Could you use hydrogen for permanent-installation balloons? (Score: 1) by wootery@pipedot.org on 2015-10-13 15:02 (#QBMZ) As I understand it, the high price of helium is one of the major issues with airships. Could you use (yes, flammable) hydrogen instead, especially for unmanned floating-installation type applications?If you want to bounce radio signals off something a mile up in the sky, would a hydrogen-filled balloon do the job? The safety issue is surely not a big one if it's not designed to regularly land: a Hindenburg situation seems unlikely if it's neither carrying people nor intended to land. Re: Could you use hydrogen for permanent-installation balloons? (Score: 1) by fnj@pipedot.org on 2015-10-13 23:19 (#QD45) The cost of helium is not a critical factor. Even at a very generous $10/m^3, the cost to fill Hindenburg 100% with helium would be $2 million. But it would cost at least $45 million (simply tracking general inflation), and quite possible $100-200 million to build Hindenburg today. Operations are such as not to expend any gas. Diffusion and leakage could certainly be kept to less than the amount of one filling per year.But yes, certainly hydrogen could technically be used if you could get your craft certified with it, and if you don't mind the hazard of flaming wreckage falling on your citizens. Re: Could you use hydrogen for permanent-installation balloons? (Score: 1) by wootery@pipedot.org on 2015-10-14 22:13 (#QGKS) and if you don't mind the hazard of flaming wreckage falling on your citizens.Ah yes. That.Could a balloon be engineered to 'fail safe'... like a self-destruct? If it burns up quickly in case of fire and carries only a light payload (some kind of radio repeater), I imagine the risk could be mitigated. I guess there's always the vulnerability to vandalism though.
Re: Could you use hydrogen for permanent-installation balloons? (Score: 1) by fnj@pipedot.org on 2015-10-13 23:19 (#QD45) The cost of helium is not a critical factor. Even at a very generous $10/m^3, the cost to fill Hindenburg 100% with helium would be $2 million. But it would cost at least $45 million (simply tracking general inflation), and quite possible $100-200 million to build Hindenburg today. Operations are such as not to expend any gas. Diffusion and leakage could certainly be kept to less than the amount of one filling per year.But yes, certainly hydrogen could technically be used if you could get your craft certified with it, and if you don't mind the hazard of flaming wreckage falling on your citizens. Re: Could you use hydrogen for permanent-installation balloons? (Score: 1) by wootery@pipedot.org on 2015-10-14 22:13 (#QGKS) and if you don't mind the hazard of flaming wreckage falling on your citizens.Ah yes. That.Could a balloon be engineered to 'fail safe'... like a self-destruct? If it burns up quickly in case of fire and carries only a light payload (some kind of radio repeater), I imagine the risk could be mitigated. I guess there's always the vulnerability to vandalism though.
Re: Could you use hydrogen for permanent-installation balloons? (Score: 1) by wootery@pipedot.org on 2015-10-14 22:13 (#QGKS) and if you don't mind the hazard of flaming wreckage falling on your citizens.Ah yes. That.Could a balloon be engineered to 'fail safe'... like a self-destruct? If it burns up quickly in case of fire and carries only a light payload (some kind of radio repeater), I imagine the risk could be mitigated. I guess there's always the vulnerability to vandalism though.