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CX2SA > SATDIG 04.09.09 16:02l 967 Lines 34373 Bytes #999 (0) @ WW
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From: CX2SA@CX2SA.LAV.URY.SA
To : SATDIG@WW
Today's Topics:
1. Re: Trolls on the -bb (John B. Stephensen)
2. PE0SAT (nachif@xxxxx.xxx.xxx
3. Re: Increasing range from LEO. (John B. Stephensen)
4. Re: Trolls on the -bb (Timothy J. Salo)
5. Re: Trolls on the -bb (Luc Leblanc)
6. Re: [suitsat2] SK -- Den Connors, KD2S (Phil Karn)
7. GRID BL11 today at 2327Z (9/3/09) (Robert Smith)
8. Re: Increasing range from LEO. (Robert Bruninga)
9. Re: Increasing range from LEO (Patrick Green)
10. Re: GRID BL11 today at 2327Z (9/3/09) (w6zkh@xxxxxxx.xxxx
11. Re: Increasing range from LEO/SpaceX/APRS (Rocky Jones)
12. Re: Improving satellite reporting (David Carr)
13. Re: Increasing range from LEO/SpaceX/APRS (Rocky Jones)
14. Re: Improving satellite reporting (George Henry)
15. Re: Improving satellite reporting (William Leijenaar)
16. Why PCSAT is hard to recover (Robert Bruninga)
----------------------------------------------------------------------
Message: 1
Date: Thu, 3 Sep 2009 19:17:27 -0000
From: "John B. Stephensen" <kd6ozh@xxxxxxx.xxx>
Subject: [amsat-bb] Re: Trolls on the -bb
To: "Bruce Robertson" <ve9qrp@xxxxx.xxx>
Cc: AMSAT-BB <amsat-bb@xxxxx.xxx>
Message-ID: <35CCDBE1A0AF4AE088B05DB468F2E619@xxxxxxxxxxxxxx>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
reply-type=original
Everyone also needs to understand that SDX makes more efficient use of
limited downlink RF power. Less power means fewer extremely costly rad-hard
solar panels and lower mass for reduced launch costs.
73,
John
KD6OZH
----- Original Message -----
From: "Bruce Robertson" <ve9qrp@xxxxx.xxx>
To: "John B. Stephensen" <kd6ozh@xxxxxxx.xxx>
Cc: "i8cvs" <domenico.i8cvs@xxx.xx>; "Luc Leblanc"
<lucleblanc6@xxxxxxxxx.xx>; "AMSAT-BB" <amsat-bb@xxxxx.xxx>
Sent: Thursday, September 03, 2009 17:50 UTC
Subject: Re: [amsat-bb] Re: Trolls on the -bb
On Thu, Sep 3, 2009 at 2:04 PM, John B. Stephensen<kd6ozh@xxxxxxx.xxx>
wrote:
> Projects that we can afford means LEOs. P3A through P3D were built for
> identified launches. AMSAT shouldn't just sit around waiting for the right
> political climate for P3E.
>
> 73,
I think that despite the difficulties in communication and personality
clashes, there is a great deal of agreement on the list about what we
want as a group.
We all want a HEO amateur communication satellite in orbit, some of us
because we've never had that experience, others because it is our
fondest memory of AMSAT operations. Barring that, or perhaps in
addition to that, we want to ensure that there are long-range
linear-transponder birds available in the future. Oddly enough,
despite all the rancor in recent days, none of it seems to be around
this core purpose of our group.
Some of our members seem to be concerned that because AMSAT is not
pursing this in a wholly direct way or because it is undertaking
projects of increased technical difficulty, it is therefore delaying
the fulfillment of the above primary goal.
It is my impression that the board members do not share this view.
They feel that the current impediment to a HEO launch in full-price
launch costs is so great that, for instance, the thousands spent on
SuitSat2 would never make a difference, since it is less than a
thousandth of the full price. Instead, we should make the best of
opportunities in LEO that might support our future work in HEO, MEO,
or wherever.
SuitSat2, since it will be the inaugural flight of the long-planned
SDX, is seen as fitting the strategy well. SDX is part of P3E and
proof that we are technically adept. This proof will be handy for
AMSAT-DL as it pursues the clearest path to the launch of P3E, namely
through government money that anticipates the mission to Mars.
According to this argument, pulling for P3E is no longer a matter of
saving pennies, but rather a matter of strutting our stuff, and SS2 is
a great way to strut and strut quickly. In this climate, enthusiasm
for SDX, SSE and, ultimately, P5 might be worth 100x any amount in
cash that we could give individually or as an organization.
Finally, SS2 provides a way of testing a core technology that might
become part of a module of a future bird, one built rapidly around a
launch opportunity.
I have to say that this strategy for fulfilling our common wishes
makes good sense to me. It is predicated on some facts which I accept
at second hand: the high cost of HEO; the lack of government sponsored
launches in NA. I'm sure that the board would be delighted to have
their dismal assessment of *that* situation refuted conclusively. If
it cannot, then we must accept that sometimes the fastest route is not
the straightest path, but if we feel that this board is not guiding us
well towards our goals, we have the opportunity to replace our
pathfinders.
73, Bruce
VE9QRP
> John
> KD6OZH
>
> ----- Original Message -----
> From: "i8cvs" <domenico.i8cvs@xxx.xx>
> To: "John B. Stephensen" <kd6ozh@xxxxxxx.xxx>; "Luc Leblanc"
> <lucleblanc6@xxxxxxxxx.xx>; "AMSAT-BB" <amsat-bb@xxxxx.xxx>
> Sent: Thursday, September 03, 2009 09:51 UTC
> Subject: [amsat-bb] Re: Trolls on the -bb
>
>
>>> It seems more reasonable to focus on projects that we can pay to launch
>>
>> All joined AMSAT togheter in the world has not the financial capability
>> to
>> pay for a HEO launch and this matter has been already discussed several
>> time on this BB
>>
>>> or where someone has already donated the launch.
>>
>> Nobody has donated a launch for free or about for free on HEO except ESA
>> for
>> OSCAR-10 OSCAR-13 and AO40 upon political strategy conducted mostly by
>> AMSAT-DL and this is why we must pull for P3E.......I agree completely
>> with
>> Luc, VE2DWE
>
> _______________________________________________
> Sent via AMSAT-BB@xxxxx.xxx. Opinions expressed are those of the author.
> Not an AMSAT-NA member? Join now to support the amateur satellite program!
> Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
>
------------------------------
Message: 2
Date: Thu, 3 Sep 2009 19:21:59 +0000
From: nachif@xxxxx.xxx.xx
Subject: [amsat-bb] PE0SAT
To: <amsat-bb@xxxxx.xxx>
Message-ID: <58084.1252005719@xxxxx.xxx.xx>
Content-Type: text/plain; charset="utf-8"
BODY { font-family:Arial, Helvetica, sans-serif;font-size:12px; }
Jan,
could you email me, please? My email is nachif at terra.com.br
I've tried to contact you several times but my mails never got
through.
73,
Luciano
------------------------------
Message: 3
Date: Thu, 3 Sep 2009 19:39:50 -0000
From: "John B. Stephensen" <kd6ozh@xxxxxxx.xxx>
Subject: [amsat-bb] Re: Increasing range from LEO.
To: <G0MRF@xxx.xxx>, <amsat-bb@xxxxx.xxx>
Message-ID: <A3DFF38273064985927AE57A7F0DA485@xxxxxxxxxxxxxx>
Content-Type: text/plain; charset="iso-8859-1"
To get good coverage you need as many LEO satellites as possible so they
should each be as small as possible. Intersatellite linking could be done via
automated ground stations. This eliminates the need for high-power transmtters
and/or high-gain antennas on the satellites for interlinkng. It's better to
put that gain and power consumption on earth. Eveything on the satellite costs
more than its weight in gold as launch costs are $700 per ounce.
73,
John
KD6OZH
----- Original Message -----
From: G0MRF@xxx.xxx
To: kd6ozh@xxxxxxx.xxx ; amsat-bb@xxxxx.xxx
Sent: Thursday, September 03, 2009 18:16 UTC
Subject: Increasing range from LEO.
In a message dated 03/09/2009 08:09:09 GMT Standard Time, kd6ozh@xxxxxxx.xxx
writes:
P3E is a HEO with the same engine as P3D and no benefactor funding a
launch.
It seems more reasonable to focus on projects that we can pay to launch or
where someone has already donated the launch.
73,
John
KD6OZH
Wacky idea No 357
Perhaps a longer term piece of AMSAT research could be to develop a
subsystem for LEO satellites that detects and then connects users between
passing LEOs. This would allow short term intersatellite communication. Very
tricky, but a nice project where boards are made available to anyone who would
like to add this facility to their LEO Sat.
Thanks
David
------------------------------
Message: 4
Date: Thu, 03 Sep 2009 14:45:47 -0500
From: "Timothy J. Salo" <salo@xxxxxxx.xxx>
Subject: [amsat-bb] Re: Trolls on the -bb
To: amsat-bb@xxxxx.xxx
Message-ID: <4AA01CEB.3060805@xxxxxxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
John B. Stephensen wrote:
> P3E is a HEO with the same engine as P3D and no benefactor funding a launch.
> It seems more reasonable to focus on projects that we can pay to launch or
> where someone has already donated the launch.
I believe that AMSAT should at least consider using the DoD
Space Test Program (STP), which provides launches for satellites
of interest to the federal government. In fact, the STP has
already launched a number of amateur satellites. Of course, HEO
launches will still be hard to come by. But, I think it is
pretty clear that amateurs can't afford an HEO launch, so we
ought to at least try to find someone else to pay for it.
But, in order to get the government to pay, we need to tell
a story that the government is interested in. In my view,
the federal government is most likely to fund at least two
types of projects:
o Projects that develop the next generation of space
scientists and engineers. (This is a large part of the
reason NASA funds ARISS and SAREX activities. I think
this is also why the Naval Academy stuff gets launched.)
o Research projects. Note that AO-40 actually flew a NASA
GPS experiment that resulted in at least one journal
article. Unfortunately, no one seems to want to talk
about research experiments that have flown on, and often
subsidized, amateur satellites (much less display this
information prominently on the AMSAT Web pages).
Perhaps more importantly, I don't believe that the federal
government is likely to fund us primarily to provide
emergency communications. There are simply too many other
alternatives available today: satellite phones,
cellular-base-stations-on-a-truck, and lots of fixed and
portable satellite ground stations.
If you have an interest in this topic, you might want to read
my DoD Space Test Program paper. (Unlike most AMSAT Symposium
presentations, it is available on the Internet. But, that is
another difficult topic for AMSAT...)
But, to be able to successfully tell these stories, AMSAT
needs to attract new classes of members, particularly
today's and tomorrow's engineers, scientists, and technically
curious. And, to attract these new classes of members, I
believe that AMSAT will need to update some of its views.
The Web is vitally important: it is probably the dominant
portion of AMSAT's public face seen by prospective members
and prospective funding agencies. For example, all the
excellent material published in the Journal would benefit
AMSAT much more if it was available on the Web.
By the way, the AFRL University Nanosatellite Program (UNP)
Web site [!] says that 3,500 students have participated in
the program over the last decade. Every one of these
young people has a demonstrated interest in building satellites.
AMSAT ought to consider every one of them a prospective member
and volunteer.
(I also believe that many of these types of prospective
members that AMSAT needs in order to be successful expect
a voluntary organization like AMSAT to operate transparently,
and for its directors and officers to be able to discuss the
organization in public in a professional manner. Does
anyone else think that it is ironic that discussions about
the future of AMSAT are categorized under "troll"?)
-tjs
------------------------------
Message: 5
Date: Thu, 03 Sep 2009 15:14:10 -0400
From: Luc Leblanc <lucleblanc6@xxxxxxxxx.xx>
Subject: [amsat-bb] Re: Trolls on the -bb
To: amsat-bb@xxxxx.xxx
Cc: eu-amsat@xxxxxxxxxxx.xxx
Message-ID: <4A9FDD42.12529.11CDADA@xxxxxxxxxxx.xxxxxxxxx.xx>
Content-Type: text/plain; charset=US-ASCII
On 3 Sep 2009 at 14:50, Bruce Robertson wrote:
Date sent: Thu, 03 Sep 2009 14:50:20 -0300
From: Bruce Robertson <ve9qrp@xxxxx.xxx>
Subject: Re: [amsat-bb] Re: Trolls on the -bb
To: "John B. Stephensen" <kd6ozh@xxxxxxx.xxx>
Copies to: i8cvs <domenico.i8cvs@xxx.xx>, Luc Leblanc
<lucleblanc6@xxxxxxxxx.xx>,
AMSAT-BB <amsat-bb@xxxxx.xxx>
>
> It is my impression that the board members do not share this view.
> They feel that the current impediment to a HEO launch in full-price
> launch costs is so great that, for instance, the thousands spent on
> SuitSat2 would never make a difference, since it is less than a
> thousandth of the full price. Instead, we should make the best of
> opportunities in LEO that might support our future work in HEO, MEO,
> or wherever.
>
As Bruce wrote "It is my impression that the board members do not share this
view" and "Instead, we should make the best of
opportunities in LEO that might support our future work in HEO, MEO,or
wherever." as articulate his text is, he's assuming something that i
understand as 1-Short term, medium and long term objectives but as far as i
know there is none written or planned on paper all is based on
Target of Opportunity lets called that a short term vision. In fact there is
nothing wrong with that but again what about the long term?
If money is a key factor how as a group of satellite communicators can we
reach the long term one? "We all want a HEO amateur communication
satellite in orbit, some of us because we've never had that experience, others
because it is our fondest memory of AMSAT operations" lets
say a HEO is the long term objective and as Domenico wrote " Nobody has
donated a launch for free or about for free on HEO except
ESA for OSCAR-10 OSCAR-13 and AO40 upon political strategy conducted mostly by
AMSAT-DL and this is why we must pull for P3E" There is room
for short and medium term projects but putting aside the long term will only
put AMSAT-NA on a side track forcing them to reevaluate their
mission as i wrote in another post.
In the mean time i all invite you Sul terrazzo di I8CVS on
http://video.google.com/videoplay?docid=8026221200764903522#
And for those who prefer golf and the summer Napoli beaches
http://fr.video.yahoo.com/watch/944416/3686620
"-"
Luc Leblanc VE2DWE
Skype VE2DWE
www.qsl.net/ve2dwe
WAC BASIC CW PHONE SATELLITE
------------------------------
Message: 6
Date: Thu, 03 Sep 2009 13:51:46 -0700
From: Phil Karn <karn@xxxx.xxx>
Subject: [amsat-bb] Re: [suitsat2] SK -- Den Connors, KD2S
To: K3IO@xxxxxxx.xxxx suitsat2@xxxx.xxx
Cc: TAPR <tapr-announce@xxxx.xxx>, AMSAT Advisors
<advisors@xxxxx.xxx>, AMSAT Officers <officers@xxxxx.xxx>, AMSAT BoD
<bod@xxxxx.xxx>, AMSAT BB <amsat-bb@xxxxx.xxx>, Time Nuts
<time-nuts@xxxx.xxx>, kd1sm@xxxx.xxx
Message-ID: <4AA02C62.7080407@xxxx.xxx>
Content-Type: text/plain; charset=UTF-8; format=flowed
Tom Clark, K3IO wrote:
> It is with much sadness that I report the passing of Den Connors, KD2S
> at 2AM this morning.
Den seemed to pretty much disappear from amateur packet radio right
after he did all that intensive early work at TAPR and just before it
really took off.
It probably had to do with his location and job change, but I always
felt that deprived him of much of the credit he was due. Success always
has many fathers, but relatively few people are actually present right
at the birth of an entirely new communication mode. Den was one of them.
I got involved after he did, and we talked quite a bit during our brief
overlap, but I never got to know him as well as I would have liked.
------------------------------
Message: 7
Date: Thu, 3 Sep 2009 12:30:17 -1000
From: "Robert Smith" <dukenuke@xxxx.xxx>
Subject: [amsat-bb] GRID BL11 today at 2327Z (9/3/09)
To: "Amsat-Bb@xxxxx. Org" <amsat-bb@xxxxx.xxx>
Message-ID: <FE118045EE3840BD9679ECD1EDF445E8@xxxxxx>
Content-Type: text/plain; charset="iso-8859-1"
Aloha All
Sorry for the late notice but I will be atop
Diamond Head crater today for the 2327Z +/-
pass of AO-27. Hopefully W6ZQ will be up
and we can do an interisland. Also, much of
the west coast will be lit up. Sawson may
try 50 mW and who knows what will happen.
Hope to hear some friends on the bird. 73
de robert
NH7WN BL11 Honolulu, Hawaii
------------------------------
Message: 8
Date: Thu, 3 Sep 2009 18:34:56 -0400
From: "Robert Bruninga" <bruninga@xxxx.xxx>
Subject: [amsat-bb] Re: Increasing range from LEO.
To: "'John B. Stephensen'" <kd6ozh@xxxxxxx.xxx>, <G0MRF@xxx.xxx>,
<amsat-bb@xxxxx.xxx>
Message-ID: <64C96FB3BC9F4F8398A87EAC7A733566@xxxxx.xxxx.xxx>
Content-Type: text/plain; charset="US-ASCII"
> To get good coverage you need as many
> LEO satellites as possible so they should
> each be as small as possible.
> Intersatellite linking could be done
> via automated ground stations. This
> eliminates the need for high-power
> transmtters and/or high-gain antennas
> on the satellites for interlinkng.
Yep, that is what we have been trying to do now for 8 years with
the APRS satellites on 145.825. We just need several of them in
orbit at the same time. We have demonstrated dual-hops several
times whenever two or more of the APRS satellites (and ARISS)
are operational at the same time. If we could get 6 to 10 of
the University cubesats to simply carry the 3.4" square APRS
transponder (Byonics TinyTrck-4), then we would have a
constellation providing nearly continuous connectivity via these
satellites from any handheld or mobile APRS radio. With 6, you
might have to wait 30 minutes or so to make yoru contacts. With
10 or so, you might have to wit no more than 5 to 10 minutes for
connectivity.
See www.aprs.org/cubesat-comms.html
> It's better to put that gain and power
> consumption on earth.
The advantage of the APRS satellite concept and Packet, is that
we can use a 5 Watt transmitter on the satellite to be able to
hit any mobile or HT using its existing omni antenna because the
packet has a low dutycycle. So running 5 watts on a cubesat is
easy, because the transmitter dutycycle is only on less than say
5% of the whole-orbit time. (average power 1/4 Watt)
Whereas ECHO which is on all the time, has to be set at 1/4 watt
TX power because it is on all the time.
Also, EVERY APRS satellite would be on the same frequency
145.825 with no doppler to track, and since every one of them
does the same generic relay, independent of callsign, then the
user on the ground just operates... He does not have to do
anything to go from one satellite to another...
Bob, WB4APR
------------------------------
Message: 9
Date: Thu, 3 Sep 2009 18:32:28 -0500
From: Patrick Green <pagreen@xxxxx.xxx>
Subject: [amsat-bb] Re: Increasing range from LEO
To: "bruninga@xxxx.xxxx <bruninga@xxxx.xxx>
Cc: "<amsat-bb@xxxxx.xxx>" <amsat-bb@xxxxx.xxx>
Message-ID: <D9D172D4-DFB1-4B79-B78F-59495F1D044B@xxxxx.xxx>
Content-Type: text/plain; charset=us-ascii; format=flowed; delsp=yes
Why is pcsat having so much trouble carrying its 5 watts then? Even
when the satellite is in full sun? Even on the Z panel? I'm not
complaining, I just want to understand what went wrong.
73 de KA9SCF.
On Sep 3, 2009, at 17:34, "Robert Bruninga" <bruninga@xxxx.xxx> wrote:
>> To get good coverage you need as many
>> LEO satellites as possible so they should
>> each be as small as possible.
>> Intersatellite linking could be done
>> via automated ground stations. This
>> eliminates the need for high-power
>> transmtters and/or high-gain antennas
>> on the satellites for interlinkng.
>
> Yep, that is what we have been trying to do now for 8 years with
> the APRS satellites on 145.825. We just need several of them in
> orbit at the same time. We have demonstrated dual-hops several
> times whenever two or more of the APRS satellites (and ARISS)
> are operational at the same time. If we could get 6 to 10 of
> the University cubesats to simply carry the 3.4" square APRS
> transponder (Byonics TinyTrck-4), then we would have a
> constellation providing nearly continuous connectivity via these
> satellites from any handheld or mobile APRS radio. With 6, you
> might have to wait 30 minutes or so to make yoru contacts. With
> 10 or so, you might have to wit no more than 5 to 10 minutes for
> connectivity.
>
> See www.aprs.org/cubesat-comms.html
>
>> It's better to put that gain and power
>> consumption on earth.
>
> The advantage of the APRS satellite concept and Packet, is that
> we can use a 5 Watt transmitter on the satellite to be able to
> hit any mobile or HT using its existing omni antenna because the
> packet has a low dutycycle. So running 5 watts on a cubesat is
> easy, because the transmitter dutycycle is only on less than say
> 5% of the whole-orbit time. (average power 1/4 Watt)
>
> Whereas ECHO which is on all the time, has to be set at 1/4 watt
> TX power because it is on all the time.
>
> Also, EVERY APRS satellite would be on the same frequency
> 145.825 with no doppler to track, and since every one of them
> does the same generic relay, independent of callsign, then the
> user on the ground just operates... He does not have to do
> anything to go from one satellite to another...
>
> Bob, WB4APR
>
> _______________________________________________
> Sent via AMSAT-BB@xxxxx.xxx. Opinions expressed are those of the
> author.
> Not an AMSAT-NA member? Join now to support the amateur satellite
> program!
> Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
------------------------------
Message: 10
Date: Thu, 3 Sep 2009 23:56:58 +0000 (UTC)
From: w6zkh@xxxxxxx.xxx
Subject: [amsat-bb] Re: GRID BL11 today at 2327Z (9/3/09)
To: amsat-bb <amsat-bb@xxxxx.xxx>
Message-ID:
<370828953.8591991252022218986.JavaMail.root@xxxxxxx.xxxxxxxxxxx.xx.xxxx
.xxxxxxx.xxx>
Content-Type: text/plain; charset=utf-8
Well, I had the honor of being the first to catch him this afternoon. Many
thanks Robert, for new state and grid.
John W6ZKH
----- Original Message -----
From: "Robert Smith" <dukenuke@xxxx.xxx>
To: "Amsat-Bb@xxxxx. Org" <amsat-bb@xxxxx.xxx>
Sent: Thursday, September 3, 2009 3:30:17 PM GMT -08:00 US/Canada Pacific
Subject: [amsat-bb] GRID BL11 today at 2327Z (9/3/09)
Aloha All
Sorry for the late notice but I will be atop
Diamond Head crater today for the 2327Z +/-
pass of AO-27. Hopefully W6ZQ will be up
and we can do an interisland. Also, much of
the west coast will be lit up. Sawson may
try 50 mW and who knows what will happen.
Hope to hear some friends on the bird. 73
de robert
NH7WN BL11 Honolulu, Hawaii
_______________________________________________
Sent via AMSAT-BB@xxxxx.xxx. Opinions expressed are those of the author.
Not an AMSAT-NA member? Join now to support the amateur satellite program!
Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
------------------------------
Message: 11
Date: Thu, 3 Sep 2009 20:12:40 -0500
From: Rocky Jones <orbitjet@xxxxxxx.xxx>
Subject: [amsat-bb] Re: Increasing range from LEO/SpaceX/APRS
To: Rocky Jones <orbitjet@xxxxxxx.xxx>
Cc: Amsat BB <amsat-bb@xxxxx.xxx>
Message-ID: <COL106-W56D185A1C947EB2A95814FD6EE0@xxx.xxx>
Content-Type: text/plain; charset="iso-8859-1"
> > the APRS satellites on 145.825. We just need several of them in
> > orbit at the same time.
SpaceX has just scored a large contract with ORBCOMM to put their next gen
birds in orbit (using the Falcon1E)...a small APRS generic satellite might
just substitute for ballast
Robert WB5MZO
_________________________________________________________________
With Windows Live, you can organize, edit, and share your photos.
http://www.windowslive.com/Desktop/PhotoGallery
------------------------------
Message: 12
Date: Thu, 03 Sep 2009 21:13:09 -0400
From: David Carr <dc@xxxxx.xxx>
Subject: [amsat-bb] Re: Improving satellite reporting
To: amsat-bb@xxxxx.xxx
Message-ID: <4AA069A5.3050806@xxxxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Hello all,
I'm glad to hear that the community is enjoying the satellite status
page. I am always very happy to visit the page and see it filled with
reports.
I also agree that the site could benefit from some improvements. As
suggested, I think stronger ties with Amsat could be beneficial and
improve its accessibility. Lets continue this discussion further and
how we can work together to make this resource as useful as possible.
In the meantime, please send me small changes (ie: new satellites or URL
updates) and I will apply them.
73s,
David Carr
KD5QGR
------------------------------
Message: 13
Date: Thu, 3 Sep 2009 20:18:16 -0500
From: Rocky Jones <orbitjet@xxxxxxx.xxx>
Subject: [amsat-bb] Re: Increasing range from LEO/SpaceX/APRS
To: Rocky Jones <orbitjet@xxxxxxx.xxx>
Cc: Amsat BB <amsat-bb@xxxxx.xxx>
Message-ID: <COL106-W573B1B453AF0D086C8E0E6D6EE0@xxx.xxx>
Content-Type: text/plain; charset="Windows-1252"
http://space.skyrocket.de/index_frame.htm?http://space.skyrocket.de/doc_sdat/o
rbcomm-2.htm
it looks like the orbcomm will go up three at a time...six launches multiple
planes...
Robert WB5MZO
_________________________________________________________________
Windows Live: Make it easier for your friends to see what you?re up to on
Facebook.
http://windowslive.com/Campaign/SocialNetworking?ocid=PID23285::T:WLMTAGL:ON:W
L:en-US:SI_SB_facebook:082009
------------------------------
Message: 14
Date: Thu, 3 Sep 2009 22:23:34 -0500
From: "George Henry" <ka3hsw@xxx.xxx>
Subject: [amsat-bb] Re: Improving satellite reporting
To: "amsat bb" <amsat-bb@xxxxx.xxx>
Message-ID: <F1FC134E33764288B2894EA579BA8F16@xxxxxxx>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
reply-type=original
----- Original Message -----
From: "Bruce Robertson" <ve9qrp@xxxxx.xxx>
To: "AMSAT-BB" <amsat-bb@xxxxx.xxx>
Sent: Thursday, September 03, 2009 8:04 AM
Subject: [amsat-bb] Improving satellite reporting
[snip]
>
> (Similarly, I hope that William's extraordinary vision in building his
> transponder board might, after broad testing and examination, be
> validated by it becoming an 'AMSAT' off-the-shelf product. With
> William's approval, let's appeal for the bucks to have a team of
> people replicate these, test them, and set them up as temporary
> terrestrial repeaters around the world. We'd much more easily convince
> a cubesat team to include one of these if we could say one was running
> uninterrupted in Toronto for a year, or if we could have them do a QSO
> through one in a live demo!)
>
>
> 73, Bruce
> VE9QRP
Hey, if William will make the boards available, I'll start building one
tomorrow!!!
73,
George, KA3HSW
------------------------------
Message: 15
Date: Fri, 4 Sep 2009 06:29:28 -0700 (PDT)
From: William Leijenaar <pe1rah@xxxxx.xxx>
Subject: [amsat-bb] Re: Improving satellite reporting
To: amsat-bb@xxxxx.xxx
Message-ID: <331692.55127.qm@xxxxxxxx.xxxx.xxx.xxxxx.xxx>
Content-Type: text/plain; charset=iso-8859-1
Hi AMSATs,
?
The tinny transponder design is finished and tested. I can make copies when
there is interrest. My visit to Ham Fair in Tokyo was for me a kind of
milestone to finish the design and?make it?public to the people. (I like
to?design something well done, before?make it available to others, this avoids
modifications and extra work later).
?
It is not easy to make the LE005-R2 transponder design without having the
right tools.?This is also the reason why I?cannot sell it like a kit for
people to solder at home.
The design is made at a profesional level?(as development engineer I am
dealing with it dayly) and can be?made with use of a pick and place machine
and reflow soldered?for large quantities in a factory when needed. This is
only profitable at large quantities.
?
For small quantities its cheaper and faster to do it with my small reflow
system. The quality is guarenteed as I?can do manual inspection and full
testing myself.
?
The next step is doing space environment tests, but that takes some more time
and money. In case you have a working thermal vaccuum chamber in your garage,
let me know ;o)
?
The LE005-R2 is designed for space environment but not officially tested yet.
However, the design is?well suited for applications like terresterial
transponders.
?
73,?with kind regards,
William Leijenaar, PE1RAH
---
?
----- Original Message -----
From: "Bruce Robertson" <ve9qrp@xxxxx.xxx>
To: "AMSAT-BB" <amsat-bb@xxxxx.xxx>
Sent: Thursday, September 03, 2009 8:04 AM
Subject: [amsat-bb] Improving satellite reporting
[snip]
>
> (Similarly, I hope that William's extraordinary vision in building his
> transponder board might, after broad testing and examination, be
> validated by it becoming an 'AMSAT' off-the-shelf product. With
> William's approval, let's appeal for the bucks to have a team of
> people replicate these, test them, and set them up as temporary
> terrestrial repeaters around the world. We'd much more easily convince
> a cubesat team to include one of these if we could say one was running
> uninterrupted in Toronto for a year, or if we could have them do a QSO
> through one in a live demo!)
>
>
> 73, Bruce
> VE9QRP
Hey, if William will make the boards available, I'll start building one
tomorrow!!!
73,
George, KA3HSW
------------------------------
Message: 16
Date: Fri, 4 Sep 2009 09:44:56 -0400
From: "Robert Bruninga" <bruninga@xxxx.xxx>
Subject: [amsat-bb] Why PCSAT is hard to recover
To: "'Patrick Green'" <pagreen@xxxxx.xxx>
Cc: amsat-bb@xxxxx.xxx
Message-ID: <6BBD00F3B0024E88AB222C1FA6A9AC74@xxxxx.xxxx.xxx>
Content-Type: text/plain; charset="US-ASCII"
> Why is pcsat having so much trouble
> carrying its 5 watts then? Even
> when the satellite is in full sun?
> Even on the Z panel? ...what went wrong.
Error in design. Since it was our first satellite, and the
first time that hamtronics TX and RX were flown in space, we put
in multiple redundancy. Two identical RX=>TNC=>TX systems. We
thought the most important thing was the command link.
To make sure we could still access both TNC systems even with a
TX or RX failure we added a second UHF RX to both systems. In
additionl we had a relay to CROSS-CONNECT the transmitters.
THen we made the mistake. We assumed that to recover from an
anomoly, the most important thing was to regain the command
link. Hence, from cold-boot, the spare UHF receivers would both
come on AND the transmitters would be cross-connected. This
assured we could access either TNC even if we had lost one RX or
one TX.
The mistake was assuming that in such a recovery effort, the
first thing we would then do is TURN OFF the extra receivers and
DISCONNNECT the cross conneced transmitters once we had command.
Well... DUH.... If the reason the spacecraft crashed back to
defaults was because it was low on power, then the last thing
you want to do is QUADRUPLE the power budget by having the
recovery-defaults turn on double the number of receivers and
double the number of transmitters!
So we need FOUR times the average power just to get command and
that only happens during mid-day passes during maximum eclipse
periods, and sometimes right at the beginning of full sun
periods in the southern hemisphere.
Our first commmand then IN SEQUENCE is
1) LOGON
2) Send command to separate the transmitters
3) Send command to turn off the two spare UHF reciverss
If those are successful, AND PCSAT then has a full orbit in full
sun, then we can recover. But the loggon password challenge
from the satellite is the LONGEST packet in the command
sequence, and if is not successful on the FIRST try, then the
battery is exhausted and you loose the pass.
Bob, Wb4APR
>
> On Sep 3, 2009, at 17:34, "Robert Bruninga"
<bruninga@xxxx.xxx> wrote:
>
> >> To get good coverage you need as many
> >> LEO satellites as possible so they should
> >> each be as small as possible.
> >> Intersatellite linking could be done
> >> via automated ground stations. This
> >> eliminates the need for high-power
> >> transmtters and/or high-gain antennas
> >> on the satellites for interlinkng.
> >
> > Yep, that is what we have been trying to do now for 8 years
with
> > the APRS satellites on 145.825. We just need several of
them in
> > orbit at the same time. We have demonstrated dual-hops
several
> > times whenever two or more of the APRS satellites (and
ARISS)
> > are operational at the same time. If we could get 6 to 10
of
> > the University cubesats to simply carry the 3.4" square APRS
> > transponder (Byonics TinyTrck-4), then we would have a
> > constellation providing nearly continuous connectivity via
these
> > satellites from any handheld or mobile APRS radio. With 6,
you
> > might have to wait 30 minutes or so to make yoru contacts.
With
> > 10 or so, you might have to wit no more than 5 to 10 minutes
for
> > connectivity.
> >
> > See www.aprs.org/cubesat-comms.html
> >
> >> It's better to put that gain and power
> >> consumption on earth.
> >
> > The advantage of the APRS satellite concept and Packet, is
that
> > we can use a 5 Watt transmitter on the satellite to be able
to
> > hit any mobile or HT using its existing omni antenna because
the
> > packet has a low dutycycle. So running 5 watts on a cubesat
is
> > easy, because the transmitter dutycycle is only on less than
say
> > 5% of the whole-orbit time. (average power 1/4 Watt)
> >
> > Whereas ECHO which is on all the time, has to be set at 1/4
watt
> > TX power because it is on all the time.
> >
> > Also, EVERY APRS satellite would be on the same frequency
> > 145.825 with no doppler to track, and since every one of
them
> > does the same generic relay, independent of callsign, then
the
> > user on the ground just operates... He does not have to do
> > anything to go from one satellite to another...
> >
> > Bob, WB4APR
> >
> > _______________________________________________
> > Sent via AMSAT-BB@xxxxx.xxx. Opinions expressed are those of
the
> > author.
> > Not an AMSAT-NA member? Join now to support the amateur
satellite
> > program!
> > Subscription settings:
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>
------------------------------
_______________________________________________
Sent via amsat-bb@xxxxx.xxx. Opinions expressed are those of the author.
Not an AMSAT member? Join now to support the amateur satellite program!
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End of AMSAT-BB Digest, Vol 4, Issue 447
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