back to article Microsoft founder Paul Allen reveals world's biggest-ever plane

Microsoft co-founder Paul Allen has shown off the “Stratolaunch”, a colossal aircraft he hopes can soon help to hoist satellites into low earth orbit. Allen's company of the same name has been working on the craft since 2011, with the help of Scaled Composites. The result of their efforts is 238 feet long, 50 feet tall and …

  1. Steve Crook

    Hang on...

    Isn't there a Thunderbirds episode about this very plane? I got the weirdest feeling of deja vue looking at the pictures. Any bald headed men with glowing eyes seen in the vicinity???

    1. AMBxx Silver badge

      Re: Hang on...

      Thunderbirds was my first thought too.

      This is the stuff we were promised as children

      1. Steve Davies 3 Silver badge
        Coat

        Re: Hang on...

        But... Can you see the strings?

        mines the one with a copy of Andy-Pandy in the pocket.

      2. Vulch

        Re: Hang on...

        Thunderbirds was my first thought too

        Elon Musk has five sons...

        1. TRT Silver badge

          Re: Elon Musk has five sons...

          Has he bought a remote volcanic island in the South Pacific Ocean?

          1. DougS Silver badge

            Re: Elon Musk has five sons...

            Obviously he's not going to tell anyone when he buys a remote volcanic island in the South Pacific Ocean. A secret base isn't secret if you tweet out "just bought a remote volcanic island in the South Pacific Ocean that will be perfect for my secret base".

            So I think we can assume he owns at least one such island, based on the fact he hasn't tweeted about it.

            1. TRT Silver badge
            2. Phukov Andigh Bronze badge

              Re: Elon Musk has five sons...

              until he has his own space station, I'm not impressed :P

          2. IT Poser

            Re: Elon Musk has five sons...

            A volcanic island in the South Pacific is too twentieth century for Musk. His volcanic lair will be on Mars. Honestly, what self-respecting super-villian wouldn't put their lair in the largest volcano in the Solar System.

            1. Michael Thibault

              Re: Elon Musk has five sons...

              "Honestly, what self-respecting super-villian wouldn't put their lair in the largest volcano in the Solar System[?]"

              One who realises that a fifty-mile-long elevator ride is going to get tiresome in a hurry?

      3. Mike Richards Silver badge

        Re: Hang on...

        Yep, me too - my second thought was the proposal from Vickers to make a jumbo jet from the VC10 - by having three fuselages flying in close formation:

        http://www.airvectors.net/avvc10.html (near foot of page)

        1. Steve Crook

          Re: Hang on...

          > make a jumbo jet from the VC10 - by having three fuselages flying

          Had to look because it was so hard to believe. In the event, utterly awesome and very definitely Thunderbirds material if the outer fuselages detached shortly after launch. I can hear the music now...

          Thanks for the link.

    2. Rich 11 Silver badge

      Re: Hang on...

      Wasn't that plane nuclear-powered?

      1. Black Rat

        Re: Hang on...

        With the exception of Thunderbird Six pretty much everything that flew was nuclear powered.

        1. Mark York 3 Silver badge
          Mushroom

          Re: Hang on...

          Including Granny cooking the food in a nuclear cooker & not being able to get the rods right if I recall correctly.

      2. Mage Silver badge

        Re: Hang on... Nuclear

        Lockheed Martin?

        It's not that people haven't thought of it.

        Try https://www.google.com/search?q=nuclear+plane+fusion

        I remember reading that USA actually considered a fission nuclear powered bomber. Or why bother with "spaceplanes" at all? Project Orion.

        1. Arthur the cat Silver badge
          Mushroom

          Re: Hang on... Nuclear

          Or why bother with "spaceplanes" at all? Project Orion.

          Orion has the bijou problemette that the resulting EMP would fry virtually all the electronics in the same hemisphere. Apart from that though, it's basically early 20th C (battle)ship building technology - loads of thick steel plate and bloody big springs.

          1. TRT Silver badge

            Re: Thunderbirds

            I was thinking more the orbital craft launch system from UFO.

            1. HelpfulJohn

              Re: Thunderbirds

              Set in the early 1980's yet here we are, over 30 years later, still wearing shirts with buttons and neckties as "smart" "professional" business attire in spite of the hazards.

              And we still don't have a Moonbase with pretty girls in purple wigs and very short skirts.

              Those skirts would be quite interesting on the Moon. Other things, too.

          2. MyffyW Silver badge

            Re: Hang on... Nuclear

            I think Orion's bijou problemette was the radiation that would rain down on mother earth with each launch. The Project calculated statistically that each launch would kill 2 people. Now that sounds bad but look how many folks (usually construction workers) die in major civil engineering projects. Still, a tough call to make and the atmospheric test ban treaty finally sealed the fate.

            Put a Project Orion craft outside the magnetosphere and said radiation wouldn't be a problem. So we're back to needing a more benign method of getting into orbit. One-and-a-half 747's strapped together suddenly doesn't look that crazy.

            1. MacroRodent Silver badge
              Mushroom

              Re: Hang on... Nuclear

              >Put a Project Orion craft outside the magnetosphere and said radiation wouldn't be a problem

              Trouble is, you would need dozens of ordinary rocket launches to deliver the little nuclear bombs to your bomb-powered interplanetary ship. They would probably cause a of concern and protest, to put it mildly. I fear this idea will not fly, until you can manufacture the bomblets off-Earth.

        2. Alan Edwards

          Re: Hang on... Nuclear

          Yep, the NB-36. The reactor never powered the plane, but it was fired up in flight.

          It already had 10 engines (4 jet, 6 piston), what's one more...

        3. dmacleo

          Re: Hang on... Nuclear

          convair nb-36h

          https://en.wikipedia.org/wiki/Convair_NB-36H

          The Convair NB-36H was a bomber that carried a nuclear reactor. It was also known as the "Crusader".[1] It was created for the Aircraft Nuclear Propulsion program, or the ANP, to show the feasibility of a nuclear-powered bomber. Its development ended with the cancellation of the ANP program.

          1. HelpfulJohn

            Re: Hang on... Nuclear

            I have sometimes wondered why they didn't go for an RTG style power plant driving propellers. That way they could have had something like a SHIELD helicarrier.

            Refuels would be as simple as plug-and-play, hot-swappable units being replaced as each was used up.

            Or is that a totally absurd, physically impossible non-starter?

            1. jake Silver badge

              Re: Hang on... Nuclear

              Simple answer. Power to weight ratio.

          2. Alan J. Wylie Silver badge

            Re: Hang on... Nuclear

            Charlie Stross:A Colder War

            "The Convair B-39 Peacemaker is the most formidable weapon in our Strategic Air Command's arsenal for peace. Powered by eight nuclear-heated Pratt and Whitney NP-4051 turbojets, it circles endlessly above the Arctic ice cap, waiting for the call.

      3. allthecoolshortnamesweretaken Silver badge

        Re: Hang on...

        "Wasn't that plane nuclear-powered?

        In the 1960ies, everything was nuclear-powered.

      4. Skylab72

        Re: Hang on...

        Nope, just a heavy lifter build with spare 747 parts.

    3. Anonymous Coward
      Anonymous Coward

      Re: Hang on...

      https://en.wikipedia.org/wiki/Zero-X

    4. Mpeler
      Paris Hilton

      Re: Hang on...

      "Any bald headed men with glowing eyes seen in the vicinity???"

      Anyone see Steve Ballmer lately?

      Paris is looking :)

    5. JCitizen
      Boffin

      Re: Hang on...

      Obviously this must be a project 'Brains' concocted - he's the glasses wearing geek behind it all!

  2. Sebastian Brosig

    LOHAN

    So it's basically LOHAN with a plane instead of a balloon?

    1. Anonymous Custard Silver badge
      Headmaster

      Re: LOHAN

      And a slight but rather crucial difference in scale, and also this one may really fly (RIP Lester, we miss you!)

    2. Eddy Ito Silver badge

      Re: LOHAN

      Coincidentally both this and LOHAN were begun in 2011. The FAA does indeed work in mysterious byzantine ways.

  3. Mage Silver badge
    Boffin

    Interesting

    I wonder why the tails are separate rather than sharing a wing,

    See

    Twin boom aircraft

    Twin fuselage aircraft

    It would maybe reduce drag (if no outer wing) and also make the structure more stable?

    ( I nearly typed Theresa May).

    This is weird: Airbus patent

    1. jake Silver badge

      Re: Interesting

      I wondered that too. All I can think of is they actually want it to have a little more flexibility. The thing is big, even a hundredth of a degree of difference between fuselages would add up to disaster if the tails were fused, especially under the kinds of load that this thing will be subject to.

    2. EricM

      Re: Interesting

      > I wonder why the tails are separate rather than sharing a wing,

      Avoiding potential turbulence from the payload?

    3. Tinslave_the_Barelegged Silver badge

      Re: Interesting

      > I wonder why the tails are separate rather than sharing a wing,

      Yes, it seems odd, but I would imagine the tail, rather like the good old Vampire, would be fried by the launching rocket, which would either leave the solution as raising the tails or leaving a blast gap. But it would be interesting to understand the engineering that allows this plane to cope with the torsional stresses it must surely experience, and it is somehow surprising that the mid-wing section is so thin. Or to put it another way, I wonder how much the two tails will move in relation to each other, especially when banking.

      1. Phil O'Sophical Silver badge

        Re: Interesting

        the tail, rather like the good old Vampire, would be fried by the launching rocket,

        Not sure I'd want to be flying that if the rocket were ignited while still attached, though. I'd been assuming more of a 'light the blue touch paper & retire" operation where they'd start a delayed ignition sequence and then drop the rocket, so they were well clear when it lit up (or blew up).

        1. SkippyBing Silver badge

          Re: Interesting

          'I'd been assuming more of a 'light the blue touch paper & retire" operation where they'd start a delayed ignition sequence and then drop the rocket'

          Probably correct, although I guess it depends how far you plan for it to drop whether there's a risk of the tailplane being damaged. Of course they may have left the gap there to reduce the chance for rocket/aircraft interference in the event of some sort of emergency requiring jettisoning the rocket.

        2. Brangdon

          Re: Interesting

          Although if it then failed to ignite, you'd probably lose rocket and payload. For comparison, during a SpaceX launch the rocket is held down by clamps for a few moments after ignition, while the computer checks the telemetry and decides whether it is healthy. Launches have been aborted after ignition, with no harm done; just fix the problem and try again. I don't know if this is standard for rockets that are not reusable.

          1. Anonymous Custard Silver badge
            Headmaster

            Re: Interesting

            And for reference, they can just look at the XS-1 space plane and its launch system plus its predecessors and parallel projects like the X-43.

            Those were usually slung under the wing of a standard aircraft and released before ignition, but it's a similar concept. Of course the release before ignition was rather crucial unless you wanted to send aforementioned aircraft into a rather interesting if short-lived spin before it hit the dirt hard.

          2. lglethal Silver badge
            Boffin

            Re: Interesting

            @ Brangdon - just for reference, if the Rocket uses liquid propellants the Engine can be switched on and off. If the Rocket uses Solid Fuels, the Motor (solids always have Motors, whilst liquids always have Engines) once ignited cannot be stopped.

            So with something which carries both liquid engine stages and solid boosters, like Ariane 5, once you've lit the solid motors, you are going to space today...

      2. John Brown (no body) Silver badge
        Flame

        Re: Interesting

        "would imagine the tail, rather like the good old Vampire, would be fried by the launching rocket,"

        If they're planning on firing the rocket engines while close enough to fry the tail, I DO NOT WANT to be aboard this aircraft. Ever!

    4. SkippyBing Silver badge

      Re: Interesting

      'I wonder why the tails are separate rather than sharing a wing,'

      I was thinking the same thing, maybe to avoid rocket efflux impinging on the horizontal stabiliser?

    5. Eddy Ito Silver badge

      Re: Interesting

      I wonder why the tails are separate rather than sharing a wing

      It may actually make it too stiff and have adverse effects on the rudder given the two fuselages look to be more or less 100' apart. Just spitballing but one might imagine a rigid beam across the back may require something akin to Ackermann geometry for the rudder deflection but if they are independent each side is free to move a bit without undue stress. It also seems to be a trend of modern design as looking at your twin fuselage link many of the newer designs have independent tails from the Pipistrel and twin C-5 Galaxy to other Scaled Composite designs like White Knight One and Two.

      1. Destroy All Monsters Silver badge

        Re: Interesting

        If they're planning on firing the rocket engines while close enough to fry the tail, I DO NOT WANT to be aboard this aircraft. Ever!

        Indeed, Sir Hugo Drax might fancy stealing it while in flight.

    6. Wayland Bronze badge

      Re: Interesting

      It's the twin cockpits and twin bodies that worry me, won't both pilots think they are flying different planes? What if they steer in different directions?

    7. imanidiot Silver badge

      Re: Interesting

      This is most likely simply about weight. A full tailplane joining the two tailbooms would be quite hefty. The only task of the tailplane is to provide a certain amount of force to keep the plane balanced and an added amount of variable force to provide pitch control. If that can be done by 2 smaller tailplanes you have less weight far aft of the CG that then needs to be compensated ahead of the CG with even more weight to keep the CG within limits.

  4. jake Silver badge

    How long before ...

    ... Ellison stops playing at toy boats? My guess is before the year is out.

    1. allthecoolshortnamesweretaken Silver badge

      Re: How long before ...

      Personal aircraft carrier, including the air wing?

      Let's see who gets the best mooring place off the coast of Saint-Tropez then, suckers!

      1. Anonymous Custard Silver badge
        Trollface

        Re: How long before ...

        He'll be one-up on the Royal Navy then, given how the beancounters have screwed that one up.

  5. Anonymous Coward
    Anonymous Coward

    What is the advantage in having two fuselages? The traditional single-fuselage design is very well developed and would seem to be optimal. And why stop at two? Why not three or seventeen fuselages?

    1. Mage Silver badge

      Advantages?

      " The twin fuselage configuration offers the advantage of a clean payload area underneath the wing centre section."

      I count about 30+ aircraft (most military) that have been twin fuselage.

      "During World War II a need sometimes also arose for a heavy fighter, which could not be met by a new design in the time needed. Joining two examples of an existing lighter aircraft was one way to achieve this."

      See also what are the advantages of twin-fuselage aircraft?

      The first seems to have been around 1915. Most didn't meet expectations of performance. There would probably be no advantage in having more than two fuselages.

      I think the single fuselage approach might end up like this family:

      Vulcan

      Still looks like SF 60 years later. Came in different sizes.

      1. Mike Richards Silver badge

        Re: Advantages?

        The Victor looks even more science fiction (albeit Buck Rogers SF). I'd love to know what they were smoking when they came up with that plane - it is a handsome villain.

        1. Mage Silver badge

          Re: Victor, Vulcan etc

          The UK did incredible stuff in 1950s.

          Including one test of spaceplane idea by firing a rocket motor in a bomb bay, I think set an altitude record.

          The Victor would look fine in a Alien's planet's war.

        2. Swarthy Silver badge

          Re: Advantages?

          Also, by locating the large hunk of temporary mass (satellite + rocket) at the Center of Mass for the plane, the CoM doesn't change (and with it flight characteristics, like not flying in circles) when the payload gets launched.

          If one were launching 2 satellites at a time, a single fuselage would be preferred, as the gobs o' mass could be balanced on either side of the CoM. Bu that would take a much larger plane.

  6. kmac499

    Burt Rutan and scaled composites do it again. The guy not only designs and builds some wonderful and weird aeroplanes, but he does it relatively cheap as well. He also designed the wing on the Pegasus rocket that this thing can carry.

  7. Allan George Dyer Silver badge
    Joke

    It's that big...

    "can launch from different runways"

    At the same time?

    1. PNGuinn Silver badge
      Joke

      Re: It's that big...

      "can launch from different runways"

      At the same time?

      No, not quite.

      You launch each fuselage from a different airfield and join 'em up in flight. A bit like in flight refuelling.

      Then they meet up with a third plane carrying the little bits they want to launch, stick 'em onto the hooks underneath the middle bit and proceed to launch.

      Simples, shirly.

      It's all about cost reduction and versatility in runway use. So I'm told.

      1. Danny 14 Silver badge

        Re: It's that big...

        I do that sort of thing in KSP all the time. Plus why don't they put rapiers on this thing so they can SSTO too.

        Pfft. Amateurs.

        1. Yet Another Anonymous coward Silver badge

          Re: It's that big...

          Means you can land somewhere outside Mother America and pickup the payload and launch it - without all the ITAR regs that the Boeing/Lockeed alliance used to block sealaunch

  8. Mage Silver badge

    Reason dual fuselage

    Probably purely to carry spacecraft centrally (heavy) and under wing. The US carried Shuttle on top to solve that. The Russian Buran was carried on top of a specially built Antanov, the largest one.

    1. Adam 52 Silver badge

      Re: Reason dual fuselage

      Perhaps relevantly the US tried a dual fuselage B52 before giving up and going 747.

    2. Yet Another Anonymous coward Silver badge

      Re: Reason dual fuselage

      Tricky to launch a rocket in mid-air when it is parked on TOP of the fuselage (at least more than once)

      Signed

      Mr Hugo Drax

    3. Sven Coenye

      Re: Reason dual fuselage

      And last year, the Chinese signed a contract to build a lot more An 225's, apparently with the intent to build a commercial launch fleet. Allen may have to hurry up working out the kinks...

      1. imanidiot Silver badge

        Re: Reason dual fuselage

        I'm very skeptical of more An-225's actually getting produced. IF they are they'll more likely be used simply for heavy/oversized cargo transport. The 225's design isn't really suitable for air-launching stuff.

  9. Anonymous Coward
    Anonymous Coward

    Why apparently two cockpits? There have been asymmetrical twin fuselage planes in the past.

    1. jake Silver badge

      Obvious answer:

      Observation deck.

    2. Jonathon Desmond
      Happy

      Ambidextrous, obvs.

      Maybe to suit both left handed and right handed pilots?

      1. Anonymous Custard Silver badge
        Trollface

        Re: Ambidextrous, obvs.

        Too young to have been influenced by the Millennium Falcon?

      2. PNGuinn Silver badge
        Happy

        Re: Ambidextrous, obvs.

        Or ambidextrous robots. Min.

    3. PNGuinn Silver badge
      Go

      "Why apparently two cockpits?"

      Pilot and copilot, natch.

      I wonder which one gets to take the dog?

    4. Youngdog
      Trollface

      It's his I.T. background...

      ..resilience by design

    5. Yet Another Anonymous coward Silver badge

      Two pilot option

      Because Empire Strikes Back was his favorite film

  10. allthecoolshortnamesweretaken Silver badge

    The 'avoiding bad weather' bit makes sense to me. And you can launch at the equator for maximum efficiency.

    Also, you could pick up the launcher and payload directly at the assembly site (if they have the runway to do it).

    But we'll have to wait and see whether it will fly more than once like one of its predecessors...

  11. lglethal Silver badge
    Joke

    Two aircraft in disguise?

    Why do I have a mental Image that its really two aircraft in disguise? Very 70's Bondesque style. Fly the two aircraft to the location, join them up, strap a rocket underneath, fly up, launch it and then break apart and fly as two seperate aircraft back to separate bases....

    No-one will suspect a thing... mwhahahahahahahaha...

    *cough* sorry... *cough*

  12. Prst. V.Jeltz Silver badge

    The most impressive thing for me was in that hangar picture - look at the distance those roof trusses are supporting over a single span. Amazing!

    1. Arthur the cat Silver badge

      Upvoted for purity of technogeekiness. (And because I thought the same thing. :-)

    2. muddysteve

      "The most impressive thing for me was in that hangar picture - look at the distance those roof trusses are supporting over a single span. Amazing!"

      That's why the two fuselages are not joined. So they can have a central pillar holding the roof up.

      1. Androgynous Cupboard Silver badge

        Having built a multi-hull boat in a too-small shed, I can confirm that accidentally building it around a central pillar is something that can easily wake you from a dream at 3am :-)

    3. Anonymous Coward
      Anonymous Coward

      "look at the distance those roof trusses are supporting over a single span. Amazing!"

      Well, its designed for the 385ft wingspan and looks form the picture to have not a great deal of extra spave which puts the span at around 400ft. Meanwhile, here in Bristol at Filton we have the Brabazon hangar which (from quite search) has 3 bays with a total length of 352m which means around 350 feet per bay ... and that's been around for ~60 years.I remember when the Concorde exhiit (shortly to re-opem a new museum) was just outside the hanger and on a tour there the guide explained that one of the bays was being used by a company the painted aircraft as they could fit anything current inside ... at the time they had a 747 which seemed a little dwarfed by the hangar

  13. Aladdin Sane Silver badge
    Facepalm

    Design

    All it is, is a scaled up White Knight Two.

  14. Simon Harris Silver badge

    "can launch from different runways"

    How many runways are wide enough for that thing?

    The one it's on looks a pretty tight squeeze!

    1. Anonymous Coward
      Anonymous Coward

      Re: "can launch from different runways"

      My first thought on seeing it outside its hanger, where you've some sense of scale, was that there won't be very many "different runways" from which this could operate at all, let alone safely, because its landing gear tracking is too wide. Whilst it may just fit on a typical runway, there won't be much 'wiggle' room between the main gears and the edges of said runway. This issue will be exacerbated by the off-center piloting position - one can imagine a conversation between the flight crew in each of the two cockpits as they try to line up with the runway for landing:

      Starboard Pilot: "Come to port a bit, come to port a bit"

      Port Pilot: "No!, come to starboard a bit, come to starboard a bit"

      In addition to the risks resulting from the closeness of the main gear to the edges of the runway, the camber of the runway is also likely to cause problems with such a wide-tracked landing gear, not just because each of the main gear sets will be running along the side of a gradient but also because dirt and other crud will tend to end up along the edges of the runway, due to both the passage of other conventional aircraft using the runway and rainfall, which will 'wash' wind-blown dirt and grit off the crown of the camber down towards the edges. It will be a bit like driving along the hard-shoulder at full motorway speed - not good.

      1. Anonymous Coward
        Anonymous Coward

        Re: "can launch from different runways"

        "It will be a bit like driving along the hard-shoulder at full motorway speed - not good."

        In Africa there are "strip" roads. Basically a single lane of tarmac with wide gravel verges. When vehicles approach each other then they each move sideways to put one set of wheels on the gravel. The sudden drag on one side is very disconcerting if you don't anticipate to counter it.

  15. steelpillow Silver badge

    Half way there

    Twin fuselages make for a clean payload space without massive undercarriage. The split tail removes any risk of interference or contact if the payload gets mardy, either before or during launch. It's becoming a classic configuration for space launchers. ISTR Rutan has retired from Scaled Composites, nevertheless I find the most surprising thing about this ship to be how conventional it is in other respects.

    Main problem is that nobody has yet built a sensible orbiter on this scale that can launch horizontally: the structural, and hence weight, penalties of turning a coke can on its side are surprisingly large. If this beast finds a customer to do it justice, that will be the real breakthrough.

  16. Anonymous Coward
    Anonymous Coward

    What happens if the pilots in each cockpit decide to bank in opposite directions?

    SNAP!

    1. S4qFBxkFFg

      Re: What happens if the pilots in each cockpit decide to bank in opposite directions?

      "SNAP"

      In a way, you aren't joking, in certain aircraft the pilot/co-pilot controls, while linked, will connect to different control surfaces (e.g. the left seat controls might be connected to the upper rudder and left elevator while the right seat's has the right elevator and lower rudder). Normally, when everything's fine, moving one set of controls moves the relevant control surfaces, and the other set of controls. If things are not fine (e.g. pilots trying to perform different manoeuvres or a dropped meal tray preventing one control column moving) the linkage is designed to break at a certain level of force, so at least some sort of control is maintained.

    2. Tikimon Silver badge
      Angel

      Re: What happens if the pilots in each cockpit decide to bank in opposite directions?

      I assume you're thinking of both pilots moving their wing down (or up) at the same time. It's definitely amusing to imagine the airplane flexing up or down in a U shape! Reality is less interesting, since that would lift or lower both wings at once and the plane would simply rise or sink.

      Nevertheless, I'm having fun imagining the plane flexing around into interesting shapes as two pilots struggle for control. If they got into an oscillation loop fighting each other, you might see the wings actually flapping up and down as it flew, wouldn't that be a sight to tell your grandkids about?

  17. anothercynic Silver badge

    Looks like the Scaled Composites White Knight...

    ... Just bigger.

    Those turbofans better be GE90s. The GE9X used on the 747-8I might be bigger in diameter, but doesn't output the highest amount of thrust.

  18. cray74

    Why air launch?

    This is an incredible feat of aerospace engineering. I'm glad to see that, as a species, we're really experimenting and dreaming again. The lulls after the Apollo program, Challenger disaster, and 1990s launch market collapse were disappointing.

    But isn't this air launch approach inherently limited? Even the gigantic Stratolaunch airplane has a payload limit of 230,000kg for an entire rocket. As I understand it - corrections and clarifications welcome - this is only offering a ~250m/s boost to the rocket, a reduction in launch drag penalties, and more flexible launch inclinations than a fixed launch pad.

    That's nice, but you can get those advantages in other ways. Like, a bigger rocket. For example, a fixed launch pad easily adopted to the growth of the 330-ton Falcon 9 v1.0 (which already had a larger capacity than anything the Stratolaunch could launch) to the 550-ton Falcon 9 Full Thrust, which saw a large jump in performance: more payload, new recovery options, new orbit options. Fixed launch pads also could handle the US shuttle's 5-segment SRBs, which gave the shuttle most of the flexibility of an air launch (like "dog leg" flight paths into polar orbits) and increases in cargo capacity. Aerial approaches couldn't handle the original launchers, never mind the enlarged ones.

    But the Stratolaunch approach is not the first aerial launch system (hello, Pegasus) so there's got to be something behind them. What are the advantages of these aerial launches over a bigger rocket?

    1. Mike Richards Silver badge

      Re: Why air launch?

      Launch when you want without worrying about rain and wind at the launch site. Get above the cloud, light the blue touch paper and you can have a small spy satellite over North Korea or replace part of a constellation in short order.

    2. Paul Smith

      Re: Why air launch?

      For a once off launch, ground launch is clearly cheaper, but at least 98% of the take off mass is lost. (Saturn V took off weighing 3,000 tons to get 40 tons on the moon and 10 tons back to earth). For repeated launches, once the cost of the bits lost getting to the air launched altitude match the cost of air launching, you are at break even, but after that is all profit. Potentially 20 or 30% lower costs per launch add up to a lot of money when you consider the current costs per kilo are (roughly) $5k to LEO and $30k to GEO.

      1. Yet Another Anonymous coward Silver badge

        Re: Why air launch?

        It's all about the size of your nozzles (ooh-err missus)

        In vacuum you want great big wide open nozzles, at sea level you need narrower ones. The result is a rocket that is less efficient at all stages of flight and least efficent at the start when you need the most thrust. The nearer you can be to vacuum when you light the blue touch paper, the more vacuum designed nozzles you can use.

      2. cray74

        Re: Why air launch?

        Launch when you want without worrying about rain and wind at the launch site.

        Yep, definitely a plus. Flexible launch sites are also part of the attraction of sea launching.

        It's all about the size of your nozzles

        Avoiding sea level-optimized nozzles helps a bit, but it's not everything. For example, the shuttle's SSME nozzles were a compromise to operate from sea level to vacuum but only gave up a bit of vacuum specific impulse. They eventually having achieved 453 seconds in vacuum (where they spent about 6 of their 8 minutes operating), while a purely vacuum-optimized nozzle would've delivered 455 seconds.

        For multi-stage, non-parallel rockets, the rocket nozzle advantages of air launch are even smaller. The Pegasus gives a good data point...

        For a once off launch, ground launch is clearly cheaper, but at least 98% of the take off mass is lost. (Saturn V took off weighing 3,000 tons to get 40 tons on the moon and 10 tons back to earth)

        ...Understood, but subsonic air launch isn't giving you much in launch mass savings. The 18,500kg Pegasus has a 443kg LEO payload (40:1), which is a worse payload ratio than the ground launched Atlas V (18:1), Delta IV (26:1), and Falcon 9 FT (24:1).

        The point of that comparison is that air launch mass savings are small enough to be wiped out by differences in propellant selections. Despite being carried to 12,000 meters and 270m/s by an L-1011 carrier aircraft, the solid-fueled Pegasus has lower mass-normalized performance than liquid-fueled ground launched vehicles.

        The all-solid, 4-stage Pegasus II slated for the Stratolauncher will also fall short of liquid fueled, ground launched rockets in performance.

        For repeated launches, once the cost of the bits lost getting to the air launched altitude match the cost of air launching

        You don't save much with an air launch except fuel, and rocket fuel is one of the lower costs in rocket operation. The purchase price of a $100 million used carrier aircraft like an L-1011 would fuel a lot of Falcon 9s.

  19. Eclectic Man

    Separate tails and twisting

    It may be that the aerodynamics means that there is no need for such a large horizontal tail surface, and the central, payload-bearing, wing section may be strong enough to cope with severe twisting in bad weather.

  20. Ryan Kendall

    Not Maetric not interested

    Sorry, but if it's not metric it could be the size of a postage stamp for all I care.

    Feet and inches mean nothing to me, thanks to my 1980s UK education.

    1. PNGuinn Silver badge
      Joke

      Re: Not Maetric not interested

      Obligatory downvote from a crusty old Imperial Fart.

      Try setting traps. I bet you'll never catch a milimetre

    2. eldakka Silver badge

      Re: Not Maetric not interested

      A wingspan of:

      838.2 Linguine, or

      12.7 Double-decker buses, or

      5.3 Brontosaurus.

      And a MTOW of:

      140403931310.0767 MicroJubs,

      140403931.3101 MilliJubs,

      140403.9313 Jubs,

      140.4039 KiloJubs.

      67782.1431 Adult Badgers;

      662.2827 Great White Sharks;

      393.131 Skateboarding Rhinoceri;

      13.1044 Austrailian Trams;

      1.1043 LINQ Hotel Recycling.

      1. Ryan Kendall

        Re: Not Maetric not interested

        662 sharks now that's an impressive number :-)

        1. Anonymous Custard Silver badge
          Joke

          Re: Not Maetric not interested

          Only if you can wrangle them for long enough to get them all in a line without their lasers blinding each other or you...

        2. eldakka Silver badge
          Mushroom

          Re: Not Maetric not interested

          662 sharks now that's an impressive number :-)

          If you think that's impressive, then just wait until that shipment of frickin lasers arrives!

          1. Anonymous Coward
            Anonymous Coward

            Re: Not Maetric not interested

            666 sharks = 1 Sharknado

    3. Anonymous Coward
      Anonymous Coward

      Re: Not Maetric not interested

      Even for non-metric types, a pound seems the wrong unit to be using when you get to the point of needing 6-digit numbers of them.

      1. Anonymous Coward
        Anonymous Coward

        Re: Not Maetric not interested

        "[...] a pound seems the wrong unit to be using when you get to the point of needing 6-digit numbers of them."

        An avoirdupois pound is a consistent weight in both the UK and USA - as long as you ignore the lighter troy or apothecaries’ weight. However hundredweights and the three variants of ton(ne)s can be significantly different measures.

        https://www.britannica.com/science/ton

        1. graeme leggett

          Re: Not Maetric not interested

          Pound may be consistent weight in UK and USA. But even for that population element of the UK that is not comfortable with kg and tonne, any large number of lbs is expressed in stones, hundredweight and (long) tons. (so 8lb of potatoes, 6-stone woman, 1/2 ton of gravel* )

          *though actually bought by the cubic yard as I remember from when I was younger.

    4. chivo243 Silver badge

      Re: Not Maetric not interested

      I have a US 1970's education, and I had to learn the metric system. I am comfortable in metric or imperial. We were told that we "had to learn the metric system, the whole world uses it" 40 or so years later the only thing the US got out of that exercise was a 2 liter bottle of Coke. Why?

      1. Rattus Rattus

        Re: Not Maetric not interested

        Re: "the only thing the US got out of that exercise was a 2 liter bottle of Coke. Why?"

        Because the US is filled with reactionary conservatives who are terrified at any sort of advancement and fight any kind of change. This is why the US is slowly surrendering its global superpower status to China.

        Also, "litre" goddamnit. Like in every other English speaking country, including Canada.

        1. chivo243 Silver badge

          Re: Not Maetric not interested

          Oh la la Litre!

    5. david 12 Bronze badge

      Re: Not Maetric not interested

      It's not "Imperial measurements". Those are "International measurements", from the international yard, adopted by the USA in 1933 / 1959. And the United Kingdom went off the "Imperial Standard Yard" in 1930 / 1963, so you aren't using Imperial measurements either.

  21. PNGuinn Silver badge
    Black Helicopters

    Look at that hanger ...

    ... There's a dirty great cutout at the middle at the top.

    What's the big bit that bolts on the top of this thing that they're not telling us about?

    1. John Brown (no body) Silver badge

      Re: Look at that hanger ...

      I was more concerned about the non-visible folding joints in those tail booms. That aircraft looks a lot longer than the depth of the hanger behind it. The hanger does appear to have a lower extension at the back, but that doesn't look high enough to accommodate the tail fins.

      1. Yet Another Anonymous coward Silver badge

        Re: Look at that hanger ...

        You just build a hanger that is bigger on the inside

        Or taxi at relativistic speeds and rely on the Lorentz contraction to get the plane into the barn

        1. This post has been deleted by its author

  22. Anonymous Coward
    Anonymous Coward

    No Way

    No way that skinny wing will hold up to the stress of trying to keep those two very long body's aligned.

    1. lglethal Silver badge
      Facepalm

      Re: No Way

      Yes, because I'm sure they never thought to have someone look over the design, do some hand calculations, do some FEM Analysis, some small scale testing and then ramp up to full scale testing.

      What? They did do all that. Oh well I'm sure that you, AC, having looked at a picture on the Internet, know more then all of those Aerospace Engineers on this topic.

      Muppet...

  23. rcp27

    Six Words

    Really, it does, I've tried it. (KXCD 1244)

  24. graeme leggett

    I like to imagine

    That somewhere in the UK, a boffin has looked up from their calculations to watch on a tv in the corner of their office news coverage of this plane.

    After a moment's consideration they grunt, shift the (unlit) pipe to the other side of their mouth and go back to their work.

    [camera pulls back to show wall covered by enormous blueprint outline of Skylon spaceplane]

  25. Fenton

    Another idea

    Rather than design a large aircraft to carry the payload up to a certain height. Why not design a smaller aircraft that attaches to the payload (with it's own fuel), that uses the engines on the payload.

    The Payload then drops the aircraft bit, which flys itself home.

    No need for large fusalages, automate the whole thing with no need for people on board.

    1. Yet Another Anonymous coward Silver badge

      Re: Another idea

      Because the whole point of this is to use the engines on the plane for flying in air - which aeroplane engines are really good at and rocket engines are really crap at.

  26. underthebrige

    Why not a balloon?

    In theory you could get higher cheaper. Though not sure if it would need to be too big for the payload.

  27. JJKing Bronze badge
    Coat

    Plus lasers?

    662 sharks now that's an impressive number :-)

    But does that also include the weight of the lasers?

    Mines the one with the Bat Shark Repellent in the pocket

  28. This post has been deleted by its author

  29. oiseau Silver badge
    Facepalm

    Most important question

    A really impressive piece of kit ...

    238 feet long, 50 feet tall, 385 foot wingspan and a potential 550,000 pounds of payload.

    But ...

    Does_it_fly?

    Cheers.

  30. John Smith 19 Gold badge
    Unhappy

    It's a monster.

    Although not a Caspian Sea Monster.

    The problem with these concepts (apart from hanging a 250 tonne rocket off a large wing) is that the you can't just tip a rocket on its side.

    Rockets are tremendously strong in 1 axis while the rocket this carries has to be very strong top-to-bottom (while it's hanging from the wing) and equally strong when the engines fire up.

    Also the aircraft does not give you anywhere near the velocity of a stage. So having spent a metric shedload of a cash to build your humougous aircraft you still need to build a 2 stage rocket anyway.

    If you could build a rocket that was SSTO (if launched from this aircraft) that would be a major breakthrough in the SoA.

    1. Eclectic Man

      Re: It's a monster.

      Have you seen the Russian rockets that get astronauts and cosmonauts to the ISS? They start on their sides and are raised into the vertical for launch.

      https://en.wikipedia.org/wiki/Vostok_(rocket_family)

      1. John Smith 19 Gold badge

        "They start on their sides and are raised into the vertical for launch."

        At which point they and there boosters are loaded with the propellants that the engines run on.Multiplying their weight about 9x.

        Which is also how SX does it.

        NASA did move the Saturn V full loaded to the pad, but only vertically. SRB's are either moved vertically (like Ariane 5) or built up on the pad like Shuttle (an astonishingly dangerous process, demanding the precision location of pieces of high explosive weighing 10s of tonnes).

        IRL you can't take a rocket designed to be fully loaded only when vertical and hang it from a single point on its side. TBH if you want to be avant garde in your rocket design go the whole hog. Optimize the shape as more of a flying wing (or lifting body) . High altitude flight at < M1 is pretty cold so let it cool the propellants and then top them up from tanks in the fuselage. Go LOX Methane if you're trying to be low price and so on.

  31. Ramazan
    Facepalm

    the world's biggest ever plane is An-224 "Mriya", it's longer _and_ heavier than this one although with a smaller wingspan indeed.

    1. John Smith 19 Gold badge
      Unhappy

      "the world's biggest ever plane is An-224 "Mriya","

      The question however is

      a) How big a payload can it carry on its back (which it was designed to do)?

      b)What's the maximum speed the plane can go while still allowing safe separation of the payload?

      c)How available is it?

      In cost terms the An224 is the OTS shelf solution if you wanted to go to orbit this way but the devils in the details.

    2. imanidiot Silver badge

      That would be the Antonov An-225.

      Maybe you got it confused with it's smaller sibling the An-124 "Ruslan"?

  32. mics39
    Pint

    Meh!

    It's ugly.

  33. Duncan Macdonald Silver badge

    Big advantage - no need for launchpad

    Existing large rockets need big expensive launch facilities - with a lot of unoccupied land around to handle the occasional large bang.Doing an air launch over an ocean removes the need for the ground based launch facility. There is also the advantage that the rocket can start in the desired orbital plane rather than having to expend fuel to allow for the difference between the desired orbital plane and the launch site (eg an equatorial orbit when launched from Cape Canaveral wastes quite a lot of fuel due to the launch point being over 28 degrees north of the equator.) For an equatorial orbit there is an additional 200 km/h advantage from launching from the equator rather than Cape Canaveral from the earth's rotational speed.

    The speed benefits

    1) Starting at 30000 feet instead of sea level - equivalent to over 400 m/s

    2) Equatorial launch (instead of Cape Canaveral) - equivalent to 200 km/h

    3) Plane velocity - around 200 m/s

    4) Orbital plane correction - ??? km/h

    There is an additional benefit from an air launch - the maximum dynamic pressure will be reduced as the spacecraft will be in thinner air than for a ground launch for any given supersonic speed.

    1. John Smith 19 Gold badge

      "1) Starting at 30000 feet instead of sea level - equivalent to over 400 m/s"

      I'm not sure where you get this from.

      Equatorial launch is normally reckoned to give about 400m/s impetus. IE about 1400Kmh.

      You've also missed one of the bigger benefits. Roughly speaking atmospheric pressure halves every 18000 ft. Flow separation on a rocket nozzle starts at about 36-40% of ambient atmospheric pressure (depends how good your design software is). That means you can put a bigger nozzle on the back as it can exhaust to a lower outside pressure to begin with. Bigger nozzle --> Higher Isp. Alternatively you can run with a lower chamber pressure, which usually makes engine design simpler.

      1. Duncan Macdonald Silver badge

        Re: "1) Starting at 30000 feet instead of sea level - equivalent to over 400 m/s"

        Simple - gravitational energy - a body falling from 30000 feet in earths gravity would attain a speed of over 400 m/s in a vacuum. This energy will be provided to the rocket by the plane rather than by burning its own fuel.

        The 400 m/s extra from equatorial launch probably includes the gain from not needing the orbital plane correction - the rotational velocity change between the equator and Cape Canaveral is about 200 m/s. I was not sure of the amount of energy consumed by the correction which is why I showed it as ??? .

        I am not a rocket design engineer so I did not know how much advantage the reduced atmospheric pressure would give to the performance of the engine so I left this out of the list of advantages.

        1. Yet Another Anonymous coward Silver badge

          Re: "1) Starting at 30000 feet instead of sea level - equivalent to over 400 m/s"

          It's not clear that equatorial launch helps so much for this.

          It has the biggest boost for GSO orbits but anything going to GSO is going to be too big for this thing (see todays other reg satelite story). Smaller payloads are going into LEO at a whole bunch of orbital inclinations that don't need equatorial boost as much, ones in a polar orbit don't benefit at all.

  34. Anonymous Coward
    Anonymous Coward

    Why do people design stupid things?

    Its a hobby to break records, but a stupid design. Too bad it will become a commercial failure and a museum piece, hence scrap.

    1. Yet Another Anonymous coward Silver badge

      Re: Why do people design stupid things?

      Yes - much better to have a monopoly of defense companies building ever bigger copies of WWII rockets for a single govt customer on a cost+ basis

  35. Anonymous Coward
    Anonymous Coward

    No mention of space junk?

    Between this and similar initiatives, 100's of pieces of junk flung into space per year... I guess the low orbit stuff doesn't remain as long? Any risk to population centers when they fall?

  36. CatW

    Thats such a crap design, they would have been so better of with a large slim delta wing with nose plane. Not only would it have been stronger and been able to 'flick' the vehicle up harder but there is no way in the even of a false launch that the vehicle could fall back on the tail damaging the launch aircraft.

    Typical Americans - one design, just make the wings longer, more engines. We built Concorde.

    1. Anonymous Coward
      Anonymous Coward

      Americans can't really innovate. Thank $DEITY for Chinese.

    2. Yet Another Anonymous coward Silver badge

      Mount the rocket underneath and you need landing gear the size of tower cranes,

      Mount the rocket on top and you do an "opening scenes from moonraker" when you fire it.

      Mount the rocket in the middle = just right.

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