Stratolaunch: General Company and Development Updates and Discussions

[Machdiamond]

Something in my the back of my mind screams, Those horizontal stabilizers should be tied together! Even if the elevators remain separate.

Me too but it makes sense, it keeps the horizontal tail away from the greatly variable payload wake. Otherwise you'd have to reassess the aircraft handling characteristics to a much larger extent for each new payload.

[RcTeller]

For the life of me I can't figure out what the four large yellow fairings are attached to the side of the fuselages under the wings.  The fittings to mount them seems substantial so it seems they will be mounted during flight. They almost seem like speedbrakes.

Cheers!

RcTeller

[suncity]

For the life of me I can't figure out what the four large yellow fairings are attached to the side of the fuselages under the wings.  The fittings to mount them seems substantial so it seems they will be mounted during flight. They almost seem like speedbrakes.

Cheers!

RcTeller

I suspect they are part of the ground support equipment, namely the interface between the aircraft and its construction frame. Keep it up when the wheels are not touching the ground.   

[FutureSpaceTourist]

A bit of drone footage:



Nice collection of stills including some I've not seen before:

[Basto]

I really would like to fly this aircraft!

Something in my the back of my mind screams, Those horizontal stabilizers should be tied together! Even if the elevators remain separate.

I had the same thought!  Any windsheer and/or turbulence would put a tremendous amount of force on that center wing segment. I am sure they took that into account and have beefed up the structure there.

[whitelancer64]

Great to see the big bird rollout.

If they use a solid booster like the Pegasus they wouldn't need to concern themselves with de-tanking the propellant after a scrub. The articles I've seen indicate the first launches from this bird in 2019, and also talked of launching up to three Pegasus rockets. How solid is this info? And is there anything about a bigger solid fueled rocket being proposed, like a "Liberty-light"?

Pretty solid.

http://seradata.com/SSI/2016/10/orbital-atk-to-supply-pegasus-launchers-to-stratolaunch/

The status of a larger rocket for Stratolaunch is uncertain, but Orbital ATK was working on one called "Thunderbolt".

[Oersted]

I really would like to fly this aircraft!

Something in my the back of my mind screams, Those horizontal stabilizers should be tied together! Even if the elevators remain separate.

I had the same thought!  Any windsheer and/or turbulence would put a tremendous amount of force on that center wing segment. I am sure they took that into account and have beefed up the structure there.

I think they actually desire the flex which is possible with the present design, rather than a more rigid box construction.

[Coastal Ron]

I really would like to fly this aircraft!

Something in my the back of my mind screams, Those horizontal stabilizers should be tied together! Even if the elevators remain separate.

I had the same thought!  Any windsheer and/or turbulence would put a tremendous amount of force on that center wing segment. I am sure they took that into account and have beefed up the structure there.

I think they actually desire the flex which is possible with the present design, rather than a more rigid box construction.

Before fly-by-wire you'd probably have to worry about induced oscillation getting out of hand, and for the current design that could have meant oscillations concurrently in multiple axis. But with modern flight computers I'm sure they are aware of what they will allow the two bodies to do in sync and out of sync.

But it's sure easy to imagine what would happen in flight if the two fuselages started porpoising in opposite directions... 

[Rocket Science]

I really would like to fly this aircraft!

Something in my the back of my mind screams, Those horizontal stabilizers should be tied together! Even if the elevators remain separate.

I can see the reasoning for payload clearance, buffeting and flutter, but I guess we will find out during the flight tests if the data will match the computer modeling. Who knows it "may" end up with a tail similar to a P-38 Lightning...

[Machdiamond]

Before fly-by-wire you'd probably have to worry about induced oscillation getting out of hand, [...]

You still would, as FBW is not a proper solution to combat flutter modes.

But nowadays structural dynamics and aeroelastics can be predicted with a high level of accuracy so you don't see these events anymore (unless someone screwed up).

Besides, I am 110% sure Stratolauncher does not have FBW since it does not need relaxed stability or flight envelope protection.

[Machdiamond]

For the life of me I can't figure out what the four large yellow fairings are attached to the side of the fuselages under the wings.  The fittings to mount them seems substantial so it seems they will be mounted during flight. They almost seem like speedbrakes.

I agree. They also seem very heavy, looks like ballast and speed brakes combined that could be jettisoned (hence the yellow paint for recovery).

Quick back of the envelope calculation, eyeballing their volume, suggests 25000 to 40000 lb weight depending on material used (steel or lead).

So maybe the weight and drag equivalent of a Pegasus but the CG looks a bit too far forward. Entirely guessing here, curious to find out.

[iamlucky13]

I tend towards skepticism about this project, but I have to admit, I was thrilled to see the rollout. I can't wait to watch this bird fly.

The articles I've seen indicate the first launches from this bird in 2019, and also talked of launching up to three Pegasus rockets. How solid is this info? And is there anything about a bigger solid fueled rocket being proposed, like a "Liberty-light"?

I'd say multiple Pegasus launches at once is entirely speculative. The Pegasus launch rate is very low due to low demand. Getting three customers willing to wait on each other's schedules seems unlikely.

A bigger rocket is presumably in works, but they've had several false starts on that, and now seem reluctant to talk publicly about their plans at the moment.

For the life of me I can't figure out what the four large yellow fairings are attached to the side of the fuselages under the wings.  The fittings to mount them seems substantial so it seems they will be mounted during flight. They almost seem like speedbrakes.

Those are not flight hardware. I agree with suncity. They look most likely to be support fittings for assembly and maintenance work. Notice they are located roughly at the aircraft center of gravity. I'm certain they connect to some of the same structure that supports the landing gear.

I had the same thought!  Any windsheer and/or turbulence would put a tremendous amount of force on that center wing segment. I am sure they took that into account and have beefed up the structure there.

Because this is a straight-winged aircraft with almost all of its weight concentrated at the CG, I suspect the actual in-flight moments on that wing segment will be lower than what a large swept-wing airline like a 747 has to be designed to deal with.

[FutureSpaceTourist]

Congrats @Stratolaunch team! We are proud to be a partner & look forward to launching #Pegasus 🚀 from this innovative launch platform

https://twitter.com/orbitalatk/status/870374366932078592

[Rocket Science]

Those yellow fixtures could be "jack-points"...

[TomH]

I don't know if it's the camera angle, lighting, or what, but the skin looks buckled.

[guyw]

If you look closely, it is the reflection of the engine pods on the side of the plane.

[TomH]

Who knows it "may" end up with a tail similar to a P-38 Lightning

Saab 21


Cessan 336/337

[TomH]

If you look closely, it is the reflection of the engine pods on the side of the plane.

Darned sure is! I knew something had to explain that! I have old fuzzy eyesight.

[TomH]

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?

[Rocket Science]

Who knows it "may" end up with a tail similar to a P-38 Lightning

Saab 21


Cessan 336/337

Or a de Havilland Vampire...