A few years ago, I heard about a safety device that consisted of a silver coated balloon, like the birthday type, and a gas (Helium?) cartridge that would inflate the balloon and allow the balloon to rise to approximately 100ft, teethered by a light string. At the time I thought this would be a great device but felt that airlines would not allow the gas cartage on the plane. Since then I never heard another word. Has anyone heard about the same device? Does it exist? And what is it's current status?