[amsat-bb] Re: LF Satellite ideas?

John Magliacane kd2bd at yahoo.com
Sat Dec 11 18:13:24 PST 2010

--- On Sat, 12/11/10, Bob Bruninga <bruninga at usna.edu> wrote:

> Is 137 KHz possible from space?


My understanding is that LF and VLF emissions of terrestrial origin don't get beyond the 'D' layer, even at night.  In fact, the 'D' layer acts as a reflector, rather than an attenuator at these frequencies.  Cosmic background radiation maintains sufficient 'D' layer ionization at night.

However, your post reminded me of project INSPIRE, which was a plan to transmit VLF signals from the Space Shuttle back in 1992 using a pulsed electron gun in the payload bay.  Details on project INSPIRE can be found here:


I'm not sure how this would penetrate the ionosphere except through brute force.

Nevertheless, compatible receivers are simple to build and readily available.

73, de John, KD2BD

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