What is the specific Impulse?
On Thursday, September 5, 2013, Samudra Haque wrote:
Hello,
Perhaps my recent work may stimulate discussion in this thread, though it
has not been proven in Space yet, but ...
my George Washington University MAE dept. micropropulsion subsystems for
small
Hello,
Perhaps my recent work may stimulate discussion in this thread, though it
has not been proven in Space yet, but ...
my George Washington University MAE dept. micropropulsion subsystems for
small spacecraft was highlighted in the September 3 issue of the School of
Engineering and Applied
Can't remember if the links on the work of N1BCD were posted earlier:
Video of presentation at
http://www.ustream.tv/recorded/22959312/highlight/267762
Slides
http://icubesat.files.wordpress.com/2012/06/icubesat-org-2012-c-1-1-_presentation_brandon_201205231623.pdf
IARU Coordination
schrieb Ken Ernandes on 2013-04-30 09:49:
I note the disclaimer at the bottom, so I'll help with the incorrect
assumptions.
1. g = 9.81 m/sec only applies to one Earth radius (i.e., the Earth's
surface). Gravitational acceleration drops of as an inverse square of the
radius.
2. GEO
--- On Tue, 30/4/13, g0...@aol.com g0...@aol.com wrote:
A compromise could be 4 Watts (ish) from MEO.
Here's an oldie but goodie. http://www.g0mrf.com/MEOSAT.htm
Yes MEO would be good. It should be possible to improve the signal levels while
keeping omni-directional antennas on the
--- On Tue, 30/4/13, Nick Pugh quadp...@bellsouth.net wrote:
Both Pumpkin and ISSIS say they have flight heritage on
50 watt panels. EaLanta has rides to 600 KM
50 watts on a CubeSat ? That surprises me, I don't know of any that have flown
so far that have generated more than about 6 watts
Thinking way outside the box, what about some sort of phased array using
dipoles, which has the boresight synthesized to point at earth. In other
words, don't use fuel to reorient the bird, electronically steer the
phase of the antennas so that earth is in focus.
--
Joe Leikhim
Leikhim and
- Original Message -
From: g0...@aol.com
To: n...@mwt.net, glasbren...@mindspring.com, amsat-bb@amsat.org
Sent: Tuesday, April 30, 2013 1:35:08 PM
Subject: [amsat-bb] Re: Path to HEO
Hi all.
Deployable gain antennas are possible, but unfortunately attitude
control is a real issue. If the orbit
Then fire to the rear forcing the little satellite faster
Yeah, but the control, er safety, folks won't give us enough mass out
the ass to propel us forward ... can't have a clip with 30 pretty
soon!
--
73 de JoAnne K9JKM
___
Sent via
I'll throw this one out there though I'm sure some of you already know
about it. Rocket Propulsion Elements is a pretty good book on the basics
of rocket propulsion. I've dabbled in it a few times but do plan on a more
comprehensive study (I'm an EE and actual coursework takes precedence over
-Original Message-
From: amsat-bb-boun...@amsat.org [mailto:amsat-bb-boun...@amsat.org] On
Behalf Of Patrick Strasser
Sent: Monday, April 29, 2013 2:50 PM
To: Amsat-bb@amsat.org
Subject: [amsat-bb] Re: Path to HEO
:
In the end, it seems that changing from LEO to GEO or HEO is possible
--- On Tue, 30/4/13, Stefan Wagener wagen...@gmail.com 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
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?
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 n...@lavabit.com 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
--- On Tue, 30/4/13, Nick Pugh quadp...@bellsouth.net wrote:
From the comments HEO is challenging but doable. So let's
get started.
But Nick it is already started, several groups have already developed CubeSat
ion motors.
The fact that, as far as I'm aware, none of the groups that have
On the Outside? :-)
just like 90% of the earlier birds they are rolled or folded up until
after deployment. IIRC: one of the first actually did use a rolled up
tame measure for the elements.
Joe WB9SBD
Sig
The Original Rolling Ball Clock
Idle Tyme
Idle-Tyme.com
http://www.idle-tyme.com
On
@amsat.org
Sent: Tue, 30 Apr 2013 17:18
Subject: [amsat-bb] Re: Path to HEO
On the Outside? :-)
just like 90% of the earlier birds they are rolled or folded up until
after deployment. IIRC: one of the first actually did use a rolled up
tame measure for the elements.
Joe WB9SBD
Sig
The Original
If the solar panels are on 1 end that could be the back side of a patch
antenna or reflectors for a Yagi. A 3U gives us about 12 inches in one
plane. We will have reaction wheels to do pointing. Both Pumpkin and ISSIS
say they have flight heritage on 50 watt panels. EaLanta has rides to 600
KM
[mailto:jamesduf...@comcast.net]
Sent: Sunday, April 28, 2013 10:35 PM
To: Franklin Antonio
Cc: James Duffey; Nick Pugh; Amsat-bb@amsat.org
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
--- On Mon, 29/4/13, Stefan Wagener wagen...@gmail.com wrote:
maybe I didn't make myself clear:
LEO (low earth orbit) from 400 to 2000km or something like that
HEO (high earth orbit) 2km
Going from 310 to 700km in a year is not doing us anything.
Romit-1 and the other CubeSats testing
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 2km.
On Mon, Apr 29, 2013 at 1:34 PM, Robert Bruninga bruni...@usna.edu wrote:
Going from 310 to 700km in a year is not
Going from 310 to 700km in a year is not doing us anything.
Im not following this closely, but that statement misses the most
important reason for doing this...
*to*stay*in*orbit!
The lifetime of a cubesat at 310km is only a few weeks at most. The life
time at 700km is tens of years.
The
--- On Mon, 29/4/13, Stefan Wagener wagen...@gmail.com 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 2km.
It's the same thing, what gets you from 310 to 700 km can
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
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
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) 2km
Going from 310 to 700km in a year is not doing us anything. We need a
highly elliptical orbit (Apogee ~6km, Perigee 900km) similar to AO-40
to
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.
___
Sent via
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
Sign me up. Sounds like the next big thing.
73 de Norm n3ykf
On Sun, Apr 28, 2013 at 2:14 PM, Nick Pugh quadp...@bellsouth.net wrote:
I have just returned from a satellite conference and I think new technology
will now give us a path to HEO. Challenging of course but for the clever
doable.
Great Job!73 to all. George, W1GMA.QTH about 20 south west of the Roger
Williams Park Zoo.
-Original Message-
From: Lizeth Norman
Sent: Sunday, April 28, 2013 2:35 PM
To: Nick Pugh
Cc: Amsat-bb@amsat.org
Subject: [amsat-bb] Re: Path to HEO
Sign me up. Sounds like the next big thing
Ditto; here, sounds like an promising direction.
--
Joe Leikhim
Leikhim and Associates
Communications Consultants
Oviedo, Florida
jleik...@leikhim.com
407-982-0446
WWW.LEIKHIM.COM
___
Sent via AMSAT-BB@amsat.org. Opinions expressed are those of
, W1GMA.QTH about 20 south west of the Roger
Williams Park Zoo.
-Original Message- From: Lizeth Norman
Sent: Sunday, April 28, 2013 2:35 PM
To: Nick Pugh
Cc: Amsat-bb@amsat.org
Subject: [amsat-bb] Re: Path to HEO
Sign me up. Sounds like the next big thing.
73 de Norm n3ykf
On Sun
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
--- On Sun, 28/4/13, Stefan Wagener wagen...@gmail.com wrote:
I always thought that to get to a suitable HEO you need to start at a
suitable GTO and not LEO.
There's no reason why you couldn't go from a 310 km LEO orbit, it just takes
time.
Romit-1 is a 2U CubeSat developed by Euroluna
Thanks,
maybe I didn't make myself clear:
LEO (low earth orbit) from 400 to 2000km or something like that
HEO (high earth orbit) 2km
Going from 310 to 700km in a year is not doing us anything. We need a
highly elliptical orbit (Apogee ~6km, Perigee 900km) similar to AO-40
to allow for
: [amsat-bb] Re: Path to HEO
I always thought that to get to a suitable HEO you need to start at a
suitable GTO and not LEO.
I guess they forgot to mention that at the conference? So it doesn't
matter
what the propulsion is unless you start at the right orbit it is not of
much use. Getting to GTO
Thanks,
maybe I didn't make myself clear:
LEO (low earth orbit) from 400 to 2000km or something like that
HEO (high earth orbit) 2km
Going from 310 to 700km in a year is not doing us anything. We need a
highly elliptical orbit (Apogee ~6km, Perigee 900km) similar to AO-40
to
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
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
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