Now I see looking at SatPC32 that it shows AO-7 in the 99,625 range in orbit count. If memory serves me right though, doesn't the TLE orbit count roll over at 99,999 (Just like a car odometer), so that would mean that we would be coming up to the 200,000th rev is that right? If I am right, then this will be coming up in less than a month. Does anybody know exactly when that will be? I am doing a presentation for a local club and would like to throw out that fact if I could. Also the day of that event would be good AO-7 operating day I would think.
73
Tom Schuessler, N5HYP EM12ms
Tom,
According to the Keps, AO-7 makes 12.54 orbits per day. It will hit 99999 on the 30th or so. You can use the Preview function to find out exactly when.
73,
Alan WA4SCA
<-----Original Message----- <From: AMSAT-BB [mailto:[email protected]] On Behalf Of <[email protected] <Sent: Sunday, July 01, 2018 23:56 PM <To: 'AMSAT BB' [email protected] <Subject: [amsat-bb] AO-7 orbit count. < <Now I see looking at SatPC32 that it shows AO-7 in the 99,625 range in orbit <count. If memory serves me right though, doesn't the TLE orbit count roll <over at 99,999 (Just like a car odometer), so that would mean that we would <be coming up to the 200,000th rev is that right? If I am right, then this <will be coming up in less than a month. Does anybody know exactly when that <will be? I am doing a presentation for a local club and would like to throw <out that fact if I could. Also the day of that event would be good AO-7 <operating day I would think. < <73 < <Tom Schuessler, N5HYP <EM12ms < < < <_______________________________________________ <Sent via [email protected]. AMSAT-NA makes this open forum available <to all interested persons worldwide without requiring membership. Opinions <expressed <are solely those of the author, and do not reflect the official views of AMSAT- <NA. <Not an AMSAT-NA member? Join now to support the amateur satellite <program! <Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
12.5×365×45 equals 205,312..5. Based on that you think it had Brolley a diameter the second time already but it might have been hiring slower when originally launched.
Sent from my iPhone
On Jul 2, 2018, at 02:47, Alan [email protected] wrote:
Tom,
According to the Keps, AO-7 makes 12.54 orbits per day. It will hit 99999 on the 30th or so. You can use the Preview function to find out exactly when.
73,
Alan WA4SCA
<-----Original Message----- <From: AMSAT-BB [mailto:[email protected]] On Behalf Of <[email protected] <Sent: Sunday, July 01, 2018 23:56 PM <To: 'AMSAT BB' [email protected] <Subject: [amsat-bb] AO-7 orbit count. < <Now I see looking at SatPC32 that it shows AO-7 in the 99,625 range in orbit <count. If memory serves me right though, doesn't the TLE orbit count roll <over at 99,999 (Just like a car odometer), so that would mean that we would <be coming up to the 200,000th rev is that right? If I am right, then this <will be coming up in less than a month. Does anybody know exactly when that <will be? I am doing a presentation for a local club and would like to throw <out that fact if I could. Also the day of that event would be good AO-7 <operating day I would think. < <73 < <Tom Schuessler, N5HYP <EM12ms < < < <_______________________________________________ <Sent via [email protected]. AMSAT-NA makes this open forum available <to all interested persons worldwide without requiring membership. Opinions <expressed <are solely those of the author, and do not reflect the official views of AMSAT- <NA. <Not an AMSAT-NA member? Join now to support the amateur satellite <program! <Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Tom,
AO-7 was launched on November 14, 1974, that's 15,935 days ago. Multiplying 15,935 by it's current mean motion of 12.53633150 revs/day gets you 199,766 orbits. The orbit number is currently 99,630, so there is a bit of error there. The mean motion should have very slightly decreased over the past 43 years as the minimal atmospheric drag ever so slightly slows it down.
73,
Paul, N8HM
On Mon, Jul 2, 2018 at 10:03 AM, Tom Schuessler [email protected] wrote:
12.5×365×45 equals 205,312..5. Based on that you think it had Brolley a diameter the second time already but it might have been hiring slower when originally launched.
Sent from my iPhone
On Jul 2, 2018, at 02:47, Alan [email protected] wrote:
Tom,
According to the Keps, AO-7 makes 12.54 orbits per day. It will hit
99999
on the 30th or so. You can use the Preview function to find out exactly when.
73,
Alan WA4SCA
<-----Original Message----- <From: AMSAT-BB [mailto:[email protected]] On Behalf Of <[email protected] <Sent: Sunday, July 01, 2018 23:56 PM <To: 'AMSAT BB' [email protected] <Subject: [amsat-bb] AO-7 orbit count. < <Now I see looking at SatPC32 that it shows AO-7 in the 99,625 range in orbit <count. If memory serves me right though, doesn't the TLE orbit count
roll
<over at 99,999 (Just like a car odometer), so that would mean that we
would
<be coming up to the 200,000th rev is that right? If I am right, then
this
<will be coming up in less than a month. Does anybody know exactly when that <will be? I am doing a presentation for a local club and would like to throw <out that fact if I could. Also the day of that event would be good AO-7 <operating day I would think. < <73 < <Tom Schuessler, N5HYP <EM12ms < < < <_______________________________________________ <Sent via [email protected]. AMSAT-NA makes this open forum available <to all interested persons worldwide without requiring membership.
Opinions
<expressed <are solely those of the author, and do not reflect the official views of AMSAT- <NA. <Not an AMSAT-NA member? Join now to support the amateur satellite <program! <Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Tom,
It has in fact turned over once already.
73,
Alan WA4SCA
Sent from my Waring blender.
<-----Original Message----- <From: Tom Schuessler [mailto:[email protected]] <Sent: Monday, July 02, 2018 09:03 AM <To: [email protected] <Cc: AMSAT BB [email protected] <Subject: Re: [amsat-bb] AO-7 orbit count. < <12.5×365×45 equals 205,312..5. Based on that you think it had Brolley a <diameter the second time already but it might have been hiring slower when <originally launched. < <Sent from my iPhone < <> On Jul 2, 2018, at 02:47, Alan [email protected] wrote: <> <> Tom, <> <> According to the Keps, AO-7 makes 12.54 orbits per day. It will hit 99999 <> on the 30th or so. You can use the Preview function to find out exactly <> when. <> <> 73, <> <> Alan <> WA4SCA <> <> <> <-----Original Message----- <> <From: AMSAT-BB [mailto:[email protected]] On Behalf Of <> <[email protected] <> <Sent: Sunday, July 01, 2018 23:56 PM <> <To: 'AMSAT BB' [email protected] <> <Subject: [amsat-bb] AO-7 orbit count. <> < <> <Now I see looking at SatPC32 that it shows AO-7 in the 99,625 range in <> orbit <> <count. If memory serves me right though, doesn't the TLE orbit count roll <> <over at 99,999 (Just like a car odometer), so that would mean that we <would <> <be coming up to the 200,000th rev is that right? If I am right, then this <> <will be coming up in less than a month. Does anybody know exactly when <> that <> <will be? I am doing a presentation for a local club and would like to <> throw <> <out that fact if I could. Also the day of that event would be good AO-7 <> <operating day I would think. <> < <> <73 <> < <> <Tom Schuessler, N5HYP <> <EM12ms <> < <> < <> < <> <_______________________________________________ <> <Sent via [email protected]. AMSAT-NA makes this open forum <available <> <to all interested persons worldwide without requiring membership. <Opinions <> <expressed <> <are solely those of the author, and do not reflect the official views of <> AMSAT- <> <NA. <> <Not an AMSAT-NA member? Join now to support the amateur satellite <> <program! <> <Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb <>
Hi Alan,
Other shoe, please? What happened to the world's prediction software (if, indeed, we even had any back then) when it rolled over? What is expected this time?
We survived Y2K, but did we learn anything from it?
Greg KO6TH
Alan wrote:
Tom,
It has in fact turned over once already.
73,
Alan WA4SCA
Sent from my Waring blender.
<-----Original Message----- <From: Tom Schuessler [mailto:[email protected]] <Sent: Monday, July 02, 2018 09:03 AM <To: [email protected] <Cc: AMSAT BB [email protected] <Subject: Re: [amsat-bb] AO-7 orbit count. < <12.5×365×45 equals 205,312..5. Based on that you think it had Brolley a <diameter the second time already but it might have been hiring slower when <originally launched. < <Sent from my iPhone < <> On Jul 2, 2018, at 02:47, Alan [email protected] wrote: <> <> Tom, <> <> According to the Keps, AO-7 makes 12.54 orbits per day. It will hit 99999 <> on the 30th or so. You can use the Preview function to find out exactly <> when. <> <> 73, <> <> Alan <> WA4SCA <> <> <> <-----Original Message----- <> <From: AMSAT-BB [mailto:[email protected]] On Behalf Of <> <[email protected] <> <Sent: Sunday, July 01, 2018 23:56 PM <> <To: 'AMSAT BB' [email protected] <> <Subject: [amsat-bb] AO-7 orbit count. <> < <> <Now I see looking at SatPC32 that it shows AO-7 in the 99,625 range in <> orbit <> <count. If memory serves me right though, doesn't the TLE orbit count roll <> <over at 99,999 (Just like a car odometer), so that would mean that we <would <> <be coming up to the 200,000th rev is that right? If I am right, then this <> <will be coming up in less than a month. Does anybody know exactly when <> that <> <will be? I am doing a presentation for a local club and would like to <> throw <> <out that fact if I could. Also the day of that event would be good AO-7 <> <operating day I would think. <> < <> <73 <> < <> <Tom Schuessler, N5HYP <> <EM12ms <> < <> < <> < <> <_______________________________________________ <> <Sent via [email protected]. AMSAT-NA makes this open forum <available <> <to all interested persons worldwide without requiring membership. <Opinions <> <expressed <> <are solely those of the author, and do not reflect the official views of <> AMSAT- <> <NA. <> <Not an AMSAT-NA member? Join now to support the amateur satellite <> <program! <> <Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb <>
Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Greg,
Fortunately this is not a TEOTWAWKI Y2K issue. Unlike most of the other numbers in the Keps, the orbit count has nothing to do with predicting the orbit, and can be completely ignored. Some programs do that. Others compute backwards and forwards from the reference epoch and orbit number in the Keps they are using. I am most familiar with SatPC32, and when working on prelaunch Keps recently, I found that if you ran it backwards in time before the launch, it will happily show negative numbers. ;)
The problem is that when the specification for the Keps we use was created, it only allowed 5 digits for the orbit count. That seemed enough, and comes from Space Track that way. So like an odometer it just rolls over. In principle, software could look for that, and automatically compensate.
I can't speak for all the software out there, but in most cases they will just roll over and keep on tracking.
73,
Alan WA4SCA
<-----Original Message----- <From: Greg D [mailto:[email protected]] <Sent: Monday, July 02, 2018 11:29 AM <To: [email protected]; 'Tom Schuessler' [email protected] <Cc: 'AMSAT BB' [email protected] <Subject: Re: [amsat-bb] AO-7 orbit count. < <Hi Alan, < <Other shoe, please? What happened to the world's prediction software <(if, indeed, we even had any back then) when it rolled over? What is <expected this time? < <We survived Y2K, but did we learn anything from it? < <Greg KO6TH < < <Alan wrote: <> Tom, <> <> It has in fact turned over once already. <> <> 73, <> <> Alan <> WA4SCA <> <> Sent from my Waring blender. <> <> <> <-----Original Message----- <> <From: Tom Schuessler [mailto:[email protected]] <> <Sent: Monday, July 02, 2018 09:03 AM <> <To: [email protected] <> <Cc: AMSAT BB [email protected] <> <Subject: Re: [amsat-bb] AO-7 orbit count. <> < <> <12.5×365×45 equals 205,312..5. Based on that you think it had Brolley a <> <diameter the second time already but it might have been hiring slower <when <> <originally launched. <> < <> <Sent from my iPhone <> < <> <> On Jul 2, 2018, at 02:47, Alan [email protected] wrote: <> <> <> <> Tom, <> <> <> <> According to the Keps, AO-7 makes 12.54 orbits per day. It will hit 99999 <> <> on the 30th or so. You can use the Preview function to find out exactly <> <> when. <> <> <> <> 73, <> <> <> <> Alan <> <> WA4SCA <> <> <> <> <> <> <-----Original Message----- <> <> <From: AMSAT-BB [mailto:[email protected]] On Behalf Of <> <> <[email protected] <> <> <Sent: Sunday, July 01, 2018 23:56 PM <> <> <To: 'AMSAT BB' [email protected] <> <> <Subject: [amsat-bb] AO-7 orbit count. <> <> < <> <> <Now I see looking at SatPC32 that it shows AO-7 in the 99,625 range in <> <> orbit <> <> <count. If memory serves me right though, doesn't the TLE orbit count <roll <> <> <over at 99,999 (Just like a car odometer), so that would mean that we <> <would <> <> <be coming up to the 200,000th rev is that right? If I am right, then this <> <> <will be coming up in less than a month. Does anybody know exactly <when <> <> that <> <> <will be? I am doing a presentation for a local club and would like to <> <> throw <> <> <out that fact if I could. Also the day of that event would be good AO-7 <> <> <operating day I would think. <> <> < <> <> <73 <> <> < <> <> <Tom Schuessler, N5HYP <> <> <EM12ms <> <> < <> <> < <> <> < <> <> <_______________________________________________ <> <> <Sent via [email protected]. AMSAT-NA makes this open forum <> <available <> <> <to all interested persons worldwide without requiring membership. <> <Opinions <> <> <expressed <> <> <are solely those of the author, and do not reflect the official views of <> <> AMSAT- <> <> <NA. <> <> <Not an AMSAT-NA member? Join now to support the amateur satellite <> <> <program! <> <> <Subscription settings: http://www.amsat.org/mailman/listinfo/amsat- <bb <> <> <> <> _______________________________________________ <> Sent via [email protected]. AMSAT-NA makes this open forum <available <> to all interested persons worldwide without requiring membership. <Opinions expressed <> are solely those of the author, and do not reflect the official views of <AMSAT-NA. <> Not an AMSAT-NA member? Join now to support the amateur satellite <program! <> Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Hi all,
Nice idea to celebrate AO-7 200th orbit anniversary, our beloved grandfather bird merits it.
Looks that 200k orbit will happen around August the 1st see: http://amsat.org.ar/ao7-200k.gif .
http://amsat.org.ar/pass?satx=ao-7 account for orbits above 100k.
We hams should be thankful to have AO-7 alive, duly recognizing those that made it possible .
73, LU7ABF, Pedro
On 7/2/18, Alan [email protected] wrote:
Greg,
Fortunately this is not a TEOTWAWKI Y2K issue. Unlike most of the other numbers in the Keps, the orbit count has nothing to do with predicting the orbit, and can be completely ignored. Some programs do that. Others compute backwards and forwards from the reference epoch and orbit number in the Keps they are using. I am most familiar with SatPC32, and when working on prelaunch Keps recently, I found that if you ran it backwards in time before the launch, it will happily show negative numbers. ;)
The problem is that when the specification for the Keps we use was created, it only allowed 5 digits for the orbit count. That seemed enough, and comes from Space Track that way. So like an odometer it just rolls over. In principle, software could look for that, and automatically compensate.
I can't speak for all the software out there, but in most cases they will just roll over and keep on tracking.
73,
Alan WA4SCA
<-----Original Message----- <From: Greg D [mailto:[email protected]] <Sent: Monday, July 02, 2018 11:29 AM <To: [email protected]; 'Tom Schuessler' [email protected] <Cc: 'AMSAT BB' [email protected] <Subject: Re: [amsat-bb] AO-7 orbit count. < <Hi Alan, < <Other shoe, please? What happened to the world's prediction software <(if, indeed, we even had any back then) when it rolled over? What is <expected this time? < <We survived Y2K, but did we learn anything from it? < <Greg KO6TH < < <Alan wrote: <> Tom, <> <> It has in fact turned over once already. <> <> 73, <> <> Alan <> WA4SCA <> <> Sent from my Waring blender. <> <> <> <-----Original Message----- <> <From: Tom Schuessler [mailto:[email protected]] <> <Sent: Monday, July 02, 2018 09:03 AM <> <To: [email protected] <> <Cc: AMSAT BB [email protected] <> <Subject: Re: [amsat-bb] AO-7 orbit count. <> < <> <12.5×365×45 equals 205,312..5. Based on that you think it had Brolley a <> <diameter the second time already but it might have been hiring slower <when <> <originally launched. <> < <> <Sent from my iPhone <> < <> <> On Jul 2, 2018, at 02:47, Alan [email protected] wrote: <> <> <> <> Tom, <> <> <> <> According to the Keps, AO-7 makes 12.54 orbits per day. It will hit 99999 <> <> on the 30th or so. You can use the Preview function to find out exactly <> <> when. <> <> <> <> 73, <> <> <> <> Alan <> <> WA4SCA <> <> <> <> <> <> <-----Original Message----- <> <> <From: AMSAT-BB [mailto:[email protected]] On Behalf Of <> <> <[email protected] <> <> <Sent: Sunday, July 01, 2018 23:56 PM <> <> <To: 'AMSAT BB' [email protected] <> <> <Subject: [amsat-bb] AO-7 orbit count. <> <> < <> <> <Now I see looking at SatPC32 that it shows AO-7 in the 99,625 range in <> <> orbit <> <> <count. If memory serves me right though, doesn't the TLE orbit count <roll <> <> <over at 99,999 (Just like a car odometer), so that would mean that we <> <would <> <> <be coming up to the 200,000th rev is that right? If I am right, then this <> <> <will be coming up in less than a month. Does anybody know exactly <when <> <> that <> <> <will be? I am doing a presentation for a local club and would like to <> <> throw <> <> <out that fact if I could. Also the day of that event would be good AO-7 <> <> <operating day I would think. <> <> < <> <> <73 <> <> < <> <> <Tom Schuessler, N5HYP <> <> <EM12ms <> <> < <> <> < <> <> < <> <> <_______________________________________________ <> <> <Sent via [email protected]. AMSAT-NA makes this open forum <> <available <> <> <to all interested persons worldwide without requiring membership. <> <Opinions <> <> <expressed <> <> <are solely those of the author, and do not reflect the official views of <> <> AMSAT- <> <> <NA. <> <> <Not an AMSAT-NA member? Join now to support the amateur satellite <> <> <program! <> <> <Subscription settings: http://www.amsat.org/mailman/listinfo/amsat- <bb <> <> <> <> _______________________________________________ <> Sent via [email protected]. AMSAT-NA makes this open forum <available <> to all interested persons worldwide without requiring membership. <Opinions expressed <> are solely those of the author, and do not reflect the official views of <AMSAT-NA. <> Not an AMSAT-NA member? Join now to support the amateur satellite <program! <> Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
I ran a simulation on my cell phone app HamSat. I know it isn’t perfect. I found that orbits rolled over from 99999 to 100000 at 04:13:28 EDT (091228 UTC). The resultant map shows it over Mongolia. So, I’m just letting my curiosity run rampant and thinking out loud. Considering that it’s period has changed over time, what constitutes an orbit? How does the software account for that?
73 EMike
EMike McCardel, AA8EM Rotating Editor AMSAT News Service Sent from my iPhone
On Jul 2, 2018, at 2:05 PM, Pedro Converso [email protected] wrote:
Hi all,
Nice idea to celebrate AO-7 200th orbit anniversary, our beloved grandfather bird merits it.
Looks that 200k orbit will happen around August the 1st see: http://amsat.org.ar/ao7-200k.gif .
http://amsat.org.ar/pass?satx=ao-7 account for orbits above 100k.
We hams should be thankful to have AO-7 alive, duly recognizing those that made it possible .
73, LU7ABF, Pedro
On 7/2/18, Alan [email protected] wrote: Greg,
Fortunately this is not a TEOTWAWKI Y2K issue. Unlike most of the other numbers in the Keps, the orbit count has nothing to do with predicting the orbit, and can be completely ignored. Some programs do that. Others compute backwards and forwards from the reference epoch and orbit number in the Keps they are using. I am most familiar with SatPC32, and when working on prelaunch Keps recently, I found that if you ran it backwards in time before the launch, it will happily show negative numbers. ;)
The problem is that when the specification for the Keps we use was created, it only allowed 5 digits for the orbit count. That seemed enough, and comes from Space Track that way. So like an odometer it just rolls over. In principle, software could look for that, and automatically compensate.
I can't speak for all the software out there, but in most cases they will just roll over and keep on tracking.
73,
Alan WA4SCA
<-----Original Message----- <From: Greg D [mailto:[email protected]] <Sent: Monday, July 02, 2018 11:29 AM <To: [email protected]; 'Tom Schuessler' [email protected] <Cc: 'AMSAT BB' [email protected] <Subject: Re: [amsat-bb] AO-7 orbit count. < <Hi Alan, < <Other shoe, please? What happened to the world's prediction software <(if, indeed, we even had any back then) when it rolled over? What is <expected this time? < <We survived Y2K, but did we learn anything from it? < <Greg KO6TH < < <Alan wrote: <> Tom, <> <> It has in fact turned over once already. <> <> 73, <> <> Alan <> WA4SCA <> <> Sent from my Waring blender. <> <> <> <-----Original Message----- <> <From: Tom Schuessler [mailto:[email protected]] <> <Sent: Monday, July 02, 2018 09:03 AM <> <To: [email protected] <> <Cc: AMSAT BB [email protected] <> <Subject: Re: [amsat-bb] AO-7 orbit count. <> < <> <12.5×365×45 equals 205,312..5. Based on that you think it had Brolley a <> <diameter the second time already but it might have been hiring slower <when <> <originally launched. <> < <> <Sent from my iPhone <> < <> <> On Jul 2, 2018, at 02:47, Alan [email protected] wrote: <> <> <> <> Tom, <> <> <> <> According to the Keps, AO-7 makes 12.54 orbits per day. It will hit 99999 <> <> on the 30th or so. You can use the Preview function to find out exactly <> <> when. <> <> <> <> 73, <> <> <> <> Alan <> <> WA4SCA <> <> <> <> <> <> <-----Original Message----- <> <> <From: AMSAT-BB [mailto:[email protected]] On Behalf Of <> <> <[email protected] <> <> <Sent: Sunday, July 01, 2018 23:56 PM <> <> <To: 'AMSAT BB' [email protected] <> <> <Subject: [amsat-bb] AO-7 orbit count. <> <> < <> <> <Now I see looking at SatPC32 that it shows AO-7 in the 99,625 range in <> <> orbit <> <> <count. If memory serves me right though, doesn't the TLE orbit count <roll <> <> <over at 99,999 (Just like a car odometer), so that would mean that we <> <would <> <> <be coming up to the 200,000th rev is that right? If I am right, then this <> <> <will be coming up in less than a month. Does anybody know exactly <when <> <> that <> <> <will be? I am doing a presentation for a local club and would like to <> <> throw <> <> <out that fact if I could. Also the day of that event would be good AO-7 <> <> <operating day I would think. <> <> < <> <> <73 <> <> < <> <> <Tom Schuessler, N5HYP <> <> <EM12ms <> <> < <> <> < <> <> < <> <> <_______________________________________________ <> <> <Sent via [email protected]. AMSAT-NA makes this open forum <> <available <> <> <to all interested persons worldwide without requiring membership. <> <Opinions <> <> <expressed <> <> <are solely those of the author, and do not reflect the official views of <> <> AMSAT- <> <> <NA. <> <> <Not an AMSAT-NA member? Join now to support the amateur satellite <> <> <program! <> <> <Subscription settings: http://www.amsat.org/mailman/listinfo/amsat- <bb <> <> <> <> _______________________________________________ <> Sent via [email protected]. AMSAT-NA makes this open forum <available <> to all interested persons worldwide without requiring membership. <Opinions expressed <> are solely those of the author, and do not reflect the official views of <AMSAT-NA. <> Not an AMSAT-NA member? Join now to support the amateur satellite <program! <> Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Sorry, I am just now reading about the AO-7 orbit "count turn over" question.
Assuming a 99,999 orbit turn over as calculated by Space-Track:
Yes, this will be the second time the data has exceeded the 99,999 orbit count limit in the SpaceTrack TLEs. Just a short history: AO-7 was launched on November 15, 1974. AO-7 became non-operational mid 1981 (after 7 years) due to battery failure. In 2002, one of the shorted batteries became open and AO-7 could then be powered without the battery by its solar panels when in sunlight. The AMSAT digital KEPs distribution system started operation sometime in 1991 with Dick Campbell (N3FKV) as Orbital Data Manager. At that time AO-7 had already gone silent due to the battery short in 1981. When I was handed the KEP distribution baton in 1993, AO-7 had been silent for about 12 years and was NOT in the KEP distribution list. But, due to loss of that battery short sometime before June 20, 2002, it came back! I first added AO-7 back in the KEPs on June 20, 2002 after 21 years of being silent. The orbit count, at that point, was 26,363 orbits. This indicates that AO-7 had already crossed its first 99,999 orbit "count turn over" sometime while it was out of service. Currently, we are at 99,696 orbits and counting on July 6, 2018.
Yes, nothing will happen after the orbit "count turn over" (like Y2K - HI). As previously noted, most if not all tracking programs do not use the orbit number data for anything. Maybe display only??? Note: The orbit count is calculated by Space-Track and is not an actual count of orbits completed. It is an indicating number that excludes many factors (particularly orbit drag). Alan (W4SCA) is right, it is just an odometer giving an indication, not an exact data point. And NOT as accurate as the odometer in your car.
And yes, what an amazing satellite and a great testimony to its builders! AO-7, the little satellite that could!
I think a 200,000 orbit celebration is warranted!
What should we do?
Ray Hoad WA5QGD AMSAT-NA Orbital Elements Manager
-----Original Message----- From: AMSAT-BB [mailto:[email protected]] On Behalf Of E.Mike McCardel Sent: Tuesday, July 3, 2018 19:25 To: Pedro Converso [email protected] Cc: AMSAT BB [email protected]; [email protected] Subject: Re: [amsat-bb] AO-7 orbit count.
I ran a simulation on my cell phone app HamSat. I know it isn’t perfect. I found that orbits rolled over from 99999 to 100000 at 04:13:28 EDT (091228 UTC). The resultant map shows it over Mongolia. So, I’m just letting my curiosity run rampant and thinking out loud. Considering that it’s period has changed over time, what constitutes an orbit? How does the software account for that?
73 EMike
EMike McCardel, AA8EM Rotating Editor AMSAT News Service Sent from my iPhone
On Jul 2, 2018, at 2:05 PM, Pedro Converso [email protected] wrote:
Hi all,
Nice idea to celebrate AO-7 200th orbit anniversary, our beloved grandfather bird merits it.
Looks that 200k orbit will happen around August the 1st see: http://amsat.org.ar/ao7-200k.gif .
http://amsat.org.ar/pass?satx=ao-7 account for orbits above 100k.
We hams should be thankful to have AO-7 alive, duly recognizing those that made it possible .
73, LU7ABF, Pedro
On 7/2/18, Alan [email protected] wrote: Greg,
Fortunately this is not a TEOTWAWKI Y2K issue. Unlike most of the other numbers in the Keps, the orbit count has nothing to do with predicting the orbit, and can be completely ignored. Some programs do that. Others compute backwards and forwards from the reference epoch and orbit number in the Keps they are using. I am most familiar with SatPC32, and when working on prelaunch Keps recently, I found that if you ran it backwards in time before the launch, it will happily show negative numbers. ;)
The problem is that when the specification for the Keps we use was created, it only allowed 5 digits for the orbit count. That seemed enough, and comes from Space Track that way. So like an odometer it just rolls over. In principle, software could look for that, and automatically compensate.
I can't speak for all the software out there, but in most cases they will just roll over and keep on tracking.
73,
Alan WA4SCA
<-----Original Message----- <From: Greg D [mailto:[email protected]] <Sent: Monday, July 02, 2018 11:29 AM <To: [email protected]; 'Tom Schuessler' [email protected] <Cc: 'AMSAT BB' [email protected] <Subject: Re: [amsat-bb] AO-7 orbit count. < <Hi Alan, < <Other shoe, please? What happened to the world's prediction software <(if, indeed, we even had any back then) when it rolled over? What is <expected this time? < <We survived Y2K, but did we learn anything from it? < <Greg KO6TH < < <Alan wrote: <> Tom, <> <> It has in fact turned over once already. <> <> 73, <> <> Alan <> WA4SCA <> <> Sent from my Waring blender. <> <> <> <-----Original Message----- <> <From: Tom Schuessler [mailto:[email protected]] <> <Sent: Monday, July 02, 2018 09:03 AM <> <To: [email protected] <> <Cc: AMSAT BB [email protected] <> <Subject: Re: [amsat-bb] AO-7 orbit count. <> < <> <12.5×365×45 equals 205,312..5. Based on that you think it had Brolley a <> <diameter the second time already but it might have been hiring slower <when <> <originally launched. <> < <> <Sent from my iPhone <> < <> <> On Jul 2, 2018, at 02:47, Alan [email protected] wrote: <> <> <> <> Tom, <> <> <> <> According to the Keps, AO-7 makes 12.54 orbits per day. It will hit 99999 <> <> on the 30th or so. You can use the Preview function to find out exactly <> <> when. <> <> <> <> 73, <> <> <> <> Alan <> <> WA4SCA <> <> <> <> <> <> <-----Original Message----- <> <> <From: AMSAT-BB [mailto:[email protected]] On Behalf Of <> <> <[email protected] <> <> <Sent: Sunday, July 01, 2018 23:56 PM <> <> <To: 'AMSAT BB' [email protected] <> <> <Subject: [amsat-bb] AO-7 orbit count. <> <> < <> <> <Now I see looking at SatPC32 that it shows AO-7 in the 99,625 range in <> <> orbit <> <> <count. If memory serves me right though, doesn't the TLE orbit count <roll <> <> <over at 99,999 (Just like a car odometer), so that would mean that we <> <would <> <> <be coming up to the 200,000th rev is that right? If I am right, then this <> <> <will be coming up in less than a month. Does anybody know exactly <when <> <> that <> <> <will be? I am doing a presentation for a local club and would like to <> <> throw <> <> <out that fact if I could. Also the day of that event would be good AO-7 <> <> <operating day I would think. <> <> < <> <> <73 <> <> < <> <> <Tom Schuessler, N5HYP <> <> <EM12ms <> <> < <> <> < <> <> < <> <> <_______________________________________________ <> <> <Sent via [email protected]. AMSAT-NA makes this open forum <> <available <> <> <to all interested persons worldwide without requiring membership. <> <Opinions <> <> <expressed <> <> <are solely those of the author, and do not reflect the official views of <> <> AMSAT- <> <> <NA. <> <> <Not an AMSAT-NA member? Join now to support the amateur satellite <> <> <program! <> <> <Subscription settings: http://www.amsat.org/mailman/listinfo/amsat- <bb <> <> <> <> _______________________________________________ <> Sent via [email protected]. AMSAT-NA makes this open forum <available <> to all interested persons worldwide without requiring membership. <Opinions expressed <> are solely those of the author, and do not reflect the official views of <AMSAT-NA. <> Not an AMSAT-NA member? Join now to support the amateur satellite <program! <> Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
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Tom Clark, K3IO (ex-W3IWI) once observed that AO-7 was the only amateur satellite known to have suffered two catastrophic failures, thereby returning it to service. Hi HI
73,
Alan WA4SCA
With any luck, AO-7 will outlive (or perhaps it already has) the IBM punch card that caused the whole 5-digit thing in the first place. Of the constants in the universe, the first one is 42, immediately followed by either 72 or 80, depending on your background. We apparently had programmers define the KEPs format, as both lines are 71 characters long... :)
Greg KO6TH
(For source code, columns 73-80 were reserved for sequence numbers, so that when you dropped your deck, the cards could be reassembled in the proper order.)
Alan wrote:
Tom Clark, K3IO (ex-W3IWI) once observed that AO-7 was the only amateur satellite known to have suffered two catastrophic failures, thereby returning it to service. Hi HI
73,
Alan WA4SCA
Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Well, it is a well known that in some universes a double negative results in a positive result. I'm interested in taking an attempt at imaging OSCAR satellites. Any tips from the community for say, AO-7, using an optical telescope and a DSLR mounted at its focus?
Samudra N3RDX.
-----Original Message----- From: AMSAT-BB [mailto:[email protected]] On Behalf Of Greg D Sent: Friday, July 6, 2018 8:07 PM To: [email protected]; 'Ray Hoad' [email protected]; [email protected] Subject: Re: [amsat-bb] AO-7 orbit count.
With any luck, AO-7 will outlive (or perhaps it already has) the IBM punch card that caused the whole 5-digit thing in the first place. Of the constants in the universe, the first one is 42, immediately followed by either 72 or 80, depending on your background. We apparently had programmers define the KEPs format, as both lines are 71 characters long... :)
Greg KO6TH
(For source code, columns 73-80 were reserved for sequence numbers, so that when you dropped your deck, the cards could be reassembled in the proper order.)
Alan wrote:
Tom Clark, K3IO (ex-W3IWI) once observed that AO-7 was the only amateur satellite known to have suffered two catastrophic failures, thereby returning it to service. Hi HI
73,
Alan WA4SCA
Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
_______________________________________________ Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb The information contained in this communication is confidential, may be privileged and is intended for the exclusive use of the above named addressee(s). If you are not the intended recipient(s), you are expressly prohibited from copying, distributing, disseminating, or in any other way using any information contained within this communication. If you have received this communication in error please contact the sender by telephone or by response via mail. We have taken precautions to minimize the risk of transmitting software viruses, but we advise you to carry out your own virus checks on any attachment to this message. We cannot accept liability for any loss or damage caused by software viruses.
Hum,
Don't know what the thought of viewing AO-7 caught my attention, but it did. So I did some quick math:
In round numbers AO-7 is about 0.06 arc seconds across (1450 KM orbit, 0.4 meters diameter). That's the theoretical resolving power of a telescope with a 16,000mm focal length and magnification of about 500, constructed with perfect optics and operated in a vacuum. So I wouldn't hold my breath thinking you can observe it with a ground based telescope.
But maybe as a point of light? N2YO.com doesn't even list a magnitude for visible passes.
73, Bob, WB4SON
On Mon, Jul 9, 2018 at 7:38 AM, Samudra Haque [TTLLC] < [email protected]> wrote:
Well, it is a well known that in some universes a double negative results in a positive result. I'm interested in taking an attempt at imaging OSCAR satellites. Any tips from the community for say, AO-7, using an optical telescope and a DSLR mounted at its focus?
Samudra N3RDX.
-----Original Message----- From: AMSAT-BB [mailto:[email protected]] On Behalf Of Greg D Sent: Friday, July 6, 2018 8:07 PM To: [email protected]; 'Ray Hoad' [email protected]; [email protected] Subject: Re: [amsat-bb] AO-7 orbit count.
With any luck, AO-7 will outlive (or perhaps it already has) the IBM punch card that caused the whole 5-digit thing in the first place. Of the constants in the universe, the first one is 42, immediately followed by either 72 or 80, depending on your background. We apparently had programmers define the KEPs format, as both lines are 71 characters long... :)
Greg KO6TH
(For source code, columns 73-80 were reserved for sequence numbers, so that when you dropped your deck, the cards could be reassembled in the proper order.)
Alan wrote:
Tom Clark, K3IO (ex-W3IWI) once observed that AO-7 was the only amateur satellite known to have suffered two catastrophic failures, thereby returning it to service. Hi HI
73,
Alan WA4SCA
Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect
the official views of AMSAT-NA.
Not an AMSAT-NA member? Join now to support the amateur satellite
program!
Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb The information contained in this communication is confidential, may be privileged and is intended for the exclusive use of the above named addressee(s). If you are not the intended recipient(s), you are expressly prohibited from copying, distributing, disseminating, or in any other way using any information contained within this communication. If you have received this communication in error please contact the sender by telephone or by response via mail. We have taken precautions to minimize the risk of transmitting software viruses, but we advise you to carry out your own virus checks on any attachment to this message. We cannot accept liability for any loss or damage caused by software viruses. _______________________________________________ Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Besides seeing the satellite - I've seen several zip through the field of view in my telescope - tracking the object, even if you knew it was coming (and which one it actually was), would be very difficult. Way too fast for regular astronomical telescope mounts. And, yes, point of light is all you'd get.
We have had (very) limited success with doing a manual track of the ISS, during a visible pass. We used a Dobsonian scope with a Telrad, and a low magnification eyepiece. One person does the tracking, arm wrapped around the OTA, while the second person tries to look through the eyepiece to see the Station, as the whole thing is moving around. Amazing when it works, but requires practice and some luck.
Greg KO6TH
Bob wrote:
Hum,
Don't know what the thought of viewing AO-7 caught my attention, but it did. So I did some quick math:
In round numbers AO-7 is about 0.06 arc seconds across (1450 KM orbit, 0.4 meters diameter). That's the theoretical resolving power of a telescope with a 16,000mm focal length and magnification of about 500, constructed with perfect optics and operated in a vacuum. So I wouldn't hold my breath thinking you can observe it with a ground based telescope.
But maybe as a point of light? N2YO.com doesn't even list a magnitude for visible passes.
73, Bob, WB4SON
On Mon, Jul 9, 2018 at 7:38 AM, Samudra Haque [TTLLC] < [email protected]> wrote:
Well, it is a well known that in some universes a double negative results in a positive result. I'm interested in taking an attempt at imaging OSCAR satellites. Any tips from the community for say, AO-7, using an optical telescope and a DSLR mounted at its focus?
Samudra N3RDX.
-----Original Message----- From: AMSAT-BB [mailto:[email protected]] On Behalf Of Greg D Sent: Friday, July 6, 2018 8:07 PM To: [email protected]; 'Ray Hoad' [email protected]; [email protected] Subject: Re: [amsat-bb] AO-7 orbit count.
With any luck, AO-7 will outlive (or perhaps it already has) the IBM punch card that caused the whole 5-digit thing in the first place. Of the constants in the universe, the first one is 42, immediately followed by either 72 or 80, depending on your background. We apparently had programmers define the KEPs format, as both lines are 71 characters long... :)
Greg KO6TH
(For source code, columns 73-80 were reserved for sequence numbers, so that when you dropped your deck, the cards could be reassembled in the proper order.)
Alan wrote:
Tom Clark, K3IO (ex-W3IWI) once observed that AO-7 was the only amateur satellite known to have suffered two catastrophic failures, thereby returning it to service. Hi HI
73,
Alan WA4SCA
Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect
the official views of AMSAT-NA.
Not an AMSAT-NA member? Join now to support the amateur satellite
program!
Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb The information contained in this communication is confidential, may be privileged and is intended for the exclusive use of the above named addressee(s). If you are not the intended recipient(s), you are expressly prohibited from copying, distributing, disseminating, or in any other way using any information contained within this communication. If you have received this communication in error please contact the sender by telephone or by response via mail. We have taken precautions to minimize the risk of transmitting software viruses, but we advise you to carry out your own virus checks on any attachment to this message. We cannot accept liability for any loss or damage caused by software viruses. _______________________________________________ Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Alan, So two wrongs make it right? Or if at first you don’t succeed fail, fail again? Hi hi EMike
EMike McCardel, AA8EM Rotating Editor AMSAT News Service Sent from my iPhone
On Jul 6, 2018, at 5:33 PM, Alan [email protected] wrote:
Tom Clark, K3IO (ex-W3IWI) once observed that AO-7 was the only amateur satellite known to have suffered two catastrophic failures, thereby returning it to service. Hi HI
73,
Alan WA4SCA
Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Samudra,
You might ask the folks at seesat-l http://www.satobs.org/seesat/seesatindex.html
It seems to me that I saw paper on viewing the early OSCARs. Either in an early newsletter or Symposium proceeding. If I can find it I’ll post it.
73 EMike
EMike McCardel, AA8EM Rotating Editor AMSAT News Service Sent from my iPhone
On Jul 9, 2018, at 9:24 AM, E.Mike McCardel [email protected] wrote:
Alan, So two wrongs make it right? Or if at first you don’t succeed fail, fail again? Hi hi EMike
EMike McCardel, AA8EM Rotating Editor AMSAT News Service Sent from my iPhone
On Jul 6, 2018, at 5:33 PM, Alan [email protected] wrote:
Tom Clark, K3IO (ex-W3IWI) once observed that AO-7 was the only amateur satellite known to have suffered two catastrophic failures, thereby returning it to service. Hi HI
73,
Alan WA4SCA
Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
EMike,
More a case that if you have one problem, there may be no solution, but if you have multiple problems they may solve each other.
73,
Alan WA4SCA
<-----Original Message----- <From: E.Mike McCardel [mailto:[email protected]] <Sent: Monday, July 09, 2018 08:24 AM <To: [email protected] <Cc: Ray Hoad [email protected]; [email protected] <Subject: Re: [amsat-bb] AO-7 orbit count. < <Alan, <So two wrongs make it right? <Or if at first you don’t succeed fail, fail again? <Hi hi <EMike < <EMike McCardel, AA8EM <Rotating Editor AMSAT News Service <Sent from my iPhone < <> On Jul 6, 2018, at 5:33 PM, Alan [email protected] wrote: <> <> Tom Clark, K3IO (ex-W3IWI) once observed that AO-7 was the only amateur <satellite known to have suffered two catastrophic failures, thereby returning <it to service. Hi HI <> <> 73, <> <> Alan <> WA4SCA <> <> _______________________________________________ <> Sent via [email protected]. AMSAT-NA makes this open forum <available <> to all interested persons worldwide without requiring membership. <Opinions expressed <> are solely those of the author, and do not reflect the official views of <AMSAT-NA. <> Not an AMSAT-NA member? Join now to support the amateur satellite <program! <> Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
participants (10)
-
Alan -
Bob -
E.Mike McCardel -
Greg D -
Paul Stoetzer -
Pedro Converso -
Ray Hoad -
Samudra Haque [TTLLC] -
tjschuessler＠verizon.net -
Tom Schuessler