea that will not see the light of day in our lifetimes. I would put it happening on a scale of 5 if 6 was a Dyson sphere.

Skylon may not happen either, but at least it has a real founding in reality.

Mind you I once said HOTOL would happen too. So I admit I can be wrong at times.

And not a single word grounded in reality.

Do you know what a murder board is?

Its what happens when you send the details of your idea to some seriously intelligent and well educated people who actually are rocket scientists who have built actual rockets, like those people in Sandia National Laboratories. You know, the ones run by Lockheed Martin who operate the skunk works.

These intelligent and well educated people run your idea through every imaginable test they can come up with, doing their best to "murder" it. Hence the name "murder board". If they can't murder it, your idea is good.

Guess what result they came up with for the Star Tram?

Now I could go ahead and make definitive internet statements like "the sky is purple with shades of puce", but I'd be wrong. The only difference between that and what you're saying is it doesn't take a team of certified geniuses to tell me that the sky is in fact blue. And when such a team tell me something, I don't make definitive internet statements in contradiction.

I leave it to yourself to figure out why.

BULLER

http://www.popsci.com/technology/article/2012-05/build-real-starship-enterprise-make-it-so-ambitious-engineer-says

I think we should build this. Like Doc Rubys super star train, its completely technically feesable!

shizz

BULLER wrote: »

http://www.popsci.com/technology/article/2012-05/build-real-starship-enterprise-make-it-so-ambitious-engineer-says

I think we should build this. Like Doc Rubys super star train, its completely technically feesable!

That man is incredibly deluded. So many technologies need to be created and proven before even considering many of the "ideas" he has for that.

Not to mention ridiculously unneeded. 3 days to the Moon? I'm guessing it's rate of acceleration is the reason but that's a terrible time for such an "advanced" proposal.

BULLER

shizz wrote: »

That man is incredibly deluded. So many technologies need to be created and proven before even considering many of the "ideas" he has for that.

Not to mention ridiculously unneeded. 3 days to the Moon? I'm guessing it's rate of acceleration is the reason but that's a terrible time for such an "advanced" proposal.

I know its hilarious!

shizz

He wants to construct THAT in space!? Ha!

Capt'n Midnight

Star Tram for power stations ?

solar panels are down to 80c / watt so they are very cheap at ground level.

Russians are big in to mirrors, a much cheaper technology to light up solar panels at night. Just put the panels in a cloudless desert.



Using superguns you can get mass into space with low tech lot capital cost. stuff like food, water, propellant , raw materials , stuff that can be suspended in water.

Slingatron - is another low cost launch system, it uses electricity instead of propellant.

Rubecula

Out of curiousity, I would like to ask something.

You have a small(ish) mountain, 20 miles of track along the ground before it goes up the side of the mountain.

You have electic motors to power up a vehicle at 1 g constant along the track.

Would the vehicle be travelling fast enough to go into orbit at the top of the mountain?

Capt'n Midnight

you need to be going ~ 7,8000m/s

at 9.81m/s that will take 795 seconds

d = ut + 0.5 a t^2 d is distance, u= initial velocity (0) , t is time

d = 0.5 * 9.81* 795^2

d = 3,100 Km


at 100g it's 7.95 seconds and 981m/s so 31Km

100g is OK for some fish (maybe), perhaps if you used that pink liquid from The Abyss


Rail makes a totally reusable first stage.

Rubecula

Thanks for that. 100g seems a tad OTT doesn't it?

Pilots sometime pul as much as 12g, but not often. I think for realism the max would have to be about 5g.

So to attain escape velocity by the time you reached the top of a mountain. Say one about 5,000m high, you would need a track leading up to it in excess of any feasible length?

Which is a pity really, as I was looking at the mountains this morning and just thinking how it would be a good idea.

Bah, me and maths never got along. :pac:

_Tombstone_

US Military Set to Unveil Concepts Based on Skylon Space Plane Tech

A bits away yet...

The Air Force Research Laboratory (AFRL) will reveal two-stage-to-orbit SABRE-based concepts either this September, at the American Institute of Aeronautics and Astronautics' (AIAA) SPACE 2016 conference in Long Beach, California, or in March 2017, at the 21st AIAA International Space Planes and Hypersonic Systems and Technologies Conference in China, said AFRL Aerospace Systems Directorate Aerospace Engineer Barry Hellman.

AFRL officials told Space.com that it views a single-stage-to-orbit Skylon space plane as "technically very risky as a first application [of SABRE]," and this is why the lab is developing two-stage-to-orbit concepts.

SABRE burns hydrogen and oxygen. It acts like a jet engine in Earth's thick lower atmosphere, taking in oxygen to combust with onboard liquid hydrogen. When SABRE reaches an altitude of 16 miles (26 kilometers) and five times the speed of sound (Mach 5), however, it switches over to Skylon's onboard liquid-oxygen tank to reach orbit. (Hypersonic flight is generally defined as anything that reaches at least Mach 5.)

_Tombstone_

Wayhey, abit of competition to hurry Skylon on - China targets 2030 for operational hybrid hypersonic spaceplane

The China Aerospace Science and Technology Corporation is beginning advanced research on hybrid combined cycle engines that can takeoff from an airport's landing strip and fly straight into orbit. The hybrid space plane's combined cycle engines would use turbofan or turbojet engines to takeoff horizontally from a landing strip. Once airborne, the engine then shifts to ramjet propulsion and, as speed increases, adjusts into a scramjet engine with supersonic airflow. At the scramjet stage, the hybrid spaceplane would enter hypersonic flight in 'near space', the part of the atmosphere between 20km to 100km above sea level. Finally, the hybrid spaceplane would use its rocket motors to push out of near space and into orbit.

Zhang Yong, a CASTC engineer, claimed that China will master the spaceplane's technologies in the next three to five years, and a full-scale spaceplane would then enter service by 2030.

Capt'n Midnight

India have flight tested a scramjet recently

http://www.isro.gov.in/update/28-aug-2016/successful-flight-testing-of-isros-scramjet-engine-technology-demonstrator