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CX2SA > SATDIG 04.07.08 00:50l 582 Lines 22414 Bytes #999 (0) @ WW
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To : SATDIG@WW
Message: 6
Date: Wed, 02 Jul 2008 22:28:16 -0800
From: Edward Cole <kl7uw(AT)acsalaska.net>
Subject: [amsat-bb] Re: NASA's American Student Moon Orbiter...
To: AMSAT BB <amsat-bb(AT)amsat.org>
Message-ID: <200807030628.m636SG1Q005934(AT)malik.acsalaska.net>
Content-Type: text/plain; charset="us-ascii"; format=flowed
The gain increase for the antenna would be deltaG = (12/4)^2 = 9, or
in dB = 10Log(9) = 9.5 dB. You get this gain in Tx and again in Rx
so the total gain = 19 dB. So this means that the spacecraft will
need to be 32-19 = 13 dB stronger than AO-40. So perhaps the S/C
antenna would be larger and maybe the Tx higher power?
Ed - KL7UW
At 08:16 PM 7/2/2008, w7lrd(AT)comcast.net wrote:
>How would my 12 foot paraclips work for this exercise?
>73 Bob W7LRD
>
>--
>"if this were easy, everyone would be doing it"
>
>-------------- Original message --------------
>From: "Andrew Glasbrenner" <glasbrenner(AT)mindspring.com>
>
> > The moon is roughly 360,000 to 400,000 km away. By comparison, AO-40 had a
> > apogee of about 60,000km. At 2.4Ghz, that's about 16db difference
> each way.
> > Put AO-40 at the moon, and if I'm doing this right, you'd need about 32
> > times the ground station antenna both coming and going to get
> with a few db.
> > I'm gonna need a bigger rotor for sure! I'm sure smarter folks
> will check my
> > math....
> >
> > 73, Drew KO4MA
> >
> > ----- Original Message -----
> > From: "Joe"
> > To: "Andrew Glasbrenner"
> > Cc: "Trevor" ; "AMSAT BB"
> > Sent: Wednesday, July 02, 2008 6:05 PM
> > Subject: Re: [amsat-bb] Re: NASA's American Student Moon Orbiter...
> >
> >
> > > what would a sample average link budget be?
> > >
> > > Andrew Glasbrenner wrote:
> > >
> > >>As far as I can recall we are pursuing both Eagle and the P4 opportunity
> > >>equally, concentrating on common elements until the details are ironed
> > >>out. Neither has been identified as a primary or secondary objective.
> > >>
> > >>I agree a package on a lunar orbiter would be neat, but also that it is
> > >>not the best use of what volunteers we have. We need more folks
> to step up
> > >>to do things, AND we need to make better use of them when they do.
> > >>
> > >>73, Drew KO4MA
> > >>
> > >>----- Original Message -----
> > >>From: "Trevor"
> > >>To: "AMSAT BB"
> > >>Sent: Wednesday, July 02, 2008 4:53 PM
> > >>Subject: [amsat-bb] Re: NASA's American Student Moon Orbiter...
> > >>
> > >>
> > >>
> > >>>--- On Wed, 2/7/08, Dave hartzell wrote:
> > >>>
> > >>>>http://www.spaceref.com/news/viewpr.html?pid=25839
> > >>>>http://asmo.arc.nasa.gov/
> > >>>>
> > >>>>Wouldn't it be fun to have a transponder on this! ;-)
> > >>>>
> > >>>Fun yes, but dare I say it, a waste of precious Volunteer resources.
> > >>>
> > >>>All lunar orbits are inherently unstable and will impact after a couple
> > >>>of years. The link budget requirements would not attract a mass user
> > >>>base.
> > >>>
> > >>>I suspect the number of Technically Capable volunteers is already being
> > >>>thinly stretched in trying to provide both the primary
> objective Phase-IV
> > >>>Lite (funded by Federal Government dollars) and the secondary objective
> > >>>the Eagle HEO.
> > >>>
> > >>>73 Trevor M5AKA
> > >>>
> > >>>
> > >>>
> > >>> __________________________________________________________
> > >>>Not happy with your email address?.
> > >>>Get the one you really want - millions of new email addresses available
> > >>>now at Yahoo! http://uk.docs.yahoo.com/ymail/new.html
> > >>>
> > >>>_______________________________________________
> > >>>Sent via AMSAT-BB(AT)amsat.org. 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(AT)amsat.org. 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(AT)amsat.org. 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(AT)amsat.org. 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: Wed, 02 Jul 2008 22:35:11 -0800
From: Edward Cole <kl7uw(AT)acsalaska.net>
Subject: [amsat-bb] Re: NASA's American Student Moon Orbiter...
To: Amsat BB <amsat-bb(AT)AMSAT.Org>
Message-ID: <200807030635.m636ZBhE067150(AT)iris.acsalaska.net>
Content-Type: text/plain; charset="us-ascii"; format=flowed
When the Apollo orbited the Moon it was behind and out of contact
about 20-minutes per orbit.
Ed - KL7UW
At 12:45 PM 7/2/2008, Nigel Gunn G8IFF/W8IFF wrote:
>Probably not. Would it not spend a significant amount of it's time
>behind the moon where you can't see it?
>
>Dave hartzell wrote:
> > http://www.spaceref.com/news/viewpr.html?pid=25839
> > http://asmo.arc.nasa.gov/
> >
> > Wouldn't it be fun to have a transponder on this! ;-)
> > _______________________________________________
> > Sent via AMSAT-BB(AT)amsat.org. 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
> >
>
>
>--
><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><>
>Nigel A. Gunn. G8IFF W8IFF (was KC8NHF)
>59 Beadlemead, Milton Keynes, MK6 4HF, England. 07951079089 OR
>1865 El Camino Drive, Xenia, OH 45385-1115, USA 937 825 5032
>e-mail nigel(AT)ngunn.net www http://www.ngunn.net
>Member of ARRL, GQRP #11396, QRPARCI #11644, SOC #548, Flying Pig #385,
> Dayton ARA #2128, AMSAT-NA AMSAT-UK, LM-1691, MKARS,
><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><>
>_______________________________________________
>Sent via AMSAT-BB(AT)amsat.org. 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: Thu, 3 Jul 2008 06:49:49 -0500
From: "Gary \"Joe\" Mayfield" <gary_mayfield(AT)hotmail.com>
Subject: [amsat-bb] Re: Commercial Mode L Antenna sources
To: "'Wayne Estes'" <w9ae(AT)charter.net>, <amsat-bb(AT)amsat.org>
Message-ID: <BLU137-DAV10D3949ED5750FEEA65F68A980(AT)phx.gbl>
Content-Type: text/plain; charset="us-ascii"
Wimo got some use in the old days as well.
http://www.ssbusa.com/wimohelix.html
I have a 23-2 which was okay (not great) with AO-40 with 10 Watts until
the
AGC started getting pumped. It is too much for AO-51, so I reduce the
power.
73,
Joe
-----Original Message-----
From: amsat-bb-bounces(AT)amsat.org [mailto:amsat-bb-bounces(AT)amsat.org]
On
Behalf Of Wayne Estes
Sent: Wednesday, July 02, 2008 12:34 PM
To: amsat-bb(AT)amsat.org
Subject: [amsat-bb] Re: Commercial Mode L Antenna sources
I'm surprised how few people have mentioned parabolic dishes during this
discussion about commercial Mode L antennas. L-band uplinks are mostly
used in combination with a S-band downlink. Most people build L/S
equipment with HEO satellites in mind. A single yagi or helix doesn't
usually provide sufficient gain for L/S band use with a HEO satellite.
You need the gain of a dish for satisfactory S-band reception of a HEO
satellite. So one practical solution is an oversized dish with a L/S
dual-band feed (helix or patch). A 4-foot dish was proven to work well
for this on AO40. In my opinion a single 4-foot dish is more practical
than, for example, cobbling together multiple yagi/helix antennas for
S-band downlink and multiple yagi/helix antennas for L-band uplink.
My 4-foot dish and dual-band patch feed were purchased commercially from
Teksharp (Rick Fletcher KG6IAL).
http://www.plumdragon.com/teksharp/hr_AO-40_products.htm
The dual-band patch feed is sold fully assembled and tested, but the
dish was a kit. I had to locally purchase 1/4 inch hardware cloth, cut
it into 8 "petals", and use 200 zip ties to attach the petals to the
frame of the dish. A mesh dish has somewhat less wind loading than a
solid dish. That's important because a solid 4-foot dish has a maximum
wind load of more than 12 square feet, exceeding the wind load rating of
my G-5500 rotor. A picture of my satellite antennas can be seen here:
http://s238.photobucket.com/albums/ff239/Wayne_Estes/Ham%20Radio/
Wayne Estes W9AE
Oakland, Oregon, USA, CN83ik
_______________________________________________
Sent via AMSAT-BB(AT)amsat.org. 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: 9
Date: Thu, 3 Jul 2008 09:46:28 -0500
From: "James Whitfield" <n5gui(AT)cox.net>
Subject: [amsat-bb] Comment on ASMO (American Student Moon Orbiter)
To: <amsat-bb(AT)amsat.org>
Message-ID: <000b01c8dd1b$93985a70$6401a8c0(AT)Sony2G4>
Content-Type: text/plain; charset="iso-8859-1"
So that you will know "where I am coming from", let me say that I am not
an
active satellite user. I am a semi-retired aerospace engineer, in that I
work
part time on a NASA project - the modification of a 747 to carry a sub-
millimeter and infrared telescope into the stratosphere. I had my hands
into
amateur radio, literally, before Sputnik, though I did not get my license
until years later. I cannot remember when I was not interested in space
exploration. My first engineering job was testing rocket motors and
associated prototype hardware for the first and second stages of what
evolved
into the Peacekeeper missile. And for a brief time I tried to be an
educator.
My opinion is that ASMO is a result of the stark realization by NASA,
whether
from within or forced on it by national leadership, that the supply of
skills
to build and operate spacecraft is rapidly drying up at a time when
national
goals are to expand our reach into space by returning to the Moon and
perhaps
sending people to Mars. Within the ASMO website is the statement that
twenty-
five persent of NASA employees are eligible to retire in less than five
years.
The problem is similar for the companies that NASA depends on to develop
and
operate its various systems. Indeed the entire aerospace industry, while
facing major difficulties due to the current fuel prices, will have severe
personnel shortages for decades.
Even when engineers and scientists can be hired, they still face the
problem
of learning what it is that they are hired to do. A problem particularly
acute for NASA since they tend to be doing things that have never been
done
before. ASMO is an attempt to find solutions to both of these areas of
concern.
You may ask how this relates to AMSAT. First, for those of you that work
with
students, you might get the opportunity, assuming of course that ASMO gets
off
the ground, to encourage students to seek a university program that will
allow
them to build and operate satellites. Presumably, you will have converted
them to AMSAT members along their path. At the very least they should
recognize that the amateur radio community is a friendly ally. And if you
are
an AMSAT member preparing to go to college, and have some interest in a
program like ASMO, then by all means go for it. ( And keep an open mind
for
projects that can attract more students to follow you. )
For those of you not already working with students, here is your chance to
influence not only the future scientists and engineers that will be
building
future spacecraft, but it is an excellent opportunity to connect with, and
begin to influence, the universities that will be training them. Not so
long
ago, I read here some comments ( Dare I say grousing? ) about university
satellite projects using amateur frequencies and assets, but then giving
nothing back to the amateur radio community for their service. Meet with
them. Propose activities to work together. Demonstrate to them that
working
with you is in their own self interest. Show your stuff. Of course you
won't
get all of them interested in your hobby, but you might get a lot more
than
you have now.
Suppose you took the time to submit some ideas to NASA about the kind of
things that a student project should include. Remember, the intent is to
allow students to learn about building and operating an entire space
probe.
Point out that the students should include communications ( not just
depend on
the existing NASA communication system ) as part of the system. There is
room
for thought about communications experiements - perhaps a radar sensor
array
could be pointed at the Earth when not being used to scan the Moon.
Students
could learn a lot more about communications, if say the "radar" was
commanded
to listen first, then transmit back something that it "heard". Think
outside
the box. Don't limit yourself to the mindset that a radar sends an
unmodulated burst and listens to the echo, which is processed for
information.
The same "box" can listen, process, then transmit. Do the math. Suggest
alternatives. Point out that if the probe can be heard on the Earth with
!
amateur radio equipment, then millions of people can listen. It certainly
worked for Sputnik.
Be realistic. If you suggest a system that you can kerchunk with an HT in
your back yard, I don't think it will get much favor. But then again, the
intent is to give student experience to a real probe that will gather
significant data to be used for future lunar exploration. This program is
not
about what you want, but about what is a good experience for the students.
If
you think about it, you might find that "good for the students" might
benefit
you as well.
You are the people who have shown interest in building and operating
spacecraft. You are the kind of people that NASA wants to hear from.
James Whitfield
n5gui
------------------------------
Message: 10
Date: Thu, 03 Jul 2008 10:53:31 -0500
From: Joe <nss(AT)mwt.net>
Subject: [amsat-bb] Re: Comment on ASMO (American Student Moon
Orbiter)
To: James Whitfield <n5gui(AT)cox.net>, amsat-bb(AT)amsat.org
Message-ID: <486CF5FB.2080600(AT)mwt.net>
Content-Type: text/plain; charset=windows-1252; format=flowed
Hi James,
Yes lots of people complain,, and even more complain and do nothing. but
there are few that do try. like us. We think of ourselves as a step
below what you are describing below in your message.
This can be done by anyone. Even just one person can do this. That's how
my group started. Just myself thinking what an awesome idea. And went
for it. And been doing it for 20 years now. Having fun all the way also.
What am I talking about?
What is called, Near Space Or Edge of Space. exploration.
Hence the name of our group
Near Space Sciences.
Please take a visit to our web site to see some of the fantastic imagery
and programs we offer to the Schools and Students.
It's at. http://www.qsl.net/wb9sbd/educators.html
The above link is our preferred site to view, but sometimes that server
is flaky,, if it doesn't work check out a stripped down mirror site at
http://www.mwt.net/~mayen1/educators.html
Our last Mission to the edge of space happened just a few weeks ago, on
May 21st.
We had a launch for several hundred boy & girl scouts at the Sauk County
Wisconsin fair grounds.
This was our 43rd flight to the ?Edge Of Space? This flight made it all
the way up to
102,528 feet! Yes One hundred two thousand, five hundred and twenty
eight feet UP!
A short video of the launch can be seen at,,
http://www.youtube.com/watch?v=NoUkgWOUbNQ
We then next had a HUGE event flight for several thousand people, at the
Richland Center Wisconsin High School,
they were celebrating the 50th anniversary of space exploration with the
50th anniversary of the launch of Sputnik.
We did a Live video flight for them, That payload actually transmitted
live video to the students on the ground the actual view
from the payload itself!
A page that is not finished yet but still under construction can be seen
at,
http://www.qsl.net/wb9sbd/nss-45.html
This isn't "Rocket Science" but it can easily be used as a beginner
platform for sure!
Joe WB9SBD
Near Space Sciences
James Whitfield wrote:
>So that you will know "where I am coming from", let me say that I am not an
active satellite user. I am a semi-retired aerospace engineer, in that I
work
part time on a NASA project - the modification of a 747 to carry a sub-
millimeter and infrared telescope into the stratosphere. I had my hands
into
amateur radio, literally, before Sputnik, though I did not get my license
until years later. I cannot remember when I was not interested in space
exploration. My first engineering job was testing rocket motors and
associated prototype hardware for the first and second stages of what
evolved
into the Peacekeeper missile. And for a brief time I tried to be an
educator.
>
>My opinion is that ASMO is a result of the stark realization by NASA, whether
from within or forced on it by national leadership, that the supply of
skills
to build and operate spacecraft is rapidly drying up at a time when
national
goals are to expand our reach into space by returning to the Moon and
perhaps
sending people to Mars. Within the ASMO website is the statement that
twenty-
five persent of NASA employees are eligible to retire in less than five
years.
The problem is similar for the companies that NASA depends on to develop
and
operate its various systems. Indeed the entire aerospace industry, while
facing major difficulties due to the current fuel prices, will have severe
personnel shortages for decades.
>
>Even when engineers and scientists can be hired, they still face the problem
of learning what it is that they are hired to do. A problem particularly
acute for NASA since they tend to be doing things that have never been
done
before. ASMO is an attempt to find solutions to both of these areas of
concern.
>
>You may ask how this relates to AMSAT. First, for those of you that work
with students, you might get the opportunity, assuming of course that ASMO
gets off the ground, to encourage students to seek a university program
that
will allow them to build and operate satellites. Presumably, you will
have
converted them to AMSAT members along their path. At the very least they
should recognize that the amateur radio community is a friendly ally. And
if
you are an AMSAT member preparing to go to college, and have some interest
in
a program like ASMO, then by all means go for it. ( And keep an open mind
for
projects that can attract more students to follow you. )
>
>For those of you not already working with students, here is your chance to
influence not only the future scientists and engineers that will be
building
future spacecraft, but it is an excellent opportunity to connect with, and
begin to influence, the universities that will be training them. Not so
long
ago, I read here some comments ( Dare I say grousing? ) about university
satellite projects using amateur frequencies and assets, but then giving
nothing back to the amateur radio community for their service. Meet with
them. Propose activities to work together. Demonstrate to them that
working
with you is in their own self interest. Show your stuff. Of course you
won't
get all of them interested in your hobby, but you might get a lot more
than
you have now.
>
>Suppose you took the time to submit some ideas to NASA about the kind of
things that a student project should include. Remember, the intent is to
allow students to learn about building and operating an entire space
probe.
Point out that the students should include communications ( not just
depend on
the existing NASA communication system ) as part of the system. There is
room
for thought about communications experiements - perhaps a radar sensor
array
could be pointed at the Earth when not being used to scan the Moon.
Students
could learn a lot more about communications, if say the "radar" was
commanded
to listen first, then transmit back something that it "heard". Think
outside
the box. Don't limit yourself to the mindset that a radar sends an
unmodulated burst and listens to the echo, which is processed for
information.
The same "box" can listen, process, then transmit. Do the math. Suggest
alternatives. Point out that if the probe can be heard on the Earth with!
!
> amateur radio equipment, then millions of people can listen. It certainly
worked for Sputnik.
>
>Be realistic. If you suggest a system that you can kerchunk with an HT in
your back yard, I don't think it will get much favor. But then again, the
intent is to give student experience to a real probe that will gather
significant data to be used for future lunar exploration. This program is
not
about what you want, but about what is a good experience for the students.
If
you think about it, you might find that "good for the students" might
benefit
you as well.
>
>You are the people who have shown interest in building and operating
spacecraft. You are the kind of people that NASA wants to hear from.
>
>
>James Whitfield
> n5gui
>
>
>_______________________________________________
>Sent via AMSAT-BB(AT)amsat.org. 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(AT)amsat.org. Opinions expressed are those of the
author.
Not an AMSAT member? Join now to support the amateur satellite program!
http://amsat.org/mailman/listinfo/amsat-bb
End of AMSAT-BB Digest, Vol 3, Issue 331
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