There is no reason to stabilize a satellite after it is boosted to the graveyard orbit. The satellite might have power and be easy to track, but the antennas won't point towards earth very often.
Wayne Estes W9AE Oakland, Oregon, USA, CN83ik
Furthermore, from what I understand, international agreements (or at least implicit agreements) now require the operators to vent any remaining fuel. This is to prevent the satellite from exploding at some point in the future due to either the (rather caustic) fuel corroding through the fuel tank, or a debris/micrometeorite hit.
Once this is complete, the operators will then permanently shut down the satellite so that there is no chance of it interfering with the operational fleet. The last thing they want is a semi-active satellite drifting past an operational satellite (at least from the POV of the earth station) and potentially confusing tracking antennas, or otherwise interfering with revenue traffic.
As far as shifting them to amateur frequencies, I doubt it's physically possible. In order to get the Tx/Rx isolation they need, the satellites will be using cavity filters, so unless you're very close to their passband, there's no hope. Heck, in my day job, we have to use different filters if we want to operate in extended ku-band filters.
Regards,
Hans Johnson VA7HAS
On Thu, Mar 12, 2009 at 3:52 PM, Wayne Estes [email protected] wrote:
There is no reason to stabilize a satellite after it is boosted to the graveyard orbit. The satellite might have power and be easy to track, but the antennas won't point towards earth very often.
Wayne Estes W9AE Oakland, Oregon, USA, CN83ik
Sent via [email protected]. 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
I was reading about the newly launched GOCE satellite and the fact that its mission will end when its 40kg tank empties - that of course may be a long time coming but as it has an S band transmitter, could this not be tweaked for us once the mission is complete?
And thinking further, for these satellites could amateur radio gear be carried so that it could be activated once the main mission is complete? Doing this over a number of years would provide a ready made supply of new birds over a period of time.
I suppose logistics and cost will be the factor but its an idea and would give us at least something!
It is possible to piggyback on a commercial satellite. The Russians did it with several successful RS amateur radio satellites.
The Amateur radio satellite community should try to focus more in Piggyback satellite rides for our future satellites. We should avoid the stuff we that we do not know how to build such as rocket motors and stability systems. And focus on what we do best and that is build “Simple / KISS” transponders.
If there is a well-funded university out here interested in going to the Moon, we can piggyback an amateur radio project on one of the new Moon landers that NASA is planing on flying. Let NASA do the hard stuff and we should focus on a simple mode b/j transponders.
Who wants to go to the Moon?
Miles WF1F Marexmg.org
--- On Tue, 3/17/09, David - KG4ZLB [email protected] wrote:
From: David - KG4ZLB [email protected] Subject: [amsat-bb] Re: old satellites To: "Hans Johnson" [email protected] Cc: [email protected] Date: Tuesday, March 17, 2009, 1:28 PM I was reading about the newly launched GOCE satellite and the fact that its mission will end when its 40kg tank empties - that of course may be a long time coming but as it has an S band transmitter, could this not be tweaked for us once the mission is complete?
And thinking further, for these satellites could amateur radio gear be carried so that it could be activated once the main mission is complete? Doing this over a number of years would provide a ready made supply of new birds over a period of time.
I suppose logistics and cost will be the factor but its an idea and would give us at least something!
-- David KG4ZLB www.kg4zlb.com
Hans Johnson wrote:
Furthermore, from what I understand, international
agreements (or at least
implicit agreements) now require the operators to vent
any remaining fuel.
This is to prevent the satellite from exploding at
some point in the future
due to either the (rather caustic) fuel corroding
through the fuel tank, or
a debris/micrometeorite hit.
Once this is complete, the operators will then
permanently shut down the
satellite so that there is no chance of it interfering
with the operational
fleet. The last thing they want is a semi-active
satellite drifting past an
operational satellite (at least from the POV of the
earth station) and
potentially confusing tracking antennas, or otherwise
interfering with
revenue traffic.
As far as shifting them to amateur frequencies, I
doubt it's physically
possible. In order to get the Tx/Rx isolation they
need, the satellites
will be using cavity filters, so unless you're
very close to their passband,
there's no hope. Heck, in my day job, we have to
use different filters if
we want to operate in extended ku-band filters.
Regards,
Hans Johnson VA7HAS
On Thu, Mar 12, 2009 at 3:52 PM, Wayne Estes
[email protected] wrote:
Sent via [email protected]. 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
clever thinking Dave. There some "experts" on this BB that know the answer 73 Bob W7LRD
----- Original Message -----
From: David - KG4ZLB
To: Hans Johnson
Sent: Tue, 17 Mar 2009 17:28:00 +0000 (UTC)
Subject: [amsat-bb] Re: old satellites
I was reading about the newly launched GOCE satellite and the fact that
its mission will end when its 40kg tank empties - that of course may be
a long time coming but as it has an S band transmitter, could this not
be tweaked for us once the mission is complete?
And thinking further, for these satellites could amateur radio gear be
carried so that it could be activated once the main mission is complete?
Doing this over a number of years would provide a ready made supply of
new birds over a period of time.
I suppose logistics and cost will be the factor but its an idea and
would give us at least something!
If they can afford to carry a kilo of amateur radio gear then they could have carried an extra kilo of fuel and extended the useful lifetime. You're not onto a winner there.
[email protected] wrote:
clever thinking Dave. There some "experts" on this BB that know the answer 73 Bob W7LRD
----- Original Message -----
From: David - KG4ZLB
To: Hans Johnson
Sent: Tue, 17 Mar 2009 17:28:00 +0000 (UTC)
Subject: [amsat-bb] Re: old satellites
I was reading about the newly launched GOCE satellite and the fact that
its mission will end when its 40kg tank empties - that of course may be
a long time coming but as it has an S band transmitter, could this not
be tweaked for us once the mission is complete?
And thinking further, for these satellites could amateur radio gear be
carried so that it could be activated once the main mission is complete?
Doing this over a number of years would provide a ready made supply of
new birds over a period of time.
I suppose logistics and cost will be the factor but its an idea and
would give us at least something!
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participants (6)
-
David - KG4ZLB -
Hans Johnson -
MM -
Nigel Gunn G8IFF/W8IFF -
w7lrd＠comcast.net -
Wayne Estes