Author Topic: Stratolaunch Announcement, Updates and Discussion  (Read 610290 times)

Offline Zed_Noir

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Re: Stratolaunch Announcement, Updates and Discussion
« Reply #2220 on: 01/21/2019 12:30 am »
I wonder if Musk is thinking about buying Stratolauncher for transport of SpaceX BFR components? It would sure simplify a lot of transportation options...

Won't fit.  The vertical clearance under the wing is about 23 ft. as I recall from when Burt briefed it to me back in 2007.

How about mounting the cargo above the wing?

Offline JazzFan

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Re: Stratolaunch Announcement, Updates and Discussion
« Reply #2221 on: 01/21/2019 12:39 pm »
I wonder if Musk is thinking about buying Stratolauncher for transport of SpaceX BFR components? It would sure simplify a lot of transportation options...

Won't fit.  The vertical clearance under the wing is about 23 ft. as I recall from when Burt briefed it to me back in 2007.

How about mounting the cargo above the wing?


Wouldn't want to be the pilot as that thing ignited and launched over my head.

Offline libra

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Re: Stratolaunch Announcement, Updates and Discussion
« Reply #2222 on: 01/21/2019 05:44 pm »
Quote
Or NASA would use it for a next-gen telescope even larger than JWST.

Hell of an idea here. Unfortunately SOFIA cost an arm and a leg and took nearly two decades to replace old C-141 KAO.
But one could indeed hang a pretty big "astronomy platform" below that thing; how high can it fly ?  Imagine a 20 ft diameter mirror IR telescope hanging there...

We should have a "Roc speculative missions / future " thread. My personal favorite would be to fit a removable cargo / passenger pod under that big wing.
think XC-120
https://en.wikipedia.org/wiki/Fairchild_XC-120_Packplane

I'm quite sure that a with a well designed cargo pod the Roc could beat the An-225 into a  pulp when carrying oversized cargo.
« Last Edit: 01/21/2019 05:47 pm by libra »

Offline ncb1397

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Re: Stratolaunch Announcement, Updates and Discussion
« Reply #2223 on: 01/21/2019 06:23 pm »
Quote
Or NASA would use it for a next-gen telescope even larger than JWST.

Hell of an idea here. Unfortunately SOFIA cost an arm and a leg and took nearly two decades to replace old C-141 KAO.

That wasn't what I meant, but it is an interesting idea as well. JWST gets packed into a container called STTARS and shipped around to various facilities - often by air. You can see how tight of a fit it is on some of the larger military transport planes here:

https://svs.gsfc.nasa.gov/12780

Offline zhangmdev

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Re: Stratolaunch Announcement, Updates and Discussion
« Reply #2224 on: 01/21/2019 07:07 pm »
Straight wing. No trailing-edge or leading-edge flaps. No spoilers. Too-wide-set and not-so-strong-looking landing gears. It is a lashed up job. I doubt it has the range or speed to compete with those Antonoves, or it could be certified to use necessary airfields. And where is the money to develop that mission pods? Its best fate is to fly once to prove it's airwirthyness then retire as a museum piece.

Online Prettz

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Re: Stratolaunch Announcement, Updates and Discussion
« Reply #2225 on: 01/21/2019 07:11 pm »
We should have a "Roc speculative missions / future " thread. My personal favorite would be to fit a removable cargo / passenger pod under that big wing.
think XC-120
https://en.wikipedia.org/wiki/Fairchild_XC-120_Packplane

I'm quite sure that a with a well designed cargo pod the Roc could beat the An-225 into a  pulp when carrying oversized cargo.
I've been wondering about a cargo pod for Roc, since that's essentially the only other thing this plane could carry. I'm wondering how wide could such a pod *safely* be, compared to the fuselage of the An-225?

Offline zhangmdev

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Re: Stratolaunch Announcement, Updates and Discussion
« Reply #2226 on: 01/21/2019 08:07 pm »
Let's layout some requirements to the cargo pod.

1. Very large, enough to contain something as big as a wind turbine blade.
2. Very strong, something as heavy as a main battle tank can drive onto it.
3. Big door and ramp accessable to oversized cargo.
4. Able to lower itself to assist cargo handling.
5. Immensely strong mating to the plane. Hundreds of tons of weight hooked on the center wing. Also removable?
6. Aerodynamic enough so it doesn't degrade range and speed too much.

A properly-designed heavy lift plane does 1-4 within its fuselage. It does not need to do 5 and 6. Passenger carrying pod needs somehow to pressurize the huge space inside. That is even harder. An-124 skipped that.

Offline libra

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Re: Stratolaunch Announcement, Updates and Discussion
« Reply #2227 on: 01/22/2019 06:40 am »
Nice description, really how I magined it.

Since the rocket was to weight 250 mt, as long as the pod weight 250 mt, too, the hardpoint on the wing should be able to handle it.
Aerodynamically however they are pretty different. Pointy rocket versus fat pod.

1. Very large, enough to contain something as big as a wind turbine blade.
2. Very strong, something as heavy as a main battle tank can drive onto it.

Fine.

3. Big door and ramp accessable to oversized cargo.

Good.

4. Able to lower itself to assist cargo handling.

Even with the ramp ? Note that unlike an An-225, the cargo area is independant from the fuselage, I mean the entire aircraft don't need to "kneel" down.

5. Immensely strong mating to the plane. Hundreds of tons of weight hooked on the center wing. Also removable?

not worse than the original rocket, if weight is limited to 250 mt, cargo included; how much would the (empty)  pod itself weight, no idea. Probably 30 mt or more.
Note that since the An-225 carries 250 mt, and roc, 250 mt too BUT without the pod weight, then the payload should be 200 mt or a little more, hence inferior to the Antonov.
 Roc strength would be that the pod interior could be designed without the internal limits of the An-225 cargo area (higher or longer or wider or without floor or ceiling limits)

6. Aerodynamic enough so it doesn't degrade range and speed too much.

Yup. Ovale or streamlined, sure.

In fact Stratolaunch should have somebody examining the interior of the An-225 cargo hold, note the limits in ceiling, length, width, and design the pod without the weaknesses, so that it could carry oversized cargo the An-225 can't.

Note that the An-225 forerunner, the VM-T (a modified 3M bomber) sometimes carried weird shaped payloads. i think a Roc cargo pod could look like the VM-T payloads.
https://en.wikipedia.org/wiki/Myasishchev_VM-T
« Last Edit: 01/22/2019 06:45 am by libra »

Offline zhangmdev

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Re: Stratolaunch Announcement, Updates and Discussion
« Reply #2228 on: 01/22/2019 09:11 am »
Expand 4 a bit. Cargo pods should support ground operation without special equipment. That means it has wheels to carry its weight, can be tugged under the plane. The deck/floor should be as close to ground as possible. Both C-5 and An-124 can kneel or lower to ground because some payload is too long to drive over the steep ramp. A separated cargo pod cannot get rid of this problem completely. And it must be able to raise to mate with the plane, then to retract its wheels to gain ground clearance for takeoff and landing. So the wheels need quite powerful and long range hydraulic system. And fairings to reduce drag. An alternative is to let the plane to lower itself to meet the pod, like the Thunderbird 2. But the pod still needs to be movable on the ground.

Plus 1-3, the pod itself is a very expensive equipment, basically a cargo plane fuselage minus flying parts. I think this idea didn't catch fire because no operator wanted those pods just sitting on the ground and not making money.
« Last Edit: 01/22/2019 09:12 am by zhangmdev »

Offline Hobbes-22

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Re: Stratolaunch Announcement, Updates and Discussion
« Reply #2229 on: 01/22/2019 11:52 am »
Too-wide-set and not-so-strong-looking landing gears.

That bit of criticism is absurd. That landing gear is straight off of a Boeing 747, on which 4 trucks/16 wheels are sufficient to land >400 tons on day in, day out for 30 years. They're using 6 trucks/24 wheels here.

Offline zhangmdev

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Re: Stratolaunch Announcement, Updates and Discussion
« Reply #2230 on: 01/22/2019 01:59 pm »
Landing gear itself is strong, but how they are installed is equally important. 747 main gears are in 4 bogies to spread the load. They are also clustered together to handle cross wind landing, and to guard against off-normal events like loss of gears. (747 can still land with 2 main gears sheared off, provided they are on the opposite sides.) I think Stratolaunch's main gears are laterally too wide apart to look strong. Maybe it is just a much bigger plane on relatively small gears. Maybe it is just the unusual twin-fuselage, a lot of this plane doesn't look right.

Offline Eric Hedman

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Re: Stratolaunch Announcement, Updates and Discussion
« Reply #2231 on: 01/22/2019 05:57 pm »
I have never understood the logic behind this design concept.  I remember when people from Scaled Composites were hinting at this at the EAA before this idea was announced.  I kept think something like this was in the works because it fits with Burt Rutan's thinking.  I just have never seen how it was going to be commercially viable.

They should fly the carrier aircraft once like the Spruce Goose to prove it works.  Then it should be parked and offered up for sale.  If no one wants it, then maybe it should become a museum piece.  My guess is that the most likely outcome is that it will be parked in the desert and eventually forgotten by most people.

To me this design is practicable, but not practical.  There is a big difference.

Offline libra

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Re: Stratolaunch Announcement, Updates and Discussion
« Reply #2232 on: 01/23/2019 07:00 pm »
For cubesats it is completely overkill. Rocketlab Electron is more practical.

For Pegasus launches, it is overkill. Stargazer did a good job for 30 years.

For satellite constellation launches, Virgin Orbit Launcher One is smaller and uses a plain old 747. Plus all the other rockets launched from the ground, either small or large.

For 7 mt launches to LEO, Arianespace Soyuz-in-kourou (and Soyuz in general) are world-beaters since... 1957.

For big GEO comsats the aircraft max payload of 250 mt makes the rocket too light compared to Ariane 5 or Proton or Falcon 9R.  250 mt is barely Delta II or Atlas II, which are long gone - they could barely launch one 2-3 mt comsat to GEO, and that was 30 years ago...

For manned flight ? 7 mt is a medium size capsule (Soyuz) but what is air launch useful for ?
With Dream Chaser it was pretty cool, but it was too heavy and the 75% subscale didn't made a lot of sense.

no, it never made any sense... that 7 mt to LEO is right in the middle of nowhere.
« Last Edit: 01/24/2019 06:53 am by libra »

Offline jongoff

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Re: Stratolaunch Announcement, Updates and Discussion
« Reply #2233 on: 01/25/2019 11:42 pm »


For VG to build SS3, they need to build a man-rated orbital-class rocket and vehicle.  They are incredibly far from that (though less far than Stratolaunch was).

But even if they could - how large can their vehicle be?  The whole GLOW for the rocket would be 250 tons.  That's closer to a Falcon 5 than it is to a Falcon 9.  So they can almost-orbit a 3-person capsule?  At what cost per seat?

Which of course begs the question for VG: "SS3 - how exactly?"  But that's for another thread.
A Falcon 5 was the original plan.
Original plan for what?  Stratolaunch? 
You know what? I think that rings a bell.

Was SpaceX fully on board and then walked away? Or was it more speculative than that?

Either way, it is obvious in retrospect: you have to build the rocket first.

What you have are people who are first and foremost airplane people creating space projects that revolve around what they love most (airplanes) and so the first thing you see are carrier planes, hangars, taxi tests, etc - and the rocket thing is "outsourced" - leading to the usual result.

Can't outsource core competency.  or rather, shouldn't.


It was an early F9 with heavy mods (https://en.wikipedia.org/wiki/Falcon_9_Air) using four Merlins. (So sayeth Wikipedia, though I recall five...)  From the start they had a problem, which was deployment off the Roc.  One of the SpaceX engineers tasked with fixing the issue contacted me (based on our AirLaunch LLC t/LAD demonstrated technology) but couldn't seemingly get his head around our solution.  I heard no more from them, and then the deal was cancelled in 2012.

Amusing anecdote:  I asked Gwynne, some time after the deal went away, what happened.  She was typically succinct.  "I didn't sign up to build a rocket with wings."

Which is kind of funny given the current Starship Design...

~Jon

Offline meekGee

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Re: Stratolaunch Announcement, Updates and Discussion
« Reply #2234 on: 01/25/2019 11:50 pm »


For VG to build SS3, they need to build a man-rated orbital-class rocket and vehicle.  They are incredibly far from that (though less far than Stratolaunch was).

But even if they could - how large can their vehicle be?  The whole GLOW for the rocket would be 250 tons.  That's closer to a Falcon 5 than it is to a Falcon 9.  So they can almost-orbit a 3-person capsule?  At what cost per seat?

Which of course begs the question for VG: "SS3 - how exactly?"  But that's for another thread.
A Falcon 5 was the original plan.
Original plan for what?  Stratolaunch? 
You know what? I think that rings a bell.

Was SpaceX fully on board and then walked away? Or was it more speculative than that?

Either way, it is obvious in retrospect: you have to build the rocket first.

What you have are people who are first and foremost airplane people creating space projects that revolve around what they love most (airplanes) and so the first thing you see are carrier planes, hangars, taxi tests, etc - and the rocket thing is "outsourced" - leading to the usual result.

Can't outsource core competency.  or rather, shouldn't.


It was an early F9 with heavy mods (https://en.wikipedia.org/wiki/Falcon_9_Air) using four Merlins. (So sayeth Wikipedia, though I recall five...)  From the start they had a problem, which was deployment off the Roc.  One of the SpaceX engineers tasked with fixing the issue contacted me (based on our AirLaunch LLC t/LAD demonstrated technology) but couldn't seemingly get his head around our solution.  I heard no more from them, and then the deal was cancelled in 2012.

Amusing anecdote:  I asked Gwynne, some time after the deal went away, what happened.  She was typically succinct.  "I didn't sign up to build a rocket with wings."

Which is kind of funny given the current Starship Design...

~Jon
Not wings... Brakerons... 

And so maybe the proof goes like this:
Is Shotwell still with SpaceX? If yes, then these things must not be wings...  QED..

ABCD - Always Be Counting Down

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