[amsat-bb] Re: FOX-2 Information (was: "Flying repeater" inquiry)
Mat_62 at charter.net
Fri Feb 14 18:26:37 PST 2014
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.
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.
> On Fri, Feb 14, 2014 at 3:44 PM, Bryce Salmi <bstguitarist at gmail.com
> <mailto: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!
> On Fri, Feb 14, 2014 at 2:25 PM, Clayton Coleman
> <kayakfishtx at gmail.com <mailto: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:
> 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
> On Feb 14, 2014 4:04 PM, "Michael" <Mat_62 at charter.net
> <mailto: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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