LOHAN's fantastical flying truss takes to the air We're pleased to report that last weekend the Low Orbit Helium Assisted Navigator (LOHAN) fantastical flying truss finally got off the ground, and we've got some video of the test for your viewing pleasure. Click here for a bigger version of the LOHAN graphic The plan, as regular readers will recall, was to see just how a …
>we had a bit of a lightbulb moment as to how to mount the Vulture 2 underneath the structure
Good job I read to the bottom because I was just going to suggest that.
You need two parallel rods, one going through each wing of the craft and something for it to shove off of. When it gets to the end of the rods it's on its own.
Does the rod need to go through the wing? Can the plane just sit on the rods, sandwiched between the bottom of the truss and the rods? If the rods are close enough to the fuselage, that should be enough to hold the plane straight and square as the motor fires.
Interesting either way!
Cheers!
Matto :)
>Does the rod need to go through the wing?
Not being privvy to the craft design the only other thing I can think of is if a hole through the wing would subtantially weaken its structural integrity then use tubes or eyelets fixed flush to the wing or possibly along the fuselage. Assuming the wings will be curved then the fuselage/tube or wing/eyelets seem more likely options.
Ever since I saw the initial design with two parallel rods I have been wondering if that isn't a high risk launch option. There are several factors that could result in those rods not staying parallel during the course of ascent.
The rods being mounted on different parts of the platform structure 'could' result in either a convergence or divergence of the rods due to thermal changes and loading stress in the platform structure as it ascends into the colder regions of our atmosphere. This would effectively 'clamp' the craft between the rails during launch and wreaking havoc on the whole platform when the engine is ignited.
My suggestion would be to use a single rod and 'hang' the craft upside down on that rod. There is no up or down in space so the launch orientation is irrelevant.
Would hate to see this fail because it got stuck on the launch rails.
The problem with one rod is that the craft might spin and the wing drag along the truss potentially causing damage. Another possibility is that during the ascent the wing remains in contact with the truss and freezes to it. Or if you really want to consider other possiblities there is nothing to say that the rod won't warp towards the truss and have the craft launch into it. This is still a possibility with a two rod solution however two rods require a shorter length than for one rod and so any warping will be less.
Furthermore I assume that the materials for the rods will be tested to ensure they don't warp too much at low temperature or if they did they would still be flexible enough that upon launch the guides would pull them back parallel.
In the meantime however there is a far more pressing and important issue which needs to be resolved.
How exactly does one obtain a Special Projects Bureau T-shirt?
If there is no official channel then perhaps someone might be good enough to upload the logo so we may do our own (copyright permitting of course), because I really REALLY want a Special Projects Bureau T-shirt (yes I am that sad)
... you could have a single point of lift but connect it to both ends, similar to this poor attempt at a diagram but with angles somewhere between 30-60° (you'd have to experiment for the optimal angle for stability
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clearly i know nothing of aerodynamics, i'm just guessing :)
Hmmmm. To be considered a true boffin, surely Katarina should sport a beard to go with the obligatory pipe?
Kudos to her for trying to clench said pipe in a suitably nonchalant way (but tbh she needs a bit of practice!).
Can't wait for LOHAN's departure into the great blue yonder.
<--- For the pipe, obviously.
Lest we be accused of resorting to imperialism again, maybe there should be a similar range safety system so you can remotely blow up any disastrous launches that may be interpreted by foreign nations as a pre-emptive strike :-)
"some (longish) rails under each wing should hold her securely through the buffetting of the ascent, but provide little resistance when the rocket kicks in."
You'd be surprised how these things can work fine on the ground, but not at altitude.The launch rails will be subject to icing and possibly thermal effects, so may not be exactly parallel at launch altitude.
To retain the rocket on a single rail I'd suggest a loop of fine fishing line through two small holes (pinholes really) in the exhaust tube; the line will have plenty of strength to hold the rocket in place but the engine will burn it away on ignition leaving the rocket free to launch.
You want a vertical truss? simple - construct a horizontal triangle, attach a balloon to each corner, attach a wire from each corner of the triangle to a corner of the truss.
Dangle a weight from the bottom of the truss.
You could also have a cable from each corner of the bottom of the truss to the triangle to stop the bottom swinging - though news items mentioning LOHANs swinging bottom might be worth reading.
The triangle will have to be large enough to allow LOHAN to pass between the orbs of course.
OR
Similar to above but with one (or more) balloon(s) mounted above the triangle. truss could then be angled as needed by tightening one of the lower wires (bottom of truss to triangle).
ttfn
Just a couple of thoughts which popped into my head during a lecture on plane design. Why not have LOHAN as a bi-plane?
This generates additional lift without having overlong wings to worry about as well as allowing it to fly considerably slower which would be great for the on board camera.
It would also look awesome the playmonaught could even take a friend to play tennis with on the wing!
Paris because not only planes can be bi
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