LOHAN's fantastical flying truss cleared for lift-off

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 …

[Vulch]

Single balloon elevated

Could either make the truss T-shaped so the top end suspension clears the wings on launch, or invert it so the launch rail is underneath avoiding the lines altogether.

[Lester Haines]

Re: Single balloon elevated

Yes - we could sling the aircraft under the truss, in which case the weight might help keep the thing more stable.

[Bill Neal]

Re: Re: Single balloon elevated

Agreed. That was the 1st thing that came to mind for me. I see no need to change the truss. Just have the flat side on the bottom perhaps. I'm eager to see the launch rail (or whatever system you choose to use).

[bertino]

Re: Re: Single balloon elevated

How about a rhombus shaped truss, top end attached to balloon(s), bottom end has electronics etc for stability, with the launch vehicle attached to the 'underside' of one side of the lower part of the rhombus, so it is pointing upwards, angle depending on angle of rhombus.

[Beau]

Re: Single balloon elevated

A "T" shaped truss is spot on! Just use the 3 ends as suspension points, triangles are more stable anyway, then decide which way up to mount the truss.

To reduce spin, a tail something like that of a kite's would help. Due to the ascent their is bound to be air flowing downwards with some horizontal vector to it.

[Pirate Dave]

why not

have the rocket at the very end of the truss and tie the tether lines for that end one or two joints back? This way the rocket is already clear of the tethers and even if LOHAN is spinning like mad, the rocket should still clear when it launches.

[Bill Neal]

Re: why not

For some reason that made me think of the insane spinning rocket contraption designed by the nazis. Can't think of the name though

[Kevin Johnston]

Style

Never mind the theory, go empirical.

The tried and trusted method of boffins through the ages (just so long as trial and error doesn't include that nice Sir Terence Pratchett's alchemists)

[Captain TickTock]

Triple Orb Configuration...

Awesome!!

[BenR]

Re: Triple Orb Configuration...

I saw that in 'Total Recall' years aqo!

Start the reactor!

[Anonymous Coward]

Re: Re: Triple Orb Configuration...

Three tits? Awesome.

[Neil Barnes]

Why assume you have to launch from the top?

Another fan of the 'hang the launch vehicle below the truss' school of orbiting...

[Anonymous Coward]

so how big ...

... do these ballons they get before they burst?

[Anonymous Coward]

Re: so how big ...

well the real meteo balloons that I bought for around 5 euro each were 60cm diameter at ground level - swelling to around 3 metres diameter just before burst? allegedly, I'm just a random guy in a pub!

[spegru]

One or two orbs?

In fact you can avoid the risk of two of them taking the truss vertical by tying them together - above the level of the joing swivel. (just thinking of your preferred headline here!)

Two would also give more lifting capacity

[spegru]

vertical

in fact if the truss is long enough you could launch vertically from one end - sticking out past the baloon. You could counterweight it by putting the payload at the other end.

[Jamie Kitson]

Testing

I hope you are going to test that the truss won't crumple into flames the microsecond that the rocket motors start.

[Lester Haines]

Re: Testing

It had crossed my mind...

[Poor Coco]

Re: Re: Testing

The exploding-into-flames issue can be solved while increasing initial acceleration, by use of a piston launcher. I have launched rockets from a launcher made of 100% flammable materials (hardwood, balsa and cardboard with no protective coatings) and the piston-launcher does an amazing job of containing the gases while they burned. Caveat: I was using black-powder, not APCP. Be empirical.

The piston launcher will allow you to use the mass of your launch rail and electronics as an inertial anchor and also to get much more efficient use of the first burst of exhaust gases. It works like this: you attach a body tube to the end of the rocket motor using a friction fit. The body tube has external sanded-down centering rings that allow a slightly larger tube to slide freely around it while still maintaining a reasonably airtight seal. The larger tube is closed off at the back end and is solidly anchored to the launcher structure (it faces substantial net forces upon launch). The inner and outer tubes should be connected with a line to disconnect the inner tube from the engine after they pull apart from each other.

When the motor fires it compresses the interior of the tubes, exerting a powerful force on the plane (and, per Newton, on the launch rig) as the two tubes separate. It also contains most of the exhaust from the initial milliseconds of burn, protecting the rig quite effectively.

[Stoneshop]

@Poor Coco

Sounds good; the one thing that needs to be taken into account is the contraction of both tubes at the temperature present at the intended launch altitude.

[Poor Coco]

Temperature coefficient

That should not be too much of a problem; the seals don't need to be really tight since they don't hold pressure for many milliseconds. Leakage is okay. Adjusting the pieces so they slide smoothly and easily coming out of a standard freezer is probably good enough.

[Anonymous Coward]

Re: Testing

Surely there's not enough oxygen at the launch altitude for the truss to be ignited?

[Anonymous Coward]

Re: Re: Testing

There could still be enough heat and exhaust to crumple the truss in some manner that changes the launch orientation of LOHAN and sends her off into an unintended direction/obstacle.

[Anonymous Coward]

Re: Re: Re: Testing

If the truss is carbon fibre it is unlikely to melt or crumple when subjected to a second or two of rocket exhaust. Most likely it'll just char a little bit.

[Anonymous Coward]

Cameras

You all probably know about these, but try searching for MD80 on ebay. Ignore the minidiscs and the remainder will be cheap self contained video cameras that record onto micro SD cards. Good for about an hour on a full charge, so maybe not long enough for the flight, but worth looking at. I've flown these on a kids kite with very little wind.

[Vladimir Plouzhnikov]

Re: Cameras

For a moment I thought you were suggesting they swing an airliner under the balloon...

[Doug 14]

Angled launch ramp

How about the single balloon elevated idea but with an angled launch ramp like an aircraft carrier , should clear the end truss cable and angle you below the balloon.

[amanfromMars 1]

OccupyD CyberSpace/ for Every IntelAIgent Feed of Need to Seed to Serve to Sow New AI Feeds/Fields

Whatever next, El Reg? A Manned Ascent in Helium Balloon Pockets, which is the Core Reality of that Adventurous Future Derivative ZerodDay Trade.

[Anonymous Coward]

Re: gibberjabber

Prior Martian missive achieved greater 3rd orbit accessibility. With regret, temporal necessities obstructed my inner script kid from constructing the requisite paired response to the chingychongy.

[Anonymous Coward]

Man rags, or just the 1?

10.00.00,-84.00.00

text

[Anonymous Coward]

Why not toss the truss, hang Lohan by her nose on a long string and light her torch? Hang the camera halfway up the top string. Tie a counter weight to her ass with the same string for stability. The balloon should climb out of the way when the weight is released while Lohan picks up speed. this should drop off when the string burns and release the top balloon too. If anything bursts, it's going to be a disaster anyway, especially if there's all that crap hanging around everywhere.

[Poor Coco]

The aircraft will be initially dynamically unstable. Without a launch rail of some sort it would just flutter around pointlessly instead of flying.

[KirstarK]

I like the new idea. I think some sort of droge (?sp?) hanging behind the assembly to stabilise the lauch is a good idea. it will rotate the assembly into the wind and stop the rotation. Think weather vane/cock

[Daedalus]

Need a stabliser for yaw

PARIS had a major issue with being swirled around as it rose. The obvious answer is indeed a vertical vane stabiliser or a small chute. Obviously a vane adds two parasitic weights: the vane itself at one end of the truss and a counterweight at the other. The drogue chute looks much more attractive. It could even be a windsock, like a sea anchor for a boat.

[Dave Bell]

Re: Need a stabliser for yaw

Somebody is sure to say that this can't work. The point is that the centre of drag is different from the centre of mass, and that can be stable, but it needs an airflow, which you don't really get as you drift down-wind. A sea-anchor does work, but it is taking advantage of the two different working fluids, air and water, and their different behaviour.

It only needs slow relative movement of the sea anchor in the water to stabilise the boat. The wind-generated surface waves aren't always moving in the same direction as the local wind, and that is when things get complicated.

No, I don't think this will work. It's about as much sense as putting sails on a Zeppelin.

[Andus McCoatover]

Re: Re: Need a stabliser for yaw

Centre of drag??

When I used to fly microlights, someone came up with the most stupid suggestion to blu-tak a piece of cotton to the front strut, thus one could tell from which direction the airflow was coming.

It made its way into the BMAA (British Microlight Aircraft Association)' monthly rag.

No-one thought that, if the plane is flying forward, in whatever air was about, it'd always point backwards. Dullards.

[Jaymax]

Re: Re: Re: Need a stabliser for yaw

Still, and yet, I assume that there is some sort of inertial delay between a shift in wind direction, and a equivalent shift in contraptional direction? If so, a vane would/should/could [?] still be useful in terms of stability.

I might go so far as to say that such a vane could ONLY work if there were inertia and constant shifting winds; but that the analogue imperative (I just made that up, wondrous what a few extra beers can do) guarantees that there will be such.

At least, I'd heartily (read: boozily) recommend that lightweight vanes are tested on the truss tests to verify my vanity.

[Camilla Smythe]

Nipples!!!!!

I insist that the balloon[s] are topped off with great big throbbing erect nipples... err, to improve the vertical ascent aerodynamics.

You can also put huge chainsaws on the leading edge of the wings to cut the guy ropes on release.

Also useful for landing if any trees or people get in the way.

[Anonymous Coward]

Re: Nipples!!!!!

I'm not sure why, probably something to do with mechanics, but aren't balloon nipples normally used for inflation, and underside... As for the throbbing, I'm far to innocent to have ever witnessed nipples dangling down from above, let alone throbbing ones!

[Anonymous Coward]

Here's my single-balloon idea!

Put the battery/avionics pack at one end of the truss, then LOHAN facing off the other end of the truss, with facing oriented 180 degrees from the battery pack . Have the cabling to the balloon go to two cables attached to the truss, one longer cable attached at the battery/avionics pack and the second , shorter cable attached a foot or two behind LOHAN, so the truss is held at an inclined angle of 45 degrees to maybe 70 degrees. That way the heavy battery pack provides stability on the truss and LOHAN will fire at an upward angle without having cables to avoid and clear the single balloon!

Now, having proved that this rocket science stuff is easy, I return to the harsh mistress that is marketing... :)

[Poor Coco]

Re: Here's my single-balloon idea!

Dynamical instability is the problem. Now go back to your marketing "work".

[Christoph]

Double balloon with tension lines

Take the double balloon setup, run tension lines from the bottom of each support line (at the end of the truss) to the top of the other support line (just under the balloon) . Launch at a slight angle to avoid hitting the crossing lines.

That should fix the problem of one balloon going higher than the other.

[Andus McCoatover]

Re: Double balloon with tension lines

Did You mean...

A vertical line from each balloon to the end of the truss it's above, another diagonal line from each balloon to the opposite end of the truss?

with the higher balloon now providing more lift, the lower balloon has less work to do, so can rise and maintain equilibrium.

To prevent LORAN hitting the lines, mount it on a small pier at 90 degrees from the centre of the truss. Have a similar 'pier' on the other side with a counterweight, to maintain balance.

This could easily be tested with a couple of cheap party helium-filled balloons (naturally, not 'scientifically filled - there will be an imbalance) , some strong fishing nylon line, a long bit of bamboo (to replicate the truss) and an observer about a couple of kilometres away - preferably on a hill - , armed with a humongously good telescope, or a big telephoto lens on a tripod-mounted (video?) camera. Material cost? About a tenner.

Just a thought.

Truss, indeed! "I thank you for your support. I shall wash it and return it presently"

[Andus McCoatover]

@ Christoph

Yes, you did. I missed a word. Sorry.

[Dave 32]

Electric

If you go with two orbs, err, balloons, you just need to give them a massive, identical electrostatic charge so that they repel each other. A few million Volts should do.

Err, was that lightning? :-(

Dave

P.S. Hey, I may have discovered a fact of nature! So that's what keeps those things apart!

Could make for a shocking experiment.

[Andus McCoatover]

I vote....

The helium balloons are now to be referred to as 'Bulgarian Airbags'. Well, they'll save a playmobil 'naught from a fate worse than meltdown, I expect....

[NoneSuch]

Fund Raising Banner Idea...

AN APPEAL ON BEHALF OF THE NATIONAL TRUSS

(Cannot tell a lie. Stole that from Monty Python)

[Ron B]

Launch option

The model I saw earlier had a V tail. This is ideal for using Delrin LOW DRAG Rail Buttons on the top of the rocket plane body and hang it on a Standard Launch Rail that runs along the bottom of the truss.

You can't perch a plane of any weight on top of a hanging truss. Long before it reached launch altitude it would simply flip over, fall off and auger into the ground. Keep the center of gravity low and hang the plane under the truss, out of the way of the suspension lines.

[Anonymous Coward]

Invert It!!

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??

[jon 13]

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.

[pwibble]

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!

[SpaceInvader]

Launch Tragectory

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 :)

[Jaymax]

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.

<code>000

\ |/

|

|

|

|/n!

/ha

/lo

</code>

I luuuurves me some tagfail!

[EddieD]

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....

[Winkypop]

Does one require a space permit?

Just wondering...

[Faye Berdache]

Triangles rule

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).

[taxman]

Optional?

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.

[Magnus_Pym]

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.

[cjoki]

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!

[Kevin Johnston]

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...

[Anonymous Coward]

Don't need no stinkin' truss

Get a cheap ultrasonic volume measurement device and dismantle it.

http://www.amazplus.com/ultrasonic-distance-area-volume-laser-measurement-device-p-240928.html

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.

© jellyandballoonsparty

[M Gale]

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.

[Terry Cloth]

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.

[M Gale]

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.