LOHAN rival to inflate bulging orbs with hydrogen We at the El Reg Special Projects Bureau are well aware that some of you are less than impressed with the choice of lifting gas for our Low Orbit Helium Assisted Navigator (LOHAN) project. Well, we're not going to be swayed on the matter, but the Hindenberg fans among you are directed to the STARS Project, a private High …
Wikipedia reports its name slightly differently: 3-[(2S)-1-methylpyrrolidin-2-yl]pyridine. The molecular formula's probably your best bet at finding its alter ego (which is in no way connected to Vitamin B2 or the reason that compound got renamed...)
Hydrogen is also a component in C8H10N4O2 (aka 1,3,7-trimethyl-1H-purine-2,6(3H,7H)-dione) and C2H6O, both of which I'm sure the Reg team have plenty of experience in handling :)
The key is tha amount of buoyancy a given volume of gas provides, not the absolute density of the gas, itself. Air weighs about 1kg per cubic metre. He weighs a lot less (about 1/20th from memory) and Hydrogen about half of that. So the difference in buoyancy between using Helium and Hydrogen is NOT a factor of two (the difference between their densities). It's the difference between their buoyancies, which for He would be about 0.95kg/m3 and 0.98kg/m3 for H2 - that's is a difference of a few percent, or in scientific units: bugger all.
There will come a day when wasting tons of precious, non-renewable helium on poxy balloons will be seen as one of the most stupid things mankind ever did.
The Earth's helium supply is small and finite. We need all of it for supercooling superconductors and various crucial machines and experiments (such as the LHC). Even now, we are due to run out of helium by ~2050 (ie. before we run out of oil).
Hydrogen supply is effectively infinite. Use it, don't smoke, don't rub the balloon on your hair until it crackles.
Job done.
Non-renewable helium? You mean the stuff that the US Government no longer offers storage for because they can't afford it? The stuff that now gets thrown away from most natural gas refineries if they can't shift it to balloonists and welders and such? Oh and some estimates of Helium depletion are 2015 - I agree thats a travesty, but not using out for balloons is not going to make it last any longer.
Hydrogen, despite the pundits, wants to kill you, Helium, use it or not..is going to get away and head off into space.
Fresnel's about right - once we'd got the Hindenburg images out of our heads, we realised that the main risks will be during the fill. We might well have a small crowd watching, so keeping them well away from the fill-and-launch area will be the most important safety factor, of course. We'll be observing electrostatic discharge precautions, and minding the other obvious risks.
Once the balloon's sealed, things become a lot safer: we just need to avoid getting the balloon anywhere near a heat source before we release.
Pic: oops...
The risk isn't very high - don't put any oxygen in the balloon and the worst it will do is burn, any hydrogen that is released into the atmosphere will soon dissipate, just don't put the hydrogen tank near anything flammable to avoid the slim chance that it could get very hot and you'll be fine.
And to re-iterate a point that I am sure must have been made before. Hydrogen is not explosive although a hydrogen/air mixture can be. The Hindenberg burnt, it did not explode, and there was remarkably little loss of life (35 out of 97 on board + one ground crew).
I would have thought Hydrogen safer to handle than LPG since it won't collect in the bottom of things like LPG does and LPG is widely used. However, as pointed out previously, the gain in buoyancy is small, about 7%.
Hi Malcolm! That's exactly correct. We'll be doing our damnedest to ensure that atmospheric gases don't get into the fill - apart from everything else, it'll reduce the lift. The effective lift gain's small but if you run the numbers through the CUSF lift calculator (http://www.srcf.ucam.org/~cuspaceflight/calc/), using a payload weight of 1kh, you'll find that using hydrogen cuts half an hour from the ascent phase.
That's not trivial: every minute saved makes it less likely that we'll need a boat for the retrieve, and more likely that there will be power to all components for the mission duration. Mind you, if any reader here knows a UK-based supplier with 1500gm/1600gm balloons in stock, please get in touch! We'd love to have the (roughly) 75 minute ascent phase that we originally wanted.
Oh, and Neil: we considered that option, but the Swedish guy got his reactor built first, and the publicity messed it up for the rest of us. Plus, the IAEA clearances process would take too long. :)
Hydrogen is (a) lighter than air, and (b) burns virtually colourlessly (to the naked eye), so although burning hydrogen was mainly responsible for the demise of the airship (and possibly the crew members within the nose cone), it was far more likely to be diesel combustion responsible for the demise of passengers, as diesel is a liquid and therefore heavier than air.
There won't be any passengers on LOHAN (unless you count the Playmonaut), and as hydrogen-filled airships had been circling the globe for years without any problems before Hindenberg, there shouldn't be much risk if the balloon does go Boom! You'd just need to devise a mechanism that would automatically detach the plane and payload in the event of premature balloon failure.
To be fair, LOHAN doesn't need hydrogen; it ought to get enough lift from helium. We're only looking at hydrogen for STARS-1 because we're marginal on payload weight, and the small added lift makes a significant difference for our flight time (see my comments to Malcolm, above).
In any other circumstance, I'm never going to complain about helium as lifting gas, because the added risks of hydrogen usually outweigh - pun semi-intended - the advantages, and the 2-4 cubic metres of helium used really doesn't make a large dent in the world's remaining reserves.
@mittfh - the LOHAN project might want to look at the UKHAB's ideas for cutaway devices (http://ukhas.org.uk/ideas:flight_support?s[]=igniter). On the advice of a pyrotechnician, we're going to experiment with variations using slightly more kinetic material to ensure a successful cutaway. First musing are on the "Links" page of the STARS website, and we'll update soon with results of our experiments. Once we've picked the shrapnel out, and bandaged... :) And for anyone wondering, the cutaway's going to be some distance from the balloon, which will have ruptured and released its gas (upward) in an oxygen-depleted (well, atmosphere-depleted) environment before the cutaway fires.
Rubber balloons go pretty brittle with hydrogen fill after a few days, although that's unlikely to be an issue for a single use balloon.
It makes for an interesting demonstration though. A lit taper simply makes a small hole and the hydrogen jets out of it as the balloon gently deflates (with a trailing big long flame)
It seems in a lot of countries hydrogen is normal for party baloons (no squeaky voice games, dammit!). The close proximity of these and candles had me "somewhat worried" at events I attended in said countries.
rest assured that you will not be the first guys burned by an encounter with Lohan.
(Or the first guys to experience a burning sensation following a close encounter with Lohan--but let's not dwell on that)
Paris icon, but imagine her in your mind as Lindsay, but not "Parent Trap" Lindsay, because that would be just plain creepy....
FFS... The flammability of H2 is a vanishingly small risk.
It's of the same order as smoking in a car which has petrol in its tank. People do this all the time. Or having a gas flame in a kitchen where there is tissue paper in one of the cupboards.
The only trick you will have to learn is not to put the flame close to the flammable material. This is a trick which humanity has managed countless times during recorded history. To suggest that it is beyond you makes us think that the HSE brigade might actually have a point - that REG staff actually need to be continuously told that water is wet, flames are hot and that if you stick a sharp point into your body red stuff will come out....
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