[amsat-bb] Re: FOX-2 Information (was: "Flying repeater" inquiry)

Bryce Salmi bstguitarist at gmail.com
Fri Feb 14 18:54:27 PST 2014

OK I do apologize, as was pointed out I completely misread your wording in
the original email. While my facts still stand on the challenges of
building the satellite I stand corrected on your argument. Sorry!


On Fri, Feb 14, 2014 at 6:26 PM, Michael <Mat_62 at charter.net> wrote:

>  Hold on.  Not once did I ever suggest that ANY satellite was "easy to
> build".  I very much respect the effort, research, testing, etc. that goes
> into every one, be it a flying repeater or not.  My reference to the term
> "easysats" comes from Clint or one of his ilk  that seems determined to
> show the rest of the amateur community how "easy" the FM sats are to work.
> That's all well and good for them to do that too.  However, I was drawn to
> satellite work because of the challenge.  I mean call me weird or crazy
> but when something loses it's challenge and becomes too easy, it begins to
> bore me pretty quickly.
> 73,
> Michael, W4HIJ
> On 2/14/2014 7:00 PM, Bryce Salmi wrote:
> To expand upon the flying repeater email.
> "I'd be interested to know if there is going to be any technical
> challenge to working Fox 2 or if it will just be yet another ones of
> Clint's Easysats."
>  Now, the actual important comment in this sentence is the reference that
> Fox-1 being an FM bird is assumed to be easy to build. Strictly and
> professionally speaking this is a huge understatement of the technical
> challenges of any satellite. I'll assume you do not work in the the
> aerospace industry or have volunteering to build one of the AMSAT
> satellites (more than welcome to give it a shot!). Even an easysat is
> incredibly hard to build. Beyond the actual transmission mode the satellite
> must maintain a healthy power budget, provide telemetry to monitor the
> status of the satellite, be implemented in a 95mmx95mmx95mm space (inside
> the cube), survive the 5 year mission's expected 30krad dose of radiation,
> and survive 16 sunrises/sunsets per day in the vacuum of space (have heat?
> can't use convection to get rid it!). Just to name a few items...
>  To put the sunrise/sunset into perspective (think of the road and other
> objects you see cracking due to expansion and contraction) MIL-STD-1540
> which is a good idea to follow and the associated specifications usually
> require a spacecraft to be designed to survive -34C to +71C temperature
> extremes. Try operating a consumer product in that environment and it will
> fail pretty quickly.
>  Also, from an extremely high-level point of view, the only difference
> between Fox-1 and Fox-2 will be the FM repeater being changed to the
> Software Defined Transponder (SDX). The SDX is a bit more power hungry so
> it requires an upgraded Maximum Power Point Tracker and more solar cells to
> produce the needed power. Otherwise, Fox-2 and Fox-1 will share a lot of
> the same technology. This is good because we don't want to re-invent the
> wheel. Therefore I respectively reject the idea that just because Fox-1 is
> an FM bird it is not technically challenging to design and build.
>  Bryce
> On Fri, Feb 14, 2014 at 3:44 PM, Bryce Salmi <bstguitarist at gmail.com>wrote:
>> You can already find out more about the prototype maximum power point
>> tracker that will be used to power the software defined transponder on
>> Fox-2!
>>  http://edge.rit.edu/edge/P13271/public/Home
>>  Bryce
>> On Fri, Feb 14, 2014 at 2:25 PM, Clayton Coleman <kayakfishtx at gmail.com>wrote:
>>> Hi Michael
>>> You're in luck.  The Phase 2 Fox series are based on the SDX transponder
>>> as
>>> tested on ARISSat-1 and not your favorite "flying repeaters."
>>> Learn more by visiting the "Meet the Fox Project" page at:
>>> http://ww2.amsat.org/?page_id=1113
>>> Welcome aboard.  You can join AMSAT and renew via the web store or by
>>> calling the office.
>>> See http://store.amsat.org/catalog/ and click on "Membership" for
>>> several
>>> options.
>>> 73
>>> Clayton
>>> W5PFG
>>> On Feb 14, 2014 4:04 PM, "Michael" <Mat_62 at charter.net> wrote:
>>> > If Fox 2 is a linear bird, I'll even put my money where my mouth is and
>>> > renew my long dormant  membership in AMSAT because I will feel that
>>> they
>>> > are moving in a direction that I and many others have interest in. If
>>> it's
>>> > just another flying repeater though well..... YAWN....I'm getting
>>> sleepy
>>> > now.
>>> > 73,
>>> > Michael, W4HIJ

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