back to article Paul Allen's six-engined monster plane prepares for space deliveries

The world's largest aircraft, designed to one day fling rockets into space, has tested out its taxiing capabilities at the Mojave Air and Space Port in New Mexico. The 500,000lb (227 metric ton) "Stratolaunch" is the brainchild of Microsoft co-founder Paul Allen and advanced materials aviation wizard Burt Rutan. The pair plan …

  1. Anonymous South African Coward Silver badge

    "Mine's bigger and better than yours"...

    By the way, which one will perform better - His Muskness's Heavy launcher or Allen's aeroplane in lifting heavy stuff?

    1. Sorry that handle is already taken. Silver badge

      If Wikipedia is to be believed, it's intended to carry a payload of 250t, which is less than half the mass of a fully fuelled Falcon 9. That's also about ten times the mass of a Pegasus XL, but it's designed to carry only three of those.

      Air-launched rockets might have a 12 km head-start in terms of altitude but they still have to burn a lot of fuel to reach orbital velocity.

      Meanwhile, a Falcon 9 launch (heaviest demonstrated payload: 9,600 kg) costs less than twice as much as a Pegasus XL launch (maximum payload: 443 kg)...

      1. S4qFBxkFFg

        "Air-launched rockets might have a 12 km head-start in terms of altitude but they still have to burn a lot of fuel to reach orbital velocity."

        Have a read of a mad (doesn't imply bad) idea to mount a space shuttle main engine on the back of a 747, allowing it to fly (for a short time) at very high speed/altitude before launching a rocket carried on its back:

        http://www.thespacereview.com/article/1608/1

        1. InfiniteApathy
          Pint

          > http://www.thespacereview.com/article/1608/1

          >>As Dana Andrews remembers it, Boeing’s engineers first proposed using the Space Shuttle Main Engine “as a major performance improvement” to the craft (747).

          That was an excellent read, cheers

        2. Alan Brown Silver badge

          "doesn't imply bad"

          Unless you count ripping the wings off.

          Mind you it'd be a fun tweak to "Star Smashers of the Galaxy Rangers"

          1. John Brown (no body) Silver badge

            Mind you it'd be a fun tweak to "Star Smashers of the Galaxy Rangers"

            They still need to discover Cheddite first.

      2. F0rdPrefect

        But it is the payload that counts, not the fuel on the rocket required to lift the fuel to lift the fuel.

        High altitude launch allows using gravity, instead of fighting it, to gather some speed and there is less air resistance to fight against.

        Buzz Aldrin laid out the idea for an air launch system, back in the 70s and has been trying to raise interest in it ever since.

    2. bombastic bob Silver badge

      at some point it may need JATO bottles or some other kind of 'rocket booster' to assist taking that really freaking heavy rocket up to altitude...

      but who knows, if it costs less than a "pure rocket" 1st stage...

      the other alternative might be a hybrid air-breather for the 1st stage rocket.

      Impulse is basically mass times delta-velocity of the stuff being ejected out of the tail end. If you double the delta velocity, it takes 4 times the energy to do it. OR, if you DOUBLE THE MASS, it only takes TWICE the energy. In both cases, you get twice the thrust.

      So if you can breathe air {and use that as a significant part of the exhaust) the rocket itself becomes more efficient. It's only when you get to an altitude where air breathing isn't practical any more that you have to use 'fuel only' to propel you.

      [it's the same basic reason why turbofan engines are so much more efficient than turbojet engines]

      In any case, strap on hybrid rocket/air-breather engines could be a third option to increase payload capacity of the aircraft. Strap them on next to the rocket you're taking up to altitude, and land with them still attached (minus fuel weight). More hybrid hybrid solutions.

      /me points out that extra booster rockets burning jet fuel + LOX could be fueled by extra 'drop tanks' carried by the aircraft. Hybrid hybrid hybrid hybrid I guess

      1. Richard Plinston Silver badge

        Re: DOUBLE THE MASS

        > If you double the delta velocity, it takes 4 times the energy to do it. OR, if you DOUBLE THE MASS, it only takes TWICE the energy. In both cases, you get twice the thrust.

        No. If you double the velocity you do not "take 4 times the energy to do it" if the mass flow (kg per sec) remains the same. However, if the nozzle is the same size then the mass flow will also double and thus it will "take 4 times the energy to do it", but it will give you FOUR TIMES the thrust

      2. Richard Plinston Silver badge

        Re: if you can breathe air

        > So if you can breathe air {and use that as a significant part of the exhaust) the rocket itself becomes more efficient. It's only when you get to an altitude where air breathing isn't practical any more that you have to use 'fuel only' to propel you.

        The only advantage of 'breathing air' is that you get to use the oxygen in it to burn the fuel rather than having to use the LOX that otherwise has to be carried. A rocket engine using fuel + LOX is completely incompatible with an air breathing engine and so there would have to be 2 completely different systems. in order to get sufficient thrust to make air breathing worth while for the short time the rocket is within the atmosphere the weight and cost are prohibitive.

        The Falcon Heavy Lift produces around 23,000Kn. - about the same as 100 747 engines - each weighing 4 tonnes just for the engine.

        Merely processing air for its mass without using the oxygen would produce no benefit at all, it would take more energy to accelerate the air than would be obtained in thrust.

        1. itzman

          Re: if you can breathe air

          You are doing some circular thinking there. The whole point is NOT to mimic the trajectory of a pure rocket.

          Use of winged aircraft and turbofan/Ramjet/Scramjet to mach 6 at 100,000 feet is probably what they are thinking of

  2. Voland's right hand Silver badge

    Allen's team instead turned to Orbital ATK, which will sell off-the-shelf Pegasus XL air-launch vehicles capable of delivering 1,000lb satellites into low-Earth orbit.

    And here is where this story ends. Pegasus cannot compete in cost with any launch system. It is costed on "you forgot to book a sea when you should, buy one last minute" basis.

    So unless they find a cheaper launcher this whole story goes nowhere.

  3. Kevin McMurtrie Silver badge

    People who know told me

    This doesn't save much fuel because lifting the rocket is nothing compared to bringing it up to orbital speed. It's about being able to build and ignite the rocket anywhere. The second part is important because people get very NIMBY about lighting up a rocket that could incinerate an entire town.

    1. John Smith 19 Gold badge
      Unhappy

      "It's about being able to build and ignite the rocket anywhere."

      Actually a big part of the original plan for Pegasus was to avoid range costs.

      You have to book a launch range in advance. It's not cheap and the costs don't scale on size. So Rocket Labs would pay about the same to launch 250Kg on their Electron LV as SX would pay to launch 22800 Kg on F9, which is why RL run their own launch range in NZ. Something others might follow.

      Likewise running the "Flight Termination System" as special software on a separate computer on the LV (rather than have a "Range Safety Officer" follow the launch and press a BRB if it fails also saves about 100 staff (and their associated costs).

      But Pegasus is still the most expensive LV in terms of $/lb to orbit on the planet.

      1. Anonymous Coward
        Anonymous Coward

        Re: "It's about being able to build and ignite the rocket anywhere."

        > rather than have a "Range Safety Officer" follow the launch and press a BRB if it fails

        Be Right Back?

        1. John Smith 19 Gold badge
          Boffin

          Be Right Back?

          Big Red Button*

          *Although IRL I suspect it's not that big, but probably does have a safety cover , since the consequences of hitting it by accident are pretty serious.

          1. AdamT

            Re: Be Right Back?

            Actually I think the BRB just got retired in favour of an fully automated system. On the last few SpaceX launches you could here someone say "ATFS enabled" just before launch - which is Autonomous Flight Termination System. Apparently this also leads to the possibility of launches on the same or consecutive days from Cape Canaveral as (I didn't realise) that one of the most time consuming bits about switching the range from launch to launch was actually re-configuring and testing all the radars/scopes/etc. - that were needed for the manual system - to the next launch trajectory. Don't know if the new ATFS will be used on manned missions though. I can imagine people still preferring the idea of having people in the loop for that. Although that can lead to "Wargames (1983)" problems and the fact that in the Shuttle era the Range Safety officers were carefully kept well away from the Astronauts and their families lest personal feelings got in the way...

    2. phuzz Silver badge
      Boffin

      Re: People who know told me

      You'd be surprised how much fuel this approach can save.

      Firstly the aircraft can add a few hundred metres per second to the rocket,. Not much, but it's a start.

      The largest help though is lifting the rocket up the first few thousand meters, because that has a relatively large effect on the air density that the rocket has to push though. It also reduces gravity losses somewhat.

      As other people have noted, it also give you complete freedom in orbital inclination, and launch times and locations.

      1. JeffyPoooh Silver badge
        Pint

        Re: People who know told me

        phuzz wrote the inherently self-contradictory, "You'd be surprised... ...Not much..." <- :-)

        "...it also give you complete freedom in orbital inclination, and launch times and locations."

        I understand that launch location and orbital inclination, if optimised for fuel, are somewhat linked. The Saturn V famously used the "Roll Program" to tune the orbital inclination to match the Moon's.

        Launch times would be impacted by weather, both the rocket's limits and now this added aircraft's limits. So it unfortunately remains lacking in "complete freedom". Perhaps they could move to a different airport the night before the storm (if that's even practical, what with having to prepare a rocket).

      2. Alan Brown Silver badge

        Re: People who know told me

        "You'd be surprised how much fuel this approach can save."

        As Elon has already proven, fuel is the least expensive part of the whole freaking deal.

  4. PhilipN Silver badge

    You'll never get me up in one of those things

    IANA scientist, or an engineer, but the forces acting on the central section are going to be massive, yes? It suggests to me, just by looking at it, that it could split in two.

    Even if the two fuselages are very light they are going to have to be robust enough also to withstand major stress, stress which the central section thus has to bear. And unlike a conventional aircraft their will be different forces to contend with such as twisting, and a few more for which there are probably technical terms.

    Seem to recall even the fuselage of the Russian Concordski blew apart in mid-air because the turn was too tight.

    If this thing flies I shall be gob-smacked. And impressed.

    1. Francis Boyle Silver badge

      Re: You'll never get me up in one of those things

      Well, I'm not an engineer* either but I don't see why having two fuselage is especially problematic. In a conventional design each wing root has to bear half the full loaded weight of the fuselage. In this design the weight of the load plus that of the fuselages is distributed across a section of the wing, which should lead to lower stresses. Sure it looks wrong, but then a 747 would probably have looked terribly wrong to the Wright brothers.

      See also: the P38 and the twin Mustang. (I'll happily go up in either if anyone's offering.)

      *I was however almost a physicist in another long-lost life.

    2. graeme leggett

      Re: You'll never get me up in one of those things

      Think less of the wings hanging off two fuselages joined together by a central section and instead think more of the fuselages hanging from the wing which runs from tip to tip. And the engines are on the wing not off the fuselage(s)

      Twin boom aircraft have been around for years. The Germans stuck two He 111 bombers together in order to tow their largest gliders. Not a great success as still couldn't get enough power but principle not new.

      1. x 7 Silver badge

        Re: You'll never get me up in one of those things

        but most twin boom aircraft are linked at the tail as well as the wing - e.g. Lockheed Lightning, de Haviland Vampire/Venom/Sea Vixen so reducing the risk of torsional rotation around the central wing spar.

        A bit of air turbulence and there's going to be a heck of a twist around that central spar, which to my (amateur) eyes looks a hell of a risk. I'd want those tails linked!

        1. AdamT

          Re: You'll never get me up in one of those things

          c.f. Virgin Galactic and the Scaled Composites carrier plane: https://en.wikipedia.org/wiki/Scaled_Composites_White_Knight_Two

        2. Adair

          Re: You'll never get me up in one of those things

          Yes, it's the potential torsional stresses, esp. in turbulence, because of the independent tails that also bother my non-engineering brain. Anyone here got the technical know-how to say why this isn't going to be an issue?

        3. jelabarre59 Silver badge

          Re: You'll never get me up in one of those things

          A bit of air turbulence and there's going to be a heck of a twist around that central spar, which to my (amateur) eyes looks a hell of a risk. I'd want those tails linked!

          I wonder if the tails are separate to prevent being damaged by payload as it gets released, and/or to avoid getting burned by rocket exhaust (any rocket motor on the payload may get spun up before it gets released)

          1. Alan Brown Silver badge

            Re: You'll never get me up in one of those things

            "any rocket motor on the payload may get spun up before it gets released"

            If you've ever seen the L1011 or B52 pegasus launches you'll know that's not the case.

            The launcher drops the rocket and peels back. The rocket loses around 1000-2000 feet in altiude before the rocket ignites and another few hundred feet before gaining enough speed to make up the loss.

            Firing the load on-wing might sound like a good idea from an efficiency point of view but consider what happens to the carrier aircraft if the rocket engines misfire or explode.

            1. Richard Plinston Silver badge

              Re: You'll never get me up in one of those things

              > Firing the load on-wing might sound like a good idea from an efficiency point of view but consider what happens to the carrier aircraft if the rocket engines misfire or explode.

              Or what happens if the release fails to release.

        4. Alan Brown Silver badge

          Re: You'll never get me up in one of those things

          "A bit of air turbulence and there's going to be a heck of a twist around that central spar"

          Meaning at the slightest hint of such, it won't fly.

          I agree though, It looks like it should have a joined tail.

        5. itzman

          Re: You'll never get me up in one of those things

          "a heck of a twist around that central spar,"

          The spar is not there to provide torsional stiffness. It is there to provide bending stiffness. In a wing made of spars and ribs the torsional stiffness is massive, provided by the actual stressed skin of the wing.

      2. Aladdin Sane Silver badge

        Re: You'll never get me up in one of those things

        What makes it look odd is the two separate tails. The Lightning and Twin Mustang both had the tails joined together.

        1. Eddy Ito Silver badge

          Re: You'll never get me up in one of those things

          This is a much larger aircraft than the Lightning or Twin Mustang and it seems the newer twin designs are moving to independent tails like White Knight 1 & 2. Consider in a turn the outboard side is taking a faster larger turn and the inboard side is making a slower but tighter turn and especially in an aircraft this large it would likely be advantageous to compensate by differing the inputs to the control surfaces as identical inputs would induce unnecessary stress on the frame and slippage over the control surfaces as neither side will be fully coordinated. If the aircraft is small like the Lightning it probably doesn't matter so much given the distance between the tails isn't great and it probably benefits from a stiffer airframe in combat maneuvers where here it just adds extra weight. Since I imagine this is also a fly by wire plane they can take advantage of computer power and sensors to ensure the optimal operation of the control surfaces.

    3. Anonymous Coward
      Anonymous Coward

      Re: You'll never get me up in one of those things

      Looking at that design, I hope they have International Rescue on standby for the maiden flight.

      I'll get my coat. Mine's the one with the Fuzzbox cassette in the walkman in the pocket....

    4. Andy The Hat Silver badge

      Re: You'll never get me up in one of those things

      I'm not an aeronautics engineer either but I believe this design probably is strong enough, based on - and apologies as this is pure speculation on my part - that there was a team of suitably qualified aero engineers involved in the design of this thing ... After all, where aircraft design is involved, aircraft designers are fairly useful guys to have on your team.

      1. x 7 Silver badge

        Re: You'll never get me up in one of those things

        Andy

        I'm sure you're right

        but it just looks so wrong........

      2. Cynic_999 Silver badge

        Re: You'll never get me up in one of those things

        It should be reasonably easy to arrange for any torsion forces to be automatically counteracted by a suitable input to the tail control surfaces on one or both of the tails. Computer or other closed-loop feedback systems are a necessary part on several types of aircraft. I believe that the Harrier would be impossible to fly if a human had to make all the control adjustments needed to keep it stable, and commercial airliners have "yaw dampers" to avoid dutch rolls.

        1. Richard Plinston Silver badge

          Re: You'll never get me up in one of those things

          > Computer or other closed-loop feedback systems are a necessary part on several types of aircraft. I believe that the Harrier would be impossible to fly if a human had to make all the control adjustments needed to keep it stable,

          The P.1127, Kestrel and Harrier were all manual control. They did not have any computer stabilization.

          1. Anonymous Coward
            Anonymous Coward

            Re: You'll never get me up in one of those things

            From a 1972 issue of Flight International

            "Command inputs from the Elliott autostabilisation system, when selected, act through the conventional surface controls. Pitch control is effected by varying the downwarddirected airflow through the nose and tail shutter valves, with the tailmounted valve carrying additional lateral shutters to control yawing moment " "in the event of an autostabilisation fault, its limited control

            authority, 20 per cent, can be readily over-ridden by the pilot. While the computer - controlled autostabiliser is capable of operation at all speeds below 250kt, the handling characteristics in the jet-borne region are such that many V/Stol transitions and landings are made without using it"

    5. Anonymous Coward
      Anonymous Coward

      Re: You'll never get me up in one of those things

      @PhilipN: I wouldn't be too worried about the strength of the center wing section because I reckon they'll have done their sums re stresses etc, and remember that this isn't a long distance transport aircraft that might be expected to fly through bad weather; it'll only be flown when the weather's acceptable, and it'll more or less a case of just going up very high up and then coming back down again.

      I reckon engine-out situations might be a bit more tricky than usual though. The engines are all a long way from the centerline and the turning/yaw moment provided by the rudders will be somewhat reduced due the relatively short fuselage length and also being off the centerline.

      1. Anonymous Coward
        Anonymous Coward

        Re: You'll never get me up in one of those things

        > I wouldn't be too worried about the strength of the center wing section because I reckon they'll have done their sums re stresses etc

        Nah, we just increased the redundancy.

        Now instead of two wings we have three wings, in case any two of them fail.

      2. John Smith 19 Gold badge

        I reckon engine-out situations might be a bit more tricky than usual though.

        An issue Reaction Engines have modeled with Skylon, since the engines (each roughly the power of 4.5x Trent 1000s on an A380) are on the wing tips.

        Yes there is a yaw component but it was manageable with the fin and throttling down the other engine. In practice

        Since this has 6 engines a single engine out would only unbalence the vehicle by 1/6, rather than 1/2 (probably 1 quarter, as SABRE in air breathing mode has 2 parallel channels from the precooler).

    6. JeffyPoooh Silver badge
      Pint

      Re: You'll never get me up in one of those things

      PhilipN was worried, "...it could split in two."

      From a Project Management point of view, this is trivial to avoid. Open DOORS database, insert new Requirement 'Structural#1837': BY THE WAY, IT SHALL NOT SPLIT IN TWO. Save, close file, go for lunch.

      Absolutely trivial. Takes only a minute.

      1. Anonymous Coward
        Anonymous Coward

        Re: You'll never get me up in one of those things

        > insert new Requirement 'Structural#1837': BY THE WAY, IT SHALL NOT SPLIT IN TWO. Save, close file, go for lunch.

        Then come back to find that the engineer in charge of structural aspects¹ has added a series of weak points along the fuselage, to ensure that it will split in at least three pieces.

        ¹ If he is anywhere as literalist as my developers.

  5. Anonymous Coward
    Anonymous Coward

    If Microsoft made planes...

    1. W4YBO

      If Microsoft made planes...

      ...you'd have to have the DVD in the drive to take off.

  6. This post has been deleted by its author

    1. Elmer Phud Silver badge

      Re: Suspects....

      you can't see?

      Ah well.

  7. Anonymous Coward
    Anonymous Coward

    I wonder if the space launch biz will bifurcate into small air-launched and large ground-launched markets?

  8. Alan J. Wylie Silver badge

    Gerry Anderson thought of it first

    Zero-X

    1. x 7 Silver badge

      Re: Gerry Anderson thought of it first

      even now, this bit of film has me spellbound

      https://www.youtube.com/watch?v=x8PR3QIwXHs

      1. Peter Gathercole Silver badge

        Re: Gerry Anderson thought of it first

        I always wondered why the tyres of lifting body 1 weren't scuffed when the wing-tips angled down. The main body was not still on it's stilts when LB1 was attached.

        I made a mean Lego model of Zero-X when I was a kid. It was about 15" long, and used nearly all of the Lego that we had. The colours were wrong, of course, and as all large Lego models were, it was a bit fragile.

        Unfortunately, I did not take any pictures, because I didn't have a camera at the time.

        1. Alan Brown Silver badge

          Re: Gerry Anderson thought of it first

          "It was about 15" long, and used nearly all of the Lego that we had."

          How much lego would a 7 foot version have used? How much would it have weighed? :)

          1. x 7 Silver badge

            Re: Gerry Anderson thought of it first

            https://ideas.lego.com/projects/c4e0d276-9ecc-4d8b-9bd6-ea04fdd69242

      2. PiltdownMan

        Re: Gerry Anderson thought of it first

        Don't forget the great Derek Meddings, who brought the fantastic models to life!!!

      3. John Brown (no body) Silver badge

        Re: Gerry Anderson thought of it first

        "even now, this bit of film has me spellbound

        https://www.youtube.com/watch?v=x8PR3QIwXHs "

        Me too, but with many more years of life behind me than at the time of first seeing it, it looks massively over-engineered, hugely over-complex and I not that some of the landing gear, on retracting, looks like it ends up inside some of the engines :-)

    2. Chozo

      Re: Gerry Anderson thought of it first

      <sigh> they don't make 'em like that any more

  9. Anonymous Coward
    Anonymous Coward

    control

    who's in charge if they have a spat between the cockpits and decide to go their own ways?

    1. SkippyBing Silver badge

      Re: control

      AIUI only one fuselage is actually pressurised and occupied, it was just cheaper to make them both with windows.

      1. I am the liquor

        it was just cheaper to make them both with windows

        Especially when you have staff discount.

    2. Roger Kynaston

      Re: control

      You beat me to it. I wondered if it was for when the pilot and co-pilot had had a row. Bit like couples in catamarans!

      1. Stoneshop Silver badge
        Windows

        Re: control

        I wondered if it was for when the pilot and co-pilot had had a row.

        Or one of them has a bad case of body odor.

    3. Anonymous Coward
      Anonymous Coward

      Re: control

      They employ twins that are pilots.

      1. Anonymous Coward
        Anonymous Coward

        Re: control

        They employ twins that are pilots.

        Which reminds me, why does a Jaeger require two pilots working out on elliptical exercisers? At least that's what it looked like.

    4. Jeffrey Nonken Silver badge

      Re: control

      Hah hah hah! Cute.

      Real answer: the captain has authority over the first officer. The two pilots are not co-equals.

      1. Anonymous Coward
        Anonymous Coward

        Re: control

        Real answer: the captain has authority over the first officer. The two pilots are not co-equals.

        ***PATRIARCHY***

        Down with this sort of thing; etc...

      2. John Brown (no body) Silver badge

        Re: control

        "co-equals"

        is that a redundant redundancy?

  10. Steven 1
    Pint

    As bat shit as that looks, I love it.

    I know it'll not make any financial sense but purely for the awesomeness factor of the engineering you've got to raise a glass to them.

  11. Brush

    If it looks right, it will fly right

    And that doesn't look right........

    1. ArrZarr Silver badge

      Re: If it looks right, it will fly right

      Sadly not true. To me, the Supermarine swift is the epitome of "looking right" but the Hawker Hunter was the better plane

      https://en.wikipedia.org/wiki/Supermarine_Swift

      https://en.wikipedia.org/wiki/Hawker_Hunter

      1. Aladdin Sane Silver badge

        Re: If it looks right, it will fly right

        Made me think of this quote by the late, great Sir Sydney Camm:

        All modern aircraft have four dimensions: span, length, height and politics.

      2. Anonymous Coward
        Anonymous Coward

        Re: If it looks right, it will fly right

        "Sadly not true. To me, the Supermarine swift is the epitome of "looking right" but the Hawker Hunter was the better plane

        https://en.wikipedia.org/wiki/Supermarine_Swift

        https://en.wikipedia.org/wiki/Hawker_Hunter"

        Interesting retro look...

        If you like a bit more of a modern vibe, this is my favourite:

        https://cdn.airplane-pictures.net/images/uploaded-images/2010/9/20/102986.jpg

        https://1.bp.blogspot.com/-hsnevsNYoug/V8m1JV6IS8I/AAAAAAAAGG8/6w_yqsOPHIIstMwaRNaWMNTiTmhATYSswCLcB/s1600/Gripen%2BF.jpg

    2. Anonymous Coward
      Anonymous Coward

      Re: If it looks right, it will fly right

      > And that doesn't look right........

      It will fly left or centre then, no big deal.

  12. steelpillow Silver badge

    On your own

    The lower end of the one-off space launch market is pretty small. SpaceX gave up on the original Falcon1 as soon as the Falcon9 appeared, because it only got a trickle of orders and piggybacking on the spare capacity of a Falcon 9 turned out far cheaper. I think Pegasus are going to hit the same wall. What this beastie needs is a 250-ton second stage tailored to shifting the heaviest possible load into low Earth orbit. And only Stratolaunch will be willing to restrict their first-stage options to the present beastie. They may well have to go it alone.

  13. Swiss Anton
    Headmaster

    The world's largest aircraft?

    Its only becomes an aircraft after its first take off. So far it's only taxied, so at the moment it's just an automobile. Perhaps though, it is the world's biggest auto.

    1. Loyal Commenter Silver badge

      Re: The world's largest aircraft?

      I think there might be some monsters used in open cast mining that are larger (and certainly heavier) in those terms. Try googling "Bagger 293"...

      1. Steve the Cynic Silver badge

        Re: The world's largest aircraft?

        The Bagger isn't truly self-propelled, though (it doesn't carry its own power source). For big self-propelled land vehicles, consider "haul trucks", although it's worth noting that they, too, are used in open-cast mining.

        https://en.wikipedia.org/wiki/Haul_truck

  14. Dr_N Silver badge

    That goose looks very spruce.

    Aviation history repeats itself?

  15. 尼尔

    Any other uses?

    I wonder if you could make a cargo hold that could be attached when needed. Possibly it could move some of the big/heavy loads that that 6 engined Antonov beast is used for.

    1. Stoneshop Silver badge
      Boffin

      Re: Any other uses?

      It's going to be very restricted regarding places to land, simply due to its size. So turning it into a generic cargo carrier isn't going to fly, I think. The Antonov 225 and 226, and the C5A are way less picky in that respect.

  16. John Smith 19 Gold badge
    Unhappy

    So much potential to carry such a little payload.

    It really does cry out for a liquid fueled, winged, LV.

    Maybe with enough margin to (dare I even suggest it?) be fully reusable?

  17. Spudley

    Whether this flies or not, the investment in space technology is worth taking note of.

    If you'd done a survey of the world's rich in, say, 1990 or 2000, you would have found very few that were investing in space in any real way. People like Larry Ellison and Warren Buffet have had bucketloads of cash, but have kept it to themselves.

    The change in the last ten or fifteen years is incredible. Musk, Bezos, Allen, Branson, and others are all pouring millions into space companies, all with very clear aims of bringing the costs down for access to space. It's a really dramatic sea change, and it is producing real results.

    There's a real chance that some of these billionaires will lose their shirt on this. That's the risk you take when you spend this kind of money on this kind of project. But I do genuinely wish them all well, because even the ones who are falling behind like this project are still pushing the boundaries and discovering stuff. Exciting times.

    1. Alan Brown Silver badge

      "all pouring millions into space companies"

      It's cover for the StArk project.

    2. John Brown (no body) Silver badge
      Coat

      "Musk, Bezos, Allen, Branson, and others are all pouring millions into space companies,"

      Maybe they know something we don't about the future of life on Earth?

  18. Teslahed

    Please note; Bernoulli's Principle is not how aircraft produce large amounts of lift. It's mostly angle of attack and Newton's third law blasting air downwards off the wing to send the aircraft upwards in an equal and opposite direction. Otherwise planes couldn't fly upside down. Everyone gets taught in school that planes fly because of Bernoulli but that effect just adds a little efficiency to the cruise more than anything else. You can fly a plane with a completely flat wing if you get the angle of incidence right. The guy writing your aviation / space based articles should really know this stuff.

    1. Bluewhelk
      Boffin

      Both are correct

      Bernoulli's and Newton's principles as applied to flight are two sides of the same coin and are both correct, confusion generally arises due to oversimplifying the problem. See ...

      https://www.grc.nasa.gov/www/k-12/airplane/bernnew.html

      or

      http://www.planeandpilotmag.com/article/bernoulli-or-newton-whos-right-about-lift/

    2. DropBear Silver badge
      Facepalm

      Thanks for pointing this out, OP, I just came to do the same. Every time someone feels inclined to show off their superior aviation chops out comes that stupid "because Bernoulli" nonsense and I'm not quite sure what happens after that because all I see is red by that point. Fair warning: I'm one more "because upper and lower flows must meet at the end of the wing" away from a full berserker mode rampage.

    3. Anonymous Coward
      Anonymous Coward

      Everyone gets taught in school that planes fly because of Bernoulli

      That's not what I was taught in pilot school. They told us planes fly because of money.

  19. }{amis}{ Silver badge
    Thumb Up

    MAXQ

    I think part of this is also reducing the stresses caused by the MaxQ.

    A lot of engineering goes into stopping a rocket being crushed between the dense low altitude air and its own motors.

    By starting the launch at altitude the air is ruffly a 5th as dense hugely reducing vibration and friction allowing for a simpler lighter rocket to do the same job.

    At the moment they are limited by having to work with off the shelf gear not really designed for their application, with any luck this will get resolved and thy will be able to make a run of this.

    PS not a rocket scientist if i have goofed this please tell me i am a Muppet ;->

    1. Stork Bronze badge

      Re: MAXQ

      Also not a rocket scientist, but I think what you gain there is easily lost around reinforcements to cope with the attachments points.

      Nevermind that the forces from placing it horizontally instead of just vertically are adding more complications as far as I can see.

  20. Anonymous Coward
    Anonymous Coward

    Virgin Galactic delays

    How much does Burt working on this affect Richard Branson's Virgin Galactic development? I was under the impression that was made by Scaled Composites too.

    1. Martin Gregorie Silver badge

      Re: Virgin Galactic delays

      It is made by Scaled Composites, but IIRC Burt Rutan retired a year or two ago. I suppose he got bored in retirement and this BFA looked like an interesting project.

  21. teknopaul Bronze badge

    500,000lb

    Whats that in one of the el reg standard units.

    500,000 packets of sugar means nothing to me.

    1. Jason Bloomberg Silver badge
      Coat

      Re: 500,000lb

      500,000 packets of sugar means nothing to me.

      Thinking of it as carrying 25,000 Tesco carrier bags with ten 1kg packs of sugar in each may help.

      The one with the long receipt hanging out the pocket ->

    2. Aladdin Sane Silver badge
      Coat

      Re: 500,000lb

      500,000 packets of sugar means nothing to me

      How much is that in Viennese whirls?

      1. The Oncoming Scorn Silver badge
        Thumb Up

        Re: 500,000lb

        One Midge Ure (Based on a comment Hazel O'Conner made up on being wrapped up with him in one).

  22. JimmyPage Silver badge
    Thumb Up

    Balloons/airships ?

    Is there any research (or any point into researching) using some sort of balloon to do the heavy lifting to 100Km, and then launching a rocket from that altitude ?

    It's a question, not a suggestion.

    If we can get a relatively cheap reliable way to get things into LEO, there's the possibility of building factories or really big moon/mars landers ?

    In theory, you could build an entire moonbase in orbit, and gently drop it onto the moon, ready for habitation ?

    Not being au fait with the science, how easy would it be to rig up a true conveyor (think paternoster lifts) between earth and a point in LEO. Mechanical stress issues about obviously. But you'd think that the descending weightpretty much matching the ascending weight would mean quite low energy to get a lot of stuff up there.

    I recall Arthur C. Clarke seriously proposed a space elevator ... and he was worth listening to.

    1. Robert Moore
      Paris Hilton

      Re: Balloons/airships ?

      I seem to recall El Reg was working on this Technology.

      https://www.theregister.co.uk/2016/02/08/tridge_lohan_linux_conf/

    2. mr.K

      Re: Balloons/airships ?

      Low earth orbit is not a particular height, but a height and speed. The height is not really where all the energy go, most go into obtaining the speed.

      A conveyor belt can't be built up to LEO without anything supporting it, so basically you have to build a couple of hundred kilometres tall structure. Our current record is about one. Then there is the space elevator which is a theoretical possible idea. The basic principle is that if you go further out the orbital velocity decreases and the length of the orbit increases. Both of these contribute to the length of the orbital period increases also. At some point it goes up to 24 hours instead of one and a half which is about what it is in LEO. At equator the ground also "orbits" the centre of earth in 24 hours. Thus an object that far out over the equator will seem to stay put or as we say synchronous. Call it geosynchronous if you will. Since you then have an object seemingly floating out there you could tie a rope to it and lower it down to the ground. This will of course shift the centre of mass of the object downwards which you compensate by having a more massive object and also place it a little outside GEO so that the rope and the object combine has a centre of mass in GEO. Pull yourself up along that rope and you have an space elevator.

      First problem, it doesn't go to LEO, but GEO. You could get something to height of LEO using it, but you still need the velocity afterwards.

      Second building it. At the moment we are not sure if there even exists a material strong enough to hold it's own weight while stretched out so far. The distance to GEO is about 36 thousand kilometres.

      1. Richard Plinston Silver badge

        Re: Balloons/airships ?

        > Pull yourself up along that rope and you have an space elevator.

        You would also need to accelerate laterally. At ground level at the equator your velocity will be 1600kph. At geostationary orbit it will need to be 11,000 kph. You cannot take energy for acceleration from the tether as this would slow down the satellite.

      2. This post has been deleted by its author

    3. Richard Plinston Silver badge

      Re: Balloons/airships ?

      > In theory, you could build an entire moonbase in orbit, and gently drop it onto the moon, ready for habitation ?

      How would you get it to be "gentle"? You couldn't use a parachute. Think: dropping a piano off the Empire state Building.

      > Not being au fait with the science,

      That is obvious.

      > how easy would it be to rig up a true conveyor (think paternoster lifts) between earth and a point in LEO.

      You cannot 'rig up' a conveyor to LEO (Low Earth Orbit). The Earth takes 24 hour to rotate, LEO is around 90 to 120 minutes. It needs to be to geostationary orbit, around 25,000 miles up.

      1. Alan Brown Silver badge

        Re: Balloons/airships ?

        "You cannot 'rig up' a conveyor to LEO (Low Earth Orbit)."

        At one level of explanation that's what a Lofstrom Loop is.

    4. Alan Brown Silver badge

      Re: Balloons/airships ?

      "Is there any research (or any point into researching) using some sort of balloon to do the heavy lifting to 100Km, and then launching a rocket from that altitude ?"

      Ballockets were tried back in the early days. There was nothing to gain from them and payload was limited by the lifting capacity of the balloon.

      You'd probably gain more with some kind of catapault mechanism under the launchpad (sproing!)

    5. Long John Brass Silver badge
      WTF?

      Re: Balloons/airships ?

      @JimmyPage

      Is there any research (or any point into researching) using some sort of balloon to do the heavy lifting to 100Km, and then launching a rocket from that altitude ?

      Yes... well sorta...

      Check out Issac Arthurs You Tube channel... https://www.youtube.com/channel/UCZFipeZtQM5CKUjx6grh54g/playlists

      Check out the orbital ring idea!

      1. DropBear Silver badge

        Re: Balloons/airships ?

        "...using some sort of balloon to do the heavy lifting..."

        Well, yes and no. Please don't laugh... too hard... http://www.arcaspace.com/en/program_stabilo.htm

    6. John Brown (no body) Silver badge

      Re: Balloons/airships ?

      "Not being au fait with the science, how easy would it be to rig up a true conveyor (think paternoster lifts) between earth and a point in LEO. "

      A space elevator needs to go all the way to geosynchronous orbit and then beyond for counterweight, either as far out again, or with a fecking big weight. ideally, a full 48,000 miles so you get the nice launch platform at the far end.

  23. sisk Silver badge

    The Falcon Heavy could well end up being the platform of choice for large payloads, but I somehow doubt it'll beat the Stratolaunch for efficiency when it comes to smaller payloads. My guess is that we'll end up using different systems for different types of payloads. There is room for both.

    1. Alan Brown Silver badge

      " I somehow doubt it'll beat the Stratolaunch for efficiency when it comes to smaller payloads."

      There is very little that is "efficient" about small payloads and when you have the ability to "hitchhike"(*) on a larger launch going in the same direction as you need, it's a lot cheaper to do so.

      (*) "Hitchhiking" implies it's free. Unless it's a sponsored scientific payload, the charges for putting a parasitic load on a launcher are calculated at some figure slightly higher than the mass fraction being taken up.

  24. IGnatius T Foobar
    Happy

    Washington state engineering!

    Paul Allen, from Washington ... oh boy, this aeroplane will be built by the same people that designed the Tacoma Narrows Bridge! And also Microsoft Bob! What could possibly go wrong?

  25. Anonymous Coward
    Anonymous Coward

    p.s. pix or it didn't happen

    here, older:

    http://www.thedrive.com/the-war-zone/10937/stratolaunchs-massive-mothership-rolls-out-of-its-nest-for-the-first-time

    and newer:

    http://www.thedrive.com/the-war-zone/18816/stratolaunch-rumbles-down-runway-as-pentagons-interest-in-rapid-space-access-mounts

    btw, funny how, depending on angle of this or that shot, this contraption looks both fugly and awe-inspiring :)

  26. DJSpuddyLizard

    I do see a huge potential problem here.

    If a rocket on a launch pad fails to start, it goes nowhere.

    If a rocket tossed out of a plane fails to start, it makes a new artificial reef.

  27. Richard Plinston Silver badge

    > using some sort of balloon to do the heavy lifting to 100Km,

    You certainly couldn't get to 100Km with any useful payload. At higher altitudes the air density falls and so does its ability to lift. At 50Km the density and lifting power is about 1/1000 of that at the surface, at 100Km it is about 1/1,000,000.

    https://en.wikipedia.org/wiki/File:Atmosphere_model.png

    The aircraft not only takes the rocket to altitude, it also gives it an initial speed of a few hundred km/hour which a balloon could not do. Rockets are launched as close to the equator as possible because the surface speed there is about 1000mph (1600kph) which is a good start to gaining orbital velocity. Another 500 or 600 kph adds to that.

  28. Richard Plinston Silver badge

    Re: You'll never get me up in one of those things

    > stress which the central section thus has to bear.

    When an aircraft flies the lift comes from all along the span. The wings try to go up, the heavy bits try to go down. By distributing the weight: payload, fuel, fuselage(s) , engines; over all the span you _reduce_ the bending load. It is likely that the critical structural point is when the rocket is dropped and the lift of the central part of the wing is producing lift while carrying less weight.

  29. Stevie Silver badge

    Bah!

    I would hazard a guess that this is intended to provide the first stage of a recoverable manned vehicle for tourist purposes rather than serious cargo-lifting, but that's only a guess.

    Based on the fact that the released rocket still will have to do a lot of work to get up to escape velocity. A Falcon 9 first stage separation velocity can vary, figures I've seen purportedly from telemetry, claim ~6000 kph to ~8300 kph (a shade over 3700 mph to a shad over 5100 mph) or between around 5 and just under 7 times the speed of sound*.

    Escape velocity is 11.2 kilometers per second, or 40320 kph or around 25053 mph, just under 34 times the speed of sound, which the other stages have to make up.

    The Starotlaunch figures for maximum velocity are not anywhere I can find them, but the Scaled Composites body doesn't "look like" a trans-sonic design.

    It would seem that whatever this launches would have a serious amount of oomph to make up.

  30. aqk
    Alien

    OMG! He looks like a straight!

    uhh... almost like ... Bill Gates!

    What happened to that beard? Does he still run the Jimi Hendrix museum? The Seahawks?

    Or is he now growing long fingernails like the Spruce Goose designer did at the end?

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