Stratolaunch: General Company and Development Updates and Discussions

[A_M_Swallow]

Does the plane have sufficient payload to make a living by flying heavy objects around the world?

[TomH]

Does the plane have sufficient payload to make a living by flying heavy objects around the world?

I wondered about that. Antonov Airlines was at one point considering building a top mounted pod with a diameter even larger than the fuselage to put on top of the An-225. I don't think they finished it though. A cargo pod for Stratolauncher would be volume limited due to diameter restrictions in being undermounted. Would the maintenance costs allow this thing to be competitive with commercial cargo carriers that run very efficient operations? Good question.

And could this thing take a top mounted Hyper-Guppy pod? Are there monolithic items too heavy for 747 or C-5 that this plane can carry?

[Asteroza]

Does the plane have sufficient payload to make a living by flying heavy objects around the world?

I wondered about that. Antonov Airlines was at one point considering building a top mounted pod with a diameter even larger than the fuselage to put on top of the An-225. I don't think they finished it though. A cargo pod for Stratolauncher would be volume limited due to diameter restrictions in being undermounted. Would the maintenance costs allow this thing to be competitive with commercial cargo carriers that run very efficient operations? Good question.

And could this thing take a top mounted Hyper-Guppy pod? Are there monolithic items too heavy for 747 or C-5 that this plane can carry?

That would also have to potentially compete with the Volga-Dnepr proposal for a vertically stretched An-124. There was also a serious proposal for a 747 bottom pod/module that would substitute the landing gear with new ones on the pod.

The interesting market is a potentially wide pod, provided it's wider than the upcoming Beluga XL, but that runs up against ground logistics for such a wide cargo after delivery. There are good reasons why megatelescope mirrors are cast/ground on site.

[iamlucky13]

Questions:

Two cockpits with active controls or one?

If only one, any crew at all on other side?

Crawlway between the two fuselages?

Will primary runway have off-centered alignment striping for pilot or will electronic display create artificial image using GPS, or will flight be primarily computer controlled?

Altitude and angle of attack at drop?

Other possible commercial use when idle?

One cockpit, no crew in the other side. Nothing has been said about a crawlway, and it wouldn't been needed anyways. If something comes up in flight, there are low odds of it being both something critical and something that can be fixed.

No word about runway plans.

Altitude has been stated as 35,000 feet. Angle is unknown.

Does the plane have sufficient payload to make a living by flying heavy objects around the world?

Outsized is probably more likely than overweight. The existing An-225 can lift roughly the same amount, and doesn't need as wide of a runway.

But conceivably a cargo pod could be designed for it that could fit items too large for the An-225.

Would the maintenance costs allow this thing to be competitive with commercial cargo carriers that run very efficient operations? Good question.

Possibly. The An-225, and even the An-124 are apparently pretty maintenance intensive. They serve a rather specialized market, rather than an efficient one. Stratolaunch doesn't have to compete with FedEx. I've seen An-124's sit unused for a week or more at time, which is not great for overall economics, but apparently they make it work.

The Stratolaunch Carrier has a lot of one-off components that tend to work against maintenance cost-effectiveness, but most of the really complex stuff that tends to generate maintenance issues came from the 747 for Stratolaunch. That means there's a large installed base with lots of spare parts becoming available as other 747's are retired, and the 747 has a well-demonstrated reliability record.

[CharlieWildman]

Does the plane have sufficient payload to make a living by flying heavy objects around the world?

Poked around in wikipedia looking at An 225 vs ROC specs.  Found it interesting that the payload capacity is very similar.  I wonder how the fuel burn/ kg of payload compares.   

An 225

Empty  285 000 kg
Fueled  585 000 kg
Engines  six @ 229 kN
Payload   253,820 kg
Range  9,569 km

Source:  https://en.wikipedia.org/wiki/Antonov_An-225_Mriya


ROC

Empty  ?
Fueled 589,679 kg
Engines six  @ 254.4 kN
Payload 230 kg
Range 3,704 km

Source:  https://en.wikipedia.org/wiki/Scaled_Composites_Stratolaunch

[MATTBLAK]

Have they released any figures for airspeed in various configs, rate of climb and operating ceiling? I've had a bit of a Google but can't see anything definitive.

[Nomadd]

Does the plane have sufficient payload to make a living by flying heavy objects around the world?

Poked around in wikipedia looking at An 225 vs ROC specs.  Found it interesting that the payload capacity is very similar.  I wonder how the fuel burn/ kg of payload compares.   

An 225

Empty  285 000 kg
Fueled  585 000 kg
Engines  six @ 229 kN
Payload   253,820 kg
Range  9,569 km

Source:  https://en.wikipedia.org/wiki/Antonov_An-225_Mriya


ROC

Empty  ?
Fueled 589,679 kg
Engines six  @ 254.4 kN
Payload 230 kg
Range 3,704 km

Source:  https://en.wikipedia.org/wiki/Scaled_Composites_Stratolaunch

I'm pretty sure the payload is more than 230 kg.

[Phil Stooke]

Is that the payload of the Pegasus?

[TomH]

Have they released any figures for airspeed in various configs, rate of climb and operating ceiling? I've had a bit of a Google but can't see anything definitive.

Airspeed cannot be as high as most commercial jets due to unswept wing. That is almost irrelevant for rocket launch, however. Altitude matters most.

[TomH]

...conceivably a cargo pod could be designed for it that could fit items too large for the An-225.

The Airbus Beluga and Boeing Dreamlifter already can carry wider cargo than the An-225.





The Beluga XL will have an 8.8m dia. fuselage.

https://www.flightglobal.com/news/articles/airbus-details-dimensions-of-a330-based-beluga-416809/

Even Super Guppy is 7.6m:



Not sure of Stratolaunch clearance at latch points, but my guess is an undermount pod could not match the above. I have no idea whether a 9m pod could be top mounted. Aerodynamics could be dicey, but then the VM-T Atland carried the Braun/Energia fuselage on top, though without cargo inside.

[RonM]

Well, there's some good arguments for building the factory at the launch site. Shipping costs on those aircraft can't be cheap.

[MATTBLAK]

Have they released any figures for airspeed in various configs, rate of climb and operating ceiling? I've had a bit of a Google but can't see anything definitive.

Airspeed cannot be as high as most commercial jets due to unswept wing. That is almost irrelevant for rocket launch, however. Altitude matters most.

I expected no less from unswept wings. I wonder how it compares to the Virgin Galactic 'Mothership'?

[intrepidpursuit]

Questions:

Two cockpits with active controls or one?

If only one, any crew at all on other side?

Crawlway between the two fuselages?
...

The website says the following:

The right fuselage houses the flight crew and the left fuselage contains flight data systems.

(EDIT: Trimmed quote.)

[Rocket Science]

I name thee "The Carbon Condor"....

[intrepidpursuit]

Anyone know if some of the propellants for the air-launched rocket are carried within the plane's fuselages before launch?

This is a great question. That plane doesn't appear big enough to store a big rocket's worth a fuel, but perhaps enough to top it off and pressurize it for flight.

It doesn't appear to have any launch vehicles right now except for the rarely flown Pegasus, but perhaps accepting cryo fuels would give more potential development options. Is there any more information about the intended uses for this thing? Any contracted Pegasus launches?

I've always liked the idea of air launch and I know that is a long discussion that would go off topic, but it would be sad to see Stratolaunch get so far and never launch anything.

[FutureSpaceTourist]

Article comparing Stratolaunch size with other aircraft:

http://fortune.com/2017/06/02/stratolaunch-worlds-biggest-plane-aircraft/

Fun graphic attached.

[HMXHMX]

Anyone know if some of the propellants for the air-launched rocket are carried within the plane's fuselages before launch?

This is a great question. That plane doesn't appear big enough to store a big rocket's worth a fuel, but perhaps enough to top it off and pressurize it for flight.

It doesn't appear to have any launch vehicles right now except for the rarely flown Pegasus, but perhaps accepting cryo fuels would give more potential development options. Is there any more information about the intended uses for this thing? Any contracted Pegasus launches?

I've always liked the idea of air launch and I know that is a long discussion that would go off topic, but it would be sad to see Stratolaunch get so far and never launch anything.

Based on what I know from our work with Scaled ten years go, no propellants would be carried inboard.  At one time Burt wanted to perform a powered "gamma maneuver" with the same hybrid motors used by SS2.  In that case, nitrous was to be carried onboard.  I'm pretty sure the gamma maneuver idea has been dropped.

[TomH]

Reusability of conventional rockets was a doubtful hypothetical when this thing was first proposed. IF Stratolaunch is limited to solid disposable launchers, I'm wondering how well it can compete financially with partially and even fully reusable liquid fueled rockets. Now if the first stage of the air-launched rocket was liquid, could glide to a landing on skids, and be reused, I wonder if that could make a difference.

[MATTBLAK]

Anyone know if some of the propellants for the air-launched rocket are carried within the plane's fuselages before launch?

This is a great question. That plane doesn't appear big enough to store a big rocket's worth a fuel, but perhaps enough to top it off and pressurize it for flight.

It doesn't appear to have any launch vehicles right now except for the rarely flown Pegasus, but perhaps accepting cryo fuels would give more potential development options. Is there any more information about the intended uses for this thing? Any contracted Pegasus launches?

I've always liked the idea of air launch and I know that is a long discussion that would go off topic, but it would be sad to see Stratolaunch get so far and never launch anything.

I was wondering if the rocket carried all of the LOX and Kero from the ground up, or just the LOX alone with the Kero being added after the climb? I was only wondering in the context of reducing the load on the wing central section during takeoff and climb events.

[TomH]

]I was wondering if the rocket carried all of the LOX and Kero from the ground up, or just the LOX alone with the Kero being added after the climb? I was only wondering in the context of reducing the load on the wing central section during takeoff and climb events.

My guess is that the rocket is going to need to be balanced on the mounting clamp at time of drop. The COG wouldn't change on a solid, nor a liquid for that matter if the prop is preloaded. If a liquid rocket is propped after aircraft launch, it will have an off balance COG at takeoff. I don't know how much leveraged force this would put on the clamps or if it even matters, but it is an observation.