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CX2SA > SATDIG 24.07.20 02:11l 704 Lines 25091 Bytes #999 (0) @ WW
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From: CX2SA@CX2SA.SAL.URY.SOAM
To : SATDIG@WW
Today's Topics:
1. Re: ORI Transponder Design Review 30 July 2020 (Robert MacHale)
2. Re: Orbit visualization & antenna performance (Leffke, Zachary)
3. Is This AMSAT's Future? (Stephen DeVience)
4. Re: Is This AMSAT's Future? (Greg D)
5. LEO sats (Joseph Trombino, Jr)
6. Re: ORI Transponder Design Review 30 July 2020 (Michelle Thompson)
7. Re: LEO sats (John Geiger)
8. Brand new to satellite (Doug Daniels)
9. Re: Orbit visualization & antenna performance (Joseph Armbruster)
10. Re: Is This AMSAT's Future? (Robert Bankston)
----------------------------------------------------------------------
Message: 1
Date: Thu, 23 Jul 2020 21:17:00 +0000 (UTC)
From: Robert MacHale <robert.machale@?????.???>
To: AMSAT BB <amsat-bb@?????.???>, Michelle Thompson
<mountain.michelle@?????.???>
Subject: Re: [amsat-bb] ORI Transponder Design Review 30 July 2020
Message-ID: <2042851001.6301928.1595539020425@????.?????.???>
Content-Type: text/plain; charset=UTF-8
Which existing product most closely match the completed P4XT functionality?
Are there any affordable modulators for Ham Radio ground stations?
[1] For
reference:?https://work-microwave.com/wp-content/uploads/2019/01/V2_DVB_SDMO_1
903-2.pdf
Robert MacHale
. KE6BLR Ham Radio License
.?http://www.aprsat.com/predict
.?http://www.spaceCommunicator.club?
. Supporting Boy Scout Merit Badges in Radio, Robotics, and Space Exploration
Silly Joke:?What did the little mountain say to the bigger mountain? Hi
Cliff!Political Quote:?He who dares not offend cannot be honest. -- Thomas
Paine
On Thursday, July 23, 2020, 01:00:27 PM PDT, Michelle Thompson via AMSAT-BB
<amsat-bb@?????.???> wrote:
Greetings all!
A design review workshop has been scheduled for 7am Pacific 30 July 2020
for the 6U digital multiplexing transponder from Open Research Institute.
This work is made available for free to the general public and assumes
AMSAT as the primary audience and beneficiary.
The design is the same as one in progress for AREx (AMSAT/ARISS USA). The
design review will be of direct benefit to AREx and meets their
requirements.
The design is under consideration for other missions.
If you would like to participate in the design review workshop, then please
write me at w5nyv@????.??? for a Zoom invite.
The communications functions and circuits are the focus of this review.
System architecture document can be found here:
https://github.com/phase4space/payload-dmt/tree/master/doc/system-architecture
(Brief) Statement of Work for Phase 1 can be found here:
https://openresearch.institute/wp-content/uploads/sites/10/2020/02/Summary-Pro
posal-Open-Research-Institute-Phase-1-P4XT-.pdf
Thank you!
-Michelle W5NYV
(One of your AMSAT Directors)
_______________________________________________
Sent via AMSAT-BB@?????.???. AMSAT-NA makes this open forum available
to all interested persons worldwide without requiring membership. Opinions
expressed
are solely those of the author, and do not reflect the official views of
AMSAT-NA.
Not an AMSAT-NA member? Join now to support the amateur satellite program!
Subscription settings: https://www.amsat.org/mailman/listinfo/amsat-bb
------------------------------
Message: 2
Date: Thu, 23 Jul 2020 21:39:36 +0000
From: "Leffke, Zachary" <zleffke@??.???>
To: AMSAT <AMSAT-BB@?????.???>
Subject: Re: [amsat-bb] Orbit visualization & antenna performance
Message-ID:
<MN2PR05MB7037D1A47138CA59F42CAC92DF760@?????????????.????????.????.???????.??
?>
Content-Type: text/plain; charset="us-ascii"
Not a direct answer to your question...but for 'orbit visualization'....
System's Tool Kit (STK) from AGI: https://www.agi.com/products/stk
There is a free license for non commercial use (e.g. Ham Radio.....). With
this you can quickly pull in TLEs for the spacecraft of interest and get
very nice 3D and 2D displays to visualize orbits. You can also do things
like run pass predictions ('accesses' in STK speak), get high time
resolution az, el, range, and range rate (for Doppler and link analysis
math) reports (in CSV format), and they have lots of tutorials for getting
up and running. What you *can't* do with the free version is incorporate
things like the Comm toolbox for direct antenna pattern visualization and
link analysis within STK. From experience during my Master's work, the
combination of 'free STK', 4NEC2 (and outputting theta/phi/Gain matrix), and
Python can be a pretty powerful combo.....but lacks the 'visualize' part
unless you want to code that up too....
The General Mission Analysis Tool (GMAT) is the free an open source
competitor to STK from NASA:
https://software.nasa.gov/software/GSC-17177-1. I have less experience
(...i mean no experience...) with this package, so not sure how easy it is
to use and whether or not is has antenna modelling features, but I know a
lot of folks use it (including folks on this list) for orbit modelling.
Finally, speaking of Python, the skyfield package
(https://rhodesmill.org/skyfield/) is a great way to 'get rid of STK' for
your own projects. Skyfield provides a baked in SGP4 propagator to handle
TLEs. That, plus modules such as pandas, matplotlib, openGL modules (for
good graphics / 3D visualization), could make for a pretty nice package that
gives you full control (and is free).....but this is a double edged sword as
it would all need to be coded up, which can eat precious 'project time.' (I
mention it because its somewhere way down on my project list...and there
might already be something out there on this).
Hope this helps!
-Other Zach, KJ4QLP (the Zach with the Hat).
--
Research Associate
Aerospace & Ocean Systems Lab
Ted & Karyn Hume Center for National Security & Technology
Virginia Polytechnic Institute & State University
Work Phone: 540-231-4174
Cell Phone: 540-808-6305
-----Original Message-----
From: AMSAT-BB <amsat-bb-bounces@?????.???> On Behalf Of Zach Metzinger via
AMSAT-BB
Sent: Thursday, July 23, 2020 12:16 PM
To: AMSAT BB <amsat-bb@?????.???>
Subject: [amsat-bb] Orbit visualization & antenna performance
Hello all,
In order to evaluate antenna effectiveness in the 70cm downlink band,
I'm trying to visualize the orbits of the following satellites:
AO-27
SO-50
RS-44
I can find the perigee/apogee and output power on these, and, so far, I
have:
AO-27 788x801 km 1W/0.5W/0.1W
SO-50 603x713 km 0.25W
RS-44 1175x1511 km 5W
On the FM birds: My observed data shows that SO-50 is difficult to hear
while AO-27 is booming, so I hypothesize that AO-27 is transmitting with
0.5W or 1W.
RS-44's beacon seems to be fairly weak, while CW/SSB signals on the
transponder are quite strong.
Does anyone know where I might find more details on RS-44's construction
such as antennas and power output for the beacon?
Thanks,
--- Zach
N0ZGO
EM12jw
_______________________________________________
Sent via AMSAT-BB@?????.???. AMSAT-NA makes this open forum available
to all interested persons worldwide without requiring membership. Opinions
expressed
are solely those of the author, and do not reflect the official views of
AMSAT-NA.
Not an AMSAT-NA member? Join now to support the amateur satellite program!
Subscription settings: https://www.amsat.org/mailman/listinfo/amsat-bb
------------------------------
Message: 3
Date: Thu, 23 Jul 2020 16:49:35 -0500
From: Stephen DeVience <sjdevience@?????.???>
To: amsat-bb@?????.???
Subject: [amsat-bb] Is This AMSAT's Future?
Message-ID:
<CAMPfQQC4k9Gd8_A4UkcfPC9ju15eAgV3or_QC+=emhXeSShuYA@????.?????.???>
Content-Type: text/plain; charset="UTF-8"
It's interesting that there are amateur satellite allocations in the 2.4
GHz and 5 GHz ranges as well. A number of groups are doing ham internet on
those frequencies using modified routers. This might be an option for some
kind of digital satellite, although dealing with doppler could be a
problem. I can envision an amateur version of Starlink.
-Stephen, N8URE
------------------------------
Message: 4
Date: Thu, 23 Jul 2020 15:14:55 -0700
From: Greg D <ko6th.greg@?????.???>
To: Stephen DeVience <sjdevience@?????.???>, amsat-bb@?????.???
Subject: Re: [amsat-bb] Is This AMSAT's Future?
Message-ID: <09c77d38-40c8-e87f-2179-4c364c25a3f2@?????.???>
Content-Type: text/plain; charset=UTF-8
Besides Doppler shift, which would definitely be a problem, there's also
the WiFi protocol itself. It's designed for short range communication,
and some of the low level protocol timers need to be adjusted for
working in WAN applications such as AREDN. I suspect that getting them
to work over orbital distances might be an ack retry too far.
Greg KO6TH
Stephen DeVience via AMSAT-BB wrote:
> It's interesting that there are amateur satellite allocations in the 2.4
> GHz and 5 GHz ranges as well. A number of groups are doing ham internet on
> those frequencies using modified routers. This might be an option for some
> kind of digital satellite, although dealing with doppler could be a
> problem. I can envision an amateur version of Starlink.
>
> -Stephen, N8URE
> _______________________________________________
> Sent via AMSAT-BB@?????.???. AMSAT-NA makes this open forum available
> to all interested persons worldwide without requiring membership. Opinions
expressed
> are solely those of the author, and do not reflect the official views of
AMSAT-NA.
> Not an AMSAT-NA member? Join now to support the amateur satellite program!
> Subscription settings: https://www.amsat.org/mailman/listinfo/amsat-bb
------------------------------
Message: 5
Date: Thu, 23 Jul 2020 18:15:46 -0400
From: "Joseph Trombino, Jr" <w2kj@?????????.???>
To: AMSAT-BB@?????.???
Subject: [amsat-bb] LEO sats
Message-ID: <96447168-F1C0-4A05-B095-AD8EA7CD739A@?????????.???>
Content-Type: text/plain; charset=utf-8
Howdy Gang.
Getting my sat station set up again after many years.
I?m familiar with AO7 and FO29 but not any of the newer LEO sats.
What are the newer LEO?s, with linear transponders for SSB/CW only, that I
should take a look at?
Many thanks for any info.
73, Joe W2KJ
------------------------------
Message: 6
Date: Thu, 23 Jul 2020 15:25:57 -0700
From: Michelle Thompson <mountain.michelle@?????.???>
To: Robert MacHale <robert.machale@?????.???>
Cc: AMSAT BB <amsat-bb@?????.???>
Subject: Re: [amsat-bb] ORI Transponder Design Review 30 July 2020
Message-ID:
<CACvjz2U70sWkwADPMjS2r=fJ3rO=e51bHFm8h_61ZOJYLSRjVg@????.?????.???>
Content-Type: text/plain; charset="UTF-8"
Good question, thank you.
We did a survey of communications systems similar to this design for the
Commodity Jurisdiction request. Most of those are substantially more
expensive than our price target. Some provided much less functionality or
had very restricted user interfaces.
Our 5GHz RF efforts focus on a design originally outlined by Mike Seguin
N1JEZ, using Skywave parts, and prototyped by Julian KF4MOT. I'm sure he'd
appreciate additional help.
There is a lot of useful feedback from recent work with the AREx team that
will be incorporated and a variety of daughter cards we use in the lab.
The goal from a product point of view is to provide more than enough
information for people to use existing SDRs and amplifiers, as well as
providing a manufactured solution.
-Michelle W5NYV
On Thu, Jul 23, 2020 at 2:17 PM Robert MacHale <robert.machale@?????.???>
wrote:
> Which existing product most closely match the completed P4XT functionality?
>
> Are there any affordable modulators for Ham Radio ground stations?
>
> [1] For reference:
> https://work-microwave.com/wp-content/uploads/2019/01/V2_DVB_SDMO_1903-2.pdf
>
> Robert MacHale
> . KE6BLR Ham Radio License
> . http://www.aprsat.com/predict
> . http://www.spaceCommunicator.club
> . Supporting Boy Scout Merit Badges in Radio, Robotics, and Space
> Exploration
>
> Silly Joke: What did the little mountain say to the bigger mountain? Hi
> Cliff!Political Quote: He who dares not offend cannot be honest. -- Thomas
> Paine
>
>
>
>
>
>
> On Thursday, July 23, 2020, 01:00:27 PM PDT, Michelle Thompson via
> AMSAT-BB <amsat-bb@?????.???> wrote:
>
>
>
>
>
> Greetings all!
>
> A design review workshop has been scheduled for 7am Pacific 30 July 2020
> for the 6U digital multiplexing transponder from Open Research Institute.
> This work is made available for free to the general public and assumes
> AMSAT as the primary audience and beneficiary.
>
> The design is the same as one in progress for AREx (AMSAT/ARISS USA). The
> design review will be of direct benefit to AREx and meets their
> requirements.
>
> The design is under consideration for other missions.
>
> If you would like to participate in the design review workshop, then please
> write me at w5nyv@????.??? for a Zoom invite.
>
> The communications functions and circuits are the focus of this review.
>
> System architecture document can be found here:
>
>
https://github.com/phase4space/payload-dmt/tree/master/doc/system-architecture
>
> (Brief) Statement of Work for Phase 1 can be found here:
>
>
https://openresearch.institute/wp-content/uploads/sites/10/2020/02/Summary-Pro
posal-Open-Research-Institute-Phase-1-P4XT-.pdf
>
> Thank you!
> -Michelle W5NYV
> (One of your AMSAT Directors)
> _______________________________________________
> Sent via AMSAT-BB@?????.???. AMSAT-NA makes this open forum available
> to all interested persons worldwide without requiring membership. Opinions
> expressed
> are solely those of the author, and do not reflect the official views of
> AMSAT-NA.
> Not an AMSAT-NA member? Join now to support the amateur satellite program!
> Subscription settings: https://www.amsat.org/mailman/listinfo/amsat-bb
>
------------------------------
Message: 7
Date: Thu, 23 Jul 2020 18:20:49 -0500
From: John Geiger <af5cc2@?????.???>
To: "Joseph Trombino, Jr" <w2kj@?????????.???>
Cc: AMSAT <AMSAT-BB@?????.???>
Subject: Re: [amsat-bb] LEO sats
Message-ID:
<CAHC1P28vZLS4cEkoTzkEyeR2YgxddhMvarVidCkKzPFWepGPxQ@????.?????.???>
Content-Type: text/plain; charset="UTF-8"
Hi Joe,
Welcome back to the satellite world! We have quite a few SSB/CW LEO sats
right now: XW-2A, XW-2B, XW-2C, XW-2D, XW-2F, which all had very good
downlink signals. In addition, there are CAS-4A and CAS-4B, EO-88 and AO73,
all of which do Mode B, and RS-44 which is in Mode J.
Hope to see you on some of them soon!
73 John AF5CC
On Thu, Jul 23, 2020 at 6:15 PM Joseph Trombino, Jr via AMSAT-BB <
amsat-bb@?????.???> wrote:
> Howdy Gang.
>
> Getting my sat station set up again after many years.
>
> I?m familiar with AO7 and FO29 but not any of the newer LEO sats.
>
> What are the newer LEO?s, with linear transponders for SSB/CW only, that I
> should take a look at?
>
> Many thanks for any info.
>
> 73, Joe W2KJ
> _______________________________________________
> Sent via AMSAT-BB@?????.???. AMSAT-NA makes this open forum available
> to all interested persons worldwide without requiring membership. Opinions
> expressed
> are solely those of the author, and do not reflect the official views of
> AMSAT-NA.
> Not an AMSAT-NA member? Join now to support the amateur satellite program!
> Subscription settings: https://www.amsat.org/mailman/listinfo/amsat-bb
>
------------------------------
Message: 8
Date: Thu, 23 Jul 2020 18:36:15 -0400
From: Doug Daniels <k1rdd73@?????.???>
To: amsat-bb@?????.???
Subject: [amsat-bb] Brand new to satellite
Message-ID:
<CAEwXZzviUOyfevVmoXtGXUDOo+C_dy5Vx2MGDZR_4ePNWX-DDQ@????.?????.???>
Content-Type: text/plain; charset="UTF-8"
Hello all,
I am brand new to satellite, and actually made my first QSO this morning on
AO-91. I found this email group in the AMSAT Getting Started With Amateur
Satellites 2020 which I purchased on a recommendation.
Is this the informational email group? (I also signed up for the New
England mailing list, but it looks like there hasn't been any activity
since 2013) I am of course looking for all the information I can find, but
this group seems to be more of a political discussion. Please point me in
the right direction.
Thanks!
--
--... ...--
Doug K1RDD
------------------------------
Message: 9
Date: Thu, 23 Jul 2020 19:55:39 -0400
From: Joseph Armbruster <josepharmbruster@?????.???>
To: "Leffke, Zachary" <zleffke@??.???>
Cc: AMSAT <AMSAT-BB@?????.???>
Subject: Re: [amsat-bb] Orbit visualization & antenna performance
Message-ID:
<CADkz4c_Rm44Ka--ce+V0dpeMkD4=b5QUm3SwzoC7bzSFqpk_Zw@????.?????.???>
Content-Type: text/plain; charset="UTF-8"
I wrote some code a while back in a google code project, that took
TLEs and plotted the orbits in KML for visualization in Google Earth.
It's all in Python, so really easy to work with from a developer
standpoint and it also gives you access to some really nice geospatial
libraries. I believe some others took the code and created githubs or
other projects off of it, so it's still out there! I never created a
homesite for it, because it literally took me one evening. I had
plotted the entirety of the ARISSat-1 orbit, using the various TLEs
published back then (and received legal permission to re-publish the
TLEs). You could use the code to do what you want... Royalty free and
100% OSS:
https://www.gearthblog.com/blog/archives/2013/04/the_google_earth_satellite_tr
acker.html
And another hams github clone of the project...
https://github.com/u0m3/ge-satellite-tracker
If you'd like to build off of it at all or need any help, reach out to
me anytime. If you PM me, I can send you my cell so you can
coordinate directly, otherwise the code is reasonably straightforward.
Joseph Armbruster
KJ4JIO
On Thu, Jul 23, 2020 at 5:45 PM Leffke, Zachary via AMSAT-BB
<amsat-bb@?????.???> wrote:
>
> Not a direct answer to your question...but for 'orbit visualization'....
>
> System's Tool Kit (STK) from AGI: https://www.agi.com/products/stk
> There is a free license for non commercial use (e.g. Ham Radio.....).
With this you can quickly pull in TLEs for the spacecraft of interest and
get very nice 3D and 2D displays to visualize orbits. You can also do
things like run pass predictions ('accesses' in STK speak), get high time
resolution az, el, range, and range rate (for Doppler and link analysis
math) reports (in CSV format), and they have lots of tutorials for getting
up and running. What you *can't* do with the free version is incorporate
things like the Comm toolbox for direct antenna pattern visualization and
link analysis within STK. From experience during my Master's work, the
combination of 'free STK', 4NEC2 (and outputting theta/phi/Gain matrix), and
Python can be a pretty powerful combo.....but lacks the 'visualize' part
unless you want to code that up too....
>
> The General Mission Analysis Tool (GMAT) is the free an open source
competitor to STK from NASA:
https://software.nasa.gov/software/GSC-17177-1. I have less experience
(...i mean no experience...) with this package, so not sure how easy it is
to use and whether or not is has antenna modelling features, but I know a
lot of folks use it (including folks on this list) for orbit modelling.
>
> Finally, speaking of Python, the skyfield package
(https://rhodesmill.org/skyfield/) is a great way to 'get rid of STK' for
your own projects. Skyfield provides a baked in SGP4 propagator to handle
TLEs. That, plus modules such as pandas, matplotlib, openGL modules (for
good graphics / 3D visualization), could make for a pretty nice package that
gives you full control (and is free).....but this is a double edged sword as
it would all need to be coded up, which can eat precious 'project time.' (I
mention it because its somewhere way down on my project list...and there
might already be something out there on this).
>
> Hope this helps!
>
> -Other Zach, KJ4QLP (the Zach with the Hat).
>
> --
> Research Associate
> Aerospace & Ocean Systems Lab
> Ted & Karyn Hume Center for National Security & Technology
> Virginia Polytechnic Institute & State University
> Work Phone: 540-231-4174
> Cell Phone: 540-808-6305
>
>
> -----Original Message-----
> From: AMSAT-BB <amsat-bb-bounces@?????.???> On Behalf Of Zach Metzinger
via AMSAT-BB
> Sent: Thursday, July 23, 2020 12:16 PM
> To: AMSAT BB <amsat-bb@?????.???>
> Subject: [amsat-bb] Orbit visualization & antenna performance
>
> Hello all,
>
> In order to evaluate antenna effectiveness in the 70cm downlink band,
> I'm trying to visualize the orbits of the following satellites:
>
> AO-27
> SO-50
> RS-44
>
> I can find the perigee/apogee and output power on these, and, so far, I
> have:
>
> AO-27 788x801 km 1W/0.5W/0.1W
> SO-50 603x713 km 0.25W
> RS-44 1175x1511 km 5W
>
> On the FM birds: My observed data shows that SO-50 is difficult to hear
> while AO-27 is booming, so I hypothesize that AO-27 is transmitting with
> 0.5W or 1W.
>
> RS-44's beacon seems to be fairly weak, while CW/SSB signals on the
> transponder are quite strong.
>
> Does anyone know where I might find more details on RS-44's construction
> such as antennas and power output for the beacon?
>
> Thanks,
>
> --- Zach
> N0ZGO
> EM12jw
>
>
>
>
> _______________________________________________
> Sent via AMSAT-BB@?????.???. AMSAT-NA makes this open forum available
> to all interested persons worldwide without requiring membership. Opinions
expressed
> are solely those of the author, and do not reflect the official views of
AMSAT-NA.
> Not an AMSAT-NA member? Join now to support the amateur satellite program!
> Subscription settings: https://www.amsat.org/mailman/listinfo/amsat-bb
> _______________________________________________
> Sent via AMSAT-BB@?????.???. AMSAT-NA makes this open forum available
> to all interested persons worldwide without requiring membership. Opinions
expressed
> are solely those of the author, and do not reflect the official views of
AMSAT-NA.
> Not an AMSAT-NA member? Join now to support the amateur satellite program!
> Subscription settings: https://www.amsat.org/mailman/listinfo/amsat-bb
------------------------------
Message: 10
Date: Fri, 24 Jul 2020 00:00:15 +0000 (UTC)
From: Robert Bankston <ke4al@?????.???>
To: AMSAT BB <amsat-bb@?????.???>
Subject: Re: [amsat-bb] Is This AMSAT's Future?
Message-ID: <43274685.6382099.1595548815092@????.?????.???>
Content-Type: text/plain; charset=UTF-8
I started working on a linked, peer-to-peer, voice communications network
for amateur satellite service, called amsalLink.? Unfortunately, the closure
of the AMSAT office due to COVID-19 has doubled my volunteer workload and
forced me to put the project on hold..
??
There are throughput limitations in satellite links for data communication.
TCP senders cannot exceed the rate at which the receiver can acknowledge
receipt of packets, where satellite latency effectively caps standard?TCP
throughput per session. TCP Spoofing, which imitates a terrestrial TCP
session by?sending false TCP packet acknowledgements, is one possible
solution. Since my focus was to develop a voice chat, I have chosen to use
UDP to overcome acknowledgement limitations.
??
My amsatLink project is described in the March/April 2020 issue of The AMSAT
Journal and https://ke4al.github.io/amsatLink/
??
Robert, KE4AL
On Thursday, July 23, 2020, 05:16:36 PM CDT, Greg D via AMSAT-BB
<amsat-bb@?????.???> wrote:
Besides Doppler shift, which would definitely be a problem, there's also
the WiFi protocol itself.? It's designed for short range communication,
and some of the low level protocol timers need to be adjusted for
working in WAN applications such as AREDN.? I suspect that getting them
to work over orbital distances might be an ack retry too far.
Greg? KO6TH
Stephen DeVience via AMSAT-BB wrote:
> It's interesting that there are amateur satellite allocations in the 2.4
> GHz and 5 GHz ranges as well. A number of groups are doing ham internet on
> those frequencies using modified routers. This might be an option for some
> kind of digital satellite, although dealing with doppler could be a
> problem. I can envision an amateur version of Starlink.
>
> -Stephen, N8URE
_______________________________________________
Sent via AMSAT-BB@?????.???. AMSAT-NA makes this open forum available
to all interested persons worldwide without requiring membership. Opinions
expressed
are solely those of the author, and do not reflect the official views of
AMSAT-NA.
Not an AMSAT-NA member? Join now to support the amateur satellite program!
Subscription settings: https://www.amsat.org/mailman/listinfo/amsat-bb
------------------------------
Subject: Digest Footer
_______________________________________________
Sent via amsat-bb@?????.???.
AMSAT-NA makes this open forum available to all interested persons worldwide
without requiring membership. Opinions expressed
are solely those of the author, and do not reflect the official views of
AMSAT-NA.
Not an AMSAT member? Join now to support the amateur satellite program!
https://www.amsat.org/mailman/listinfo/amsat-bb
------------------------------
End of AMSAT-BB Digest, Vol 15, Issue 295
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