Probably a dumb question and still new to this - apologies in advance. Am I right in thinking the amateur sats switch comms off when not in sight of the sun? Are there any that continue to run in darkness?
Best,
Dominic G6NQO
Hi Dominic,
It's a great question!
If the satellite has batteries that can keep the communications payload ON, the satellite can continue to support communications during an eclipse (what we call the time spent in darkness).
Some satellites do not have batteries, so they will support communications only when in the sun (DO-64 for example).
IO-26 has batteries that are pretty old--yet it continues to operate through pretty long (20 mins or more) of eclipse each orbit. So yes, there are examples where the transmitters work through eclipse (IO-26, VO-52, etc.).
For AO-51, it's all about power management--both by the bird and by the command stations. Right now, AO-51 sees sun all the time. Around January 1, it will begin to experience ecslipses again. Its batteries have lost much of their capacity, and we expect that there will be enough power to keep the computer alive during eclipses, but the transmitters will need to be shut OFF. The computer and software onboard AO-51 help do that automatically (for the most part).
Hope that helps!
73,
Mark N8MH
On Fri, Nov 19, 2010 at 8:29 AM, Dominic Hawken dominic@del.co.uk wrote:
Probably a dumb question and still new to this - apologies in advance. Am I right in thinking the amateur sats switch comms off when not in sight of the sun? Are there any that continue to run in darkness?
Best,
Dominic G6NQO
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
Hi Mark,
I remember a while ago you mentioned that it may be possible to reconfigure IO-26 to be used like LO-16? Was I seeing things or was this a true and has any progress been made on this?
Thanks, Chris
-----Original Message----- From: amsat-bb-bounces@amsat.org [mailto:amsat-bb-bounces@amsat.org] On Behalf Of Mark L. Hammond Sent: 19 November 2010 13:55 To: Dominic Hawken Cc: amsat-bb@amsat.org Subject: [amsat-bb] Re: Sats after dark
Hi Dominic,
It's a great question!
If the satellite has batteries that can keep the communications payload ON, the satellite can continue to support communications during an eclipse (what we call the time spent in darkness).
Some satellites do not have batteries, so they will support communications only when in the sun (DO-64 for example).
IO-26 has batteries that are pretty old--yet it continues to operate through pretty long (20 mins or more) of eclipse each orbit. So yes, there are examples where the transmitters work through eclipse (IO-26, VO-52, etc.).
For AO-51, it's all about power management--both by the bird and by the command stations. Right now, AO-51 sees sun all the time. Around January 1, it will begin to experience ecslipses again. Its batteries have lost much of their capacity, and we expect that there will be enough power to keep the computer alive during eclipses, but the transmitters will need to be shut OFF. The computer and software onboard AO-51 help do that automatically (for the most part).
Hope that helps!
73,
Mark N8MH
On Fri, Nov 19, 2010 at 8:29 AM, Dominic Hawken dominic@del.co.uk wrote:
Probably a dumb question and still new to this - apologies in advance. Am I right in thinking the amateur sats switch comms off when not in sight of the sun? Are there any that continue to run in darkness?
Best,
Dominic G6NQO
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
-- Mark L. Hammond [N8MH] _______________________________________________ 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
Hi Chris,
You have a great memory :)
We had hoped that with some experimenting that we could configure IO-26 into a "bent-pipe FM/SSB repeater" like we did with AO-16. Thus far, I haven't been successful. It is likely that the hardware isn't in place to permit this. We haven't completely abandoned the idea, but our best guess attempts at making it work haven't work out. It may be something we can again attempt over the holidays (between Thanksgiving and New Years) when we are on holiday with some extra hours in the shack!
Last weekend I turned AO-16 on; it stayed up for about 30 secs--not long enough to be useful.
Glad you asked.
73,
Mark N8MH
On Fri, Nov 19, 2010 at 9:34 AM, Chris Bloy chris@photofuture.co.uk wrote:
Hi Mark,
I remember a while ago you mentioned that it may be possible to reconfigure IO-26 to be used like LO-16? Was I seeing things or was this a true and has any progress been made on this?
Thanks, Chris
-----Original Message----- From: amsat-bb-bounces@amsat.org [mailto:amsat-bb-bounces@amsat.org] On Behalf Of Mark L. Hammond Sent: 19 November 2010 13:55 To: Dominic Hawken Cc: amsat-bb@amsat.org Subject: [amsat-bb] Re: Sats after dark
Hi Dominic,
It's a great question!
If the satellite has batteries that can keep the communications payload ON, the satellite can continue to support communications during an eclipse (what we call the time spent in darkness).
Some satellites do not have batteries, so they will support communications only when in the sun (DO-64 for example).
IO-26 has batteries that are pretty old--yet it continues to operate through pretty long (20 mins or more) of eclipse each orbit. So yes, there are examples where the transmitters work through eclipse (IO-26, VO-52, etc.).
For AO-51, it's all about power management--both by the bird and by the command stations. Right now, AO-51 sees sun all the time. Around January 1, it will begin to experience ecslipses again. Its batteries have lost much of their capacity, and we expect that there will be enough power to keep the computer alive during eclipses, but the transmitters will need to be shut OFF. The computer and software onboard AO-51 help do that automatically (for the most part).
Hope that helps!
73,
Mark N8MH
On Fri, Nov 19, 2010 at 8:29 AM, Dominic Hawken dominic@del.co.uk wrote:
Probably a dumb question and still new to this - apologies in advance. Am I right in thinking the amateur sats switch comms off when not in sight of the sun? Are there any that continue to run in darkness?
Best,
Dominic G6NQO
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
-- Mark L. Hammond [N8MH] _______________________________________________ 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
Dominic,
Welcome! Actually, most satellites start out operating continuously. They run on batteries when they are in the dark. Normally the batteries over time lose capacity. Then, various techniques are implemented to conserve power so that they can continue to operate when in darkness. Recently there have been a few satellites designed to operate only when illuminated, such as DO-64. Generally the ones which require illumination are old satellites such as AO-7 and NO-44 which no longer have functioning batteries or control systems. Fortunately satellites are usually, but not always, illuminated even when the area below is dark.
Alan WA4SCA
-----Original Message----- From: amsat-bb-bounces@amsat.org [mailto:amsat-bb-bounces@amsat.org] On Behalf Of Dominic Hawken Sent: Friday, November 19, 2010 7:29 AM To: amsat-bb@amsat.org Subject: [amsat-bb] Sats after dark
Probably a dumb question and still new to this - apologies in advance. Am I right in thinking the amateur sats switch comms off when not in sight of the sun? Are there any that continue to run in darkness?
Best,
Dominic G6NQO
_______________________________________________ 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
participants (4)
-
Alan P. Biddle -
Chris Bloy -
Dominic Hawken -
Mark L. Hammond