Siamese Jets
April 16, 2019 9:19 PM   Subscribe

What's bigger than an American football field and flies? The Stratolaunch. April 13 saw its first flight, a two and half hour shakedown over the Mojave. Previously.
posted by Tell Me No Lies (45 comments total) 10 users marked this as a favorite
 
too floppy to be aerodynamic, too ambitious to be earthbound
posted by eye of newt at 9:35 PM on April 16, 2019 [56 favorites]


Those dual-fuselage set-ups make me anxious. Some part of my hamster-brain is waiting for them to decide they want to fly separately . . .
posted by pt68 at 9:39 PM on April 16, 2019 [9 favorites]


I'll tell you what I don't want to see. A fly bigger than an American football field.
posted by hippybear at 10:28 PM on April 16, 2019 [9 favorites]


It does look ungainly, but like hanging engines on the wing rather than the fuselage, it actually reduces the overall structural load. It's too bad the entire venture is ultimately doomed, because it's very impressive.

It will either fail outright or be restricted to a very small niche thanks to the tyranny of the rocket equation, limitations of powered flight, and the economics of sharing larger launch vehicles. Basically, the Spruce Goose of spaceflight. (Maybe the Sea Dragon would be more aptly compared to that, but it never actually flew)
posted by wierdo at 10:36 PM on April 16, 2019 [2 favorites]


Those dual-fuselage set-ups make me anxious.

So, a thing I learned a while ago, is that one reason that freight trains have gotten so long (an issue if you live out west in Rail Country like I do), is that they've developed systems that let the leading engines perfectly coordinate with the rear engines for speed and such. I once saw a train that was probably 2 miles long with 5 leading engines and 2 rear engines. (I live in Rail Country... did I mention that?)

If they can get rail engines communicating well along 2 miles of interconnected cars, they can get two airplane fuselages flying next to each other to coordinate as one. That's the least of my worries about this.

They say they can carry up to 500,000 pounds. But it's nowhere near actual Low Earth Orbit launching altitude at this point. 17,000 feet altitude? That's not even cruising altitude for our jetliners which themselves are nowhere near a good launch altitude to achieve orbit off of a slow-flying plane.

They're going to have to drastically improve speed and altitude if this dream is going to work.
posted by hippybear at 10:37 PM on April 16, 2019 [2 favorites]


It can fly much higher than 17,000 feet--probably double this. This was just a test flight--its very first flight. Think of it as a baby's first steps. Don't judge yet.

And they already launch Pegasus launch vehicles from a plane (the Lockheed L1011). They are planning a Pegasus launch from the Stratolaunch.

Just getting above much of the lower altitude higher density air saves a lot on rocket fuel, plus you can 'launch' from anywhere the plane can fly.

Probably the important number, though, is price per kilogram for the payload, and Space X is very competitive (the Falcon 9 is about $4.6k/kg). Europe has a new Ariane 6 launch vehicle they are finishing up in a couple of years and they are already worried they won't be able to match that price. I doubt the Stratolaunch can either.

Still--it is very impressive--the largest wingspan of any aircraft.
posted by eye of newt at 11:03 PM on April 16, 2019 [4 favorites]


The target altitude for payload release is 11 km per the wiki page.
posted by flyingfox at 11:12 PM on April 16, 2019 [1 favorite]


The giant plane was a project of Microsoft co-founder Paul Allen. Since his death last year the plane's future may be limited.
posted by Cranberry at 12:22 AM on April 17, 2019


From wikipedia:

The pilot, co-pilot and flight engineer are accommodated in the right fuselage cockpit, while the left fuselage cockpit is empty and unpressurized.[22] The flight data systems are in the left fuselage

So it's a right-hand drive, I wonder what drove that decision.
posted by each day we work at 1:02 AM on April 17, 2019 [4 favorites]


There are a far number of advantages to launching your rocket from 10km up. Rockets burn a lot of fuel getting high enough up that the air is thin enough that rolling over & starting that orbital burn parallel to the earth’s surface makes sense, plus having to design bells that are reasonably efficient (& don’t blow up on you) at both ground air pressure & high altitiutude compromises the design & makes them less efficient at both.

But in a world where SpaceX has pretty much nailed (most of the time) re-usable surface rockets it’s not clear that these advantages are going to allow them to make much headway in the market.
posted by pharm at 3:13 AM on April 17, 2019 [1 favorite]


Also, you can launch from anywhere in range of a suitable runway & in any direction, which is kind of handy - saves on awkward & expensive (in reaction mass) orbital transition burns.

Even so, the general feeling online seems to be that Stratolaunch is about deniably filling a hole in US military capability, because no one can work out why else you’d build the thing - the above advantages don’t seem to be enough to outweigh the disadvantages. But if your need was to get a new satellite pronto, regardless of the state of your usual launch sites? Roll one of these beasties out the hanger, strap your rocket on and off you go. That’s a capability the military might be quite interested in having in their back pocket should the need arise.
posted by pharm at 3:30 AM on April 17, 2019 [5 favorites]


I'm guessing they can't ignite the engines until the launch vehicle has detached. That makes for some pretty unpleasant abort scenarios.
posted by RobotVoodooPower at 4:35 AM on April 17, 2019


But if your need was to get a new satellite pronto, regardless of the state of your usual launch sites? Roll one of these beasties out the hanger, strap your rocket on and off you go.

...just so long as your new satellite doesn't mass more than a couple hundred kilos.
posted by GCU Sweet and Full of Grace at 4:53 AM on April 17, 2019


too floppy to be aerodynamic, too ambitious to be earthbound

I'm reading the front page top to bottom so didn't recognize the brilliance of this comment until later, but I had to come back. Hat tip to you, you magnificent mefite.
posted by Literaryhero at 5:06 AM on April 17, 2019 [8 favorites]


I await the inevitable plane with four asses.
posted by snuffleupagus at 5:17 AM on April 17, 2019 [6 favorites]


> Those dual-fuselage set-ups make me anxious. Some part of my hamster-brain is waiting for them to decide they want to fly separately . . .

For me, I'm not so worried about each half flying in different directions as I feel like they're going to twist around the center wing.
posted by ardgedee at 5:17 AM on April 17, 2019 [2 favorites]


So it's a right-hand drive, I wonder what drove that decision.

Jousting, obviously.
posted by pompomtom at 5:19 AM on April 17, 2019 [9 favorites]


That’s a capability the military might be quite interested in having in their back pocket should the need arise.

This is plausible, but it is also right out of a Dale Brown novel.
posted by snuffleupagus at 5:20 AM on April 17, 2019 [1 favorite]


Basically, the Spruce Goose of spaceflight. (Maybe the Sea Dragon would be more aptly compared to that, but it never actually flew)

Not surprising, really. It doesn't look very aerodynamic at all.
posted by Naberius at 5:34 AM on April 17, 2019 [1 favorite]


Those dual-fuselage set-ups make me anxious. Some part of my hamster-brain is waiting for them to decide they want to fly separately . . .

For me, I'm not so worried about each half flying in different directions as I feel like they're going to twist around the center wing.


Twin-fuselage aircraft have been a thing for a while, although the Twin Mustang was also joined at the tails. More common was the twin-boom design of the P-38.

Stratolaunch's development and performance will also presumably be used to advance MAV's other work with The Spaceship Company, i.e. launching Spaceship Two.
posted by snuffleupagus at 5:39 AM on April 17, 2019 [2 favorites]


This was my idea when I was about ten years old: why do they spend money on all those expensive space shuttles when they could just fly a plane up and up and up until it reaches space? This isn't exactly that, but it sort of splits the difference. I wonder how feasible it actually could be in putting new satellites into orbit.
posted by zardoz at 5:56 AM on April 17, 2019


I've wondered why we don't have dirigible launch platforms, to avoid dealing with high density at low altitudes by floating the vehicle up at a more leisurely pace, but given the age of that tech I presume it's been studied and discarded.
posted by snuffleupagus at 6:08 AM on April 17, 2019 [1 favorite]


Oh man

I'm making a mental plan for a twin-paper-airplane attached with a skewer that has a hook dangling down in the middle that attaches to a rubber band for launching purposes

(Hey, I'm not a billionaire, I have to make do with whatever I can find around my desk)
posted by duffell at 6:12 AM on April 17, 2019 [1 favorite]


Those dual-fuselage set-ups make me anxious. Some part of my hamster-brain is waiting for them to decide they want to fly separately . . .

Can I interest you in a flight on my BV 141?

No?

Okay, how about my Rutan Boomerang?
posted by Big Al 8000 at 6:33 AM on April 17, 2019 [2 favorites]


Some people are still working on airship launch platforms. The problem with all of this kind of stuff is that you usually still have to build a two-stage rocket. So you have a choice between being a company that makes an aircraft/giant blimp/tall tower/railgun and a two-stage rocket, or just putting more kerosene in your rocket's first stage and eating the efficiency hit you get from needing an engine that works at sea-level.

There are some other operational advantages to air-launch, but no-one's made it pay (Virgin Orbit's simpler, 747 based, approach seems more likely to work out to me, especially if they get a launch off this year), and now that Stratolaunch's funding is gone, and they're no longer developing the larger rockets, I don't see it working for them either. I don't think there is any particular reason to launch Pegasus rockets from a Roc vs an L-1011, unless you want to launch 5 at a time or something weird like that.

Cool plane though. I'm glad they at least got it flying.
posted by rhamphorhynchus at 6:38 AM on April 17, 2019 [3 favorites]


747 based approach

They tried that. It didn’t turn out well.
posted by Tell Me No Lies at 6:53 AM on April 17, 2019 [2 favorites]


The problem is not getting a rocket way up high, a balloon could do that but getting it to go fast, really really fast. Not super sonic fast, the ISS leaves the fastest military jet in the dust, the Blackbird spy plane went 2000 mph, orbital speed is over 8 times that fast. And the Blackbird could barely get it's own weight off the ground and needed to be refueled in the air for any practical mission.

Going really fast in the atmosphere shakes things apart so rocket get above the air as quick as possible, once that high gotta bring your own O2 and now you're a rocket.

Getting rockets into space is less some great new science than many small engineering details, for instance the SpaceX Falcon 9 series has improved it's efficiency to where it's power overlaps the next generation Heavy models. It's possible at some point the weight power equation will make the air launch practical but that will never happen if there are not tests and improvements that make it work for any but the tiniest payload.
posted by sammyo at 7:00 AM on April 17, 2019 [2 favorites]


I once saw a train that was probably 2 miles long with 5 leading engines and 2 rear engines.

Canyonero!
posted by Faint of Butt at 7:08 AM on April 17, 2019 [3 favorites]


One of my favorite historians is Richard Bulliet (pronounced Dick Bullet), and he maintains that in Indo-European cultures, the concept of Unity is associated with the Two instead of One, and as a result, throughout history these peoples have been unable to harness animals except in yokes of two. There's something fundamentally wrong with having only one; to be whole, you need two, and one is only a half.

This reminds me of that. This is a yoke of planes!
posted by I-Write-Essays at 7:12 AM on April 17, 2019 [3 favorites]


Air-launch has a long history - indeed, the 1960's era X-15 was air-launched and reached space (but not orbit) a couple of times. There's several advantages of air-launched rockets - you generally don't have to worry about the weather because the altitude you air-drop from is above the clouds; Max Q is lower because by the time you get up to speed you will be at a higher altitude; Because the craft that does the air-drop is jet-engine based, it's very efficient; you can launch from anywhere within range of the aircraft; and you need a much smaller rocket because you don't have to worry about getting past the dense soupy atmosphere in the troposphere.

That said, air-drop gives you a whole bunch of additional headaches, namely: The tanks have to be designed to lie flat - in a standard rocket you need them to be longitudinally strong but not necessarily laterally strong, and you need both for air-drop; If the fuels for the rocket are cryogenic, you need a way to keep them cool whilst the aircraft gets to the target altitude and position; Additional failure modes ; The expense of designing and maintaining a massive plane ; Bolting on extra boosters for bigger launches is significantly harder because you're limited to a particular size that the plane can carry ;

Whether it's worth pursuing, who knows, but as someone mentioned it's possible there's a military application where the ability to launch a small satellite to a particular inclination from anywhere may be useful.
posted by BigCalm at 7:16 AM on April 17, 2019 [4 favorites]


Somehow I missed Paul Allen passed away.
posted by zenon at 7:56 AM on April 17, 2019


deniably filling a hole in US military capability

Delivering a single tank so fucking big it outclasses most countries entire military on its own.
posted by Segundus at 8:01 AM on April 17, 2019 [1 favorite]


> Delivering a single tank so fucking big it outclasses most countries entire military on its own.

Do you mean, GUNDAM?!
posted by I-Write-Essays at 8:34 AM on April 17, 2019 [3 favorites]


Any self-respecting gundam designer knows to include rockets in the feet, making this craft unnecessary.

Stratolaunch totally overestimated the market for gundam transportation.
posted by Big Al 8000 at 8:51 AM on April 17, 2019 [6 favorites]


Air launch has the potential to allow for launching from sites that aren't south out of Vandenberg or east out of Cape Canaveral, which is fairly limiting. Opening up additional (niche) launch sites would allow for more launches and more routes to (different parts of) space. Humanity's fundamental limitation with rocketry is cost. Not in the dollars sense, but the amount of fuel it's possible to put into orbit, and then what to allow ourselves to spend the limited amount of fuel on, once there.

SpaceX blew up multiple rockets trying to land on a goofy barge in the middle of the ocean because launching the rocket east out of Cape Canaveral and then flying it back to land at Cape Canaveral takes up a helluva lot of fuel, fuel that could be better used to send the rocket higher, thus it was important to get barge landings working. Which they did. (Safety was an important factor too.)

Unfortunately, there's no technology on the horizon that can fundamentally change the equation from being absolutely dominated by fuel cost. Opening up more convenient routes to space will change that and hopefully the opening up of Space to tourists, which will bring in (more sources of) money to get to Space, and then maybe the Moon and Mars.
posted by fragmede at 8:59 AM on April 17, 2019 [2 favorites]


Uh guys, clearly this is to deliver jaegers.
posted by soren_lorensen at 9:12 AM on April 17, 2019 [1 favorite]


Seems like overkill when six Chinooks can do it.
posted by Tell Me No Lies at 9:16 AM on April 17, 2019


I think BigCalm pretty much has it. If I were to speculate, certain US three-letter agencies might be interested in the ability to put up a spy sat in any orbit they choose at very short notice, without being hindered by potential poor weather at conventional launch sites.
posted by Eleven at 10:36 AM on April 17, 2019


It looks a bit like a fake Youtube thumbnail ("10 Aircraft you won't believe!" with optional Shocked Dude face)
posted by kurumi at 11:20 AM on April 17, 2019 [1 favorite]


Is there much that a TLA would want to orbit that fits in the 270-400kg payload Pegasus can loft?
posted by GCU Sweet and Full of Grace at 11:24 AM on April 17, 2019


the general feeling online seems to be that Stratolaunch is about deniably filling a hole in US military capability

It is hard to come up with any other scenario than this. Though it still represents more long-term thinking than I'm used to seeing.

The Pegasus (the only launch vehicle the Stratolaunch is planned to utilize, at least right now) was originally designed to be launched from a B-52 mothership. Northrop/Orbital uses a modified L-1011, which is somewhat ironic since there are now fewer 1011s flying around than B-52s. But if you wanted to get a new launch platform for military payloads, moving it back to the B-52 would make a lot more sense. Or redesign the launch hardware/electronics for a more common modern airframe, like the 737 (which the USAF flies as the C-40).

I've heard some speculative theories that the Stratolaunch is meant as a air-launched ICBM platform, or a non-nuclear kinetic weapon (Prompt Global Strike) but of course that doesn't make a ton of sense either—again, you'd be better off going back to the B-52 as a launch platform: there are more of them, they're more survivable, they have all sorts of ECM stuff that Stratolaunch presumably doesn't, the logistics to support them from various airbases already exists, there's lots of qualified pilots, etc. I guess you could probably drop more than one off the Stratolaunch per mission, but... if you're the Air Force, why not just task a few '52s for the same thing? Doesn't wash. Same with a bigger weapon: the Stratolaunch has ~7 times the payload of a B-52, but modern US ICBMs aren't that big, and there's no advantage in making them bigger, once you've got the capability of putting a solid-fueled weapon in LEO, mission accomplished. Unless you want to nuke the moon, I guess. (A possibility that has been explored in this excellent documentary.) I'd like to believe it's all part of a plan to intercept asteroids, but... probably not.

You get the same thing in the civilian market: the Stratolaunch looks like it'd be physically capable of launching multiple Pegasus vehicles in a single flight, but why would you want to do that? It adds a ton of complexity and probably significant failure risk, and all you're saving is the cost of fuel and pilot time, hauling the thing up to launch altitude. I can't imagine that's really enough of a cost savings to justify a new aircraft.

Basically: the Stratolaunch doesn't make sense as a launch platform for Pegasus. Really, it only makes sense if you're planning to develop some sort of reusable, quick-turnaround spaceplane, in which case it's quite ideal. Basically it's the Conroy Virtus 2.0 (the Virtus was going to be two B-52 fuselages strapped together, very similar to the Stratolaunch, and would have air-launched the Shuttle). But there's a reason that the Virtus was never built; it didn't make sense vs. the Shuttle's actual configuration with the SRBs, and probably even less sense than Saturn-Shuttle, which is probably what we should have done all along.

So... without any obvious reason for it to exist to launch the Pegasus, you quickly get into speculative territory, with stuff like the X-37 playing a big role. The X-37 was drop-tested from the White Knight, which was the predecessor to Stratolaunch (built by Rutan's Scaled Composites before its acquisition by NG). So... if you were going to build a bigger X-37, even if you were planning on launching it some other way, you might want something like Stratolaunch to conduct atmospheric testing.

That said, air-drop gives you a whole bunch of additional headaches

Air-drop does give you at least one advantage, though: you can use air-augmented rockets (basically, rocket ramjets) or a liquid-air cycle engine without having to boost the vehicle up to speed with SRBs or conventional jet engines. And air-augmented engines have some significant theoretical advantages over standard rockets in terms of the fuel equation. You can get air-augmented rockets with non-cryo fuels (jet kero and RFNA) that have the same specific impulse as hydrogen burners, at least when they have air to breathe—and they work in pretty thin air. Off the top of my head, and without doing any math, maybe it would reduce max Q by letting you take more time getting up and out of atmosphere? That might be useful for delicate payloads. The British played around with LACE engines for their HOTOL SSTO concept.

Anyway, I don't see anything obvious sitting around that makes a lot of sense to haul up in the air with the Stratolaunch, but maybe someone decided it was too nice a capability to just see scrapped, when it was so close to completion when Allen died. That makes it a platform looking for a purpose, which is not the best situation to be in, but it'll be interesting to see what it ends up doing.
posted by Kadin2048 at 11:30 AM on April 17, 2019 [6 favorites]


Is there much that a TLA would want to orbit that fits in the 270-400kg payload Pegasus can loft?

With half the world testing their own ant-satellite weapons, I’d say that microsatellites are coming into their heyday.
posted by Tell Me No Lies at 12:28 PM on April 17, 2019 [1 favorite]


Unfortunately, there's no technology on the horizon that can fundamentally change the equation from being absolutely dominated by fuel cost.
There is no current launch system whose launch price is remotely close to dominated by fuel cost. A few hundred k$ of kerosene is burnt during a $60M Falcon 9 launch for example.

If I were to speculate, certain US three-letter agencies might be interested in the ability to put up a spy sat in any orbit they choose at very short notice, without being hindered by potential poor weather at conventional launch sites.
Yup. DARPA are running a whole thing on this.

if you were going to build a bigger X-37, even if you were planning on launching it some other way, you might want something like Stratolaunch to conduct atmospheric testing.
How much bigger?! The Shuttle did its drop testing from a mere 747, and it's hard to imagine anyone going bigger than that. I don't think there's much need for conspiracy theories here; they're doing Pegasus because it's available, and they had plans for bigger rockets and a spaceplane, but those have been shelved.

The British played around with LACE engines for their HOTOL SSTO concept.
If you haven't heard the Interplanetary Podcast's recent interviews with Alan Bond, you'd probably find them interesting. Fascinating guy.
posted by rhamphorhynchus at 2:05 PM on April 17, 2019 [3 favorites]


So it's a right-hand drive, I wonder what drove that decision

It would put the pilot closest to the aircraft certerline, but that probably wasn't it.
posted by achrise at 8:06 AM on April 18, 2019


O.k. super late, but for posterity: An ICBM being launched by dropping it out of the back of a C5 galaxy
posted by JoJoPotato at 2:09 PM on May 2, 2019


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