The Stratolaunch Is Flying, But Can It Do Cargo?

The world’s largest aircraft is flying. Stratolaunch took to the skies in test flights leading up to its main mission to take rockets up to 20,000 feet on the first stage of their flight to space. But the Stratolaunch is a remarkable aircraft, a one-of-a-kind, and unlike anything ever built before. It can lift a massive 250 tons into the air, and it can bring it back down again.

By most measures that matter, the Stratolaunch is the largest aircraft ever flown. It has the largest wingspan of any aircraft, and it has the largest cargo capacity of any aircraft. In an industry that is grasping at interesting and novel approaches to spaceflight like rockoons and a small satellite launcher from a company whose CTO is still a junior in college, the Stratolaunch makes unexpected sense; this is a launch platform above the clouds, that can deliver a rocket to orbit, on time.

But the Stratolaunch is much more than that. This is an aircraft whose simple existence deserves respect. And, like others of its kind, the Antonov AN-225, the Spruce Goose, there is only one. Even if it never launches a rocket, the Stratolaunch will live on by the simple nature of its unique capabilities. But what are those capabilities? Is it possible for the Stratolaunch to serve as a cargo plane? The answer is more interesting than you think.

Cargo has always been the backbone of aviation. The first airlines weren’t interested in passengers, and air mail made up the bulk of a manifest. The venerable 747, the queen of the skies, wasn’t meant to be a passenger airliner, it was meant to haul cargo. It’s with cargo that aviation gets its most interesting accomplishments, and here history bears this point.

Containers of Cargo

The Fairchild C-119 was a military transport plane designed in the post-war period with an interesting mission. The sole purpose of this plane was to deliver cargo and the mechanized equipment of war in the modern era. A thousand or so were built, and they served the role well. However, in the years after the production of the C-119, a quite literal sea change occurred in the shipping industry. The rise of containerization happened. Instead of longshoreman unloading boats packed to the gills with wooden crates, container ships started to head into port. These ships, still seen at shipyards today, were designed to fit a standard 40-foot container. Load up a box at a factory, put it on a truck, drive to the port, load it onto a ship, and repeat the process backwards again in a few weeks. This is the modern reality of shipping, but aside from standard pallets in the decks of cargo aircraft, it never really happened in aviation.

The XC-120 Packplane featured a removable, standard cargo pod

The XC-120 Packplane was the answer to containerization of the air. This was a standard C-119, highly modified to turn the entire cargo deck into a large container that would easily fit on a truck. The idea was solid, and one aircraft was built. This thing flew, but it just wasn’t considered practical. There’s no forward or backward-opening door on the XC-120 cargo pod, so rolling jeeps into the thing would be impossible. nevertheless, this is an idea that just keeps popping up in the aviation world every few years or so.

The Trick Isn’t Flying a Lot Of Cargo, It’s Flying Weird Cargo

Right now, the largest operating cargo aircraft on the planet is the Antonov AN-225. It’s enormous, and the cargo deck is longer than the Wright Brothers’ first flight. If you’ve ever wanted to see the inside of this gigantic airplane, the Points Guy has a much better job than me.

The AN-225 was built in the 80s for a specific purpose: to carry the space shuttle. The USSR’s Buran spacecraft was an improvement over NASA’s space shuttle orbiter, and if you build a space shuttle, you’re going to have to move it around. NASA solved this problem by modifying a 747. The Soviets solved this problem by building the largest aircraft ever.

The Buran program and the idea of Soviet supremacy dissolved, but this gigantic aircraft lived on. Antonov Airlines inherited the aircraft, and they did what anyone would do with an incredible, one-of-a-kind machine: they rented it out. Right now, if you need to move something big, now, you contract Antonov Airlines. They’re on call to move anything that would take too long to move by ship.

With the right design for a cargo pod, this is something the Stratolaunch could do very well. If cargo were simply shoved into a pod, just like the XC-120 Packplane, the Stratolaunch could carry heavy, difficult-to-transport, and time-sensitive cargo to destinations around the globe. This isn’t an aircraft explicitly designed to launch rockets, it’s just an airplane meant to carry huge cargo. Even without a single launch, the Stratolaunch could still be a viable aircraft in the oversize cargo market.

Of Course, Carrying Cargo To Space Still Counts

The entire point of the Stratolaunch is to carry cargo. In the next year or so, a few Pegasus rockets will be launched from the air, carrying 370kg to Low Earth Orbit. This has already been proven with a B-52 and L-1011 carrier aircraft, and a Pegasus rocket will probably be the first rocket ever launched from this gigantic aircraft.

After that, larger rockets, still on the drawing board, will be sent skyward from the Stratolaunch. There’s a Medium Launch Vehicle that will be able to carry almost ten times as much stuff to Low Earth orbit over the Pegasus. A heavy launch vehicle with three core will be able to carry six tons to orbit. There will be a spaceplane eventually, and some day astronauts could ride to the International Space Station by first hopping up to 20,000 feet with a Stratolaunch.

But an aircraft as unique as the Stratolaunch demands respect. It can do things no other aircraft can, and it doesn’t make any money sitting on the ground. Whether or not we’ll see a container strapped to the Stratolaunch filled with weird and wonderful cargo is an open question, but in any event the Stratolaunch will be airborne soon ready to carry something somewhere.

31 thoughts on “The Stratolaunch Is Flying, But Can It Do Cargo?

      1. Balloons provide access to parts of the atmosphere dense enough to support a balloon, i.e. very much not space. Their powerpoint rockoon, being vaporware at this point, provides access to nowhere.

        The rockoon concept has worked for suborbital sounding rockets before, but it fell out of fashion quite a while ago as the world got better at building rockets. Now the extra complexity of mixing balloon and rocket operations, along with the poor controllability of buoyant flight, ends up more burdensome than just launching a bigger rocket from the ground. It would be neat to see their rocket fly, but the both the concept and their graphics contain enough questionable engineering (why does it have so much engine for so little tankage? why three stages when starting from a balloon should let you reduce complexity, not increase it?) that I seriously doubt that will ever happen.

        1. Its about the velocity. Getting altitude isn’t the problem you need the horizontal velocity relative to the ground. Any large lift rocket actually rolls over onto its “back” to get as much “horizontal” velocity as possible after the initial lift off the pad. The same thing is still a probelm for a baloon. The horizontal velocity is that enables the satellite to orbit “as the ground falls away from it”.

          If you could plop an object at 600 km altitude, as if it poppped into existance in the dark void, it would immediatly start to fall to towards Earth.

          So if you’re using a ballon, you’ve only solved the first part of the lift problem. Which, admittedly is a huge part of the problem.

    1. Dirigibles, contrary to popular belief, are neutral buoyant, they are not like party balloons. They are carefully ballasted so they neither go up or down. So when you let go of 50 tons of cargo, all of a sudden the dirigible will have 50 tons extra lift, and will shoot up like a rocket. The air force wanted a cargo dirigible (program Walrus) but the stumbling block is always how to control buoyancy.

      1. I remember reading somewhere about using compressed air in bladders next to the lifting gas as ballast. the air itself has weight, but you also use it to “squeeze” the lifting gas so it takes up less volume and produces less lift. I’m not sure if this was an actual working system or someone’s chalkboard concept.

  1. The problem with the Strato Launch as a cargo carrier is two things. One, I don’t think it’s narrow enough for standard runways, which will limit where it can go. Second, having to build a custom box (or several) just to carry cargo isn’t going to fly. Sorry, bad pun. :-)

    1. What I came here to say. With the completion of the Panama Canal, it became impractical to build cargo ships greater than a certain length, beam, and draft, because anything that wouldn’t fit through the Panama Canal would have to go around the entire South American continent to get from the Pacific to the Atlantic or vice-versa. As a result, there is a class of ships known as “Panamax” that fit into the locks of the Panama Canal with inches of clearance, and although there are “Super-Panamax” ships, but they are used only for routes where the Panama Canal is not an option anyway.

      The same has happened at airports. The sizes of the A380 and the 777 were limited by the requirements of the many airports in the world that were designed around the 747. In effect, the industry decided that they’d never need anything bigger than a 747, so it is now impractical to ever build anything bigger. So yeah, if you have a cargo that’s so special that you don’t mind trucking it out to the middle of a desert, and then trucking it out of the middle of another desert to get to its destination, then this is your ride.

    1. Actually, the 747 derived from Boeing’s entry to the CX-HLS cargo aircraft program (which resulted in the Lockheed C-5). The high mounted cockpit was meant to accommodate a swinging nose and front loading ramp.

    2. To expand just a little: the 747 was a stop-gap project, because an upgrade for the 707 and 727 was needed much sooner than the 2707 (SST) could possibly be put into production. It was a secondary objective (to justify the enormous development cost for the 747) to target it for the cargo market, where supersonic wasn’t a big advantage.

  2. Aside: the C-119 provided one very unusual, inverse space traffic usage, as it was the first aircraft known to have performed aerial recovery of cargo dropped from satellites. US Corona spy satellites dropped film packages that the C-119 recovered in air, to prevent loss of sensitive data. They had down to 1 foot imaging resolution from orbit, and over 100 reels of film were successfully recovered.

      1. https://en.wikipedia.org/wiki/Mid-air_retrieval has some info about the general idea, and some specifically about the corona project (as does the corona entry.)
        The catch system was developed from an equally exciting system used to pick up people off the ground from a flying aircraft. Even better, a subvariant of this was used to yank-lift gliders off the ground and into flight, for recovery of used/empty military gliders after they had transported troops.

  3. Am I the only one thinking that this is a terrible idea? fuel prices keep going up, and they will continue doing so, and the plane is so big that not many runways will accept it.

    1. Fuel prices are mainly a political issue. If some crazy president messes with the oil market, e.g. threatening Iran or if some oeko-fascist environmentalists want to bring us back into the stone age, then oil prices rise. If the responsible people calm down again, then the problem mostly vanishes.

  4. It’s a little weird that the story mentions the Shuttle Carrier Aircrafts as modified 747s, but contrasts that with the An-225 as just getting…made? The An-225 is definitely developed from the An-124, though admittedly the “distance” from the An-124 to the An-225 is much greater than from the 747 to the SCA.

  5. I just looked at the cover art for September 1990 Popular Mechanics. Giant 2 million pound hydrogen powered planes will carry cargo halfway across the world. It looks like two 747’s with lots of engines on the two joining spars.

    Imagine how many pies (tarts) it will carry. Raspberry Tarts.

  6. If it can handle a large enough diameter it could transport rockets non air launch rockets that are too cumbersome to transport by road such as New Glenn,Vulcan, and StarShip that normally would have to ride a barge to the launch site.

      1. And now I realize you mean LAUNCHING shuttles from this. Then you should know: The solid rocket boosters detached at about 150,000 ft, so if you’re thinking of just using this instead of the SRBs, and maybe also using a smaller external fuel tank for the main engines, then this would have to be able to lift it to about that altitude. Not going to happen.

        1. Not only that but the SRBs detached at 150.000 feet AND already moving at 1284 m/s (nearly Mach 4) There is no way this monster is ever going to get close to those speeds

  7. With its lift capability it could handle standard CONEX with aerodynamic nose and tail cones added. Dunno how much drag the sides and bottom would add. Could have a coated fabric ‘sling’ to wrap tightly to slick it up. Wouldn’t want to deadhead back to home base without cargo. The least problem would be what to do with the aero cones without a CONEX.

    To save a bunch of weight from the standard steel CONEX, build air freight ones with aluminum frames and smooth composite panels, like many semi-trailers.

    Whatever the box style, flying CONEX with stratolaunch would have to be reserved for high value and/or very time sensitive stuff.

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