Re: [sarex] ISS ON HF

[Roger Harrison <rogerh@xxxxxxxxxxxxxxxxxx>]

At 08:04 PM 28-08-99 -0700, Jim Romelfanger, K9ZZ wrote:
>Roger Harrison wrote:
>> 
>> This could be interesting!
>> 
>> From:  SpaceNews 16-Aug-99:
>> 
>> * ISS ON HF *
>> =============
>> Will Marchant, KC6ROL, reports that in addition to including VHF and UHF
>> capabilities, the Amateur Radio station on the International Space Station
>> (ISS) will also include HF radio equipment.  An HF antenna will be
installed
>> on the outside of the ISS during a spacewalk on STS-101 in December, and
>> HF transceivers will be flown after 2000.
>> --------------------------------
>> 
>> Things will begin to happen on the down slope of the current solar cycle,
>> but that should prove interesting in itself and opportunities for
>> interesting propagation (and propagation studies) should INCREASE through
>> the solar cycle minimum (like some interesting experiments in the 80m 'DX
>> Window' and gray-line propagation) .
>> 
>> 73, Roger VK2ZRH
>> ----
>> Via the sarex mailing list at AMSAT.ORG courtesy of AMSAT-NA.
>> To unsubscribe, send "unsubscribe sarex" to Majordomo@amsat.org
>
>
>G'day, Roger!
>
>Just FYI, my current (underscore CURRENT) understanding of the HF gear
>on ISS is that the "bottom" band is to be 20 metres. That is, 14 MHz,
>then all the way to 70cm at the top end.
>
>Nevertheless, I've been wondering and speculating for some time about
>studies from above the F-layer!
>
>I do not know if anything that will work below 14 MHz is or will be
>manifested - yet. I'd guess the limiting factor will be the antennae. I
>believe there are 4 antenna ports on Zarya for ARISS (and ISS) use.
>
>If things get back on schedule, we would see some limited activity on
>VHF from ISS in early 2000. However, Russia seems behind on the next
>module. I believe that one (third) has to before the fourth, which will
>be a shuttle delivery. But as you know our shuttle fleet is grounded for
>a while for examination of the hydrogen fuel lines in each orbiter. I
>believe there are about 1,600 such lines in each orbiter. (It sounds
>like a task I would NOT enjoy!)
>
>Well, it will all get up there eventually. 
>
>If you care to pull in a 200K file, I have a NASA photo of Mir taken in
>January 1998 at:
>
>http://members.baraboo.com/BSSS/mirstn.jpg
>
>I wanted to post it in a way that would display some detail, not a
>thumbnail.
>
>73 from Wisconsin.
>-- 
>Best regards, Jim Romelfanger, K9ZZ
>
Hi Jim,

thanks for the info. Well, they might start out with 14 MHz but, as ISS is
a long-term venture, it seems there might be opportunities further down the
track. 

The nighttime ionosphere regularly has a vertical penetration frequency
(foF2) of 3 Mhz and below, so 80m is not out of the question. In any event,
there are "holes" in the ionosphere - the so-called Southern High Latitude
Trough being one such (none in the northern hemisphere) - where the
electron/ion density is often so low that foF2 can fall in the LF region
below 400 kHz (famous radio astronomer Grote Reber did a study of celestial
noise sources from Tasmania by 'looking through' this trough).

In the 1970s, the Canadians launched as series of ionospheric sounding
satellites with HF swept-frequency radars aboard that sounded the
ionosphere from above. There are numerous papers on, for example, the
Journal of Geophysical Research on the subject.

Shortwave broadcasting from satellites was another thing considered in the
late-70s/early-80s, I remember.

I saw a note on your MIR image - great picture!

73, Roger VK2ZRH
----
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