World's Largest Aircraft (Stratolaunch) Flies for the First Time

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Marc Zeitlin

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I thought there was already a pitch up lob plan for the jet only version of Stratolaunch, wasn’t there?
No. It was considered for both Stratolaunch as well as the SS1/SS2 programs, but it turns out that if you're trying to go as high as you can, there's no energy left over for a pitch up. And if you stay lower so that you've got excess energy for the pitch up, the angle isn't much and you don't get back what you lost from launching lower. Horizontal launch at the highest possible altitude turned out to be optimal. And in fact, you don't want to go TOO high, because then the wings on the rocket need to be very large in order to effect the gamma turn.

I think the best chance of success for the SL is versatility of mission capability. Orbital launch missions I think will be few and far apart, but the ability to carry a variety of loads would allow it to be used in other ways such as fire bomber, modular cargo pod carrier, or even a replacement for the Edwards test drop mothership. You could even use it for unusual or bizarre applications like citywide leaflet drops, record setting formation skydive drops, rocket section carriage, large fish repopulation drops in lakes, large scale paratrooper invasion force deployment, large sample statistical test to check the likelihood that cats will land on their feet, and shade at airshows.
Since the plane needs a dedicated launch facility to support it, and there are a VERY small number of airports out of which it can operate, I'd be extremely surprised if it's repurposed for anything other than rocket launches, and since it won't be doing that...
 

MikeK

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Thanks, Marc for the good post. From tv videos and movies, it seemed that they turned really soon. I remember hearing something about 'rotation' in the shuttle launches. I think that's when the shuttle rolled over with it's back to the Earth, and seemed not to be going straight up anymore.
Also, isn't 100k about the orbital altitude for some satellites? By the time they make that altitude, it's all horizontal, unless centrifugal force is used to go higher?
Obviously, I'm just guessing here, really like this forum.
 

Wanttaja

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Thanks, Marc for the good post. From tv videos and movies, it seemed that they turned really soon. I remember hearing something about 'rotation' in the shuttle launches. I think that's when the shuttle rolled over with it's back to the Earth, and seemed not to be going straight up anymore.
Also, isn't 100k about the orbital altitude for some satellites? By the time they make that altitude, it's all horizontal, unless centrifugal force is used to go higher?
The Shuttle would roll 120 degrees right after launch to put the vehicle, basically, inverted. This was primarily an efficiency thing; the upside-down position gave about a 20% higher payload capacity due to the balance between the solids and liquid rocket thrust and the aerodynamics involved.

I don't know the vertical vs. horizontal attitude timing during ascent. But the vehicle needs to get out of the sensible Earth atmosphere..."Space" is considered to start at 62 miles altitude...as well as increase speed from zero to about 18,000 miles an hour. All in a few minutes.

Found this piece of artwork online. It's a plot of the optimal, not the actual, ascent angle, but probably gives a good idea of the real thing. Not sure of the reason for the discontinuity at 50 seconds, but it's probably related to the algorithm used to compute this.

While 62 miles (about 330,000 feet) is considered the boundary of space, that's still waaay to low for mission life of any duration. Most systems try get up to ~150 miles MINIMUM. The ISS is at about 250 miles, and they lose about a mile a month and occasionally have to boost back up. One of my payloads went to 300 miles and deorbited about two years later.

BTW, I'm a satellite operations guy, not a launch guy. So there may be some mistakes in this....

Ron Wanttaja
 

Aesquire

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The many ways to skin the Tiger.

SSTO, single stage to orbit, is the Grail, but may remain mythical as current materials still don't give a useable payload, depending on assumptions.

so two stage is generally how it's done, today. ( third stage for higher orbits )

I liked Blackhorse. Horizontal take off, then aerial refuling, before pitch up and orbital speed run. Winged Vehicle. They assume cryogenic fuel transfer is easy. not yet built.

in the fictional "The Goliath Stone" by Niven & Harrington, the first stage is "the world's largest airplane" with a piggy back next gen winged orbiter/lander. The trick on this idea is an on-board liquid oxygen system that fills the oxidizer tanks on both birds after lift off, from the air it climbs through. Then rocket boost much higher & faster than Stratolaunch, before separation. Currently fictional.

The philosophical divide is artillery rockets vs. Space plane.

von Braun & early NASA until the Shuttle was dominated by artillery thinking. Expendable boosters releasing the payload to ballistic flight.

Stepped rockets, multi stage systems, are all from the artillery side of the business.

Fly on wings to orbit concepts haven't had the funding, and so far, require staged flight too.

So mixed philosophy designs like the U.S. Shuttle, or Rutan's SS1, are the "crazy fringe guys" as are the SpaceX reusable boosters. While the big, throw away artillery rockets are mainstream.

It's an awesome time to be alive, with ideas that were science fiction just a few years ago appearing in real form.

For MikeK, I have the Congressional report on the Shuttle program. Some wild ideas that were not pursued because of budget weirdness.

Congress favors programs that cost less per year, but far more in total, using a logic of their own. And....that's enough politics.

Chrysler developed a system much like the ZMC-2, for building huge fuel tanks, but instead of the riveting machine, they used spin welding. Same row on row circular track, same lift from one end as the machine at ground level fastens the plates together.

Should work great on your proposed plastic construction.
 

autoreply

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Interestingly, one of the original thoughts (and I'm pretty sure I mentioned this in a previous thread) was to have rocket boosters in the twin booms to provide extra thrust, so that the aircraft could climb at a 45 degree angle during the launch, to eliminate 1/2 or more of the gamma turn. And that would have made a large difference in payload capacity of the rocket. However, the idea of having even liquid or hybrid motors that could theoretically be shut off go asymmetric in thrust due to a failure of some type was deemed far too risky, given the non-centerline thrust - it would essentially guarantee loss of the aircraft and crew, and the idea was discarded.
Do you know whether the possibility of starting the rocket's engines before release was ever seriously looked into.

As a sidenote, how does 250 tonnes of water+foam on a forest fire look like?
 

Victor Bravo

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=World smallest 5-place jet...
WTF does this have to do with the subject of this thread?

Back on topic, the Strato Launch... Is there a potential usage model for this aircraft carrying a large modular passenger pod? The Sikorsky Skycrane was envisioned as being able to use this kind of pod in one of its proposed versions.

I am talking aboaut a model where there are loaded passenger pods waiting at each destination, that streamlines/improves the entire pre- and post-flight infrastructure?

Land in Tokyo, the passenger pod (or pods) are dropped onto a wheeled vehicle and driven off of the airport to a terminal away from the airport. Another loaded passenger pod is loaded under thr mother ship within ten minutes, and it taxis back to the runway and takes off for Los Angeles.

Just as with freight trains, this huge aircraft could carry more than one pod, not all of which are going to the same destination. One set of passengers from Los Angeles are being offloaded in Tokyo, the other two are going all the way to China and India. The new one that was loaded into the empty space at Tokyo is full of people traveling from Tokyo to India, even though the folks in the other pod were going from LA to China and Mumbai.

NO gates, baggage handling and food service needed at the airport any more. The passenger terminal, and that !(#*%$ airport parking nightmare, and full public transit access, and car rental, and hotels, and TSA security can all be at satellite locations that are de-centralized and a lot cheaper to operate. And none of these components and processes slow down the operation of the "air" side of the airport.

What was the "airport access traffic jam" on the freeways and streets, the nightmare of holiday chaos at the airport, is now divided into several non-chaotic places ten miles outside of the airport.

This would likely have the effect of adding more capacity in the same size airport facility.

OK, fire away with both barrels, what am I missing?
 

narfi

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Perhaps difficult to use with an existing platform but I really like the idea of modular 'pods'
If the pods were researched and standardized, they could be sized for passenger/luggage or cargo.
If standardized there could be different sized lifting platforms designed for one or more such pods depending on the route needed.

Like you said, layovers could be much shorter, Pods would be relativly cheaper than an entire aircraft and could have extras at each location for cleaning, loading, etc.....
If the pods can be trucked or tugged, then really they could be loaded anywhere within a 5-10 mile radius of the airport.
Aircraft wouldnt need to park near buildings, pods could be 'docked' anywhere on the ramp.
Lines and congestion and cargo loading could be moved further away from the airport.

Basically the cargo containers of the air.

Lots of positives, but would require an entire paradigm shift as is the case for many 'efficient system ideas'

I can see it being THE way it is done in a utopian future.
 

radfordc

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Perhaps difficult to use with an existing platform but I really like the idea of modular 'pods'
If the pods were researched and standardized, they could be sized for passenger/luggage or cargo.
If standardized there could be different sized lifting platforms designed for one or more such pods depending on the route needed.
/QUOTE]

I like it....it just takes the concept of "cattle car" to the next logical step.
 

narfi

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I like it....it just takes the concept of "cattle car" to the next logical step.
Heck if you have the money, you can own your own pod for the ultimate first class experience.... It just needs to conform to the pod standards.
A full range of cattle car for you and me, to first class for the business traveler, to personal luxury pods for the rich and famous.
 

Wanttaja

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Heck if you have the money, you can own your own pod for the ultimate first class experience.... It just needs to conform to the pod standards.
They used to do this ~100 years ago. The rich had their own railroad cars, and if they needed to go somewhere, they just paid to have their car hitched to whatever train was headed there.

It would only make economic sense in an aircraft mode if the carrier could haul, say, five pods at a time. Four could be cattle-car expresses, with one slot left over for personally-owned pods.

Ron Wanttaja
 

BJC

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They used to do this ~100 years ago. The rich had their own railroad cars, and if they needed to go somewhere, they just paid to have their car hitched to whatever train was headed there.

It would only make economic sense in an aircraft mode if the carrier could haul, say, five pods at a time. Four could be cattle-car expresses, with one slot left over for personally-owned pods.

Ron Wanttaja
Isn’t Stratolaunch privately owned?


BJC
 

MikeK

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I think this is a fine thought experiment, good to move forward in air transport. I just wonder how much servicing a passenger plane needs, besides the usual cabin cleaning, refurbishing, etc., as far as the aircraft itself between flights. Personally, I would want the plane looked over carefully after a long flight. They are not locomotives.
 

Wanttaja

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Do you know whether the possibility of starting the rocket's engines before release was ever seriously looked into.
Way back in the dawn o' time, I worked in the "bullpen" environment at Boeing. They'd have a big room with rows and rows of desks, surrounded by manager's offices. Each manager had five or ten engineers working for them, USUALLY clumped together in the bullpen, but not always. What this mean is, no matter what you were working on, yourself, you got exposed to what other folks were up to.

I was in a normal office desk next to a drafting table with man named John Jacob Olson...we all called him Jack. He always proudly described himself as an engineer...but he also WAS an artist. He would design a space system, then paint a beautiful image of it in operation.


Anyway, I was working a study for survivable satellites, and Jack was working on a program for rapid replenishment of destroyed satellites. They were looking at using a 747 like the Stratolaunch system...hauling the payload up to 40,000 or so, then launching it.

One configuration needed more oooomphhhh....so Jack added a Space Shuttle Main Engine at the back end of the 747. Looked REAL Bad-XXX. I actually contributed to the painting. Jack wanted to show it over Peterson Field (NORAD headquarters at Colorado Springs) and wanted to know the color of the terrain in the area (answer: brown).

Jack usually put an Easter Egg or two into his painting. He was a sailplane pilot, and often slipped a glider into the background. No glider in the Mars lander painting above...at least as far as I can see...but it has at least two Easter Eggs.

Ron Wanttaja
 

Wanttaja

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Jack usually put an Easter Egg or two into his paintings.
This is my absolutely, most favorite Jack Olson/Easter Egg. I'm overjoyed I found the image online. Jack himself told me the story, about 35 years ago.

His boss was scheduled to give a presentation on the Apollo program, and had asked Jack for a painting showing the lander on the Moon with astronauts starting to explore.

Jack finished the painting, and got his boss's OK. Afterwards, he decided the lunar surface looked a lot like the Arizona desert. He made one addition, then had the image photographed and added to his manager's chart pack.

A few days later, the boss was giving the presentation. This image was flipped onto the screen. Someone giggled. Someone else giggled. Soon the who audience was laughing. The boss turned slowly around and viewed the image on the screen. He looked for a moment, then turned back to the audience. "I've got an engineer who's a real card......"

How long will it take you to spot it?

They had a display of Jack's paintings at the Air And Space museum about twenty years ago. Didn't remember seeing this one....

Ron Wanttaja
 

Marc Zeitlin

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Do you know whether the possibility of starting the rocket's engines before release was ever seriously looked into.
Not seriously, no. The failure modes boggle the mind.

As a sidenote, how does 250 tonnes of water+foam on a forest fire look like?
Useful, but this plane is NOT a quick turnaround thing (firefighting airplanes land, fuel/water up, and are back out in an hour or so. That's not going to happen here. And there may only be 3 - 4 airports in the US from which it can operate, if that.

It'd be a hell of a thing to see, though - I've seen the DC-10 firefighting aircraft do a drop a few miles from my house, and it's **** impressive.
 
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