Posted on by VirtualAstro

UK and European Space Agencies Give a Go For Skylon Spaceplane

After 30 years of development, the UK and European space agencies have given a go for the Skylon Spaceplane.

The Skylon, which is being developed at the Oxfordshire-based Reaction Engines in the UK, is an unpiloted and reusable spacecraft that can launch into Low Earth Orbit after taking off from a conventional runway.

Looking like something out of Star Wars, Skylon is a self contained, single stage, all in one reusable space vehicle. There are no expensive booster rockets, external fuel tanks or huge launch facilities needed.

The vehicle’s hybrid SABRE engines use liquid hydrogen combined with oxygen from the atmosphere at altitudes up to 26km and speeds of up to Mach 5, before switching over to on-board fuel for the final rocket powered stage of ascent into low Earth orbit.

The Skylon is intended to cut the costs involved with commercial activity in space, delivering payloads of up to 15 tons including satellites, equipment and even people into orbit at costs much lower than those that use expensive conventional rockets.

Once the spacecraft has completed its mission, it will re-enter Earth’s atmosphere and return to base, landing like an airplane on the same runway, making it a totally re-usable spaceplane, with a fast mission turn around.

Skylon has received approval from a European Space Authority panel tasked with evaluating the design. “No impediments or critical items have been identified for either the Skylon vehicle or the SABRE engine that are a block to further development,” the panel’s report concludes.

“The consensus for the way forward is to proceed with the innovative development of the engine which in turn will enable the overall vehicle development.”

The UK Space Agency says that Reaction Engines will carry out an important demonstration of the SABRE engine’s key pre-cooler technology later this summer.

Source: Reaction Engines Ltd.

55 Replies to “UK and European Space Agencies Give a Go For Skylon Spaceplane”

      1. Howcome droids are getting all the cool rides these days? Have we finally made ourselves obsolete? Where’s Buck Rogers? The unemployment line I guess.

  3. this is one of those ones, Britain will talk a good fight but nothing will happen as they have no money to fund the kind of reserch needed. they have done this so many time before. good concept though.

    1. I’m also extremely skeptical (and I’m also British). All we have here is a paper design. Everyone is very good at paper designs. Now the difficult part comes : funding it. The government has already said they won’t fund it and they expect private enterprise to do so. Right.

      And it’s not easy to actually engineer this technology. After all NASA has been working on similar concepts for years now.

      1. NASA/DoD worked on scramjets that airbreathed to the highest speeds possible in the atmosphere (and the materials that could take it). Skylon engines don’t function as ramjets, supersonic combustion or otherwise. As it turns out, airbreathing above Mach 4 or so to get to orbit (as opposed to sustained hypersonic flight), is more technical trouble than it’s worth. Alan Bond has been clear about this before, and his is not a path NASA has ever followed.

      2. I believe they already have some private funding lined up and promises that if they pass this engine cooling technology, more will become available. If they pass a full-scale engine test, still more will become available etc. etc. until you have a fully functioning spaceplane.

        In any case, they never intended to have the government fund it. It was always meant to be a private enterprise.

    2. If the program’s data really adds up, perhaps this would be a good time for NASA or the USAF to ask if they can buy in? If Frank Whittle had been offered such a deal in the 1930’s when he was struggling along as “Power Jets Limited”, and being so broke that he couldn’t afford to renew his own patents, research might have proceeded faster. The result might have been a practical jet engine available to the Allies well before the spring of 1944.

  4. I am very excited about space flight becoming less expensive.

    On a more amusing note, it looks like a giant penis.

  5. I am very excited about space flight becoming less expensive.

    On a more amusing note, it looks like a giant penis.

    2. If your penis looks like that, I would recommend you have a long serious talk with your doctor.

  6. It truly looks like Fireball XL-5. Seriously, it basically consists of two hydrogen tanks with a payload bay in the middle and without staging, I wonder how it would reach orbit. Cool plane though, Batman would love it!

    1. The staging of sorts consists of switching over between different oxidation supply modes. It has one LH2 tank and one LO2 tank, the later massing twice as much.

      “The SABRE engines have a dual mode capability. In rocket mode the engine operates as a closed cycle Lox/Lh2 high specific impulse rocket engine. In air-breathing mode (from take-off to Mach 5) the liquid oxygen flow is replaced by atmospheric air, increasing the installed specific impulse 3-6 fold. The airflow is drawn into the engine via a 2 shock axisymmetric intake and is cooled to cryogenic temperatures prior to compression. The hydrogen fuel acts as a heatsink for the closed cycle helium loop before entering the combustion chamber.” [Reaction Engines]

      Essentially the engine mode is a LH2/LO2 rocket, it uses different modes (breathing vs tank supply) for supplying the LO2 oxidizer to save weight while saving on complexity.

  7. “The vehicle’s hybrid SABRE engines use liquid hydrogen combined with oxygen from the atmosphere at altitudes up to 26km and speeds of up to Mach 5, before switching over to on-board fuel for the final rocket powered stage of ascent into low Earth orbit”.

    So surely it’s combusting hydrogen on board from the start (no way is there enough hydrogen in the atmosphere for this) – before it ‘switches over to’ also using onboard oxygen as the atmosphere gets thinner with altitude.

    So, is it burning hydrogen to enable horizontal take off? That would be quite a show.

  8. Finally, the Brits and the Europeans make a bold move! This is great news. Now, will the governments actually get behind it, fund it fully and operate it efficiently?

    1. Nope, and I believe they have said as much. They help with the qualification; apparently getting the pre-cooler qual and demo through will release commercial development money.

      Also, as I said elsewhere on this, the Skylon is projected to lower the cost per kilogram to orbit with a factor 2 vs the current Falcon Heavy estimate, because the later promises to cut the cost some factor 5 against todays lifters. Assuming the FH is correct as Musk seems to know what he is doing (mostly piecing together already developed Falcon-9s), but the Skylon runs into the usual 50 – 100 % added cost between project estimates and actual turn out, there is nothing much for the Skylon to compete with.

      Skylon turnaround advantage may be mooted against a Falcon Heavy fleet turnaround. Remains the Wow factor with SSTO crafts, natch.

      I would deem this is an unlikely commercial contender, but it may make it and I hope it will. Because, Wow!

    2. Nope, and I believe they have said as much. They help with the qualification; apparently getting the pre-cooler qual and demo through will release commercial development money.

      Also, as I said elsewhere on this, the Skylon is projected to lower the cost per kilogram to orbit with a factor 2 vs the current Falcon Heavy estimate, because the later promises to cut the cost some factor 5 against todays lifters. Assuming the FH is correct as Musk seems to know what he is doing (mostly piecing together already developed Falcon-9s), but the Skylon runs into the usual 50 – 100 % added cost between project estimates and actual turn out, there is nothing much for the Skylon to compete with.

      Skylon turnaround advantage may be mooted against a Falcon Heavy fleet turnaround. Remains the Wow factor with SSTO crafts, natch.

      I would deem this is an unlikely commercial contender, but it may make it and I hope it will. Because, Wow!

      1. Just FYI, and I only say this because you’ve done it a couple of times, the word you’re looking for is “latter” 🙂 (you’re spelling it “later”)

      2. Nice catch, but he could have done ‘worser’ like using ‘ladder’. It is so much worse in the concept department, don’tcha think Squidy?

        Mary

      3. One of my former girl friends were severely distraught when I referred to luncheon as “chow” in the local lingo. Go figure…

      4. latter [?læt?]

        adj (prenominal)
        1.
        a. denoting the second or second mentioned of two: distinguished from former
        b. (as noun; functioning as sing or plural) the latter is not important
        2. near or nearer the end the latter part of a film
        3. more advanced in time or sequence; later

        It is the later (latter; second) of two things.

        But I see your point, in english you distinguish between these as opposed to my first language:

        “to choose the second or latter (not later) of two alternatives.”.

        Thanks, I believe _I_ was the one annoyed by this confusion originally, when my english was fresh. What one can forget/confuse over time…

      5. So who is actually going to fund the development and getting Skylon into service?

        Have other factors been taken into account, like where it is to take off from and land? For instance, if the government closes one of the RAF airfields, could you take it over and use it as a space port? What about space law? Does this country need to change any of its laws to allow Skylon to operate? [Don’t forget the UK never developed the rocket because of a safety law on the use gunpowder passed in 1875!]

        Basically what I’m asking is has anyone identified the potential longer term obstacles and started doing what needs to be done to get them out of the way?

      6. I think they have, by and large, although some aspects of space law has not been dealt with by ANYONE (SpaceX, Virgin Galactic, whoever). But a lot of that will be the job of the operator, and not Reaction Engines themselves. Still, I’m sure they can find some country with laws that allow them to develop and use it.

      7. IIRC I got that from the news release, but I’m sure it’s on the company web site.

      8. Just to correct a statement made here “The UK never developed a rocket…”.

        Untrue. The United Kingdom had a space program, started shortly after the war. It was so badly funded, that it took until 1971 to get it into orbit.

        Then the project was scrapped on cost grounds. I seem to remember hearing that the project was receiving the princely sum of £2 million/year…

        Look up “Black Arrow” on the wiki. The UK remains the only nation to develop a launch capability, and then give it up.

        In a word: Sad.

      9. You are perfectly correct… I should have added before the World War 2 when other countries were leading the way e.g. Germany with its V1 and V2 bombs.

        Agree that the history of Black Arrow is one of the sadder episodes of engineering in this country.

      10. You are perfectly correct… I should have added before the World War 2 when other countries were leading the way e.g. Germany with its V1 and V2 bombs.

        Agree that the history of Black Arrow is one of the sadder episodes of engineering in this country.

      11. But it seems like the projected prices for the Falcon rockets have been steadily increasing–they’re still a great deal compared to the dinosaur of the Space Shuttle, but they aren’t as low as once predicted. Also, Skylon is probably going to really benefit from large scale launches. Projections say that if you were to build a solar power satellite (which there have been feasibility studies on) then the price per launch could get down to $1 million. Let’s add a 100% error and its still a tiny cost for launching 15 tonnes.

        Not to say that will necessarily happen, but I think it is good to have people working on getting stuff to orbit from different angles.

  10. Yes, hydrogen “jet” rocket nacelles will be a hoot.

    But mainly I think the upcoming pre-cooler demonstration will be a show: AFAIU they have to use a jet engine in front to heat the air to simulate cooling capability up to Mach 4. Even with this tandem engine demo can’t get the air hot enough to demonstrate all the way to Mach 5!

    Here are some other hydrogen powered jet crafts, and historically the fuel runs deep, at least for prototyping:

    “In 1935 Hans von Ohain started work on a similar design in Germany, apparently unaware of Whittle’s work.[7] His first device was strictly experimental and could only run under external power, but he was able to demonstrate the basic concept. Ohain was then introduced to Ernst Heinkel, one of the larger aircraft industrialists of the day, who immediately saw the promise of the design. Heinkel had recently purchased the Hirth engine company, and Ohain and his master machinist Max Hahn were set up there as a new division of the Hirth company. They had their first HeS 1 centrifugal engine running by September 1937. Unlike Whittle’s design, Ohain used hydrogen as fuel, supplied under external pressure. [Wikipedia]

    (The HeS 1 never flew, the first flown HeS 3 was gasoline-fuelled.)

  11. This has been a long time coming. Concorde should have lead to Concorde 2, a bigger and more commercially viable aircraft. Some of that development branched off to be HOTOL and HOTOL 2. I remember getting excited about the original HOTOL. The HOTOL concept was to prove the technology on unmanned flights, which reduced the development risks and costs. I think this is an unmanned craft too for the first flights at least.

    The name probably comes from the metal tower built for the Festival of Britain in 1951.

    1. The article says it’s unpiloted, which to me suggests it will always be an automated craft (perhaps there’s no space for a pilot? or it’s too risky?) but could nevertheless be used to deliver astronauts to space.

      1. I’m quite familiar with Skylon (I’ve read almost the entire website on it). It will always be automatic, but on manned (pardon the sexism) flights there would be an “spaceline representative.” Reaction Engines Ltd., who’s developing Skylon, specifically dislikes the term pilot in that context, because this representative would take over only in an emergency. I assume that most of the time they’d act more like a flight attendant.

    2. Concorde should have lead to Concorde 2

      It _did_ lead to international flight zones without supersonic flight over land. Not all technological advance is straight forward.

  12. Doesn’t look like there’s enough rudder surface to keep it flying in a straight line if it loses power to one engine during the ascent/descent stages through the atmosphere. A small rudder is also problematic for recovering control if any kind of spin develops. Otherwise it’s a lovely concept. Good luck Skylon.

    1. I’m sure the appropriate calculations / simulations have been done.

      In any case, I would imagine that if one engine shut down at mach 5 the whole thing would rip itself apart, no matter how big the rudder was. But I speak strictly as a non-engineer.

    2. A rudder is not needed if the ailerons are replaced with spoilerons, they can act als ailerons but can also split so they provide equal drag on both sides of the wing, making the craft yaw or counteracting yaw. There are examples of flying wings like the B2 that use this concept.

  13. This title is a little bit misleading, it suggests Skylon is a huge, government-funded project. ESA and UKSA are not actually developing Skylon. They are interested in case it looks like it will go somewhere, and cannot see any showtopping problems (yet) with the design but are putting seroius money into it. Skylon development is to be privately funded according to the team behind the concept.

  15. This reminds me of the ship Princess Amidala got away from Naboo with (wasn’t that a J-Type 327 Nubian?). I wonder if it comes in silver? 🙂

    On a more serious note, does anyone have an idea about the angled engines? Are they made that way to provide lift as well as thrust; if so, why not angle the engine up a bit while maintaining a straight x-axis?

    There has to be a reason for that.

    1. “about the angled engines”

      Let’s see if anyone has a straight answer…

  17. hmm, sounds like the one step less advanced version of the Indian Avatar. I think I’d prefer a ride on one of Copenhagen Sub-Orbitals Tycho-Brahe taxis.

    1. Interesting, I didn’t know about that proposal.

      Sure, naively a successful Skylon type coolant stack could collect liquid oxygen for tank storage as well as used up directly in the Skylon engine.

      The problem is that scramjets haven’t been proved in continuous operation yet. Scramjets have hit Mach 5 @ 200 s (X-51) but Mach 10 @ 10 s only (X-43).

      So the Avatar concept isn’t one but two more complications.

  20. “That would be quite a show.”

    No more than seeing the Space Shuttle Main Engines in operation. Burning hydrogen doesn’t radiate as much light/heat as hydrocarbon fuels do. On the Shuttle, the shock diamonds in the exhaust are about all you see. Same with its RL-10 engines, when the DC-X was in operation. Expect similar.

  21. With a maximum take-off mass of 345 tonnes and a wingspan of only 25 meters, I guess this bird is going to have a very high take-off speed.

    Yep, I was right, the manual says close to Mach 0.5. That’s almost 600 kph, the max speed of early WW2 aircraft!

    I think normal tires won’t handle the stress.

  22. With a maximum take-off mass of 345 tonnes and a wingspan of only 25 meters, I guess this bird is going to have a very high take-off speed.

    Yep, I was right, the manual says close to Mach 0.5. That’s almost 600 kph, the max speed of early WW2 aircraft!

    I think normal tires won’t handle the stress.

  23. NASA’s Orion capsule seems pale in comparison? WHERE is the innovation? Luck with that engine design!

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