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CX2SA > SATDIG 25.05.10 20:06l 1036 Lines 35920 Bytes #999 (0) @ WW
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To : SATDIG@WW
Today's Topics:
1. Re: [CubeSat] Cubesat Group purchase of EMCOR cells
(chantal cappelletti)
2. Re: [CubeSat] Cubesat Group purchase of EMCOR cells
(Ignacio de Le?n)
3. Re: [CubeSat] Cubesat Group purchase of EMCOR cells (Tom Hill)
4. Re: SatPC3 v 12.8a (George Henry)
5. Re: S and L band suggestions (Armour, Randy (ITS))
6. Re: SatPC3 v 12.8a Windows 7 64 bit (Bill Bordy, NJ1H )
7. Re: S and L band suggestions (Bob- W7LRD)
8. UNITEC-1 ARRL Announcement (Trevor .)
9. Transystem 3731 vs. 3733 (Rich Dailey (Gmail))
10. Re: S and L band suggestion (Ron Miles)
11. Re: Transystem 3731 vs. 3733 (Ron Miles)
12. Re: Transystem 3731 vs. 3733 (Rich Dailey (Gmail))
13. 'Zombie-sat' and the clever orbital dance (David - KG4ZLB)
14. Gordon West's Technician Class 2010-2014 Book (Clint Bradford)
15. Re: 'Zombie-sat' and the clever orbital dance (Trevor .)
----------------------------------------------------------------------
Message: 1
Date: Mon, 24 May 2010 08:58:23 +0200
From: chantal cappelletti <chantal.cappelletti@xxxxx.xxx>
Subject: [amsat-bb] Re: [CubeSat] Cubesat Group purchase of EMCOR
cells
To: Nick Pugh K5QXJ <quadpugh@xxxxxxxxx.xxx>
Cc: Gonzalo Sotta <gsotta@xxxxx.xxx>, amsat-bb@xxxxx.xxxx
cubesat@xxxxxxx.xxxx Jos? Luis Vila <JLV@xxxx.xxx.xx>, Javier Ramos
<javramos@xxxxx.xxx>, Cal Poly CubeSat <cubesat.workshop@xxxxx.xxx>
Message-ID:
<AANLkTikpUOVireq86t7sA1ZIEWmjaOYjHpQHPxOe5S4J@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1
We would be interested also,
Chantal
(UniCubesat)
2010/5/21 Nick Pugh K5QXJ <quadpugh@xxxxxxxxx.xxx>:
> We would be interested
> nick
>
> -----Original Message-----
> From: amsat-bb-bounces@xxxxx.xxx [mailto:amsat-bb-bounces@xxxxx.xxxx On
> Behalf Of Robert Bruninga
> Sent: Friday, May 21, 2010 1:16 PM
> To: 'Cal Poly CubeSat'; cubesat@xxxxxxx.xxx
> Cc: amsat-bb@xxxxx.xxxx 'Gonzalo Sotta'; 'Javier Ramos'; 'Jos? Luis Vila'
> Subject: [amsat-bb] Cubesat Group purchase of EMCOR cells
>
> AMSAT and CUBESAT:
>
> A student CUBESAT group in Uruguay wants to partner with another
> CUBESAT group to purchase the minimum quantity (150) of triple
> jnction solar cells from EMCOR. ?They only need a dozen.
>
> Anyone want to team up?
>
>
>
> _______________________________________________
> 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
>
> _______________________________________________
> CubeSat mailing list
> CubeSat@xxxxxxx.xxx
> http://lists.cubesat.org/mailman/listinfo/cubesat
>
--
Chantal Cappelletti
ITALY : +39-0688346436
+393336200333 o +393890504362 (cell)
G.A.U.S.S.
Gruppo di Astrodinamica Universit? degli Studi Sapienza di Roma
via Salaria 851,
00138 ROMA
USA : 001-606-783-9597 (office)
001-908-294-1164 (mobile)
Space Science Center
Morehead State University
200A Chandler Place
Morehead, Kentucky 40351
------------------------------
Message: 2
Date: Mon, 24 May 2010 11:11:30 -0300
From: Ignacio de Le?n <roverano8@xxxxx.xxx>
Subject: [amsat-bb] Re: [CubeSat] Cubesat Group purchase of EMCOR
cells
To: bruninga@xxxx.xxxx Cal Poly CubeSat <cubesat.workshop@xxxxx.xxx>,
cubesat@xxxxxxx.xxx
Cc: chantal cappelletti <chantal.cappelletti@xxxxx.xxx>, Gonzalo Sotta
<gsotta@xxxxx.xxx>, amsat-bb@xxxxx.xxxxxxxxx Harvey
<tjharvey@xxxxxxxxxxxx.xxx>, Ignacio de Le?n <roverano8@xxxxxxx.xxx>,
Javier Ramos <javramos@xxxxx.xxx>, Jos? Luis Vila <JLV@xxxx.xxx.xx>
Message-ID:
<AANLkTin_z5_EaOG4W-Ydh0eAanS1jVFAmKS4d5Cw5ZYl@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=windows-1252
Hi Jeff,
This is the email that Emcore answered to me.
EMCORE does offer mechanical/visual (MV) bare solar cells (MV cells are not
available in SCA's). MV solar cells have mechanical anomalies or
discoloration that make them unusable for space. MV solar cells have an
efficiency typically greater than 25% at AM0 and 28?C.
*Price *
EMCORE offers MV cells for $50.00 (USD) each with a minimum order quantity
of 150 cells.
*Terms and Conditions*
EMCORE?s MV cells are offered on an ?as available, first come, first serve?
basis. EMCORE?s standard terms and conditions for MV cells are as follows:
1. Parts sold on an ?as is? basis with no warranty. All sales are final.
2. Quantities offered are subject to continued inventory availability.
3. Payment is required in advance of shipment by bank transfer or credit
card.
4. Customer is responsible for all shipping costs (including
insurance) from freight forwarding office.
5. Minimum purchase price is $7,500.00 for any order.
The standars cells cost $650 (USD) aprox per cell
We are searching solar cells or non qualified solar cells for a cubesat to
make electrical test.
It is not important if they are form Emcore, Spectrolab or whatever.
We need between 6 and 12 cells.
We can not pay more than $70 (USD) per cell
Warm regards from Uruguay
Thank you very much.
Ignacio de Le?n
2010/5/24 Gonzalo Sotta <gsotta@xxxxx.xxx>
>
>
> ---------- Mensaje reenviado ----------
> De: Jeff Harvey <tjharvey@xxxxxxxxxxxx.xxx>
> Fecha: 24 de mayo de 2010 09:27
> Asunto: RE: [CubeSat] Cubesat Group purchase of EMCOR cells
> Para: bruninga@xxxx.xxxx Cal Poly CubeSat <cubesat.workshop@xxxxx.xxx>,
> cubesat@xxxxxxx.xxx
> Cc: amsat-bb@xxxxx.xxxx Gonzalo Sotta <gsotta@xxxxx.xxx>, Javier Ramos <
> javramos@xxxxx.xxx>, Jos? Luis Vila <JLV@xxxx.xxx.xx>
>
>
> We might be interested. How much are they per cell?
>
> Jeff
>
> T. Jeffrey (Jeff) Harvey PE
> MMA Design LLC
> 303 258 7365 Office
> 303 859 4146 Cell
>
>
> -----Original Message-----
> From: cubesat-bounces@xxxxxxx.xxx [mailto:cubesat-bounces@xxxxxxx.xxxx On
> Behalf Of Robert Bruninga
> Sent: Friday, May 21, 2010 12:16 PM
> To: 'Cal Poly CubeSat'; cubesat@xxxxxxx.xxx
> Cc: amsat-bb@xxxxx.xxxx 'Gonzalo Sotta'; 'Javier Ramos'; 'Jos? Luis Vila'
> Subject: [CubeSat] Cubesat Group purchase of EMCOR cells
>
> AMSAT and CUBESAT:
>
> A student CUBESAT group in Uruguay wants to partner with another
> CUBESAT group to purchase the minimum quantity (150) of triple
> jnction solar cells from EMCOR. They only need a dozen.
>
> Anyone want to team up?
>
>
>
> _______________________________________________
>
> CubeSat mailing list
> CubeSat@xxxxxxx.xxx
> http://lists.cubesat.org/mailman/listinfo/cubesat
>
>
>
------------------------------
Message: 3
Date: Mon, 24 May 2010 07:31:53 -0700 (PDT)
From: Tom Hill <tom@xxxxxxxxxxxx.xxx>
Subject: [amsat-bb] Re: [CubeSat] Cubesat Group purchase of EMCOR
cells
To: Nick Pugh K5QXJ <quadpugh@xxxxxxxxx.xxx>, bruninga@xxxx.xxxxxxxxxx
Poly CubeSat'" <cubesat.workshop@xxxxx.xxx>, cubesat@xxxxxxx.xxx
Cc: amsat-bb@xxxxx.xxxx 'Gonzalo Sotta' <gsotta@xxxxx.xxx>, 'Javier
Ramos' <javramos@xxxxx.xxx>, 'Jos? Luis Vila' <JLV@xxxx.xxx.xx>
Message-ID:
<23018208.1274711516224.JavaMail.root@xxxxxxxxxxxxxx.xxx.xx.xxxxxxxxx.xxx>
Content-Type: text/plain; charset=UTF-8
Remember to get some spares.
Out of curiosity, what's the cost per sell in this type of purchase?
Tom
-----Original Message-----
>From: Nick Pugh K5QXJ <quadpugh@xxxxxxxxx.xxx>
>Sent: May 21, 2010 11:59 AM
>To: bruninga@xxxx.xxxx 'Cal Poly CubeSat' <cubesat.workshop@xxxxx.xxx>,
cubesat@xxxxxxx.xxx
>Cc: amsat-bb@xxxxx.xxxx 'Gonzalo Sotta' <gsotta@xxxxx.xxx>, 'Javier Ramos'
<javramos@xxxxx.xxx>, 'Jos? Luis Vila' <JLV@xxxx.xxx.xx>
>Subject: Re: [CubeSat] [amsat-bb] Cubesat Group purchase of EMCOR cells
>
>We would be interested
>nick
>
>-----Original Message-----
>From: amsat-bb-bounces@xxxxx.xxx [mailto:amsat-bb-bounces@xxxxx.xxxx On
>Behalf Of Robert Bruninga
>Sent: Friday, May 21, 2010 1:16 PM
>To: 'Cal Poly CubeSat'; cubesat@xxxxxxx.xxx
>Cc: amsat-bb@xxxxx.xxxx 'Gonzalo Sotta'; 'Javier Ramos'; 'Jos? Luis Vila'
>Subject: [amsat-bb] Cubesat Group purchase of EMCOR cells
>
>AMSAT and CUBESAT:
>
>A student CUBESAT group in Uruguay wants to partner with another
>CUBESAT group to purchase the minimum quantity (150) of triple
>jnction solar cells from EMCOR. They only need a dozen.
>
>Anyone want to team up?
>
>
>
>_______________________________________________
>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
>
>_______________________________________________
>CubeSat mailing list
>CubeSat@xxxxxxx.xxx
>http://lists.cubesat.org/mailman/listinfo/cubesat
------------------------------
Message: 4
Date: Mon, 24 May 2010 23:24:17 -0500
From: "George Henry" <ka3hsw@xxx.xxx>
Subject: [amsat-bb] Re: SatPC3 v 12.8a
To: "amsat bb" <amsat-bb@xxxxx.xxx>
Message-ID: <42FBC98F3F0D42C78036DEA07B53470D@xxxxxxx>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
reply-type=original
Yes, it works fine, although I have not tried to steer the rotors or tune
the radio with it under Windows 7 yet.
One suggestion, though: during installation, do NOT accept the default
installation directory. Install it into a custom folder in the root
directory to avoid user account control issues.
George, KA3HSW
----- Original Message -----
From: "Don" <don1018@xxxxxxx.xxx>
To: <amsat-bb@xxxxx.xxx>
Sent: Monday, May 24, 2010 9:50 PM
Subject: [amsat-bb] SatPC3 v 12.8a
> Has anyone used this software with Windows 7 64 bit ?
>
> If so does it work ok?
>
>
>
> WB8ZOM Don
------------------------------
Message: 5
Date: Tue, 25 May 2010 00:10:53 -0500
From: "Armour, Randy (ITS)" <Randy.Armour@xxxxxxxxx.xxx>
Subject: [amsat-bb] Re: S and L band suggestions
To: <amsat-bb@xxxxx.xxx>
Message-ID:
<3864B6BF16397A46B79F0EF8AC226A16015591CE@xxxxxxxxxxx.xxxxxxxxx.xxx>
Content-Type: text/plain; charset="us-ascii"
I am also interested in operating S and/or L band... especially since
information on this list indicates AO-51 may be using one of these modes
during the ARRL field day this year. Suggested down-converters and
source(s) of purchase of them would be appreciated.
Randy - KI4LMR
>>-----Original Message-----
>>From: amsat-bb-bounces@xxxxx.xxx [mailto:amsat-bb-bounces@xxxxx.xxxx
On Behalf Of Reid Crowe
??Sent: Monday, May 24, 2010 6:25 PM
To: amsat-bb@xxxxx.xxx
>>Subject: [amsat-bb] S and L band suggestions
>>I am thinking I want to get into S and L band operations. Does anyone
>>have any suggestions on getting started? What equipment is everyone
using?
>>73
>>Reid, OX/N0RC
------------------------------
Message: 6
Date: Tue, 25 May 2010 01:17:31 -0400
From: "Bill Bordy, NJ1H " <nj1h@xxxxxxx.xxx>
Subject: [amsat-bb] Re: SatPC3 v 12.8a Windows 7 64 bit
To: Don <don1018@xxxxxxx.xxx>
Cc: amsat-bb@xxxxx.xxx
Message-ID: <4BFB5D6B.7020800@xxxxxxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
I have used it with my FT-736R using the radio serial port using a
Edgeport USB to 8-port serial converter and with USB port LVB tracker
Yaesu G-5400 rotor control. All worked fine under Windows 7 64 bit Home
Edition .
I do seem to have an issue of RF interfering with the LVB tracker unit.
Occasionally, the LVB tracker communications is lost when I am
transmitting. If I disconnect the USB cable and reconnect it, LVB
tracker works again. I have tested receive only operation for many hours
and never had a problem with the rotor tracking or radio control.
73,
Bill
NJ1H
On 5/24/2010 10:50 PM, Don wrote:
> Has anyone used this software with Windows 7 64 bit ?
>
> If so does it work ok?
>
>
>
> WB8ZOM Don
>
>
>
> _______________________________________________
> 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: 7
Date: Tue, 25 May 2010 08:11:50 +0000 (UTC)
From: Bob- W7LRD <w7lrd@xxxxxxx.xxx>
Subject: [amsat-bb] Re: S and L band suggestions
To: Reid Crowe <kc0idi@xx.xxx>
Cc: amsat-bb@xxxxx.xxx
Message-ID:
<1527701633.912221274775110033.JavaMail.root@xxxxxxx.xxxxxxxxxx.xx.xxxx.xxxxxx
x.xxx>
Content-Type: text/plain; charset=utf-8
Hi Reid and those interested-
-Getting into L & S can be as simple or as complicated ? as one tries to
make it.??Many of us are using modified MMDS downconverters
http://www.google.com/search?sourceid=navclient&ie=UTF-8&rlz=1T4GGLL_enUS379US
379&q=mmds ?for what means.?
The downconverter takes the 2.4ghz downlink and "usually" converts it to the
2M band.? However usually for a 2M output the crystal and some minor filter
modification is required.? Generally if used without modification the output
is around 123mhz.? A downconverter can be had for as much as about $500 for
the UEK-3000 or a Keps for about $225 or a surplus MMDS unit can be? ?found
on Ebay for as little as $5 (caveat emptor). ?For AO-51 in mode S (downlink)
reception has been reported with a simple patch antenna connected directly
to the DC.? Or a simple 5 turn (left hand ci rcular polarization) in front
of a 18 inch TV type dish will work well.? Or a longer (10 turn +) RHCP
helix can work.? Again the DC is connected directly to the antenna/feed to
reduce losses.? Usually power for the DC is feed up the coax (RG6) to the DC
from a bais tee(power inserter).? A larger dish could be the 36"X30"
primestar, from that now defunct direct TV system.? They are usually free,
just watch?r!
oof lines around your neighborhood.? The bigger the dish the higher the
gain and the necessity for accurate pointing.? I use a Transystem 3731AA
(MMDS) downconverter/5 turn helix feed/Primestar dish which is connected to
an old TS-700A transceiver with Tx disabled to avoid that maj or ooops of?
accidently transmitting into the DC.? For 1.2ghz (L band) uplink will
usually cost some coin! Many "satellite" radios, like the IC-910, FT-736
etc. and several others can be had and adding the optional 1.2ghz module.?
Again not too cheap.? Or a transverter.? If in your area there is local L
band terrestial activity, it can be quite interesti ng.? L band antennas can
be loopers, yagi's or a helix.? I can get into AO51 quite?well with 10W from
an IC-910 to a 16 turn helix.? I have some pictures available which can
answer many questions.? Good luck with your efforts.? There are ma ny on
this bb that have been doing this for a long time, and are wealth of
information.
73 Bob W7LRD
Seattle
----- Original Message -----
From: "Reid Crowe" <kc0idi@xx.xxx>
To: amsat-bb@xxxxx.xxx
Sent: Monday, May 24, 2010 4:25:07 PM GMT -08:00 US/Canada Pacific
Subject: [amsat-bb] ?S and L band suggestions
I am thinking I want to get into S and L band operations. ?Does anyone
have any suggestions on getting started? ?What equipment is everyone using?
73
Reid, OX/N0RC
_______________________________________________
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: 8
Date: Tue, 25 May 2010 11:17:59 +0000 (GMT)
From: "Trevor ." <m5aka@xxxxx.xx.xx>
Subject: [amsat-bb] UNITEC-1 ARRL Announcement
To: amsat-bb@xxxxx.xxx
Message-ID: <731785.14936.qm@xxxxxxxx.xxxx.xxx.xxxxx.xxx>
Content-Type: text/plain; charset=utf-8
ARRL - Amateur Community Needed to Assist Japanese Amateur Interplanetary
Satellite
http://www.arrl.org/news/amateur-community-needed-to-assist-japanese-amateur-i
nterplanetary-satellite
73 Trevor M5AKA
Daily Amateur Radio Email/RSS News: http://www.southgatearc.org/
Email Your News To: editor at southgatearc.org
Or Upload Using Form At: http://www.southgatearc.org/news/your_news_1.htm
----
------------------------------
Message: 9
Date: Tue, 25 May 2010 07:48:21 -0400
From: "Rich Dailey (Gmail)" <redailey1@xxxxx.xxx>
Subject: [amsat-bb] Transystem 3731 vs. 3733
To: amsat-bb@xxxxx.xxx
Message-ID: <7.0.0.16.2.20100525074436.023aa2e0@xxxxxxxxxx.xxx>
Content-Type: text/plain; charset="us-ascii"
Can someone tell me the major difference between the two downconverters?
Ten years ago or so, I used a 3733 un-modded at the fed point of an 8ft dish
to
copy ao-40 tlm. Today I read a lot of references to the 3731, but not much
about
the 3733. Just wondering if one is preferable to the other.
Rich, N8UX
------------------------------
Message: 10
Date: Tue, 25 May 2010 08:09:01 -0700
From: Ron Miles <conimicut@xxxxx.xxx>
Subject: [amsat-bb] Re: S and L band suggestion
To: amsat-bb <amsat-bb@xxxxx.xxx>
Message-ID:
<AANLkTinlx-AhTEyz4g8C-M-2L8Z_FYlgXKRWwDqsNuiM@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=windows-1252
Hello Reid:
If you don?t mind experimenting, connect one of these 2.4G MMDS grid
antennas
http://www.amazon.com/2-4GHz-24dBi-Outdoor-Antenna-Cable/dp/B001J1Y7IA/ref=cm_
cr_pr_product_top
to the downconverter taken from this antenna
http://cgi.ebay.com/Yagi-MMDS-ITFS-AFN-High-Gain-Antenna-Downconverter-Used-/1
20541331846?cmd=ViewItem&pt=LH_DefaultDomain_0&hash=item1c10d2c186
The downconverter IF output is given at 222-408 MHz. The noise figure which
isn?t all that great is listed as < 2dBi.
I use a grid antenna because it has much less wind load than the solid
surface of a TV dish.
For my S Band downlink, I use the AIDC 3731 downconverter tuned to the 2M
band. For test tuning purposes, I built one of these 2.4GHz source
oscillators to locate the 2M IF output from the downconverter.
http://ve2zaz.net/SigSourc/SigSourc.htm
DC power to the downconverter is explained here for a Bias T.
http://www.hamtv.com/pdffiles/biasT.pdf
Finally, if you want Doppler frequency control, a program called SATPC32
explains how to write the Doppler.SQF file based on the downconverter Local
Oscillator offset frequency.
You can expect others with better suggestions. But, the above detail
works well for me. Squelch quieting for AO-51 V/S band downlink often pushes
the S meter full scale (there are also deep fades with AO-51).
73, Ron n6paa
------------------------------
Message: 11
Date: Tue, 25 May 2010 09:37:19 -0700
From: Ron Miles <conimicut@xxxxx.xxx>
Subject: [amsat-bb] Re: Transystem 3731 vs. 3733
To: amsat-bb <amsat-bb@xxxxx.xxx>
Message-ID:
<AANLkTilpU97rvW6HRkHEim3pneCqItsuD1Af09uD3qjK@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1
Rich:
Maybe you've seen these popular links already, here they are again
regarding the 3731 and 3733
73, Ron n6paa
http://www.k3roj.com/images/AIDC3733downconvtr.txt
http://www.jrmiller.demon.co.uk/products/patfot.htm
http://www.amsat.org/amsat/archive/amsat-bb/200110/msg00136.html
http://128.54.16.15/amsat/archive/amsat-bb/200104/msg00285.html
http://www.jrmiller.demon.co.uk/products/patfot.htm
------------------------------
Message: 12
Date: Tue, 25 May 2010 13:09:17 -0400
From: "Rich Dailey (Gmail)" <redailey1@xxxxx.xxx>
Subject: [amsat-bb] Re: Transystem 3731 vs. 3733
To: Ron Miles <conimicut@xxxxx.xxx>
Cc: amsat-bb@xxxxx.xxx
Message-ID: <7.0.0.16.2.20100525130652.058ca1a0@xxxxx.xxx>
Content-Type: text/plain; charset="us-ascii"
Thanks for the links, Ron. It's been a while since I've dabbled with 2.4ghz,
since AO-40's heyday. Going to get my old toys back out this summer.
This info will help stir those brain cells back up.
Rich
>http://www.k3roj.com/images/AIDC3733downconvtr.txt
>
>http://www.jrmiller.demon.co.uk/products/patfot.htm
>
>http://www.amsat.org/amsat/archive/amsat-bb/200110/msg00136.html
>
>http://128.54.16.15/amsat/archive/amsat-bb/200104/msg00285.html
>
>http://www.jrmiller.demon.co.uk/products/patfot.htm
>_______________________________________________
>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: 13
Date: Tue, 25 May 2010 14:03:08 -0400
From: David - KG4ZLB <kg4zlb@xxxxxxxxxx.xxx>
Subject: [amsat-bb] 'Zombie-sat' and the clever orbital dance
To: amsat-bb@xxxxx.xxx
Message-ID: <4BFC10DC.2020509@xxxxx.xxx>
Content-Type: text/plain; charset="iso-8859-1"
The "dead-but-alive" telecommunications satellite, Galaxy-15
<http://www.orbital.com/SatellitesSpace/Communications/PanAmSat/>, has
begun to enter the space of neighbouring craft, and their operators are
planning evasive action.
"Zombie-sat" has captured the imagination of the internet space forums
these past few weeks. It's probably the nickname that's done it.
When we sit on the sofa skipping across the smorgasbord of channels with
our remote-controls, we don't usually give much thought to the "bent
pipes" that sit 36,000km above our heads, delivering the televisual feast.
Intelsat's Galaxy-15
<http://www.intelsat.com/resources/galaxy-15/operational-status.asp>
satellite was put in geostationary orbit five years ago to re-distribute
TV services to cable companies across North America, and also to send
navigation data to aeroplanes to improve the accuracy of their GPS
receivers.
But the "bird" experienced a major hiccup at the beginning of April.
It's not known precisely what happened. One possibility is that it was
damaged by high-speed particles billowing off the Sun in a solar storm -
an ever-present danger for orbiting electronics.
The satellite is still operational: it's still "on", but Intelsat cannot
control it. Any signal it receives, it re-transmits at high power. It's
a very unusual situation.
What doesn't help is the fact that Galaxy-15, which is supposed to sit
at 133 degrees West (over the eastern Pacific), is drifting slowing
eastwards by about 0.05 degrees a day. This will take it into the path
of other satellites, and first to have an issue is AMC-11
<http://www.ses-worldskies.com/worldskies/satellites/01_amc-fleet/amc-11/index
.php>,
another TV services spacecraft operated by SES World Skies
<http://www.ses-worldskies.com/worldskies/index.php>.
If SES were to do nothing, Zombie-sat would soon start picking up and
retransmitting signals sent to AMC 11. To users on the ground who depend
on AMC 11 for their daily dose of MTV, this could lead to a horrendous
mash-up.
It would be like trying to listen to two people who are shouting the
same conversation at you.
So, SES World Skies will today begin a delicate orbital dance, in which
they will allow AMC 11 to drift in tandem with Galaxy-15 while at the
same time sneaking up another satellite behind the pair.
The plan is for the SES controllers to then leapfrog many of the
services on AMC-11 across to this other satellite, known as SES-1,
thereby minimising the disruption to customers.
The manoeuvres are unprecedented, says Alan Young, the chief technology
officer with SES World Skies.
"The closest AMC-11 and Galaxy-15 will come is measured in
kilometres, and in space terms that's quite close. But the risk here
is not one of collision; we're not at all concerned about that. The
problem is that they're so close when viewed from Earth that it's
not easy to distinguish between the two satellites and seeing as
they both operate in the same frequency band, there will be
interference if we're not careful.
"We've gone to a number of measures, including moving customers on
AMC-11 on to a very large uplink antenna. This means we can very
finely discriminate between the two spacecraft so that we can direct
all of the energy into AMC-11 and as little energy as possible into
Galaxy-15. If you don't put anything into Galaxy-15, you won't get
anything out."
AMC-11 will eventually be moved back to its orbital slot to resume
normal operations once the zombie has passed through, which should be 7
June.
All satellite operators and comms companies will have to work out what
Galaxy-15 means to them. Here at the BBC, we've had to consider how some
of our international services like the BBC World News channel
<http://www.bbcworldnews.com> might be affected.
This channel is fed through Intelsat's Galaxy-13 platform. The most
recent calculations suggest everything should be fine.
Anyone sitting on their sofa in North America should be oblivious to the
space waltz that is about to take place.
There are some wider issues, however. For satellite manufacturers, there
will be keen interest in understanding exactly what happened to Galaxy-15.
Satellites have redundant, or back-up systems
<http://news.bbc.co.uk/1/hi/sci/tech/8458203.stm>; and when they have
major upsets, there are usually modes that will completely re-boot the
spacecraft automatically after a period of time.
Galaxy-15 was made by Orbital Sciences <http://www.orbital.com/>, but
Patrick Wood, the chief technical officer for EADS Astrium satellites
<http://www.astrium.eads.net/>, told me the entire industry had an
interest in finding out what went wrong:
"Part of our design review process is to check through the
architecture to ensure there isn't a single point that, were it to
fail, we'd lose complete control of the spacecraft. Clearly
Galaxy-15 has had a major event and most organisations will want to
understand what happened. From an industrial point of view, the
surprising thing is that Galaxy-15 is locked on full power. This
tends to suggest the control/tele-command side of the spacecraft has
failed and left the spacecraft in whatever mode it was in when it
was last commanded. It's a very unusual case."
And, of course, the whole episode raises once again the issue of orbital
space debris <http://news.bbc.co.uk/1/hi/sci/tech/7916582.stm>. Galaxy
15 will likely end its days in one of the two great "garbage patches" in
the sky.
These libration points
<http://en.wikipedia.org/wiki/Geostationary_orbit#Earth_orbital_libration_poin
ts>,
as they are known, are located at roughly 105 degrees West and 75
degrees East. They are gravitational "sweet-spots" where drifting
objects will naturally coalesce.
The two libration points now contain more than 150 defunct satellites
[395Kb PDF]
<http://www.secureworldfoundation.org/siteadmin/images/files/file_460.pdf>.
Satellite operators are urged to put their geostationary spacecraft in a
"graveyard orbit" once their missions are complete. This usually means
pushing the platforms even higher into the sky.
But of the 21 spacecraft which reached end of life in 2009, only 11 were
disposed of in accordance with the Inter-Agency Space Debris
Coordination Committee's (IADC) re-orbiting guidelines [99 Kb PDF]
<http://www.iadc-online.org/Documents/Docu/IADC_Mitigation_Guidelines_Rev1_Sep
07.pdf>.
We may all love our satellite TV, but we're starting to build a problem
for ourselves.
Watch this space.
------------------------------
Message: 14
Date: Tue, 25 May 2010 11:30:38 -0700
From: Clint Bradford <clintbradford@xxx.xxx>
Subject: [amsat-bb] Gordon West's Technician Class 2010-2014 Book
To: AMSAT BB <amsat-bb@xxxxx.xxx>
Message-ID: <88F3AE3D-4139-4DBE-9F24-414D9802FC09@xxx.xxx>
Content-Type: text/plain; charset=us-ascii
Well, we didn't get the entire text I submitted to Gordon printed in the new
exam prep manual. Darn those editors! (grin)
But AMSAT did get their "Ham Hint" box with a plug and Web address on Page
100.
And of the URLs I submitted, the following appear as "Web Site Resources" on
Page 104:
AMSAT.org
Heavens-Above.com
RT Systems - cloningsoftware.com
ArrowAntennas.com
K6LCS' Work-Sat.com site
BigFatTail.com software
DogParkSoftware.com
So "we" did OK. I'll "Shoot for More in 2-0-1-4" for the new book release!
Clint, K6LCS
http://www.k6lcs.com
909-241-7666
------------------------------
Message: 15
Date: Tue, 25 May 2010 18:44:47 +0000 (GMT)
From: "Trevor ." <m5aka@xxxxx.xx.xx>
Subject: [amsat-bb] Re: 'Zombie-sat' and the clever orbital dance
To: amsat-bb@xxxxx.xxx
Message-ID: <256056.66382.qm@xxxxxxxx.xxxx.xxx.xxxxx.xxx>
Content-Type: text/plain; charset=iso-8859-1
The BBC are running the video on their website
http://news.bbc.co.uk/1/hi/science_and_environment/10150614.stm
73 Trevor M5AKA
--- On Tue, 25/5/10, David - KG4ZLB <kg4zlb@xxxxxxxxxx.xxx> wrote:
> The "dead-but-alive"
> telecommunications satellite, Galaxy-15
<http://www.orbital.com/SatellitesSpace/Communications/PanAmSat/>,
> has begun to enter the space of neighbouring craft, and
> their operators are planning evasive action.
>
> "Zombie-sat" has captured the imagination of the internet
> space forums these past few weeks. It's probably the
> nickname that's done it.
>
> When we sit on the sofa skipping across the smorgasbord of
> channels with our remote-controls, we don't usually give
> much thought to the "bent pipes" that sit 36,000km above our
> heads, delivering the televisual feast.
>
> Intelsat's Galaxy-15
<http://www.intelsat.com/resources/galaxy-15/operational-status.asp>
> satellite was put in geostationary orbit five years ago to
> re-distribute TV services to cable companies across North
> America, and also to send navigation data to aeroplanes to
> improve the accuracy of their GPS receivers.
>
> But the "bird" experienced a major hiccup at the beginning
> of April.
>
> It's not known precisely what happened. One possibility is
> that it was damaged by high-speed particles billowing off
> the Sun in a solar storm - an ever-present danger for
> orbiting electronics.
>
> The satellite is still operational: it's still "on", but
> Intelsat cannot control it. Any signal it receives, it
> re-transmits at high power. It's a very unusual situation.
>
> What doesn't help is the fact that Galaxy-15, which is
> supposed to sit at 133 degrees West (over the eastern
> Pacific), is drifting slowing eastwards by about 0.05
> degrees a day. This will take it into the path of other
> satellites, and first to have an issue is AMC-11
<http://www.ses-worldskies.com/worldskies/satellites/01_amc-fleet/amc-11/index
.php>,
> another TV services spacecraft operated by SES World Skies
> <http://www.ses-worldskies.com/worldskies/index.php>.
>
> If SES were to do nothing, Zombie-sat would soon start
> picking up and retransmitting signals sent to AMC 11. To
> users on the ground who depend on AMC 11 for their daily
> dose of MTV, this could lead to a horrendous mash-up.
>
> It would be like trying to listen to two people who are
> shouting the same conversation at you.
>
> So, SES World Skies will today begin a delicate orbital
> dance, in which they will allow AMC 11 to drift in tandem
> with Galaxy-15 while at the same time sneaking up another
> satellite behind the pair.
>
> The plan is for the SES controllers to then leapfrog many
> of the services on AMC-11 across to this other satellite,
> known as SES-1, thereby minimising the disruption to
> customers.
>
> The manoeuvres are unprecedented, says Alan Young, the
> chief technology officer with SES World Skies.
>
> ???"The closest AMC-11 and Galaxy-15 will
> come is measured in
> ???kilometres, and in space terms that's
> quite close. But the risk here
> ???is not one of collision; we're not at all
> concerned about that. The
> ???problem is that they're so close when
> viewed from Earth that it's
> ???not easy to distinguish between the two
> satellites and seeing as
> ???they both operate in the same frequency
> band, there will be
> ???interference if we're not careful.
>
> ???"We've gone to a number of measures,
> including moving customers on
> ???AMC-11 on to a very large uplink antenna.
> This means we can very
> ???finely discriminate between the two
> spacecraft so that we can direct
> ???all of the energy into AMC-11 and as
> little energy as possible into
> ???Galaxy-15. If you don't put anything into
> Galaxy-15, you won't get
> ???anything out."
>
> AMC-11 will eventually be moved back to its orbital slot to
> resume normal operations once the zombie has passed through,
> which should be 7 June.
>
> All satellite operators and comms companies will have to
> work out what Galaxy-15 means to them. Here at the BBC,
> we've had to consider how some of our international services
> like the BBC World News channel <http://www.bbcworldnews.com> might be
affected.
>
> This channel is fed through Intelsat's Galaxy-13 platform.
> The most recent calculations suggest everything should be
> fine.
>
> Anyone sitting on their sofa in North America should be
> oblivious to the space waltz that is about to take place.
>
> There are some wider issues, however. For satellite
> manufacturers, there will be keen interest in understanding
> exactly what happened to Galaxy-15.
>
> Satellites have redundant, or back-up systems
<http://news.bbc.co.uk/1/hi/sci/tech/8458203.stm>;
> and when they have major upsets, there are usually modes
> that will completely re-boot the spacecraft automatically
> after a period of time.
>
> Galaxy-15 was made by Orbital Sciences <http://www.orbital.com/>, but
Patrick Wood, the
> chief technical officer for EADS Astrium satellites
<http://www.astrium.eads.net/>, told me the entire
> industry had an interest in finding out what went wrong:
>
> ???"Part of our design review process is to
> check through the
> ???architecture to ensure there isn't a
> single point that, were it to
> ???fail, we'd lose complete control of the
> spacecraft. Clearly
> ???Galaxy-15 has had a major event and most
> organisations will want to
> ???understand what happened. From an
> industrial point of view, the
> ???surprising thing is that Galaxy-15 is
> locked on full power. This
> ???tends to suggest the control/tele-command
> side of the spacecraft has
> ???failed and left the spacecraft in
> whatever mode it was in when it
> ???was last commanded. It's a very unusual
> case."
>
> And, of course, the whole episode raises once again the
> issue of orbital space debris
<http://news.bbc.co.uk/1/hi/sci/tech/7916582.stm>.
> Galaxy 15 will likely end its days in one of the two great
> "garbage patches" in the sky.
>
> These libration points
<http://en.wikipedia.org/wiki/Geostationary_orbit#Earth_orbital_libration_poin
ts>,
> as they are known, are located at roughly 105 degrees West
> and 75 degrees East. They are gravitational "sweet-spots"
> where drifting objects will naturally coalesce.
>
> The two libration points now contain more than 150 defunct
> satellites [395Kb PDF]
<http://www.secureworldfoundation.org/siteadmin/images/files/file_460.pdf>.
>
> Satellite operators are urged to put their geostationary
> spacecraft in a "graveyard orbit" once their missions are
> complete. This usually means pushing the platforms even
> higher into the sky.
>
> But of the 21 spacecraft which reached end of life in 2009,
> only 11 were disposed of in accordance with the Inter-Agency
> Space Debris Coordination Committee's (IADC) re-orbiting
> guidelines [99 Kb PDF]
<http://www.iadc-online.org/Documents/Docu/IADC_Mitigation_Guidelines_Rev1_Sep
07.pdf>.
>
>
> We may all love our satellite TV, but we're starting to
> build a problem for ourselves.
>
> Watch this space.
>
>
>
> -----Inline Attachment Follows-----
>
> _______________________________________________
> 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
>
------------------------------
_______________________________________________
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 5, Issue 237
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