Our Low Orbit Helium Assisted Navigator experimental flying truss is just about poised for lift-off, but before it leaves the ground we thought we'd update LOHAN fans on the proposed test rigs. Apprentice boffin Katarina poses with the finished truss Click here for a bigger version of the LOHAN graphic Our initial plan was …
You could retain the width of the truss simply be inverting it. That is so the apex of the trust points skyward, no chance of the wires getting in the way then??
Drag-chute/tail to give a bit of tension to the balloon string then a picavet suspension to hold the truss as level as possible. It works for kite photography so apart from neither end being attached to the ground it might be a viable self-levelling arrangement. No motors needed just a few pulleys and string.
Single Balloon Elevated
My money's on the Single Balloon Elevated approach... maybe some juicy headline material in there about Vulture 2 being "erect for launch"....
By the way nice to see El Reg responding to the readers there.,, and it's certainly a good idea to "just try the three different ideas".... the proof of the pudding and all that!
How about side mounting the plane on the truss with some sort of delayed timer/explosive bolt setup.
The idea i am having would happen thusly.
Vulture2 is mounted horizontally along the side of the truss on a pivoted swivel platform, during the lift to reduce resistance, at height x, bolts 1 and 2 are blown/released to allow the platform to rotate through to the vertical, at height y, bolt 3 is blown/released, this bolt could be a slide bolt to hold the pivot at 90* to the truss, to allow the pivoted platform to lean away from the truss, then at height z, you ignite the launcher.
The benifit of this is you can use 1 or 2 ballons, if you used 2, there may be an argument to not apply bolt 3, and you will achieve a perfect vertical launch. Also, the swivel would ensure a vertical launch regardless of the angle of the truss (if you weighted the bottom edge).
Make the platform from lightweight carbon fibre, or balsa wood http://www.theregister.co.uk/Design/graphics/icons/comment/happy_32.png, as you see fit.
You will see, i am rarely wrong :)
Slings are diiiiirty
And thus, underslung should she be.
Then tie together as many nippled globes as you like, providing the -common- thread is longer than any dangling rubber entrails, the whole thing gets considerably closer to something even a blond could comprehend.
I luuuurves me some tagfail!
Okay, this won't work.
Fit a small but fast gyroscope, horizontally on the boom. A tendency for the boom to move off its axis would be reduced, or removed by the gyroscope.
Given the lift of the mighty orbs though, a gyroscope sufficient to keep the boom stable would probably be a tad too weighty.
It's Friday - don't expect me to come up with plausible suggestions. My other idea was to have a tilt switch move a weight along the boom to balance the stucture...okay, I know - very complex, lots of moving parts, prone to icing at altitude...I'll get my coat....
Does one require a space permit?
I think a flat triangular platform having tether wires at each apex, with triangular bracing would be quite sufficient if you are making it out of carbon fibre. I also think the vertical fin would work in spite of the fact that the rig will be travelling with the wind as it would provide inertial drag against rotation (like a shock absorber). Placing the equipment towards the rear of the triangular platform would ensure that it is pointing upwards in the right direction. Slinging the rocket plane under the platform would add extra complexity in requiring a release running rail to ensure that the rocket was moving in the right direction before it left the launch platform (you dont want a stall drop like in the PARIS launch).
Is it my old tired eyes or are those balloons the same sort that you used to be able to get from the Family Planning Clinic? Bizarrely enough - and to keep in with the space theme - they were then called Atlas.
Oh, and keep with the triangular frame. If LOHAN were launched from inside it would be a reminder of Battlestar Glactica!
Well, nearly 2pm. Bar calls.
Long thin ballon
If the balloon was long and thin cigar shape, Zeppelin style, it would be more aerodynamic in one direction and should find a stable situation relative to the wind. The shape would help stabilize the truss by hanging it from the front at the back of the zeppelin negating the need for different launch methods.
It might even be possible to construct a lightweight net which could hold a number of smaller balloons, constraining them to the required cigar shape. The number of balloons might mitigate against a fault in a single balloon bringing down the whole operation.
currious...ok maybe stupid.
Is it possible to use 2 balloons in a stacked configuration? one on top of the other...with maybe a flexible netting used on the bottom balloon to serve as a anchor for the top balloon.
This would allow for more lift while still using the angled truss launch andyou would have a great headline....LOHAN is stacked!
Right - beat this idea
To stop all the problems with attitude control and getting clear of balloons and all that stuff, and co-incidentally to add some extra records to the list, just use ten balloons with a volunteer aeronaut who can go up with the balloons and aim the rocket in the right direction and trigger the launch just prior to claiming the new altitude record fo a HALO jump.
Simples, and if I wasn't booked out all that week I would be the first to volunteer...
Don't need no stinkin' truss
Get a cheap ultrasonic volume measurement device and dismantle it.
Make an balloon inflation bung with two tubes. One for the ultrasonic emitter thingy wires and the other for inflation.
Attach thin metal strip to LOHAN and make an electromagnetic release mechanism.
Program on-board computer to release when the volume of the balloon is at maximum (rate of change has levelled) or infinity (balloon has burst).
Adjust LOHAN's centre of gravity so that before the propellant is used it is stern heavy and afterwards neutral. The rocket is fired by a reed switch when the electromagnet releases.
Can you not get "real" helium?
That picture there looks like balloon gas to me. I think it's about half helium, and half air. Much less lifting capacity, which means having to inflate the balloon more, which means it bursts at a lower altitude. False economy and all that.
Re: Can you not get "real" helium?
To hell with helium, pure or otherwise. This ain't the Hindenburg. Why not go with hydrogen? More lift for equivalent volume -> higher altitude for the same size orb. It's not as if you'd be using enough to endanger the surroundings, and when the orb(s) burst at altitude, it would dissipate harmlessly. You can send the royalty payments to my Paypal account.
Re: Re: Can you not get "real" helium?
I think the objections to hydrogen are more to do with things exploding and singeing eyebrows at ground level. That said, if we can suggest a foolproof way of remotely filling and releasing a hydrogen launcher... Oh go on, Lester. Make it happen.