Paul Allen just rolled out the world’s largest airplane.

Called Stratolaunch, the plane has some impressive stats: a wingspan of 385 feet, or longer than a football field, a height of 50 feet. Unfueled, it weighs 500,000 pounds. But it can carry 250,000 pounds of fuel, and its total weight can reach as high as 1.3 million pounds.

I am an aviation buff so I love to see new aviation records even if it is Spruce Goose 2.0. That is one big-ass plane. I guess they are serious about air launching large rockets to put satellites in space but I don’t understand why that is such a big deal. They are only going to launch them from 35,000 feet which doesn’t seem like it would be a huge difference to me compared to a ground launch.

Does anyone know why you need the biggest plane in the world to help launch 1000 pound satellites into orbit from airliner altitude?

ETA - some good reasons are in the article comments. Apparently a head start like this greatly simplifies rocket design.

Cool, but I wonder why the super huge plane was needed. Looking at small-lift launch vehicles that lifted ~1500lb satellites to LEO, their weight was 75K kg to 100K kg. I presume the whole point of launching from high up is using up less fuel - so let’s say 50K kg? A regular Boeing can easily do that.

So why the huge plane?

There appears to be two cockpits. Does it require two pilots to fly it?

That is one big-ass plane!

Looks like someone had double mustang fascination?
Or some frankenstein dream involving a P38-J mating with a…

Wiki article on the basic concept.

It seems the main advantages are to get out of the more dense part of the atmosphere and to start the rocket at a high speed so it doesn’t need so much change in velocity (delta-v) to get to orbit. Basically using air breathing engines where they are more efficient than a rocket and then using the rocket once the air breathers run out of go. Other advantages include being able to manoeuvre around weather.

And an article on the aircraft itself. Bigger in wingspan than any thing else and about the same weight, with payload, as an A380. It used B747 parts to reduce development costs.

Not sure how it works with the two cockpits. Is one just a shell? Presumably two pilots required but they would be in the same cockpit I would’ve thought.

Looks like there’d be an awful lot of twisting force on that center wing section. I wouldn’t be at all surprised if the left and right control surfaces can operate independently, with some serious computing power controlling things to keep the two fuselages as parallel as possible. And I’d still only fly it in very calm weather to avoid turbulence.

I remember a class back in college where I saw some performance graphs of a Saturn V rocket. It weighed something like 6 million pounds at launch. It takes a lot of thrust to get 6 million pounds moving straight u[\p; it takes a lot of fuel to generate that much thrust, which weighs a lot, which takes a lot of thrust, etc. The rocket burned off about 3/4 of its weight in the first few minutes.

There’s a multiplier effect. Every little bit helps. You’re not only getting the rocket up to 35,000 feet, but you also get 500 mph (or whatever the launch speed is) of horizontal velocity in exactly the direction you want. And it could probably travel around a bit and launch from wherever in the world is most advantageous for the orbit they want.

With the two cockpits I can’t help but imagine two pilots co-ordinating and then getting it wrong:

“OK, we turn left x degrees in 3, 2, 1…”

“Dammit, I said left!”

[sounds of tearing metal…]

The vast majority of fuel used in a rocket launch is used in the first 30 seconds or so of its flight. Atmosphere is denser at ground level, and they have to get all that weight - including the fuel necessary to get to higher altitudes - off the ground and moving. If it’s already at altitude, you save all that fuel, and the rocket’s already moving, and you have much thinner atmosphere - Your thousand pound satelite will no longer need a monster-ass booster stage. Essentially, you’ve just eliminated the entire first stage of teh rocket.

So how big are these rockets going to be, can this thing theoretically launch IRBM’s

Goddamnitsomuch.

I saw the Antonov An-225 parked at the MSP airport a couple of years ago. Spotted it as we were rolling up to the gate on my return from Denver and about freaked. Newspaper story the next day said it was in town picking up some large AC units to take to the middle east (of course!).

Now some dumb bastard has to go and make one bigger.

There are windshields at the front of both fuselages, but I can’t see any reason to have two pilots separated like that. I have to think that it’s for commonality of tooling, or maybe there will be launch controllers or observers on one side.

Actually, I guess there could be a reason for pilots on both sides. During a launch, the rocket motors might generate some amount of debris. If there’s a risk of that breaking a windshield or breaching the flight deck, you’ve got a pilot on the other side who can still land the thing.

When you’re a billionaire, you can play Kerbal Space Program with tangible parts.

Given that it has been built to some extent using B747 parts to save cost, I suspect as you say it would be a tooling issue. It’s probably cheaper to use existing parts to build the nose of the non-pilot side than to re-tool to build a custom non-pilot nose. And the non-pilot cockpit windows could presumably be put to good use for something to do with controlling or observing the rocket.

It’s not nearly that good. This craft will probably go around 250 m/s. A typical first-stage booster is more like 2000-3000 m/s. The launch vehicles will all still be multi-stage; the air launch doesn’t enable SSTO.

The launch flexibility with regards to weather, etc. is much more useful.

It’s not clear to me exactly which vehicles they’ll end up using, but it looks like they wanted to use liquid fuels, had some issues, and have switched to solids. Which is a pretty huge performance loss and eats any gains they might get from the plane. Carrying around a giant tank of liquid oxygen seems… tricky.

I like big planes and novel launcher systems more than anyone, but I really have a hard time seeing the value of this approach.

The photos make it look like it’s got two flat fronts rather than the more traditional nose cones. Are they just not affixed yet or is this some new design?

There is only one cockpit on the right side, with a crew of three.

Not only is everyone in the starboard side, the port side is not even pressurized.
The torque on the center span must be, well,* interesting*…

Similarly, this photo shows them using two tugs to tow the plane out of the hangar, one tug under each cockpit. Seems like it would be a challenge to have both tugs pulling in the same direction; any misalignment in tow direction would result in the tugs pulling both cockpits toward or away from each other, putting large bending loads on the fuselages and the middle wing section.

Good aerial drone video of the rollout here; drone footage starts at 0:39, and drone slowly traverses from one wingtip to another (albeit high above and in front of the aircraft).