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CX2SA > SATDIG 29.04.13 20:32l 765 Lines 27363 Bytes #999 (0) @ WW
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To : SATDIG@WW
Today's Topics:
1. nee-01 pegaso (Lizeth Norman)
2. Re: Shack cleaning sale (Glenn AA5PK)
3. Relay Turksat3usat Posting (JoAnne Maenpaa)
4. Re: Path to HEO (James Duffey)
5. Re: Orbits Questions And Satellite Safety (Franklin Antonio)
6. Re: satpc32 etc (R Oler)
7. Shack cleaning sale (Glenn A. Miller)
8. Re: Path to HEO (Luc Leblanc)
9. Re: Path to HEO (Daniel Schultz)
10. Re: Path to HEO (Nick Pugh)
11. Re: Path to HEO (M5AKA)
12. Re: G5500 Rotor motor Question (David Palmer KB5WIA)
13. Successful Powered Flight For SpaceShipTwo (B J)
14. Observations From ESA's Herschel Observatory End (B J)
15. More On SpaceShipTwo's Flight (B J)
16. What birds (anelson@xxx.xxxxx.xxxx
----------------------------------------------------------------------
Message: 1
Date: Sun, 28 Apr 2013 19:36:07 -0400
From: Lizeth Norman <normanlizeth@xxxxx.xxx>
To: "<,amsat-bb@xxxxx.xxxxxxxx <amsat-bb@xxxxx.xxx>
Subject: [amsat-bb] nee-01 pegaso
Message-ID:
<CAJUhCTMREoCxusrCOn_-==G1pYJkJu9+okGrwt2KUT895GYUgA@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1
See here for the latest news:
http://translate.google.com/translate?sl=es&tl=en&js=n&prev=_t&hl=en&ie=UTF-8&
eotf=1&u=http%3A%2F%2Fwww.exa.ec%2Fbp49%2F&act=url
73 de Norm n3ykf (Off to oa4 in the am)
------------------------------
Message: 2
Date: Sun, 28 Apr 2013 18:57:41 -0500
From: "Glenn AA5PK" <aa5pk@xxxxxxxxxx.xxx>
To: <amsat-bb@xxxxx.xxx>
Subject: [amsat-bb] Re: Shack cleaning sale
Message-ID: <8937C1A1AF994D4DA56523E5E5C446BA@xxxxxxxxxx>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
reply-type=response
Icom AG-25 mast mount 2 meter preamp
Mirage KP-1/440 70 cm GaAsFET preamp
G-5500 control box and elevation rotor (no az rotor)
Alinco ELH-730D 70 cm linear amp (3W in for 30W out) w/preamp
Radio Shack 2 meter amp (Cat. # 19-1122)
Pix available. If interested, please contact me off list.
Glenn AA5PK
------------------------------
Message: 3
Date: Sun, 28 Apr 2013 19:16:11 -0500
From: "JoAnne Maenpaa" <k9jkm@xxxxxxx.xxx>
To: "'amsat-bb'" <amsat-bb@xxxxx.xxx>
Subject: [amsat-bb] Relay Turksat3usat Posting
Message-ID: <002b01ce446e$c1f39320$45dab960$@xxx>
Content-Type: text/plain; charset="iso-8859-9"
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
------------------------------
Message: 4
Date: Sun, 28 Apr 2013 21:34:47 -0600
From: James Duffey <jamesduffey@xxxxxxx.xxx>
To: Franklin Antonio <antonio@xxx.xxxxxxxx.xxx>
Cc: Amsat-bb@xxxxx.xxx
Subject: [amsat-bb] Re: Path to HEO
Message-ID: <83797187-8341-46A2-AE4E-67004FD4975B@xxxxxxx.xxx>
Content-Type: text/plain; charset=us-ascii
Well I did a rough back of the envelope calculation for the time required to
accumulate the energy necessary to get from LEO to HEO, but there are a lot
of details that still need to be calculated. And the devil is in the
details. But this will get things started
The difference in orbital energy between a LEO and GEO is about 25 MJ/kg.
So, for a 10 kg nano sat, we would need to supply at least 250 MJ. Now I
suspect that when all is said and done, it cannot be done for that, but I
haven't done any detailed orbital transfer calculations.
OK, suppose we have Nick's 50 Watt solar panel, and lets also say that
initially half of that power can be put into propulsion, the other half
being needed for navigation, housekeeping, comm, and telemetry. You could
probably get away with more for propulsion.
So say we need to generate at least 250,000,000 (it is probably more) Joules
of energy to get from LEO to HEO. The solar panel can supply 25 Watts or 25
Joules per second. so it will take 10,000,000 seconds to generate the 250MJ
required.
Now the satellite is only illuminated for roughly half an orbit, so we need
to double the time to 20,000,000 seconds on orbit. Now there 31,536,000
seconds in a year, so it would take 231 days to accumulate the minimum
amount of energy to get to GEO.
Well, I neglected inefficiencies in the system, such as the ability of the
ion-thruster to convert electricity into thrust and how efficiently the
batteries or capacitors can be charged and store energy. I also ignored the
drag at lower latitudes, which may be considerable. I suppose that one could
only operate the thrusters while the spacecraft is illuminated and that
would eliminate the storage problem. Say the whole system is 50% efficient,
and I am guessing here, that would make it 462 days, or 15 months.
I suppose that whether or not that is a long time, depends on your point of
view. I'll bet if the transfer burn strategy is calculated it gets even
worse. Things seldom get better. You can't do a simple Hohmann transfer, but
would need to do multiple burns, or a continuous burn over the illuminated
part of the orbit. I suppose that would produce an orbit that is not really
circular at any given time but it might all average out over all the burns.
A constant burn may be more efficient in terms of energy use that a Hohmann;
I don't remember. I do remember that one wants to burn at apogee to get the
biggest bang for the buck, and I suspect that the illuminated portion of the
orbit is not always at apogee, so the energy will not be used efficiently.
Now a GEO orbit, while a desirable goal, is not necessarily what is needed
for amateur radio communication. Something short of GEO, and even elliptical
would still be useful and only require repointing of the antenna from day to
day, and perhaps hour to hour at Apogee. Orbits significantly higher than
LEO, but lower than GEO are also very useful. Compare for example the
available time per pass between ISS and AO-7, and for that matter the RS10,
11, 12 and 13 birds.
One would need to plan how to go through the Van Allen belts, as with such a
slow burn one would spend a lot of time where the radiation is high.
All of this is not meant to be a rigorous calculation, but rather just an
indication of whether it is reasonable, and if it is worth pursuing further.
It does to seem to be within the realm of possibly, and probably should be
pursued further, at least until a real show stopper shows up. - Duffey KK6MC
--
KK6MC
James Duffey
Cedar Crest NM
On Apr 28, 2013, at 3:34 PM, Franklin Antonio <antonio@xxx.xxxxxxxx.xxx>
wrote:
> At 11:14 AM 4/28/2013, Nick Pugh wrote:
>> I have just returned from a satellite conference and I think new technology
>> will now give us a path to HEO.
>
> I've thought for a long time that ion engines (small thrust pushing for a
long time, powered by electricity) could be of great value to us.
>
> Has anyone done the calculation to see how long it would take to go from
LEO to HEO with an achievable ion engine? This seems like the first thing
to calculate. If it takes less than 1 year, it seems worth serious
investigation.
>
> There are many other hurdles, of course, such as attitude control (keeping
solar panels pointed at the sun while at the same time keeping engine
pointed in the direction we want thrust, over a long period of time). The
schemes and compromises for these issues can be worked if the basic thrust
math works out.
>
> N6NKF
>
> _______________________________________________
> 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: 5
Date: Sun, 28 Apr 2013 21:19:16 -0700
From: Franklin Antonio <antonio@xxx.xxxxxxxx.xxx>
To: Dave Marthouse <dmarthouse@xxxxx.xxx>
Cc: amsat-bb@xxxxx.xxx
Subject: [amsat-bb] Re: Orbits Questions And Satellite Safety
Message-ID:
<aef541aa-8b06-4bc7-8639-2a4f0fb41af8@xxxxxxxxxxx.xx.xxxxxxxx.xxx>
Content-Type: text/plain; charset="us-ascii"; format=flowed
At 03:59 PM 4/28/2013, Dave Marthouse wrote:
>I know that the earth is surrounded by radiation belts that have the
>potential of damaging satellites. How dense are they and around what
>altitudes do they have their most harmful affects?
http://en.wikipedia.org/wiki/Van_Allen_Belts
------------------------------
Message: 6
Date: Sun, 28 Apr 2013 14:10:12 -0500
From: R Oler <orbitjet@xxxxxxx.xxx>
To: Bob- W7LRD <w7lrd@xxxxxxx.xxx>, "APBIDDLE@xxxxxxx.xxxx
<apbiddle@xxxxxxx.xxx>
Cc: Amsat BB <amsat-bb@xxxxx.xxx>
Subject: [amsat-bb] Re: satpc32 etc
Message-ID: <BLU176-W29A57EBEFB4DFF6F4C1893D6B10@xxx.xxx>
Content-Type: text/plain; charset="iso-8859-1"
In this case absent propulsion there probably was not much of a
ride...however SpaceX is coming up with some launches (like the upcoming one
from Vandy) where they are mass plus and the second stage is going to make
some post deployment burns...to bad nothing to stick on it Robert WB5MZO
> Date: Sun, 28 Apr 2013 18:44:33 +0000
> From: w7lrd@xxxxxxx.xxx
> To: APBIDDLE@xxxxxxx.xxx
> CC: amsat-bb@xxxxx.xxx
> Subject: [amsat-bb] Re: satpc32 etc
>
> yep a low orbit for that block of aluminum . I was Googleing around trying
to find out when and where it will deorbit. Will not that much mass make
land fall? It would probably create a meteor like trail. Maybe our meteor
scatter folks could make some use of that 8,377 block of aluminum.
> 73 Bob W7LRD
>
> ----- Original Message -----
> From: "Alan" <wa4sca@xxxxx.xxx>
> To: "Bob- W7LRD" <w7lrd@xxxxxxx.xxx>, amsat-bb@xxxxx.xxx
> Sent: Sunday, April 28, 2013 6:02:31 AM
> Subject: RE: [amsat-bb] satpc32 etc
>
> Bob,
>
> Take a look at the orbit.
>
> Alan
> WA4SCA
>
>
> -----Original Message-----
> From: amsat-bb-bounces@xxxxx.xxx [mailto:amsat-bb-bounces@xxxxx.xxxx On
> Behalf Of Bob- W7LRD
> Sent: Sunday, April 28, 2013 12:34 AM
> To: amsat-bb@xxxxx.xxx
> Subject: [amsat-bb] satpc32 etc
>
>
> Thanks to many and Dave KB1PVH I can now input keps in my computer all by
> myself. I read this in the weekly AMSAT bulletins
>
> The Castor 30 second stage motor, built by ATK, ignited for a burn lasting
> two-and-a-half minutes, accelerating the rocket to more than 17,000 mph.
> Engineers declared the rocket reached orbit, and the upper stage deployed a
> 8,377-pound block of aluminum designed to mimic the mass characteristics of
> the
> Cygnus spacecraft, which will take the dummy
> payload's place on the next Antares
> launch.
>
> Why does this want me to pull out what little hair I have left?? 8,377Lbs!
> I'm sure I am missing something, what did AO-40 weigh?
> 73 Bob W7LRD
>
> _______________________________________________
> 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-NA member? Join now to support the amateur satellite program!
> Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
------------------------------
Message: 7
Date: Sun, 28 Apr 2013 17:54:30 -0500
From: "Glenn A. Miller" <gamiller1@xxxxxxxxxx.xxx>
To: <amsat-bb@xxxxx.xxx>
Subject: [amsat-bb] Shack cleaning sale
Message-ID: <9DD67C3084E747D797E2E9009A648BA7@xxxxxxxxxx>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
reply-type=original
Icom AG-25 mast mount 2 meter preamp
Mirage KP-1/440 70 cm GaAsFET preamp
G-5500 control box and elevation rotor (no az rotor)
Alinco ELH-730D 70 cm linear amp (3W in for 30W out) w/preamp
Radio Shack 2 meter amp (Cat. # 19-1122)
Pix available. If interested, please contact me off list.
Glenn AA5PK
------------------------------
Message: 8
Date: Sun, 28 Apr 2013 20:29:08 -0400
From: Luc Leblanc <lucleblanc6@xxxxxxxxx.xx>
To: Amsat-bb@xxxxx.xxx
Subject: [amsat-bb] Re: Path to HEO
Message-ID: <517DBED4.22639.290EC6C@xxxxxxxxxxx.xxxxxxxxx.xx>
Content-Type: text/plain; CHARSET=US-ASCII
> Thanks,
>
> maybe I didn't make myself clear:
>
> 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.
>
> Stefan VE4NSA
>
On January 23 I was on UL mode with a DL and an Italian station i was just
testing my new L Band amp and it was my 802 QSO on AO-40 my last
one snif snif. The rest is old story who can be shared only with those guys
who enjoy one of the best AMSAT satellite.
For those who just start to flirt with satellite here is how the story end
On 25 January 2004, telemetry from the main battery was observed to go to an
extremely low voltage by Stacey Mills (amateur radio call sign
W4SM), a member of the Command Team. This caused the onboard Internal
Housekeeping Unit (IHU) computer to cut power to the transponder
payloads. Just prior to the loss of control of the satellite, the auxiliary
battery came online in parallel with the main battery. When the
main battery failed, it effectively short-circuited the auxiliary battery,
killing the spacecraft. Many attempts were made to disconnect
the main battery, but insufficient voltage was available to drive the
relays. One day an open-circuit failure may occur in the main
battery, in which case the spacecraft may come to life again. Though the
command team believe that the main battery failure was probably a
consequence of damage done during the event, and it is likely that similar
damage was done to the auxiliary battery, making an eventual
recovery of AO-40 unlikely.
What the story does not tell it is possible that a manual command was the
culprit here but all the folks who work on the AO-40 project are
also human and perfectible as you and me.
It is a refreshing breeze to start to hear HEO again so sorry for those who
pass by to the eternal DX cluster.
"-"
Luc Leblanc VE2DWE
Quebec provincial Hamfest HTTP://www.hamfest.qc.ca
DSTAR urcall VE2DWE
WAC BASIC CW PHONE SATELLITE
------------------------------
Message: 9
Date: Mon, 29 Apr 2013 00:51:03 -0400
From: "Daniel Schultz" <n8fgv@xxx.xxx>
To: <amsat-bb@xxxxx.xxx>
Subject: [amsat-bb] Re: Path to HEO
Message-ID: <696RDCeYD3024S04.1367211063@xxxxx.xxx.xxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1
>In addition, doesn't the process getting from GTO to HEO require some form
>of rapid acceleration? If yes, ion engines and solar sails are out.
The main requirement for escaping from LEO is that the engine thrust must
exceed the atmospheric drag force. The time required to reach a HEO orbit
mainly depends on how much electrical power you can generate, more power means
more thrust and a faster ride to the desired orbit. A Cubesat power budget
will be somewhat limited, deployable solar panels might help somewhat.
Most Cubesat launches are deliberately sent to low orbits to insure rapid
reentry and burn-up to meet orbital debris requirements, that is why Cubesat
launches to GTO are rare. A higher orbit will require a disposal plan, but
electric propulsion can help with that too. Please see my paper in the 2012
AMSAT Symposium Proceedings.
Dan Schultz N8FGV
------------------------------
Message: 10
Date: Mon, 29 Apr 2013 04:03:24 -0500
From: "Nick Pugh" <quadpugh@xxxxxxxxx.xxx>
To: "'James Duffey'" <jamesduffey@xxxxxxx.xxx>, "'Franklin Antonio'"
<antonio@xxx.xxxxxxxx.xxx>
Cc: Amsat-bb@xxxxx.xxxx Daniel Schultz <n8fgv@xxx.xxx>
Subject: [amsat-bb] Re: Path to HEO
Message-ID: <016901ce44b8$68ec4930$3ac4db90$@xxx>
Content-Type: text/plain; charset="us-ascii"
Hi James et all
Thanks for the very nice comments. Here are some additional thoughts
1. The Van Allen belt radiation might be our toughest challenge so
let think about an orbit 16000 KM
2. IF we were to put 3 sat up this would give us nice coverage and
longer operating time
3. There are flight heritage reaction wheels that consume < 2 watts
4. We a little luck we can start from 600 KM orbit
5. If we are really clever we might have a sat to sat relay to
extend time and range coverage.
nick
-----Original Message-----
From: James Duffey [mailto:jamesduffey@xxxxxxx.xxxx
Sent: Sunday, April 28, 2013 10:35 PM
To: Franklin Antonio
Cc: James Duffey; Nick Pugh; Amsat-bb@xxxxx.xxx
Subject: Re: [amsat-bb] Re: Path to HEO
Well I did a rough back of the envelope calculation for the time required to
accumulate the energy necessary to get from LEO to HEO, but there are a lot
of details that still need to be calculated. And the devil is in the
details. But this will get things started
The difference in orbital energy between a LEO and GEO is about 25 MJ/kg.
So, for a 10 kg nano sat, we would need to supply at least 250 MJ. Now I
suspect that when all is said and done, it cannot be done for that, but I
haven't done any detailed orbital transfer calculations.
OK, suppose we have Nick's 50 Watt solar panel, and lets also say that
initially half of that power can be put into propulsion, the other half
being needed for navigation, housekeeping, comm, and telemetry. You could
probably get away with more for propulsion.
So say we need to generate at least 250,000,000 (it is probably more) Joules
of energy to get from LEO to HEO. The solar panel can supply 25 Watts or 25
Joules per second. so it will take 10,000,000 seconds to generate the 250MJ
required.
Now the satellite is only illuminated for roughly half an orbit, so we need
to double the time to 20,000,000 seconds on orbit. Now there 31,536,000
seconds in a year, so it would take 231 days to accumulate the minimum
amount of energy to get to GEO.
Well, I neglected inefficiencies in the system, such as the ability of the
ion-thruster to convert electricity into thrust and how efficiently the
batteries or capacitors can be charged and store energy. I also ignored the
drag at lower latitudes, which may be considerable. I suppose that one could
only operate the thrusters while the spacecraft is illuminated and that
would eliminate the storage problem. Say the whole system is 50% efficient,
and I am guessing here, that would make it 462 days, or 15 months.
I suppose that whether or not that is a long time, depends on your point of
view. I'll bet if the transfer burn strategy is calculated it gets even
worse. Things seldom get better. You can't do a simple Hohmann transfer, but
would need to do multiple burns, or a continuous burn over the illuminated
part of the orbit. I suppose that would produce an orbit that is not really
circular at any given time but it might all average out over all the burns.
A constant burn may be more efficient in terms of energy use that a Hohmann;
I don't remember. I do remember that one wants to burn at apogee to get the
biggest bang for the buck, and I suspect that the illuminated portion of the
orbit is not always at apogee, so the energy will not be used efficiently.
Now a GEO orbit, while a desirable goal, is not necessarily what is needed
for amateur radio communication. Something short of GEO, and even elliptical
would still be useful and only require repointing of the antenna from day to
day, and perhaps hour to hour at Apogee. Orbits significantly higher than
LEO, but lower than GEO are also very useful. Compare for example the
available time per pass between ISS and AO-7, and for that matter the RS10,
11, 12 and 13 birds.
One would need to plan how to go through the Van Allen belts, as with such a
slow burn one would spend a lot of time where the radiation is high.
All of this is not meant to be a rigorous calculation, but rather just an
indication of whether it is reasonable, and if it is worth pursuing further.
It does to seem to be within the realm of possibly, and probably should be
pursued further, at least until a real show stopper shows up. - Duffey KK6MC
--
KK6MC
James Duffey
Cedar Crest NM
On Apr 28, 2013, at 3:34 PM, Franklin Antonio <antonio@xxx.xxxxxxxx.xxx>
wrote:
> At 11:14 AM 4/28/2013, Nick Pugh wrote:
>> I have just returned from a satellite conference and I think new
>> technology will now give us a path to HEO.
>
> I've thought for a long time that ion engines (small thrust pushing for a
long time, powered by electricity) could be of great value to us.
>
> Has anyone done the calculation to see how long it would take to go from
LEO to HEO with an achievable ion engine? This seems like the first thing
to calculate. If it takes less than 1 year, it seems worth serious
investigation.
>
> There are many other hurdles, of course, such as attitude control (keeping
solar panels pointed at the sun while at the same time keeping engine
pointed in the direction we want thrust, over a long period of time). The
schemes and compromises for these issues can be worked if the basic thrust
math works out.
>
> N6NKF
>
> _______________________________________________
> 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: Mon, 29 Apr 2013 13:24:54 +0100 (BST)
From: M5AKA <m5aka@xxxxx.xx.xx>
To: amsat-bb@xxxxx.xxx
Subject: [amsat-bb] Re: Path to HEO
Message-ID:
<1367238294.17905.YahooMailClassic@xxxxxxxxx.xxxx.xxx.xxxxx.xxx>
Content-Type: text/plain; charset=utf-8
--- On Mon, 29/4/13, Stefan Wagener <wageners@xxxxx.xxx> wrote:
> maybe I didn't make myself clear:
> 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.
Romit-1 and the other CubeSats testing ion engines will definitely give us
something - proof that it works in practice or an opportunity to learn from
any problems / design issues that arise.
Given that Space is a demanding environment I'm sure not all the ion motor
CubeSats currently being developed will work as planned when deployed, it'll
be a learning experience.
Going from a 310 to a 700 km orbit in a year using the limited solar power
generated from a standard 2U CubeSat will be a major step forward.
It follows that to get up to 7200 km or even better 20000 km will take years
but could be speeded up by having CubeSats with large fold-out solar panels
and more powerful motor.
I say CubeSats rather than Microsats because of cost, a 35 kg microsat could
cost $1 million just to get into LEO.
I hope the various groups that have developed ion motor CubeSats are
eventually successful is getting launches to LEO to test them out.
73 Trevor M5AKA
----
------------------------------
Message: 12
Date: Mon, 29 Apr 2013 09:29:04 -0700
From: David Palmer KB5WIA <kb5wia@xxxxx.xxx>
To: amsat-bb@xxxxx.xxx
Subject: [amsat-bb] Re: G5500 Rotor motor Question
Message-ID:
<CAO-vtPNiu-Fr9x0HAjMsXtVGzxXfckkkRL8FndqAqvvBMhB+XA@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1
Oh, I didn't measure the rotation speed of the motor during my rebuild,
unfortunately. In all the research I did prior to the rebuild (=scrambling
to find an equivalent motor) I didn't see any published specs on the unit
either. I'd think Domenico's calculations would probably be the closest,
since it is a simple 2-pole AC motor.
73! Dave KB5WIA
On Sun, Apr 28, 2013 at 2:31 PM, Gregory Beat <gregory.beat@xxxxxxx.xxx>wrote:
> You could ask Dave Palmer, KB5WIA if he noted that spec.,
> when he rebuilt his Yaesu motor last year (March 2012)
> http://kb5wia.blogspot.com/2012/03/yaesu-g5500-rotator-motor-repair.html
>
> w9gb
> ==
> From: "Mike Hoblinski"
> To: <amsat-bb@xxxxx.xxx>
> Subject: [amsat-bb] G5500 Rotor motor Question
>
> Anybody know what the rpm of the AC motors are. I know from the Yaesu
> specs that after all of the gear reduction they list EL as 67 seconds for
> EL
> and 58 Seconds for AZ.
>
------------------------------
Message: 13
Date: Mon, 29 Apr 2013 17:14:01 +0000
From: B J <va6bmj@xxxxx.xxx>
To: amsat-bb <amsat-bb@xxxxx.xxx>
Subject: [amsat-bb] Successful Powered Flight For SpaceShipTwo
Message-ID:
<CAP7QzkP_DEGExMtVDU24-6qcXKpv85tt1-5K9L0TeNkG=q0NHA@xxxx.xxxxx.xxx>
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http://www.newspacejournal.com/2013/04/29/spaceshiptwos-first-powered-flight-a
-success/
http://spacecoalition.com/blog/spaceshiptwo-en-route-for-projected-first-power
ed-flight
73s
Bernhard VA6BMJ @ DO33FL
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Message: 14
Date: Mon, 29 Apr 2013 17:20:55 +0000
From: B J <va6bmj@xxxxx.xxx>
To: amsat-bb <amsat-bb@xxxxx.xxx>
Subject: [amsat-bb] Observations From ESA's Herschel Observatory End
Message-ID:
<CAP7QzkMzfAxY9-W-mcM8XBmiMGSoVHr-X48FjUFL2kvasaNNgQ@xxxx.xxxxx.xxx>
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http://sci.esa.int/science-e/www/object/index.cfm?fobjectid=51550
73s
Bernhard VA6BMJ @ DO33FL
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Message: 15
Date: Mon, 29 Apr 2013 17:51:06 +0000
From: B J <va6bmj@xxxxx.xxx>
To: amsat-bb <amsat-bb@xxxxx.xxx>
Subject: [amsat-bb] More On SpaceShipTwo's Flight
Message-ID:
<CAP7QzkPXPRoT-BqYBKgZw54+ybhASQe_FBzv=9-bWThb6t6-3A@xxxx.xxxxx.xxx>
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http://www.parabolicarc.com/2013/04/29/pictures-of-spaceshiptwos-first-powered
-flight/
http://www.parabolicarc.com/2013/04/29/spaceshiptwo-completes-first-powered-fl
ight/
http://www.virgingalactic.com/news/item/virgin-galactic-breaks-speed-of-sound-
in-first-rocket-powered-flight-of-spaceshiptwo/
73s
Bernhard VA6BMJ @ DO33FL
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Message: 16
Date: Mon, 29 Apr 2013 13:27:31 -0500
From: <anelson@xxx.xxxxx.xxx>
To: <amsat-bb@xxxxx.xxx>
Subject: [amsat-bb] What birds
Message-ID: <72A71EA7E24144BE8E1BE4991FC320FD@xxxxx>
Content-Type: text/plain; charset="iso-8859-1"
Thanks to everyone that answered. Hope to work you on one of them
one of these days.
Thanks again
Nels W0TUP
North Dakota
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End of AMSAT-BB Digest, Vol 8, Issue 136
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