"Missile Defence Command"
Is it just with me that this phrase evokes memories of a trackball and rapidly lengthening lines of death approaching my cities?
The US military will deploy an "optionally manned" 250-foot surveillance airship to Afghanistan by the middle of 2011, according to reports. The dirigible spy-ship will be able to lurk high above Afghan battlefields for up to three weeks at a time, relaying information to ground commanders. Aviation Week reports that the …
'The new, bigger ship will be termed the Long Endurance Multi-intelligence Vehicle (LEMV)'
Yes, very good, but it will still be called a 'blimp', 'zeppelin' or 'balloon' so giving it another name is pretty pointless.
I suppose one way to address the bouyancy issue is to have a seperate 'blimp', which supports around 80% of the cargo weight and is attached to the top of the main unit, that is released at the same time as the cargo.
OR
You could even arrange for every cargo 'package' to have it's own tailored additional lift 'blimp' with it's own collett which the LEMV could connect to and provide the additional bouyancy/lift via it's own engines.
Once the item is delivered it would just be a matter of disconnecting from the collet and flying away - the 'blimp' can stay connected to the cargo and is kept to be used for the next load to be taken away.
That way the release of the cargo would be less traumatic.
only a thought, I'll get my coat.
ttfn
it's a better lifting gas and you could design it to go crashing into the enemy if you were shot at. Not only that, you'd be able to explode or burn off the excess gas. Or just vent it without substantial cost (unlike pricey helium).
Obviously the loitering version would use Helium. But the rapid insertion version could use hydrogen. It could even operate as a fuel source for propulsion either to make insertion quicker or to allow self-extraction.
Would a mix of hydrogen and CO2 work?
H2 2g per mole. CO2 44g per mole. IE volume for volume CO2 is 22x heavier than H2. The question is of course can you reduce the flamability of the H2 by diluting it with not too much CO2
But then you could dilute it with H2 (4g per mole) instead.
Provided you can find some way to seperate out the H2 from the dilutant in the first place.
Mine will be the one with the Chemistry A level in the side pocket.
Correctly designed and built, esp. for unmanned cargo drops, I don't see the problem.
Sure, hydrogen is highly flammable. But the pure hydrogen in your gas balloons is not going to random explode. If punctured, the balloon would burn, but probably not explode (Or at least, not until the hydrogen mixture in it is sufficiently mixed with oxygen from the air).
Use hydrogen for unmanned drops of material and supplies into relatively safe areas, where the vulnerability of the blimp isn't a major issue. And if it does get shot down (One inevitably will), it'll probably cost a lot less than a helium lifted version or a full on drone copter.
I think that Glen will find that hydrogen mixed with carbon dioxide will still burn when mixed with air. Sure, if the mixture was mostly CO2 then it won't burn but then it won't lift either.
Consider that the air that the Hindenburg burned in was mostly nitrogen, another inert gas. Didn't seem to help much, did it? Of course it would have burnt much better if the atmosphere was pure oxygen, but as is it burnt quite adequately.
@Remy Redert
"Correctly designed and built, esp. for unmanned cargo drops, I don't see the problem"
You are aware that this is not an option at present due to size? The current design is for a surveillance drone carrying about 2500Lb of equipment (about the same as a Vietnam era Huey).
@Glen 9
I meant He as the alternative dilutant. The idea has knocked around for some time and some Russian claims to have a way to do the seperation which was mentioned in a previous Reg article. Burning H2 down to water would also generate added ballast on site. The joker in the pack is that typically these payloads are single units and cannot be gradually offloaded while their weight is offset by the H2 burn.