vfl

VFL


 * Very low frequency ** or ** VLF ** is the [|ITU] designation for [|radio frequencies] (RF) in the range of 3 [|kHz] to 30 kHz and corresponding [|wavelengths] from 100 to 10 kilometres, respectively. - https://en.wikipedia.org/wiki/Very_low_frequency

http://mashable.com/2017/05/19/human-radiation-bubble-around-earth/#cH.SoIA7aaq9 http://www.newsweek.com/nasa-barrier-earth-artificial-protect-space-weather-611356