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From: wmartin@brl-tgr.ARPA (Will Martin )
Newsgroups: net.ham-radio,net.space
Subject: Re: Quality of NASA space-to-ground links
Message-ID: <10797@brl-tgr.ARPA>
Date: Fri, 17-May-85 17:28:41 EDT
Article-I.D.: brl-tgr.10797
Posted: Fri May 17 17:28:41 1985
Date-Received: Sun, 19-May-85 08:23:27 EDT
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Reply-To: wmartin@brl-bmd.UUCP
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Summary: Radio equipment in spacecraft

A good question, and an opening for a topic I had been meaning to post
for some time now, and always forgot to...

What has the radio equipment available to the astronauts been, over the
history of the manned-spaceflight program, and especially now, in the Shuttle?
As a longtime DXer, I have always wondered what it would be like to have
radios in orbit, and be able to tune around and see what I get. Can the
astronauts do this?

I would expect that you'd get some shortwave and medium wave signals --
the portion that punched through the ionosphere and wasn't reflected,
and that part radiated straight up, which doesn't get reflected, as
you pass over those antennae. Higher frequencies would go right through
the ionosphere, of course, but I'd expect to get a mixture of everything
on the hemisphere transmitting on that particular frequency (with the
closer transmitters dominating, so it would constantly change as the
receiver orbits).

So, do the astronauts now have general-coverage receivers that they can
tune, or is all the radio gear fixed-frequency and dedicated to the
mission? What about video reception? Do they have PAL and SECAM and
NTSC equipment to look at TV signals from all over the world as they orbit?
I like to think of getting a mix of every US station on channel 5 at
the same time... surrealistic TV DX!

The latest episode of the PBS "Spaceflight" series mentioned how
deadly bored the Gemini astronauts were during scheduled sleeptimes
(when they weren't sleepy) and during the last part of long-endurance
missions. I DX at times like those -- did they have the chance to?

What about antennae? Spacecraft being metal cans, it probably is 
necessary to get some sort of antennae outside the craft and the
signal fed through. Are there spare or unused antennae that can be
used for recreational radio reception? What about HF -- are there
reeled-out longwire antennae on the Shuttle for HF, or is that
portion of the spectrum ignored? (Could you receive LF or VLF
from orbit, or are those all ground-hugging signals?)

Any NASA types out there who have info on the the radio-related
aspects of the space program, please post info on this! Inquiring
minds want to know!

Regards,
Will Martin

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