Stratolaunch unveils its giant mother ship

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Capitalism in space: Stratolaunch today finally revealed the giant airplane, the largest ever built, that it wants to use as a first stage for launching satellites cheaply into space.

From their webpage:

Over the past few weeks, we have removed the fabrication infrastructure, including the three-story scaffolding surrounding the aircraft, and rested the aircraft’s full weight on its 28 wheels for the first time. This was a crucial step in preparing the aircraft for ground testing, engine runs, taxi tests, and ultimately first flight.

Once we achieved weight-on-wheels, it enabled us to weigh the Stratolaunch aircraft for the first time, coming in at approximately 500,000 lbs. That may sound heavy, but remember that the Stratolaunch aircraft is the world’s largest plane by wingspan, measuring 385 ft. – by comparison, a National Football League field spans only 360 ft. The aircraft is 238 ft. from nose to tail and stands 50 ft. tall from the ground to the top of the vertical tail.

The Stratolaunch aircraft is designed for a max takeoff weight of 1,300,000 lbs., meaning it’s capable of carrying payloads up to approximately 550,000 lbs. As we announced last fall , we will initially launch a single Orbital ATK Pegasus XL vehicle with the capability to launch up to three Pegasus vehicles in a single sortie mission. We have already started preparations for launch vehicle delivery to our Mojave facilities. We’re actively exploring a broad spectrum of launch vehicles that will enable us to provide more flexibility to customers.

They plan to do ground tests throughout this year, aiming for a first flight test in 2019.



  • wodun

    That things looks really beefy.

  • Willi

    Misplaced “r” in first word of headline.

  • Willi: Thank you. Spelling error fixed.

  • Alex

    That is craziest and stupidest aerospace project/idea, which I have seen for decades. It is difficult to understand that a billionaire has given his money for it.

  • Gealon

    I still have huge misgivings about this thing’s stability. I maintain that they should have joined the tail booms with a single horizontal plane. Oh well, we’ll see if this monster sheers apart in flight. Hopefully if/when it does, the pilots are able to get out.

  • BSJ.


    I think you’re on to something!

    If they loose a couple engines on one side it’ll try to torque itself to death. Uneven side wind loads. Failure of one side of the tail control surfaces will all put ungodly stress on that cross spar. Whether it can carry a rocket on it or not.

    Pretty scary!

  • Gealon

    BSJ, Yes, I wrote up a rather detailed analysis of my concerns a while back, I think the last time Rob posted a Stratolaunch update. It all boils down to that single wing joining the two halves of the plane together. Any number of malfunctions or atmospheric conditions could cause the aircraft to sheer apart, mainly as I see it, by one fuselage pitching up and the other down and the wing just twisting to pieces. A joined tail like on the P-38 would help eliminate this instability. But it appears that the beast’s designers appear to be more focused on making the plane look like the White Knight carrier for Spaceship 1, rather then building a safe, stable aircraft.

  • Edward

    Gealon started a discussion on this topic, a couple of months ago, nicely stating his concerns:

    I’m beginning to think that Stratolaunch made the horizontal stabilizer (tailplane) separated in order to accommodate a long rocket, as the wing mount-point looks to be higher than the tailplane. However, they could have moved the tailplane higher on the tail and connected them up there. Perhaps some day we will hear from one of the designers to find out their thoughts on this design.

    I, too, prefer designs that take advantage of geometry to assure strength and structural integrity. As Gealon pointed out, a connected tailplane similar to the P-38 would help to provide that integrity. However, I do maintain that composite materials work differently enough than homogeneous materials that the concerns presented by Gealon and BSJ. should have been addressed by the designers by applying the correct layup of the fibers on the wing crossbeams, etc. I would be enormously surprised if they hadn’t been addressed during the design phase.

    It will be interesting to view the first flight from onboard cameras, as it sounds like Gealon and BSJ expect to see some amount of twisting action during flight. Even if it turns out to be minor motions, that would be an interesting sight.

    I expect some amount of motion, too, because when it comes to forces and vibration, everything is a spring.

  • Edward

    In the comments in another post, I noted some advantages of an air launch over a vertical launch from the ground.

    You concluded that the biggest advantage of air launch is that the reduction of the max-Q.

    I may have missed an advantage. As I recall from when Orbital ATK (then Orbital Sciences) was first introducing their Pegasus air launched rocket, they were expecting to be able to use a smaller, simpler, and less expensive rocket to put the same weight payload into orbit than could be done with a vertical launch. Judging from Orbital’s pricing, they may have missed their cost savings goal.

    Stratolaunch’s initial announcement noted the advantages of flexibility in launch sites and final orbits, as well as simplifying the ground support equipment and reducing costs.

    Officials tout the air-launch nature of the system as giving the flexibility to send the rocket on any trajectory to reach any desired orbit, hauling the rocket over the open ocean to aim in all directions, which is something not possible from ground-based pads that are restricted from sending boosters flying over populated areas.

    ‘We believe this technology has the potential to someday make spaceflight routine by removing many of the constraints associated with ground launched rockets,’ Griffin said. ‘Our system will also provide the flexibility to launch from a large variety of locations.’

    It has become evident that the industry needs a responsive and operationally flexible solution to increase flight rate resulting in lower cost missions. This non-traditional approach to launch could open up the market for truly privatizing human spaceflight.

    We will have to see whether Stratolaunch is successful in reducing launch costs.

  • Dick Eagleson

    As noted, the Stratolaunch “Roc” resembles White Knight and White Knight Two. Given that the same guy designed all three, that is unsurprising. Given that both previous aircraft flew just fine without twisting to pieces, I think such concerns anent Roc are a tad overblown.

    This thing is a rocket carrier. Rockets don’t launch in inclement weather. No one is going hurricane hunting in this bird.

  • ken anthony

    Mr. Eagleson, I always rely on your sober analysis… but, that thing looks dangerous which was my reaction before reading the other’s comments. I’ve been in clear skies and had a plane be thrown about. Sailing, the wind seems a living thing. I love flying on small planes especially when thrilling but would not fly in that thing.

    It’s going to flex and eventually fail. Probably when they trust it the most.

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