| |
CX2SA > SATDIG 30.04.13 17:01l 775 Lines 26040 Bytes #999 (0) @ WW
BID : AMSATBB8138
Read: GUEST
Subj: AMSAT-BB-digest V8 138
Path: IZ3LSV<IW0QNL<IW2OHX<IR2UBX<IK8VKW<F1OYP<ZL2BAU<CX2SA
Sent: 130430/1454Z @:CX2SA.SAL.URY.SA #:5711 [Salto] FBB7.00e $:AMSATBB8138
From: CX2SA@CX2SA.SAL.URY.SA
To : SATDIG@WW
Today's Topics:
1. Re: Path to HEO (M5AKA)
2. EL94 (Andrew Glasbrenner)
3. Re: Path to HEO (Burns Fisher)
4. Sat32PC (James Luhn)
5. Dayton, Satellites, Fun !!!!! (James Luhn)
6. Re: Path to HEO (Joe Leikhim)
7. Re: Relay Turksat3usat Posting (Dave W?DHB)
8. Re: Path to HEO (Patrick Strasser)
9. Re: Path to HEO (Stefan Wagener)
10. Re: Path to HEO (Gus)
11. Re: Dayton (Mike Farkas)
12. Imagine RIT Festival May 4th - AMSAT Fox-2 Maximum Power
Point Tracker Senior Design Project Exhibit (Bryce Salmi)
13. Re: Path to HEO (Nick Pugh)
14. Re: Path to HEO (M5AKA)
15. Re: Path to HEO (N0JY)
16. Re: Path to HEO (Andrew Glasbrenner)
----------------------------------------------------------------------
Message: 1
Date: Mon, 29 Apr 2013 20:31:12 +0100 (BST)
From: M5AKA <m5aka@xxxxx.xx.xx>
To: Robert Bruninga <bruninga@xxxx.xxx>, Stefan Wagener
<wageners@xxxxx.xxx>
Cc: AMSAT BB <Amsat-bb@xxxxx.xxx>
Subject: [amsat-bb] Re: Path to HEO
Message-ID:
<1367263872.29263.YahooMailClassic@xxxxxxxxx.xxxx.xxx.xxxxx.xxx>
Content-Type: text/plain; charset=utf-8
--- On Mon, 29/4/13, Stefan Wagener <wageners@xxxxx.xxx> wrote:
> Thanks Bob,
> That's why it is important to read the complete conversation.
> This is NOT about Cubesats, staying in orbit, etc. It is about getting
> into an HEO beyond 20000km.
It's the same thing, what gets you from 310 to 700 km can also get you to
7200 or 20000 km. But first the technology needs to be proved in Space
CubeSats like Romit-1 will do that if they can get launches.
Bob, on the topic of extending orbit lifetime there's a UK company, a
University of Southampton spin-off, who are doing some interesting work in
this area.
Mars-Space Ltd have developed a Pulse Plasma Thruster for a 1U CubeSat
designed to extend orbit lifetime which was shown at a recent CubeSat
Workshop, details at
http://www.mars-space.co.uk/Pages/MicroPPTforCubesats.aspx
They are also working on Ion Motors.
73 Trevor M5AKA
------------------------------
Message: 2
Date: Mon, 29 Apr 2013 15:39:44 -0400 (GMT-04:00)
From: Andrew Glasbrenner <glasbrenner@xxxxxxxxxx.xxx>
To: amsat-bb <amsat-bb@xxxxx.xxx>
Subject: [amsat-bb] EL94
Message-ID:
<2672940.1367264384668.JavaMail.root@xxxxxxxxxxxxx.xxx.xx.xxxxxxxxx.xxx>
Content-Type: text/plain; charset=UTF-8
Looks like I'll be on Marathon in the Keys Weds night to Friday early
morning. If you need EL94 on satellite let me know and we'll make a schedule.
73, Drew KO4MA
------------------------------
Message: 3
Date: Mon, 29 Apr 2013 16:05:20 -0400
From: Burns Fisher <burns@xxxxxx.xx>
To: AMSAT BB <amsat-bb@xxxxx.xxx>
Subject: [amsat-bb] Re: Path to HEO
Message-ID:
<CABX7KxU+mEDys9RHVOqTV=ZgooHG3eCo2Zo428ynT6f=Lppg2Q@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1
One thing that would seem to be a concern to me is how to keep the attitude
steady while the ion engine is firing. Yes, not much thrust, but to make
the most of it, you want it pointing in as close to the ideal direction as
possible. I don't know how the various probes like Hayabusa and Dawn do
it.. Cold gas? Gyro? I would not think a bar magnet would be good enough
(certainly not for deep space probes, but even for earth orbit). Starting
to get more complicated.
Another thought about the really cool energy analysis done by KK6MC:
Besides the duty cycle imposed by wanting to be out of eclipse, there is
another duty cycle imposed by the starting orbit and the desired
eccentricity. For example if you were starting from a highly elliptical
GTO and you want to get to high circular, you need to thrust mainly at the
apogee in order to raise the perigee. If you are circular and you want to
be elliptical with perigee equal to the starting height, you thrust at what
will be the perigee to raise the apogee. (Of course you probably want to
raise both ends some, and you may want to change the plane too but that's
the general idea.)
Thanks for bringing this up...great thought experiments, and that's how
real projects begin!
Burns, W2BFJ
------------------------------
Message: 4
Date: Mon, 29 Apr 2013 15:52:12 -0500
From: James Luhn <luhn@xx.xxx>
To: amsat-bb@xxxxx.xxx
Subject: [amsat-bb] Sat32PC
Message-ID: <517EDD7C.6000204@xx.xxx>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
I need some advice. I have been trying to run Sat32PC to track
satellites with my G5500 rotor and LVB Tracker. It seems I am running
into one problem after another. Many times the program stops working
when I get towards a lower elevation while tracking the satellite. I
get most of the pass and then everything stops. I cannot park the rotor
and must reboot the computer as restarting the program gives com
errors. This afternoon Sat32PC was tracking a ghost. It clearly
thought something was flying above. The only satellite I had selected
was FO-29 and it definitely was well past a fly over. In fact, I could
not find an amateur satellite that was anywhere that the program should
be tracking. I would really like to get the bugs out as I plan to use
my Panasonic Toughbook in a portable operation. I am using the XP
Professional operating system with the USB communicating with the LVB
Tracker. I also have a Macbook and MacDoppler has operated flawlessly.
It does what it is suppose to do and does it well. Please no flame wars
over Mac vs PC. I use both and basically am happy with both. On
Sat32PC, the Keps are updated so I am not feeding the controller wrong
info. On the screen, the satellite position is visibly correct. On the
bottom of the screen the Azimuth / Elevation were wrong when it was
tracking the ghost. I have two Toughbooks and both exhibit the same
problem. Has anyone had the same or similar problems?
73,
-james
W5AOO
------------------------------
Message: 5
Date: Mon, 29 Apr 2013 16:22:39 -0500
From: James Luhn <luhn@xx.xxx>
To: amsat-bb@xxxxx.xxx
Subject: [amsat-bb] Dayton, Satellites, Fun !!!!!
Message-ID: <517EE49F.9010604@xx.xxx>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
I am gathering up my clothes for my trip to Dayton. I hope to see and
meet as many satellite folks as possible! I have my name in the hat to
work at the AMSAT booth. I worked last year and had the best time!
I keep seeing many emails about what satellites are operating. It seems
many think that none are working. Well I can tell you that I am having
a blast working FO-29, SO-50 , VO-52, and grandpa AO-7. I do admit that
AO-7 has a bit of a stutter step when too many get on or someone cranks
their power up too much. Take a look at the link Bob, W7LRD, posted
regarding active satellites: http://aar29.free.fr/sat/indexlogin.php
Each contact is so exciting. OMG, I worked Brazil last night too!
FO-29 sounded just like 20 meters last night! It is so nice to hear
those making their first contact and so nice to renew old friendships.
Hope to meet you or at least work you!
73,
-james
W5AOO
...still excited about amateur radio after being active for 50+ years!
------------------------------
Message: 6
Date: Mon, 29 Apr 2013 17:44:08 -0400
From: Joe Leikhim <rhyolite@xxxxxxxx.xxx>
To: amsat-bb@xxxxx.xxx
Subject: [amsat-bb] Re: Path to HEO
Message-ID: <517EE9A8.70300@xxxxxxxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Even if the technique required 5 years to advance to HEO it would be a
positive step since the amateur launch opportunities directly to HEO are
measured in decades and the cost in 10's millions of dollars.
This reminds me of a commercial payload that failed to make GEO. The
folks at AGI (STK Satellite Toolkit) devised a path circling the moon
which used the lunar gravity to accelerate and return the satellite to
its intended GEO position without depleting much of its limited station
keeping fuel.
--
Joe Leikhim
Leikhim and Associates
Communications Consultants
Oviedo, Florida
JLeikhim@xxxxxxx.xxx
407-982-0446
WWW.LEIKHIM.COM
------------------------------
Message: 7
Date: Mon, 29 Apr 2013 17:20:10 -0600
From: Dave W?DHB <dave@xxxxx.xxx>
To: "'JoAnne Maenpaa'" <k9jkm@xxxxxxx.xxx>, "'amsat-bb'"
<amsat-bb@xxxxx.xxx>
Subject: [amsat-bb] Re: Relay Turksat3usat Posting
Message-ID: <000001ce4530$188b6b60$49a24220$@xxx>
Content-Type: text/plain; charset="iso-8859-9"
Any further updates ?
Did not copy TurkSAT3USAT on 2 passes over US today 16:47 and 18:25
Did copy CubeBUG both passes, still just a carrier, no packet
Dave W0DHB
----Original Message-----
From: amsat-bb-bounces@xxxxx.xxx [mailto:amsat-bb-bounces@xxxxx.xxxx On
Behalf Of JoAnne Maenpaa
Sent: Sunday, April 28, 2013 6:16 PM
To: 'amsat-bb'
Subject: [amsat-bb] Relay Turksat3usat Posting
Some on amsat-bb are not on Facebook. The Turksat3usat Team posts most
of their updates on Facebook. Here is a copy/paste from Turksat3usat
Fan Club on Facebook today:
Turksat3usat Fan Club
?nemli: TURKSAT-3USAT uydumuz bu gece T?rkiye ?zerinden y?ksek a??da
ge?ecek. Radyo amat?rlerinden ricam?z tekrar duyuru yap?lana kadar
sadece beacon sinyalini izlemeleri ve olabildi?ince y?ksek kaliteli
(ve s?k??t?rma yapmadan) ses kayd? yapmalar?d?r. Kay?tlar?n?z?
do?rudan turksat3usat@xxxxxx.xxx.xx adresine g?nderebilirsiniz. Sinyal
kayd?n?z ne kadar d???k olursa olsun t?m kay?tlar?n?z? g?nderiniz.
Te?ekk?rler.
-----
Important: TURKSAT-3USAT uydumuz from Turkey will be high angle
tonight. Radio beacon signal until the announcement again please only
amat?rlerinden monitor, and high-quality as possible (and without any
compression) audio recording make bids. Records directly to
turksat3usat@xxxxxx.xxx.xx. No matter how low the signal records all
records. Thanks. (Translated by Bing)
-----
AMSAT-NA and AMSAT-DL also have Facebook groups.
--
73 de JoAnne K9JKM
k9jkm@xxxxx.xxx
Editor, AMSAT Journal
_______________________________________________
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: Mon, 29 Apr 2013 21:50:19 +0200
From: Patrick Strasser <patrick@xxxxxxxx.xxxx.xx>
To: Amsat-bb@xxxxx.xxx
Subject: [amsat-bb] Re: Path to HEO
Message-ID: <517ECEFB.8060408@xxxxxxxx.xxxx.xx>
Content-Type: text/plain; charset=ISO-8859-1
schrieb Stefan Wagener on 2013-04-29 01:29:
> LEO (low earth orbit) from 400 to 2000km or something like that
> HEO (high earth orbit) >20000km
>
> Going from 310 to 700km in a year is not doing us anything. We need a
> highly elliptical orbit (Apogee ~60000km, Perigee 900km) similar to AO-40
> to allow for cross continental communication.
Let's check with some maths (*):
Energy at 300 km:
-----------------
Total Energy = kinetic energy + potential energy
E_kin + E_pot =
(m*v^2)/2 + m*g*h
For simplicity, we choose
mass as 1 kg,
h = 300km,
v = 1st cosmic velocity =~ 7100m/s
1*7200? + 1*9.81*300x10^3 = 2.8148x10^7 [Joule]
Potential Energy is some 10% of the total energy.
As this is for one kg of mass, and m goes linear in the above equations,
you can scale with the mass of your satellite.
Energy at 36000 km:
-------------------
Speed from radius and time for one orbit (1 day=84600 sec)
v = 2*r*pi/t = 2*36x10^6*3.14159265/84600 = 2673.7 m/s
E_kin + E_pot =
(m*v^2)/2 + m*g*h =
3.57x10^6 + 3.53^8 =~ 3.56?10^8 [Joule]
Now kinetic energy is only about 1% of the total energy!
A LEO has about 8% the energy of an GEO. The satellite needs 3.29x10^8
J/Kg Energy to get from LEO to GEO.
Lets say it's 10kg and has 50 W of power for thrust.
3.3x10^8 * 10 = 3.3x10^9 J thrust
1 Joule is 1 Watt / 1 second, 1 Watt second = 1 Joule
1 Watt day = 84600 Joule = 8.46x10^4 Joule
Our 50 Watt ion drive can increase the energy by 4.23x10^6 Joule a day.
How much days will LEO to GEO take:
We have some 10^8 divided by some 10^6, it's a matter of months, the
calculation says 77.8. But we should be satisfied to get an order of
magnitude after the rough assumtions and estimations made before.
If I made a mistake above, maybe this is off by an factor of 10, then
it's 2 year. Still fine!
Of course you have to count in the gas you want to ionize, which reduces
the weight over time (but I was really bad at differential equations and
would not get that right), and maybe the weight and power estimations
are not very realistic, and using steady thrust instead of short
impulses decreases efficiency in orbit changes, and changing from polar
to equatorial orbit takes extra energy, and maybe an elliptic orbit
takes less energy, and maybe some inaccuracies more. But this does not
matter:
In the end, it seems that changing from LEO to GEO or HEO is possible in
sensible time.
Regards
Patrick
(*) Disclaimer: This is High School maths, please double check and
correct my calculations
--
Engineers motto: cheap, good, fast: choose any two
Patrick Strasser <patrick at wirklich priv at>
------------------------------
Message: 9
Date: Mon, 29 Apr 2013 20:26:25 -0500
From: Stefan Wagener <wageners@xxxxx.xxx>
To: Patrick Strasser <patrick@xxxxxxxx.xxxx.xx>
Cc: AMSAT BB <Amsat-bb@xxxxx.xxx>
Subject: [amsat-bb] Re: Path to HEO
Message-ID:
<CAKu8kHDi+oHuPERLrh-yuP_9t3bKQ3EF=4spWXQ2PZGSFXAkmA@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1
Thanks,
I like simple math. A 3U Cubesat can have deployable solar cells which will
give you between 45 and 70 watts of power. That should drive an ion engine.
Will need an active attitude control system and should start at the right
orbit. Getting +-3kg to GTO is a $100.000? Don't know what the satellite
would cost but we are now in a $ range that could be funded.
Thoughts?
Stefan
On Mon, Apr 29, 2013 at 2:50 PM, Patrick Strasser
<patrick@xxxxxxxx.xxxx.xx>wrote:
> schrieb Stefan Wagener on 2013-04-29 01:29:
>
> > LEO (low earth orbit) from 400 to 2000km or something like that
> > HEO (high earth orbit) >20000km
> >
> > Going from 310 to 700km in a year is not doing us anything. We need a
> > highly elliptical orbit (Apogee ~60000km, Perigee 900km) similar to AO-40
> > to allow for cross continental communication.
>
> Let's check with some maths (*):
>
> Energy at 300 km:
> -----------------
>
> Total Energy = kinetic energy + potential energy
> E_kin + E_pot =
> (m*v^2)/2 + m*g*h
>
> For simplicity, we choose
> mass as 1 kg,
> h = 300km,
> v = 1st cosmic velocity =~ 7100m/s
>
> 1*7200? + 1*9.81*300x10^3 = 2.8148x10^7 [Joule]
>
> Potential Energy is some 10% of the total energy.
> As this is for one kg of mass, and m goes linear in the above equations,
> you can scale with the mass of your satellite.
>
> Energy at 36000 km:
> -------------------
>
> Speed from radius and time for one orbit (1 day=84600 sec)
> v = 2*r*pi/t = 2*36x10^6*3.14159265/84600 = 2673.7 m/s
>
> E_kin + E_pot =
> (m*v^2)/2 + m*g*h =
> 3.57x10^6 + 3.53^8 =~ 3.56?10^8 [Joule]
>
> Now kinetic energy is only about 1% of the total energy!
>
> A LEO has about 8% the energy of an GEO. The satellite needs 3.29x10^8
> J/Kg Energy to get from LEO to GEO.
>
> Lets say it's 10kg and has 50 W of power for thrust.
> 3.3x10^8 * 10 = 3.3x10^9 J thrust
>
> 1 Joule is 1 Watt / 1 second, 1 Watt second = 1 Joule
> 1 Watt day = 84600 Joule = 8.46x10^4 Joule
>
> Our 50 Watt ion drive can increase the energy by 4.23x10^6 Joule a day.
> How much days will LEO to GEO take:
>
> We have some 10^8 divided by some 10^6, it's a matter of months, the
> calculation says 77.8. But we should be satisfied to get an order of
> magnitude after the rough assumtions and estimations made before.
> If I made a mistake above, maybe this is off by an factor of 10, then
> it's 2 year. Still fine!
>
> Of course you have to count in the gas you want to ionize, which reduces
> the weight over time (but I was really bad at differential equations and
> would not get that right), and maybe the weight and power estimations
> are not very realistic, and using steady thrust instead of short
> impulses decreases efficiency in orbit changes, and changing from polar
> to equatorial orbit takes extra energy, and maybe an elliptic orbit
> takes less energy, and maybe some inaccuracies more. But this does not
> matter:
>
> In the end, it seems that changing from LEO to GEO or HEO is possible in
> sensible time.
>
> Regards
>
> Patrick
>
> (*) Disclaimer: This is High School maths, please double check and
> correct my calculations
> --
> Engineers motto: cheap, good, fast: choose any two
> Patrick Strasser <patrick at wirklich priv at>
>
------------------------------
Message: 10
Date: Mon, 29 Apr 2013 21:28:32 -0400
From: Gus <8p6sm@xxxx.xxx>
To: amsat-bb@xxxxx.xxx
Subject: [amsat-bb] Re: Path to HEO
Message-ID: <517F1E40.9030208@xxxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
On 04/29/2013 03:50 PM, Patrick Strasser wrote:
> Speed from radius and time for one orbit (1 day=84600 sec)...
Uh, 86400 sec... But the difference isn't particularly significant.
--
73, de Gus 8P6SM
Barbados, the easternmost isle.
------------------------------
Message: 11
Date: Mon, 29 Apr 2013 21:57:15 -0400
From: Mike Farkas <mikef1234@xxxxx.xxx>
To: AMSAT-BB@xxxxx.xxx
Subject: [amsat-bb] Re: Dayton
Message-ID:
<CAN8j7+cSLKfazKrOMFsLeKY6kiu=QQBRNvO65ymk8XxrDM=f6Q@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1
Hi Jim!
I'm also starting to get my things together for the Dayton Fest. I think
hands down AMSAT has the best demo there. You can see and hear guys
actually work the birds, see the setup and ask questions. Hope to see you
there!
Mike/N8GBU.
------------------------------
Message: 12
Date: Tue, 30 Apr 2013 03:59:49 -0400
From: Bryce Salmi <bts2637@xxx.xxx>
To: Amsat BB <AMSAT-BB@xxxxx.xxx>
Subject: [amsat-bb] Imagine RIT Festival May 4th - AMSAT Fox-2 Maximum
Power Point Tracker Senior Design Project Exhibit
Message-ID:
<CAN5j0spNn+5Vxn85yqOoXGV_kvt2moN3evZk=pzp7STrQu+oGg@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1
Hello everyone,
I am a senior studying Electrical Engineering at the Rochester
Institute of Technology (RIT) and I am a member of a senior design group
that was sponsored by AMSAT to produce an engineering prototype *Maximum
Power Point Tracker* (MPPT) for the Fox-2 satellite. Most members of our
team are licensed radio amateurs and active members of the RIT Amateur
Radio Club K2GXT and have had quite the experience with this project! We've
worked extremely hard over the past 20 weeks to design and build a working
MPPT. We'd enjoy sharing this experience with anyone interested.
* Everyone who is in the Rochester, NY area or are willing to drive to
the area is invited to come to the RIT campus this Saturday May 4th
for the Imagine
RIT Innovation & Creativity Festival <http://www.rit.edu/imagine/>. This is
a completely free event on the RIT campus*.The previous link will have all
the information to get here and find exhibits of interest. Also,
here's a pretty
concise video <https://www.youtube.com/watch?v=fsQoh-_xOmY> on what the
event is about. The AMSAT Maximum Power Point Project is exhibit
#491<https://www.rit.edu/imagine/planyourday13/exhibit.php?id=491>and
will be located in what is known as the "infinity quad" outside the
engineering building (There's a big Mobius strip in the middle). We're
pretty much in the center of outside activity which is very nice for
showing people our project.
- Google StreetView of the Infinity
quad/loop<https://maps.google.com/maps?q=Rochester+Institute+of+Technology,+On
e+Lomb+Memorial+Drive,+Rochester,+NY+infinity+quad&hl=en&ll=43.084181,-77.6762
69&spn=0.002496,0.003954&sll=42.746632,-75.770041&sspn=5.138664,8.096924&t=h&h
q=Rochester+Institute+of+Technology,+One+Lomb+Memorial+Drive,+Rochester,+NY+in
finity+quad&radius=15000&z=18&layer=c&cbll=43.084254,-77.676732&panoid=LJOF2Kx
qFiMfpXqFOXhuBQ&cbp=12,277.89,,0,18.32>
- 2013 Imagine RIT Festival
Map<http://www.rit.edu/imagine/planyourday13/images/2013_map.jpg>(We
will be between the orange GLE and red LBR, you'll see a star, mobius
strip, and question mark on the map where I am referring too, sorry if it's
not clear)
Our project is part of the Kate Gleason College of Engineering senior
design program and we proposed this project as a group last Summer. Tony
Monteiro has been our "customer" for the project and has been great to work
with. You can find out more information on our P13271 RIT EDGE
wiki<http://edge.rit.edu/edge/P13271/public/Home>which is pretty
up-to-date pending a few updates (since PCB bring-up) but
largely a great resource for those interested for a more in-depth look into
our project. We have not completed our project but will be displaying the
working prototype MPPT during the festival and be more than happy to
explain/show it to anyone interested. There are some final tests and
reports that are left to finish before our project is complete.
Some links to high-interest items on our EDGE Server:
- 1 Page Project
Summary<http://edge.rit.edu/edge/P13271/public/FinalDocuments/Planning_Executi
on/1_Page_Project_Summary.pdf>
- Project
Poster<http://edge.rit.edu/edge/P13271/public/MSD_Poster/MSD_Poster_r1.pdf>
- MPPT Block
Diagram<http://edge.rit.edu/edge/P13271/public/FinalDocuments/Systems_Design/H
igh-Level_MPPT_Diagram-P13271.pdf>
- MPPT
Schematics<http://edge.rit.edu/edge/P13271/public/KiCad/MPPT/trunk/AMSAT_7W_MP
PT_Schematic.pdf>(slightly
out of date, some final values will be updated soon, largely
up-to-date)
- MSP430 firmware
information<http://edge.rit.edu/edge/P13271/public/Health%20%26%20Status%20Fir
mware>
Well, I think I've thoroughly linked to areas people might have
interest in. Feel free to poke around the project documentation and learn
more or ask questions. If you have any questions about Imagine RIT or
anything related to the festival please ask as well. I look forward to
potentially seeing some of you at the festival!
Sincerely,
Bryce Salmi
KB1LQC
Project Manager P13271
------------------------------
Message: 13
Date: Tue, 30 Apr 2013 03:19:22 -0500
From: "Nick Pugh" <quadpugh@xxxxxxxxx.xxx>
To: "'Patrick Strasser'" <patrick@xxxxxxxx.xxxx.xx>,
<Amsat-bb@xxxxx.xxx>
Subject: [amsat-bb] Re: Path to HEO
Message-ID: <02db01ce457b$6c867c50$459374f0$@xxx>
Content-Type: text/plain; charset="us-ascii"
-----Original Message-----
From: amsat-bb-bounces@xxxxx.xxx [mailto:amsat-bb-bounces@xxxxx.xxxx On
Behalf Of Patrick Strasser
Sent: Monday, April 29, 2013 2:50 PM
To: Amsat-bb@xxxxx.xxx
Subject: [amsat-bb] Re: Path to HEO
:
In the end, it seems that changing from LEO to GEO or HEO is possible in
sensible time.
Regards
Patrick
>From the comments HEO is challenging but doable. So let's get started. Let
bring up this idea at Dayton. I noticed that none of the board of directors
of AMSAT have commented on this thread. If we want to go to HEO we will have
to speak a little louder
Nick k5qxj
------------------------------
Message: 14
Date: Tue, 30 Apr 2013 10:54:47 +0100 (BST)
From: M5AKA <m5aka@xxxxx.xx.xx>
To: Patrick Strasser <patrick@xxxxxxxx.xxxx.xx>, Stefan Wagener
<wageners@xxxxx.xxx>
Cc: AMSAT BB <Amsat-bb@xxxxx.xxx>
Subject: [amsat-bb] Re: Path to HEO
Message-ID:
<1367315687.214.YahooMailClassic@xxxxxxxxx.xxxx.xxx.xxxxx.xxx>
Content-Type: text/plain; charset=utf-8
--- On Tue, 30/4/13, Stefan Wagener <wageners@xxxxx.xxx> wrote:
> I like simple math. A 3U Cubesat can have deployable solar
> cells which will give you between 45 and 70 watts of power.
I made it at best a theoretical 15-20 watts from a 3U with deployable panels
but having less solar power only extends the time it takes to get to the
target orbit, it still gets there in the end.
> Getting +-3kg to GTO is a $100.000?
I reckon the cost of a launch to get a 3U just to a 700 km LEO could be
about $150-200,000 but still affordable.
73 Trevor M5AKA
------------------------------
Message: 15
Date: Tue, 30 Apr 2013 08:01:26 -0500
From: N0JY <n0jy@xxxxxxx.xxx>
To: amsat-bb@xxxxx.xxx
Subject: [amsat-bb] Re: Path to HEO
Message-ID: <517FC0A6.1060801@xxxxxxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
I wonder about the amount of time spent in the Van Allen belts on the
way up there. We're concerned about radiation at a 650 km orbit, it
might take some heavy duty ($$) radiation tolerant components to survive
a few years trip through the radiation belts as well as the final high
orbit?
Jerry
N0JY
------------------------------
Message: 16
Date: Tue, 30 Apr 2013 10:51:15 -0400
From: Andrew Glasbrenner <glasbrenner@xxxxxxxxxx.xxx>
To: "n0jy@xxxx.xxxx <n0jy@xxxx.xxx>
Cc: "amsat-bb@xxxxx.xxxx <amsat-bb@xxxxx.xxx>
Subject: [amsat-bb] Re: Path to HEO
Message-ID: <CC765F01-4ACA-4E99-AD0D-737958CB6CAE@xxxxxxxxxx.xxx>
Content-Type: text/plain; charset=us-ascii
Where do the gain antennas go on a 10x10x30cm HEO?
73, Drew KO4MA
Sent from my iPhone
On Apr 30, 2013, at 9:01 AM, N0JY <n0jy@xxxxxxx.xxx> wrote:
> I wonder about the amount of time spent in the Van Allen belts on the way
up there. We're concerned about radiation at a 650 km orbit, it might take
some heavy duty ($$) radiation tolerant components to survive a few years
trip through the radiation belts as well as the final high orbit?
>
> Jerry
> N0JY
>
>
>
> _______________________________________________
> 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!
http://amsat.org/mailman/listinfo/amsat-bb
End of AMSAT-BB Digest, Vol 8, Issue 138
****************************************
Read previous mail | Read next mail
| |
