Hello Everybody, I totally agree with you James... the process is a continuous evolution.
I did my prediction on October 6th for the "Chicken Little Competition" and my date was January 23rd 2012.
It surprisingly agrees with your prediction done almost one month later, this make me think that my assumptions were right, up to now at least.
73s Fabio IW8QKU/5
Hi Jim,
Thanks for the update on your AMSAT Journal article. There are several people on the bb who are following this topic and are busy plotting data. Any futher thoughts you have, as we move towards January would, I am sure be of interest.
73 John G7HIA
________________________________ From: DeYoung James deyoung_james@yahoo.com To: amsat-bb amsat-bb@amsat.org Sent: Tuesday, 15 November, 2011 17:29:31 Subject: [amsat-bb] ARISSat-1 (37772) decay
Greetings,
First, thank you Mineo for reading the AMSAT Journal and making several of my papers available on your web site. My AMSAT Journal paper published in the March/April 2011 issue is actually still fairly valid for the scenarios shown in the paper. The solar flux has turned out to be somewhat higher than was used/predicted in the paper. This has caused the atmospheric densities to be higher which results in higher decay rates. When I wrote the paper I had this nagging feeling that stopping the release height scenarios at 370-km was not going to be high enough. We are very fortunate that the ISS was boosted to such a height before release of ARISSat-1 and not after release!
There is a valuable lesson, I think, to be made with respect to predicting satellite decay dates far into the future. The future state of the atmosphere, i.e. the atmospheric density that the satellite will pass through is poorly predictable in the long-term, say starting greater than a week or two into the future. Predictions of satellite decay dates months in the future should be evaluated with the understanding that your date of prediction errors may be large. The errors are due to the future uncertainties of the orbital path which grow quickly with time in a prediction. The atmospheric density is not the only source of error. Your orbit model, the integrator, and the accounting of the gravitational and drag forces among others will affect your results. Predictions of satellite decay dates are not do-and-forget. The general process is to make a prediction, get new measured observations of the height in the future, and at some point re-do your prediction when the errors become significant to you. With that all said here is my current prediction using the same tools used in the AMSAT J. paper and produced as of 2011 November 13th. The decay of ARISSat-1 (37772) will happen nominally on 2012 January 30th with a 10% rule-of-thumb error allowance of 18 days around this date. The errors may be larger than the rule-of-thumb indicates! Jim, N8OQ _______________________________________________ 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,
So far all my analyses of the evolution of the orbit of ARISSat 1 have resulted in a predicted decay date sometime in December 2011. Actually my current predicted decay date for this satellite is December 17. Obviously it depends very much on how solar activity develops in the coming weeks.
So now we have seen decay predictions ranging from December 2011 to April 2012. Let's see how we converge to the actual decay date.
73, Nico PA0DLO
On 2011-11-16 20:28, Fabio Azzarello wrote:
Hello Everybody, I totally agree with you James... the process is a continuous evolution.
I did my prediction on October 6th for the "Chicken Little Competition" and my date was January 23rd 2012.
It surprisingly agrees with your prediction done almost one month later, this make me think that my assumptions were right, up to now at least.
73s Fabio IW8QKU/5
Hi Jim,
Thanks for the update on your AMSAT Journal article. There are several people on the bb who are following this topic and are busy plotting data. Any futher thoughts you have, as we move towards January would, I am sure be of interest.
73 John G7HIA
From: DeYoung Jamesdeyoung_james@yahoo.com To: amsat-bbamsat-bb@amsat.org Sent: Tuesday, 15 November, 2011 17:29:31 Subject: [amsat-bb] ARISSat-1 (37772) decay
Greetings,
First, thank you Mineo for reading the AMSAT Journal and making several of my papers available on your web site. My AMSAT Journal paper published in the March/April 2011 issue is actually still fairly valid for the scenarios shown in the paper. The solar flux has turned out to be somewhat higher than was used/predicted in the paper. This has caused the atmospheric densities to be higher which results in higher decay rates. When I wrote the paper I had this nagging feeling that stopping the release height scenarios at 370-km was not going to be high enough. We are very fortunate that the ISS was boosted to such a height before release of ARISSat-1 and not after release!
There is a valuable lesson, I think, to be made with respect to predicting satellite decay dates far into the future. The future state of the atmosphere, i.e. the atmospheric density that the satellite will pass through is poorly predictable in the long-term, say starting greater than a week or two into the future. Predictions of satellite decay dates months in the future should be evaluated with the understanding that your date of prediction errors may be large. The errors are due to the future uncertainties of the orbital path which grow quickly with time in a prediction. The atmospheric density is not the only source of error. Your orbit model, the integrator, and the accounting of the gravitational and drag forces among others will affect your results. Predictions of satellite decay dates are not do-and-forget. The general process is to make a prediction, get new measured observations of the height in the future, and at some point re-do your prediction when the errors become significant to you. With that all said here is my current prediction using the same tools used in the AMSAT J. paper and produced as of 2011 November 13th. The decay of ARISSat-1 (37772) will happen nominally on 2012 January 30th with a 10% rule-of-thumb error allowance of 18 days around this date. The errors may be larger than the rule-of-thumb indicates! Jim, N8OQ _______________________________________________ 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 _______________________________________________ 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,
With its relatively high area to mass ratio, ARISSat 1 is quite sensitive to space weather changes. In the past two weeks solar flux values have been relatively low, around 140, while they were around 180 in the weeks before. Also there have not been any magnetic storms.
As a result of this low solar activity, the expected decay date of ARISSat 1 has now slipped to the end of December. My current prediction is 27 December. But if solar activity stays at these low levels, the decay date will even shift into early January. So it is still too early to make any sensible predictions.
73, Nico PA0DLO
On 2011-11-18 15:05, Nico Janssen wrote:
Hi,
So far all my analyses of the evolution of the orbit of ARISSat 1 have resulted in a predicted decay date sometime in December 2011. Actually my current predicted decay date for this satellite is December 17. Obviously it depends very much on how solar activity develops in the coming weeks.
So now we have seen decay predictions ranging from December 2011 to April 2012. Let's see how we converge to the actual decay date.
73, Nico PA0DLO
Hi Nico, Good to see postings on this topic. I plotted daily change in Mean Motion, and then plotted Solar Flux for the same period. (15days). It'snot obvious from the shapes of the two graphs that SF is producing the daily variation. I tried the correlation function in Excel which returned a figure of -0.54 for the two data sets. ( 1= perfect correlation) Fairly new to "orbital decay predictions" so would be interested in any comments you may have, or anyone else on the list who is knowledeable on this subject. 73 John G7HIA
________________________________ From: Nico Janssen hamsat@xs4all.nl To: amsat-bb@amsat.org Sent: Monday, 28 November 2011, 20:36 Subject: [amsat-bb] Re: ARISSat-1 (37772) decay
Hi,
With its relatively high area to mass ratio, ARISSat 1 is quite sensitive to space weather changes. In the past two weeks solar flux values have been relatively low, around 140, while they were around 180 in the weeks before. Also there have not been any magnetic storms.
As a result of this low solar activity, the expected decay date of ARISSat 1 has now slipped to the end of December. My current prediction is 27 December. But if solar activity stays at these low levels, the decay date will even shift into early January. So it is still too early to make any sensible predictions.
73, Nico PA0DLO
On 2011-11-18 15:05, Nico Janssen wrote:
Hi,
So far all my analyses of the evolution of the orbit of ARISSat 1 have resulted in a predicted decay date sometime in December 2011. Actually my current predicted decay date for this satellite is December 17. Obviously it depends very much on how solar activity develops in the coming weeks.
So now we have seen decay predictions ranging from December 2011 to April 2012. Let's see how we converge to the actual decay date.
73, Nico PA0DLO
_______________________________________________ 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 John,
A 100 % correlation between the decay rate and the daily solar flux values is not to be expected. But there is a relation with the longer term average solar flux values.
Furthermore, not only the solar flux (actually the UV radiation levels) but also variations in the solar wind, in combination with the polarity of the interplanetary magnetic field, influence the decay rate.
73, Nico PA0DLO
On 2011-11-28 23:11, John Heath wrote:
Hi Nico,
Good to see postings on this topic.
I plotted daily change in Mean Motion, and then plotted Solar Flux for the same period. (15days). It'snot obvious from the shapes of the two graphs that SF is producing the daily variation. I tried the correlation function in Excel which returned a figure of -0.54 for the two data sets. ( 1= perfect correlation)
Fairly new to "orbital decay predictions" so would be interested in any comments you may have, or anyone else on the list who is knowledeable on this subject.
73 John G7HIA
From: Nico Janssenhamsat@xs4all.nl To: amsat-bb@amsat.org Sent: Monday, 28 November 2011, 20:36 Subject: [amsat-bb] Re: ARISSat-1 (37772) decay
Hi,
With its relatively high area to mass ratio, ARISSat 1 is quite sensitive to space weather changes. In the past two weeks solar flux values have been relatively low, around 140, while they were around 180 in the weeks before. Also there have not been any magnetic storms.
As a result of this low solar activity, the expected decay date of ARISSat 1 has now slipped to the end of December. My current prediction is 27 December. But if solar activity stays at these low levels, the decay date will even shift into early January. So it is still too early to make any sensible predictions.
73, Nico PA0DLO
On 2011-11-18 15:05, Nico Janssen wrote:
Hi,
So far all my analyses of the evolution of the orbit of ARISSat 1 have resulted in a predicted decay date sometime in December 2011. Actually my current predicted decay date for this satellite is December 17. Obviously it depends very much on how solar activity develops in the coming weeks.
So now we have seen decay predictions ranging from December 2011 to April 2012. Let's see how we converge to the actual decay date.
73, Nico PA0DLO
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 _______________________________________________ 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,
Solar activity has remained at relatively low levels. There have not been any M or X class solar flares nor magnetic storms in the past several weeks. As a result, the expected decay date of ARISSat 1 has shifted into January. It is now to be expected around January 3, but depending on solar activity it may be more than 5 days later or earlier.
73, Nico PA0DLO
On 2011-11-28 21:36, Nico Janssen wrote:
Hi,
With its relatively high area to mass ratio, ARISSat 1 is quite sensitive to space weather changes. In the past two weeks solar flux values have been relatively low, around 140, while they were around 180 in the weeks before. Also there have not been any magnetic storms.
As a result of this low solar activity, the expected decay date of ARISSat 1 has now slipped to the end of December. My current prediction is 27 December. But if solar activity stays at these low levels, the decay date will even shift into early January. So it is still too early to make any sensible predictions.
73, Nico PA0DLO
On 2011-11-18 15:05, Nico Janssen wrote:
Hi,
So far all my analyses of the evolution of the orbit of ARISSat 1 have resulted in a predicted decay date sometime in December 2011. Actually my current predicted decay date for this satellite is December 17. Obviously it depends very much on how solar activity develops in the coming weeks.
So now we have seen decay predictions ranging from December 2011 to April 2012. Let's see how we converge to the actual decay date.
73, Nico PA0DLO
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,
My current prediction for the decay of ARISSat 1 is January 4, 2012, +/- 3 days. If solar and geomagnetic activity really increase before the end of December, as some predictions suggest, the decay may be a few days earlier.
73, Nico PA0DLO
On 2011-12-11 15:24, Nico Janssen wrote:
Hi,
Solar activity has remained at relatively low levels. There have not been any M or X class solar flares nor magnetic storms in the past several weeks. As a result, the expected decay date of ARISSat 1 has shifted into January. It is now to be expected around January 3, but depending on solar activity it may be more than 5 days later or earlier.
73, Nico PA0DLO
On 2011-11-28 21:36, Nico Janssen wrote:
Hi,
With its relatively high area to mass ratio, ARISSat 1 is quite sensitive to space weather changes. In the past two weeks solar flux values have been relatively low, around 140, while they were around 180 in the weeks before. Also there have not been any magnetic storms.
As a result of this low solar activity, the expected decay date of ARISSat 1 has now slipped to the end of December. My current prediction is 27 December. But if solar activity stays at these low levels, the decay date will even shift into early January. So it is still too early to make any sensible predictions.
73, Nico PA0DLO
On 2011-11-18 15:05, Nico Janssen wrote:
Hi,
So far all my analyses of the evolution of the orbit of ARISSat 1 have resulted in a predicted decay date sometime in December 2011. Actually my current predicted decay date for this satellite is December 17. Obviously it depends very much on how solar activity develops in the coming weeks.
So now we have seen decay predictions ranging from December 2011 to April 2012. Let's see how we converge to the actual decay date.
73, Nico PA0DLO
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,
My prediction for the decay of ARISSat 1 still stays on the same date: January 4 +/- 1 day.
As the aerodynamic drag increases, the telemetry of the satellite should show ever higher temperatures in the coming days. Especially interesting is the data from the Kursk experiment, that measures the density of the air around the satellite.
Happy New Year to all!
73, Nico PA0DLO
On 2011-12-22 16:15, Nico Janssen wrote:
Hi,
My current prediction for the decay of ARISSat 1 is January 4, 2012, +/- 3 days. If solar and geomagnetic activity really increase before the end of December, as some predictions suggest, the decay may be a few days earlier.
73, Nico PA0DLO
On 2011-12-11 15:24, Nico Janssen wrote:
Hi,
Solar activity has remained at relatively low levels. There have not been any M or X class solar flares nor magnetic storms in the past several weeks. As a result, the expected decay date of ARISSat 1 has shifted into January. It is now to be expected around January 3, but depending on solar activity it may be more than 5 days later or earlier.
73, Nico PA0DLO
On 2011-11-28 21:36, Nico Janssen wrote:
Hi,
With its relatively high area to mass ratio, ARISSat 1 is quite sensitive to space weather changes. In the past two weeks solar flux values have been relatively low, around 140, while they were around 180 in the weeks before. Also there have not been any magnetic storms.
As a result of this low solar activity, the expected decay date of ARISSat 1 has now slipped to the end of December. My current prediction is 27 December. But if solar activity stays at these low levels, the decay date will even shift into early January. So it is still too early to make any sensible predictions.
73, Nico PA0DLO
On 2011-11-18 15:05, Nico Janssen wrote:
Hi,
So far all my analyses of the evolution of the orbit of ARISSat 1 have resulted in a predicted decay date sometime in December 2011. Actually my current predicted decay date for this satellite is December 17. Obviously it depends very much on how solar activity develops in the coming weeks.
So now we have seen decay predictions ranging from December 2011 to April 2012. Let's see how we converge to the actual decay date.
73, Nico PA0DLO
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
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
Do we really expect the temp to get substantially higher before it begins to tumble? Just sort of thinking about putting my hand out the window of my car, there's a lot of aero force before it gets hot...
Tom
KJ4EAW
On Dec 31, 2011, at 9:46 AM, Nico Janssen hamsat@xs4all.nl wrote:
Hi,
My prediction for the decay of ARISSat 1 still stays on the same date: January 4 +/- 1 day.
As the aerodynamic drag increases, the telemetry of the satellite should show ever higher temperatures in the coming days. Especially interesting is the data from the Kursk experiment, that measures the density of the air around the satellite.
Happy New Year to all!
73, Nico PA0DLO
On 2011-12-22 16:15, Nico Janssen wrote:
Hi,
My current prediction for the decay of ARISSat 1 is January 4, 2012, +/- 3 days. If solar and geomagnetic activity really increase before the end of December, as some predictions suggest, the decay may be a few days earlier.
73, Nico PA0DLO
On 2011-12-11 15:24, Nico Janssen wrote:
Hi,
Solar activity has remained at relatively low levels. There have not been any M or X class solar flares nor magnetic storms in the past several weeks. As a result, the expected decay date of ARISSat 1 has shifted into January. It is now to be expected around January 3, but depending on solar activity it may be more than 5 days later or earlier.
73, Nico PA0DLO
On 2011-11-28 21:36, Nico Janssen wrote:
Hi,
With its relatively high area to mass ratio, ARISSat 1 is quite sensitive to space weather changes. In the past two weeks solar flux values have been relatively low, around 140, while they were around 180 in the weeks before. Also there have not been any magnetic storms.
As a result of this low solar activity, the expected decay date of ARISSat 1 has now slipped to the end of December. My current prediction is 27 December. But if solar activity stays at these low levels, the decay date will even shift into early January. So it is still too early to make any sensible predictions.
73, Nico PA0DLO
On 2011-11-18 15:05, Nico Janssen wrote:
Hi,
So far all my analyses of the evolution of the orbit of ARISSat 1 have resulted in a predicted decay date sometime in December 2011. Actually my current predicted decay date for this satellite is December 17. Obviously it depends very much on how solar activity develops in the coming weeks.
So now we have seen decay predictions ranging from December 2011 to April 2012. Let's see how we converge to the actual decay date.
73, Nico PA0DLO
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
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
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
Try driving at 17,500 mph...
-----Original Message----- From: amsat-bb-bounces@amsat.org [mailto:amsat-bb-bounces@amsat.org] On Behalf Of Tom Williams Sent: Saturday, December 31, 2011 12:43 PM To: Nico Janssen Cc: amsat-bb@amsat.org Subject: [amsat-bb] Re: ARISSat-1 (37772) decay
Do we really expect the temp to get substantially higher before it begins to tumble? Just sort of thinking about putting my hand out the window of my car, there's a lot of aero force before it gets hot...
Tom
KJ4EAW
On Dec 31, 2011, at 9:46 AM, Nico Janssen hamsat@xs4all.nl wrote:
Hi,
My prediction for the decay of ARISSat 1 still stays on the same date: January 4 +/- 1 day.
As the aerodynamic drag increases, the telemetry of the satellite should show ever higher temperatures in the coming days. Especially interesting is the data from the Kursk experiment, that measures the density of the air around the satellite.
Happy New Year to all!
73, Nico PA0DLO
On 2011-12-22 16:15, Nico Janssen wrote:
Hi,
My current prediction for the decay of ARISSat 1 is January 4, 2012, +/- 3 days. If solar and geomagnetic activity really increase before the end of December, as some predictions suggest, the decay may be a few days earlier.
73, Nico PA0DLO
On 2011-12-11 15:24, Nico Janssen wrote:
Hi,
Solar activity has remained at relatively low levels. There have not been any M or X class solar flares nor magnetic storms in the past several weeks. As a result, the expected decay date of ARISSat 1 has shifted into January. It is now to be expected around January 3, but depending on solar activity it may be more than 5 days later or earlier.
73, Nico PA0DLO
On 2011-11-28 21:36, Nico Janssen wrote:
Hi,
With its relatively high area to mass ratio, ARISSat 1 is quite sensitive to space weather changes. In the past two weeks solar flux values have been relatively low, around 140, while they were around 180 in the weeks before. Also there have not been any magnetic storms.
As a result of this low solar activity, the expected decay date of ARISSat 1 has now slipped to the end of December. My current prediction is 27 December. But if solar activity stays at these low levels, the decay date will even shift into early January. So it is still too early to make any sensible predictions.
73, Nico PA0DLO
On 2011-11-18 15:05, Nico Janssen wrote:
Hi,
So far all my analyses of the evolution of the orbit of ARISSat 1 have resulted in a predicted decay date sometime in December 2011. Actually my current predicted decay date for this satellite is December 17. Obviously it depends very much on how solar activity develops in the coming weeks.
So now we have seen decay predictions ranging from December 2011 to April 2012. Let's see how we converge to the actual decay date.
73, Nico PA0DLO
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
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
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
_______________________________________________ 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
Hello,
I captured the attached file a few days ago from ARISSAT-1 but have not been successful feeding it into MMSSTV or the MIXW SSTV program using the "PLAY:<filename>" macro. Can someone help me with either getting this decoded through one of these programs or send me the resulting image from an SSTV decoder. I've done this in the past, but not having much luck at this time.
All help appreciated!!
EHNY (Early Happy New Year!) to the group
tnx es 73
Bruce - W3NJ
Hi,
My updated prediction for the decay of ARISSat 1: January 4, 10:00 UTC +/- 18 hours.
Recent predictions from other sources: - USSTRATCOM TIP message: January 4, 07:46 UTC +/- 48 hours - Aerospace: January 4, 07:34 UTC +/- 28 hours (http://reentrynews.aero.org/1998067ck.html).
73, Nico PA0DLO
On 2011-12-31 15:46, Nico Janssen wrote:
Hi,
My prediction for the decay of ARISSat 1 still stays on the same date: January 4 +/- 1 day.
As the aerodynamic drag increases, the telemetry of the satellite should show ever higher temperatures in the coming days. Especially interesting is the data from the Kursk experiment, that measures the density of the air around the satellite.
Happy New Year to all!
73, Nico PA0DLO
On 2011-12-22 16:15, Nico Janssen wrote:
Hi,
My current prediction for the decay of ARISSat 1 is January 4, 2012, +/- 3 days. If solar and geomagnetic activity really increase before the end of December, as some predictions suggest, the decay may be a few days earlier.
73, Nico PA0DLO
On 2011-12-11 15:24, Nico Janssen wrote:
Hi,
Solar activity has remained at relatively low levels. There have not been any M or X class solar flares nor magnetic storms in the past several weeks. As a result, the expected decay date of ARISSat 1 has shifted into January. It is now to be expected around January 3, but depending on solar activity it may be more than 5 days later or earlier.
73, Nico PA0DLO
On 2011-11-28 21:36, Nico Janssen wrote:
Hi,
With its relatively high area to mass ratio, ARISSat 1 is quite sensitive to space weather changes. In the past two weeks solar flux values have been relatively low, around 140, while they were around 180 in the weeks before. Also there have not been any magnetic storms.
As a result of this low solar activity, the expected decay date of ARISSat 1 has now slipped to the end of December. My current prediction is 27 December. But if solar activity stays at these low levels, the decay date will even shift into early January. So it is still too early to make any sensible predictions.
73, Nico PA0DLO
On 2011-11-18 15:05, Nico Janssen wrote:
Hi,
So far all my analyses of the evolution of the orbit of ARISSat 1 have resulted in a predicted decay date sometime in December 2011. Actually my current predicted decay date for this satellite is December 17. Obviously it depends very much on how solar activity develops in the coming weeks.
So now we have seen decay predictions ranging from December 2011 to April 2012. Let's see how we converge to the actual decay date.
73, Nico PA0DLO
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
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
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,
My updated prediction for the decay of ARISSat 1: January 4, 18:00 UTC ± 12 hours.
Recent predictions from other sources: - USSTRATCOM TIP message: January 4, 12:06 UTC ± 24 hours - Aerospace: January 4, 07:34 UTC ± 28 hours (http://reentrynews.aero.org/1998067ck.html).
73, Nico PA0DLO
On 2012-01-01 15:49, Nico Janssen wrote:
Hi,
My updated prediction for the decay of ARISSat 1: January 4, 10:00 UTC +/- 18 hours.
Recent predictions from other sources:
- USSTRATCOM TIP message:
January 4, 07:46 UTC +/- 48 hours
- Aerospace:
January 4, 07:34 UTC +/- 28 hours (http://reentrynews.aero.org/1998067ck.html).
73, Nico PA0DLO
On 2011-12-31 15:46, Nico Janssen wrote:
Hi,
My prediction for the decay of ARISSat 1 still stays on the same date: January 4 +/- 1 day.
As the aerodynamic drag increases, the telemetry of the satellite should show ever higher temperatures in the coming days. Especially interesting is the data from the Kursk experiment, that measures the density of the air around the satellite.
Happy New Year to all!
73, Nico PA0DLO
On 2011-12-22 16:15, Nico Janssen wrote:
Hi,
My current prediction for the decay of ARISSat 1 is January 4, 2012, +/- 3 days. If solar and geomagnetic activity really increase before the end of December, as some predictions suggest, the decay may be a few days earlier.
73, Nico PA0DLO
On 2011-12-11 15:24, Nico Janssen wrote:
Hi,
Solar activity has remained at relatively low levels. There have not been any M or X class solar flares nor magnetic storms in the past several weeks. As a result, the expected decay date of ARISSat 1 has shifted into January. It is now to be expected around January 3, but depending on solar activity it may be more than 5 days later or earlier.
73, Nico PA0DLO
On 2011-11-28 21:36, Nico Janssen wrote:
Hi,
With its relatively high area to mass ratio, ARISSat 1 is quite sensitive to space weather changes. In the past two weeks solar flux values have been relatively low, around 140, while they were around 180 in the weeks before. Also there have not been any magnetic storms.
As a result of this low solar activity, the expected decay date of ARISSat 1 has now slipped to the end of December. My current prediction is 27 December. But if solar activity stays at these low levels, the decay date will even shift into early January. So it is still too early to make any sensible predictions.
73, Nico PA0DLO
On 2011-11-18 15:05, Nico Janssen wrote:
Hi,
So far all my analyses of the evolution of the orbit of ARISSat 1 have resulted in a predicted decay date sometime in December 2011. Actually my current predicted decay date for this satellite is December 17. Obviously it depends very much on how solar activity develops in the coming weeks.
So now we have seen decay predictions ranging from December 2011 to April 2012. Let's see how we converge to the actual decay date.
73, Nico PA0DLO
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
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
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
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,
My updated (and probably last) prediction for the decay of ARISSat 1: January 4, 09:00 UTC ± 5 hours.
Recent predictions from other sources: - USSTRATCOM TIP message: January 4, 05:34 UTC ± 11 hours - Aerospace: January 4, 07:35 UTC ± 4 hours (http://reentrynews.aero.org/1998067ck.html).
For those who would like to track ARISSat 1 till the very end, but who do not have access to the latest orbital data, I have generated the following two-line element sets.
After 2012-01-04, 01:10 UTC, use this set: 1 37772U 98067CK 12004.04907143 .10590547 82197-1 80387-3 0 94757 2 37772 51.6192 213.1232 0005039 247.4614 112.4853 16.39580411 24076
After 2012-01-04, 02:35 UTC, use this set: 1 37772U 98067CK 12004.10999442 .12344606 11664+0 78957-3 0 94751 2 37772 51.6188 212.7785 0004712 247.7188 112.2313 16.40971462 24087
After 2012-01-04, 04:05 UTC, use this set: 1 37772U 98067CK 12004.17086135 .14945730 18056+0 77289-3 0 94750 2 37772 51.6183 212.4335 0004334 247.9765 111.9774 16.42620927 24090
After 2012-01-04, 05:30 UTC, use this set: 1 37772U 98067CK 12004.23166040 .19278117 32316+0 63018-3 0 94754 2 37772 51.6178 212.0879 0003875 248.2346 111.7241 16.44675832 24107
After 2012-01-04, 07:00 UTC, use this set: 1 37772U 98067CK 12004.29237155 .28278236 77737+0 51650-3 0 94753 2 37772 51.6170 211.7417 0003268 248.4933 111.4719 16.47481875 24116
73, Nico PA0DLO
On 2012-01-02 16:38, Nico Janssen wrote:
Hi,
My updated prediction for the decay of ARISSat 1: January 4, 18:00 UTC ± 12 hours.
Recent predictions from other sources:
- USSTRATCOM TIP message:
January 4, 12:06 UTC ± 24 hours
- Aerospace:
January 4, 07:34 UTC ± 28 hours (http://reentrynews.aero.org/1998067ck.html).
73, Nico PA0DLO
On 2012-01-01 15:49, Nico Janssen wrote:
Hi,
My updated prediction for the decay of ARISSat 1: January 4, 10:00 UTC +/- 18 hours.
Recent predictions from other sources:
- USSTRATCOM TIP message:
January 4, 07:46 UTC +/- 48 hours
- Aerospace:
January 4, 07:34 UTC +/- 28 hours (http://reentrynews.aero.org/1998067ck.html).
73, Nico PA0DLO
On 2011-12-31 15:46, Nico Janssen wrote:
Hi,
My prediction for the decay of ARISSat 1 still stays on the same date: January 4 +/- 1 day.
As the aerodynamic drag increases, the telemetry of the satellite should show ever higher temperatures in the coming days. Especially interesting is the data from the Kursk experiment, that measures the density of the air around the satellite.
Happy New Year to all!
73, Nico PA0DLO
On 2011-12-22 16:15, Nico Janssen wrote:
Hi,
My current prediction for the decay of ARISSat 1 is January 4, 2012, +/- 3 days. If solar and geomagnetic activity really increase before the end of December, as some predictions suggest, the decay may be a few days earlier.
73, Nico PA0DLO
On 2011-12-11 15:24, Nico Janssen wrote:
Hi,
Solar activity has remained at relatively low levels. There have not been any M or X class solar flares nor magnetic storms in the past several weeks. As a result, the expected decay date of ARISSat 1 has shifted into January. It is now to be expected around January 3, but depending on solar activity it may be more than 5 days later or earlier.
73, Nico PA0DLO
On 2011-11-28 21:36, Nico Janssen wrote:
Hi,
With its relatively high area to mass ratio, ARISSat 1 is quite sensitive to space weather changes. In the past two weeks solar flux values have been relatively low, around 140, while they were around 180 in the weeks before. Also there have not been any magnetic storms.
As a result of this low solar activity, the expected decay date of ARISSat 1 has now slipped to the end of December. My current prediction is 27 December. But if solar activity stays at these low levels, the decay date will even shift into early January. So it is still too early to make any sensible predictions.
73, Nico PA0DLO
On 2011-11-18 15:05, Nico Janssen wrote: > Hi, > > So far all my analyses of the evolution of the orbit of ARISSat 1 > have resulted in a predicted decay date sometime in December 2011. > Actually my current predicted decay date for this satellite is > December 17. Obviously it depends very much on how solar activity > develops in the coming weeks. > > So now we have seen decay predictions ranging from December 2011 > to April 2012. Let's see how we converge to the actual decay date. > > 73, > Nico PA0DLO > > _______________________________________________ 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
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
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
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
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,
Unfortunately my previous message did not make it through the BB because it was down.
As expected, ARISSat 1 has now decayed. According to the first "Final Report" of USSTRATCOM their last decay prediction was at 07:00 UTC +/- 3 hours on January 4, 2012, during an ascending pass in orbit 2411 when the satellite was near 12.7 S, 354.3 E. The latest report from Aerospace shows their decay prediction at 07:40 UTC ± 100 minutes on January 4, 2012.
Since USSTRATCOM usually issues two or three "Final Reports", we have to wait for the real final verdict.
73, Nico PA0DLO
On 2012-01-03 21:39, Nico Janssen wrote:
Hi,
My updated (and probably last) prediction for the decay of ARISSat 1: January 4, 09:00 UTC ± 5 hours.
Recent predictions from other sources:
- USSTRATCOM TIP message:
January 4, 05:34 UTC ± 11 hours
- Aerospace:
January 4, 07:35 UTC ± 4 hours (http://reentrynews.aero.org/1998067ck.html).
For those who would like to track ARISSat 1 till the very end, but who do not have access to the latest orbital data, I have generated the following two-line element sets.
After 2012-01-04, 01:10 UTC, use this set: 1 37772U 98067CK 12004.04907143 .10590547 82197-1 80387-3 0 94757 2 37772 51.6192 213.1232 0005039 247.4614 112.4853 16.39580411 24076
After 2012-01-04, 02:35 UTC, use this set: 1 37772U 98067CK 12004.10999442 .12344606 11664+0 78957-3 0 94751 2 37772 51.6188 212.7785 0004712 247.7188 112.2313 16.40971462 24087
After 2012-01-04, 04:05 UTC, use this set: 1 37772U 98067CK 12004.17086135 .14945730 18056+0 77289-3 0 94750 2 37772 51.6183 212.4335 0004334 247.9765 111.9774 16.42620927 24090
After 2012-01-04, 05:30 UTC, use this set: 1 37772U 98067CK 12004.23166040 .19278117 32316+0 63018-3 0 94754 2 37772 51.6178 212.0879 0003875 248.2346 111.7241 16.44675832 24107
After 2012-01-04, 07:00 UTC, use this set: 1 37772U 98067CK 12004.29237155 .28278236 77737+0 51650-3 0 94753 2 37772 51.6170 211.7417 0003268 248.4933 111.4719 16.47481875 24116
73, Nico PA0DLO
On 2012-01-02 16:38, Nico Janssen wrote:
Hi,
My updated prediction for the decay of ARISSat 1: January 4, 18:00 UTC ± 12 hours.
Recent predictions from other sources:
- USSTRATCOM TIP message:
January 4, 12:06 UTC ± 24 hours
- Aerospace:
January 4, 07:34 UTC ± 28 hours (http://reentrynews.aero.org/1998067ck.html).
73, Nico PA0DLO
On 2012-01-01 15:49, Nico Janssen wrote:
Hi,
My updated prediction for the decay of ARISSat 1: January 4, 10:00 UTC +/- 18 hours.
Recent predictions from other sources:
- USSTRATCOM TIP message:
January 4, 07:46 UTC +/- 48 hours
- Aerospace:
January 4, 07:34 UTC +/- 28 hours (http://reentrynews.aero.org/1998067ck.html).
73, Nico PA0DLO
On 2011-12-31 15:46, Nico Janssen wrote:
Hi,
My prediction for the decay of ARISSat 1 still stays on the same date: January 4 +/- 1 day.
As the aerodynamic drag increases, the telemetry of the satellite should show ever higher temperatures in the coming days. Especially interesting is the data from the Kursk experiment, that measures the density of the air around the satellite.
Happy New Year to all!
73, Nico PA0DLO
On 2011-12-22 16:15, Nico Janssen wrote:
Hi,
My current prediction for the decay of ARISSat 1 is January 4, 2012, +/- 3 days. If solar and geomagnetic activity really increase before the end of December, as some predictions suggest, the decay may be a few days earlier.
73, Nico PA0DLO
On 2011-12-11 15:24, Nico Janssen wrote:
Hi,
Solar activity has remained at relatively low levels. There have not been any M or X class solar flares nor magnetic storms in the past several weeks. As a result, the expected decay date of ARISSat 1 has shifted into January. It is now to be expected around January 3, but depending on solar activity it may be more than 5 days later or earlier.
73, Nico PA0DLO
On 2011-11-28 21:36, Nico Janssen wrote: > Hi, > > With its relatively high area to mass ratio, ARISSat 1 is > quite sensitive to space weather changes. In the past two > weeks solar flux values have been relatively low, around > 140, while they were around 180 in the weeks before. Also > there have not been any magnetic storms. > > As a result of this low solar activity, the expected decay > date of ARISSat 1 has now slipped to the end of December. > My current prediction is 27 December. But if solar activity > stays at these low levels, the decay date will even shift > into early January. So it is still too early to make any > sensible predictions. > > 73, > Nico PA0DLO > > > On 2011-11-18 15:05, Nico Janssen wrote: >> Hi, >> >> So far all my analyses of the evolution of the orbit of ARISSat 1 >> have resulted in a predicted decay date sometime in December 2011. >> Actually my current predicted decay date for this satellite is >> December 17. Obviously it depends very much on how solar activity >> develops in the coming weeks. >> >> So now we have seen decay predictions ranging from December 2011 >> to April 2012. Let's see how we converge to the actual decay date. >> >> 73, >> Nico PA0DLO >> >> > _______________________________________________ > 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 >
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
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
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
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
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 (6)
-
Bruce -
Fabio Azzarello -
John Heath -
Ken Ernandes -
Nico Janssen -
Tom Williams