[amsat-bb] Re: Another Great Tech Tuesday Net

Anthony Monteiro aa2tx at comcast.net
Fri Feb 14 15:53:40 PST 2014

On 2/14/2014 4:57 PM, Michael wrote:
> OK then, I have a legitimate satellite question.  Is Fox 2 going to be a
> linear bird? See, I have some confusion on this....

Hi Michael,

Good question. I think I can clear this up.

The main point of Fox-2 is to develop and fly an
advanced, software defined transponder (SDX.)
An SDX can be programmed to be any kind of
transponder. It will be a linear, inverting,
mode-J transponder by default.

We would also like to try some new and
interesting digital modes perhaps including
digital voice which would be my personal favorite.
That is the tremendous flexibility you get with
an SDX. You can change the transponder in software.

ARISSat-1 was our first attempt at an SDX and it
worked very well. It could only be programmed on
the ground though. The SDX for Fox-2 will
be programmable in orbit.

Fox-2 will be a 3U CubeSat (3x the size of Fox-1)
providing a lot more power and space for the

The source of confusion may be because we are
building four Fox-1 flight units. The idea is
to have them available and ready to fly so
we can easily team up with universities that want
to fly science missions and get free launches.
Building them all at once is also a much cheaper
way to build satellites.

All four Fox-1 units will have the same hardware
and avionics. The universities will supply their
experiment cards and the software can be customized
for each satellite as needed.

Once the Fox-1 flight models are built, the engineering
team can begin working on Fox-2. That should start
this year.

The status of the Fox-1 satellites is as follows:

Fox-1 (Fox-1A) is scheduled to fly on NROL-55.

RadFxSat (Fox-1B) is a joint project with Vanderbilt
University. It has already been accepted into the
NASA ELaNa program but it has not been assigned a
launch yet.

Fox-1C and Fox-1D are not currently assingned.


Best satellite DX and 73,
Tony AA2TX

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