Serious question regarding satellite durability. It seems with HO68, SO67, and now AO51, the FM satellites are quickly going away. It also seems that the older linear counterparts such as AO7, VO52 and FO29 all seem to continue working properly.
Is there a design issue with the FM birds that limits the useful lifespan or is it purely random luck? Usage rates, etc... play a role?
It seems to happen far too often (even with a small sample size) to be a fluke.
Zach N4ERZ
Zach,
Good question. Part of the answer depends on your definitions of "working properly," and "quickly."
HO-68 and SO-67 have gone away quickly, that is within about a year of launch. By comparison, AO-51 was launched in 2004, with many years of service. AO-7 was dead for a couple of decades before returning to life, albeit with a bit of senility. FO-29 has periods of outages. AO-27, an FM bird launched almost 20 years ago, remains quirky in scheduling but popular. SO-50, 10 years old, also gets much use.
When you look at them all, there isn't much correlation between the type satellite and lifetime. Issues such as the technology used, and the orbit, are much bigger issues. And as always, Murphy gets the last laugh.
73s,
Alan WA4SCA
-----Original Message----- From: amsat-bb-bounces@amsat.org [mailto:amsat-bb-bounces@amsat.org] On Behalf Of zach hillerson Sent: Tuesday, November 29, 2011 9:49 AM To: amsat-bb@amsat.org Subject: [amsat-bb] satellite durability fm vs. linears
Serious question regarding satellite durability. It seems with HO68, SO67, and now AO51, the FM satellites are quickly going away. It also seems that the older linear counterparts such as AO7, VO52 and FO29 all seem to continue working properly.
Is there a design issue with the FM birds that limits the useful lifespan or is it purely random luck? Usage rates, etc... play a role?
It seems to happen far too often (even with a small sample size) to be a fluke.
Zach N4ERZ _______________________________________________ Sent via AMSAT-BB@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
----- Original Message ----- From: "zach hillerson" qstick333@yahoo.com To: amsat-bb@amsat.org Sent: Tuesday, November 29, 2011 4:48 PM Subject: [amsat-bb] satellite durability fm vs. linears
Serious question regarding satellite durability. It seems with HO68, SO67, and now AO51, the FM satellites are quickly going away. It also seems that the older linear counterparts such as AO7, VO52 and FO29 all seem to continue working properly.
Zach N4ERZ
Hi Zach, N4EZR
You are right,the FM satellites are going away but the older linears continue to work very well and particularly VO52 but there are no many users on VO52 at most three or four stations when the bird is over North of Europe and nobody when the bird is over North Africa.
Yesterday on the ascending orbit Nr 35527 I was in contact with IW6OVD chatting in SSB for 12 minutes only with him the full orbit like on the telephone.
IW6OVD posted a mp3 file of the above QSO at the following address:
http://hamradio.selfip.com/iw6ovd/VO-52.mp3
If you haven't worked either of these three historic satellites,AO7 VO52 (and FO29 when is active) do it NOW!
73" de
i8CVS Domenico
The thing I've been wondering (and this is in no way accusatory, just a question out of curiosity) is why we didn't build the IHU's with NVRAM and a circuit to cut the batteries completely out of the loop. Since the cell failure seems inevitable, it would only make sense to design the satellites in a way that they can work without the batteries when the batteries do fail.
In my humble opinion, I think DO-64 was genius. It happened to fail for another reason, but it was an interesting concept. Their telemetry program was pretty neat too.
On Tue, Nov 29, 2011 at 3:10 PM, i8cvs domenico.i8cvs@tin.it wrote:
----- Original Message ----- From: "zach hillerson" qstick333@yahoo.com To: amsat-bb@amsat.org Sent: Tuesday, November 29, 2011 4:48 PM Subject: [amsat-bb] satellite durability fm vs. linears
Serious question regarding satellite durability. It seems with HO68, SO67, and now AO51, the FM satellites are quickly going away. It also seems that the older linear counterparts such as AO7, VO52 and FO29 all seem to continue working properly.
Zach N4ERZ
Hi Zach, N4EZR
You are right,the FM satellites are going away but the older linears continue to work very well and particularly VO52 but there are no many users on VO52 at most three or four stations when the bird is over North of Europe and nobody when the bird is over North Africa.
Yesterday on the ascending orbit Nr 35527 I was in contact with IW6OVD chatting in SSB for 12 minutes only with him the full orbit like on the telephone.
IW6OVD posted a mp3 file of the above QSO at the following address:
http://hamradio.selfip.com/iw6ovd/VO-52.mp3
If you haven't worked either of these three historic satellites,AO7 VO52 (and FO29 when is active) do it NOW!
73" de
i8CVS Domenico
Sent via AMSAT-BB@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
Would now be a good time to mention that Fox-1 is designed to operate while illuminated, even after a battery failure?
73, Jerry N0JY
On 11/29/2011 5:36 PM, Andrew Koenig wrote:
The thing I've been wondering (and this is in no way accusatory, just a question out of curiosity) is why we didn't build the IHU's with NVRAM and a circuit to cut the batteries completely out of the loop. Since the cell failure seems inevitable, it would only make sense to design the satellites in a way that they can work without the batteries when the batteries do fail.
participants (5)
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Alan P. Biddle -
Andrew Koenig -
i8cvs -
N0JY -
zach hillerson