[amsat-bb] Re: A0 40 replacement

Zach Leffke zleffke at vt.edu
Thu Sep 5 07:03:42 PDT 2013

Just throwing this out there:

1.  University cubesats tend to want to occupy amateur satellite service
spectrum for their science missions, V/U is common.
2.  Most *science* missions are only designed to last a few years, but the
orbits will last a while longer.
3.  How many science missions have been completed, but the spacecraft is
still in orbit and occupying amateur spectrum? (I don't know the answer but
I suspect it's a decent number, probably out of single digits and into
double digits, see
http://www.nasa.gov/directorates/heo/home/CSLI_selections.html to get an
idea of the number of cubesats going up from universities, note the number
of "in work")
4.  What if those university spacecraft carried Software Defined Radio
technology as their primary method for delivering their mission data to the
5.  What if upon completion of their mission the universities turned over
control of the spacecraft to AMSAT.
6.  AMSAT then reconfigures the spacecraft such that the SDRs are now used
for voice or data relay (FM, Linear, packet, whatever).
7.  Now all of a sudden, hams don't have to wait for a new spacecraft to get
built and find a launch.  Birds already in orbit, that are using Amateur
Spectrum, now all of a sudden are providing a service to the Amateur

Personally, I'm glad the universities are using Amateur Radio spectrum for
their science missions.  I view the skies as a "target rich environment"
even if all I can do is listen to these birds.  However, it would be nice if
the birds occupying amateur spectrum actually provided a service to the
amateur community.  But what if the SDX that flew on ARISSat, or the one
that will be developed for the Future of the Fox series could be "sold" (or
given) to the university cubesat community as a radio capable of being used
to deliver science data?  Their science mission concludes, control is turned
over to AMSAT, the radios are reconfigured, and they become transponder
birds for the ham community.

At the rate that these spacecraft are going up, even if we nab only 10% of
the spacecraft listed on the link above and convince them to fly SDRs that
can be reconfigured, that's roughly 9 satellites that over time become
useable by the ham community as voice/data transponders.  We don't have to
build them, we don't have to find a launch, we don't have to do anything but
wait until the science mission is over and then play.  Will the spacecraft
be of the same quality of what comes out of AMSAT? Maybe, maybe not, but
even if one only lasts a year as an FM or Linear Transponder, I'd take it,
and use it.

Granted, who knows what the orbits would be, so a replacement for AO-40?
Probably not.  But would the Amateur Satellite community accept maybe
instead of 1 really long pass from a HEO bird, maybe in that same time frame
10 or 20 or maybe even 50 passes from multiple lower birds (I made these
numbers up, no idea what the actual numbers would be)?

Granted, there is a LOT that would go into making this idea possible.  We'd
have to have an SDR the universities are willing to use, probably one with
flight history (cough, Fox-2, cough).  We'd have to have someone go around
to the Universities and "sell it" to the Principal Investigators that our
radio will work for them (technical issues aside, maybe they get a little PR
by adding support for the Amateur community onto their list of mission
objectives). If they agree to fly the radio, and then turn over control, we
need to be capable of supporting those spacecraft from an Operational point
of view when the time comes.  We would need to have some sort of "filter"
such that if they drive the heck out of their spacecraft to the point that
it is nearly dead when their science mission concludes we have the option to
reject taking the spacecraft over. Etc. Etc. Etc.

There's a lot of "what ifs" up there, but my favorite "what if" to think
about is: what if the 89 satellites on that link above were capable of
supporting amateur use at the conclusion of their science missions (Fox-1 is
on that list, so ok 88 satellites)?  89 satellites + what AMSAT has and is
still putting up?  Can't make a contact during field day on an FM bird
because of crowding, no problem, you have 5 other satellites to choose from
and try.

My second favorite "what if" to think about is: what if the university
cubesats occupying amateur spectrum actually provided a service to the
amateur community?

A traditional replacement of AO-40? No.  Effectively reproducing the similar
amounts of access time and capabilities of AO-40? Maybe.

Like I said, just throwing the idea out there...

-Zach, KJ4QLP

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