6 ms·

it's a proven design. scaled composites, which built this also built the GlobalFlyer with similar configuration. https://en.wikipedia.org/wiki/Virgin_Atlantic

it's a proven design. scaled composites, which built this also built the GlobalFlyer with similar configuration. https://en.wikipedia.org/wiki/Virgin_Atlantic_GlobalFlyer https://en.wikipedia.org/wiki/Virgin_Atlantic_GlobalFlyer

monk_e_boy 9y ago
So the bit of wing that joins the two fuselages is made of carbon fibre? Are there any details on how it was constructed? Imagine that thing, fully loaded taking off into turbulent air. Scary.
- kashkhan 9y ago
  the plane structure is all carbon/CFRP. you can see in the earlier pictures in the hangar before. http://www.stratolaunch.com/gallery.html http://www.stratolaunch.com/gallery.html the black is cfrp under the white paint. Scaled Composites has some secret CFRP processes of construction which non Americans are not allowed to know about under ITAR regulations, so i cannot tell you haha.
  - rbanffy 9y ago
    > Scaled Composites has some secret CFRP processes of construction which non Americans are not allowed to know about under ITAR regulations Everybody knows that. We just don't want you to know we know ;-)
SkyMarshal 9y ago
Well, proven at small scale. I'm sure the new bigger one will work fine too under most anticipated conditions, but I wonder what its structural safety factor is.
- deleted 9y ago
  [deleted]
endorphone 9y ago
Clearly Allen and his team did the necessary engineering work, but I'm not sure the GlobalFlyer is a good example. It had a single mid-mounted engine, and had a gross, fully loaded weight of 22,000lbs. This thing has 70,000+ lbs of engines alone. The torque has to be absolutely colossal. Again, I know that much smarter people did the math, but from the eye check this does not look like a tenable design.
- blunte 9y ago
  I agree. There are so many forces at such incredible potential levels of torque that the center wing must be almost entirely full of structural elements... and those probably pass through to the outer wings. Imagine differing oscillations of pitch or yaw from each fuselage happening at the same time... and at just the right/wrong frequency for the connecting structure. I'm sure I'm just overly paranoid, but often we find out long after something is built that some "little possibility" was overlooked.
  - SkyMarshal 9y ago
    >Imagine differing oscillations of pitch or yaw from each fuselage happening at the same time... and at just the right/wrong frequency for the connecting structure. Exactly. I expect they have real-time computer control of all control services that quickly adapt the relative attitude of both fuselages to prevent over-stressing the wing, but what about "rogue waves" of turbulence hitting each fuselage differently. What's the safety factor on both the adaptive controls and, as a backup, the structural integrity of the wing?
JumpCrisscross 9y ago
> it's a proven design No. This is breakthrough science. Scaled proofed a specific implementation of one of its materials.
- kashkhan 9y ago
  Almost every aircraft Burt Rutan has built is a breakthrough. Mostly asking questions that other designers weren't, like does a twin need to be symmetric. twin tail booms have a long history. e.g p38 with twin engines. Burt Rutan's key realization was that the connected skinny horizontal tail doesn't really add much torsional stiffness and it's easy to obtain the required stiffness with the wing center box.

monk_e_boy 9y ago

So the bit of wing that joins the two fuselages is made of carbon fibre? Are there any details on how it was constructed? Imagine that thing, fully loaded taking off into turbulent air. Scary.

kashkhan 9y ago
the plane structure is all carbon/CFRP. you can see in the earlier pictures in the hangar before. http://www.stratolaunch.com/gallery.html http://www.stratolaunch.com/gallery.html the black is cfrp under the white paint. Scaled Composites has some secret CFRP processes of construction which non Americans are not allowed to know about under ITAR regulations, so i cannot tell you haha.
- rbanffy 9y ago
  > Scaled Composites has some secret CFRP processes of construction which non Americans are not allowed to know about under ITAR regulations Everybody knows that. We just don't want you to know we know ;-)

SkyMarshal 9y ago

Well, proven at small scale. I'm sure the new bigger one will work fine too under most anticipated conditions, but I wonder what its structural safety factor is.

deleted 9y ago
[deleted]

endorphone 9y ago

Clearly Allen and his team did the necessary engineering work, but I'm not sure the GlobalFlyer is a good example. It had a single mid-mounted engine, and had a gross, fully loaded weight of 22,000lbs. This thing has 70,000+ lbs of engines alone. The torque has to be absolutely colossal. Again, I know that much smarter people did the math, but from the eye check this does not look like a tenable design.

blunte 9y ago
I agree. There are so many forces at such incredible potential levels of torque that the center wing must be almost entirely full of structural elements... and those probably pass through to the outer wings. Imagine differing oscillations of pitch or yaw from each fuselage happening at the same time... and at just the right/wrong frequency for the connecting structure. I'm sure I'm just overly paranoid, but often we find out long after something is built that some "little possibility" was overlooked.
- SkyMarshal 9y ago
  >Imagine differing oscillations of pitch or yaw from each fuselage happening at the same time... and at just the right/wrong frequency for the connecting structure. Exactly. I expect they have real-time computer control of all control services that quickly adapt the relative attitude of both fuselages to prevent over-stressing the wing, but what about "rogue waves" of turbulence hitting each fuselage differently. What's the safety factor on both the adaptive controls and, as a backup, the structural integrity of the wing?

JumpCrisscross 9y ago

> it's a proven design No. This is breakthrough science. Scaled proofed a specific implementation of one of its materials.

kashkhan 9y ago
Almost every aircraft Burt Rutan has built is a breakthrough. Mostly asking questions that other designers weren't, like does a twin need to be symmetric. twin tail booms have a long history. e.g p38 with twin engines. Burt Rutan's key realization was that the connected skinny horizontal tail doesn't really add much torsional stiffness and it's easy to obtain the required stiffness with the wing center box.