Since this is journalism, I think you and some others are right. If one simply looks at latitude as a number, then the latitude near the inclination will have a higher probability of appearing. But the best feedback came from Ralph W0RPK who pointed out this page which is tracking the orbit with updated predictions: http://www.aerospace.org/CORDSuploads/TiangongStoryboard.png
And the USA is about as far as you can get from the predicted impact. The USA is 12 hours out of cycle with the orbit.
The prediction there is currently showing about 0000 UTC which is 8 PM EDT plus or minus 2.5 hours. (which is about 3 orbits worth). And although those orbits cover a vast Pacific and Atlantic oceans, a good portion of them cross the middle east through Russia and china.
Bob, WB4APR
On Sun, Apr 1, 2018 at 11:26 AM, Gary Bender, WS5N [email protected] wrote:
I was thinking the favoring of higher latitudes for reentry was because the apparent sine wave of the ground track naturally slows down in "latitude velocity" as it peaks at 43 degrees and reverses. Add in the rotation of the earth under it and you end up with a bit more dwell time above 38 degrees. It is changing latitude much faster between the extremes. (Or maybe I am over thinking it.) -- Gary, WS5N
----- Original Message ----- From: "Robert Bruninga" [email protected] To: "amsat bb" [email protected] Cc: "TAPR APRS Mailing List" [email protected] Sent: Saturday, March 31, 2018 5:55:17 PM Subject: Re: [aprssig] [amsat-bb] Tiangong Re-entry on Heavens bove
Hi Bob, do you know the object number by chance?
No, but this link shows that the higher probabilities or re-entry are between about 38 to 43 degree latitudes north and south.
https://www.theguardian.com/science/2018/mar/30/chinas-tiangong-1-space-st ation-will-crash-to-earth-this-weekend https://www.theguardian.com/science/2018/mar/30/chinas-tiangong-1-space-st%0Aation-will-crash-to-earth-this-weekend
Im not sure why those would be slightly higher. 43 degrees is its maximum excursion (matches its inclination)... Maybe its because as it passes over the equatorial bulge, it sees the higher drag and that will start the demise which will occur then 20 minutes later?
Bob -----Original Message----- From: Robert Bruninga Sent: Saturday, March 31, 2018 9:16 AM Subject: [amsat-bb] Tiangong Re-enetry on Heavens bove
You can see the live track of Taengong to re-enter in the next 24 hours on http://www.heavens-above.com/
Just remember, as it suffers increased drag, it will speed up and be ahead of classic predictions.
But at least you can see when you are under the orbit as to whether it is worth going outside. I 'd go out several minutes before the prediction since we dont know how quickly they are updating the elements as it speeds up.
and even if it is daytime, you will see it if it comes in in your area...
Bob _______________________________________________ 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 _______________________________________________ aprssig mailing list [email protected] http://www.tapr.org/mailman/listinfo/aprssig
I just updated the keps on gPredict, and Tiangong-1 disappeared from the list. Where'd it come down, or are rumors of its demise ever so slightly exaggerated? Heavens-above still thinks it's up there.
Greg KO6TH
Robert Bruninga wrote:
Since this is journalism, I think you and some others are right. If one simply looks at latitude as a number, then the latitude near the inclination will have a higher probability of appearing. But the best feedback came from Ralph W0RPK who pointed out this page which is tracking the orbit with updated predictions: http://www.aerospace.org/CORDSuploads/TiangongStoryboard.png
And the USA is about as far as you can get from the predicted impact. The USA is 12 hours out of cycle with the orbit.
The prediction there is currently showing about 0000 UTC which is 8 PM EDT plus or minus 2.5 hours. (which is about 3 orbits worth). And although those orbits cover a vast Pacific and Atlantic oceans, a good portion of them cross the middle east through Russia and china.
Bob, WB4APR
On Sun, Apr 1, 2018 at 11:26 AM, Gary Bender, WS5N [email protected] wrote:
I was thinking the favoring of higher latitudes for reentry was because the apparent sine wave of the ground track naturally slows down in "latitude velocity" as it peaks at 43 degrees and reverses. Add in the rotation of the earth under it and you end up with a bit more dwell time above 38 degrees. It is changing latitude much faster between the extremes. (Or maybe I am over thinking it.) -- Gary, WS5N
----- Original Message ----- From: "Robert Bruninga" [email protected] To: "amsat bb" [email protected] Cc: "TAPR APRS Mailing List" [email protected] Sent: Saturday, March 31, 2018 5:55:17 PM Subject: Re: [aprssig] [amsat-bb] Tiangong Re-entry on Heavens bove
Hi Bob, do you know the object number by chance?
No, but this link shows that the higher probabilities or re-entry are between about 38 to 43 degree latitudes north and south.
https://www.theguardian.com/science/2018/mar/30/chinas-tiangong-1-space-st ation-will-crash-to-earth-this-weekend https://www.theguardian.com/science/2018/mar/30/chinas-tiangong-1-space-st%0Aation-will-crash-to-earth-this-weekend
Im not sure why those would be slightly higher. 43 degrees is its maximum excursion (matches its inclination)... Maybe its because as it passes over the equatorial bulge, it sees the higher drag and that will start the demise which will occur then 20 minutes later?
Bob -----Original Message----- From: Robert Bruninga Sent: Saturday, March 31, 2018 9:16 AM Subject: [amsat-bb] Tiangong Re-enetry on Heavens bove
You can see the live track of Taengong to re-enter in the next 24 hours on http://www.heavens-above.com/
Just remember, as it suffers increased drag, it will speed up and be ahead of classic predictions.
But at least you can see when you are under the orbit as to whether it is worth going outside. I 'd go out several minutes before the prediction since we dont know how quickly they are updating the elements as it speeds up.
and even if it is daytime, you will see it if it comes in in your area...
Bob _______________________________________________ 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 _______________________________________________ aprssig mailing list [email protected] http://www.tapr.org/mailman/listinfo/aprssig
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
http://www.aerospace.org/CORDSuploads/TiangongStoryboard.png
Shows it on what's expected to be it's last orbit.
73, Roger W7TZ CN83ia Grid Busters w7tz.webs.com
On Sun, Apr 1, 2018 at 5:03 PM, Greg D [email protected] wrote:
I just updated the keps on gPredict, and Tiangong-1 disappeared from the list. Where'd it come down, or are rumors of its demise ever so slightly exaggerated? Heavens-above still thinks it's up there.
Greg KO6TH
Robert Bruninga wrote:
Since this is journalism, I think you and some others are right. If one simply looks at latitude as a number, then the latitude near the inclination will have a higher probability of appearing. But the best feedback came from Ralph W0RPK who pointed out this page which is
tracking
the orbit with updated predictions: http://www.aerospace.org/CORDSuploads/TiangongStoryboard.png
And the USA is about as far as you can get from the predicted impact.
The
USA is 12 hours out of cycle with the orbit.
The prediction there is currently showing about 0000 UTC which is 8 PM
EDT
plus or minus 2.5 hours. (which is about 3 orbits worth). And although those orbits cover a vast Pacific and Atlantic oceans, a good portion of them cross the middle east through Russia and china.
Bob, WB4APR
On Sun, Apr 1, 2018 at 11:26 AM, Gary Bender, WS5N [email protected] wrote:
I was thinking the favoring of higher latitudes for reentry was because the apparent sine wave of the ground track naturally slows down in "latitude velocity" as it peaks at 43 degrees and reverses. Add in the rotation of the earth under it and you end up with a bit more dwell time above 38 degrees. It is changing latitude much faster between the extremes. (Or maybe I am over thinking it.) -- Gary, WS5N
----- Original Message ----- From: "Robert Bruninga" [email protected] To: "amsat bb" [email protected] Cc: "TAPR APRS Mailing List" [email protected] Sent: Saturday, March 31, 2018 5:55:17 PM Subject: Re: [aprssig] [amsat-bb] Tiangong Re-entry on Heavens bove
Hi Bob, do you know the object number by chance?
No, but this link shows that the higher probabilities or re-entry are between about 38 to 43 degree latitudes north and south.
tiangong-1-space-st
ation-will-crash-to-earth-this-weekend <https://www.theguardian.com/science/2018/mar/30/chinas-
tiangong-1-space-st%0Aation-will-crash-to-earth-this-weekend>
Im not sure why those would be slightly higher. 43 degrees is its
maximum
excursion (matches its inclination)... Maybe its because as it passes over the equatorial bulge, it sees the higher drag and that will start
the
demise which will occur then 20 minutes later?
Bob -----Original Message----- From: Robert Bruninga Sent: Saturday, March 31, 2018 9:16 AM Subject: [amsat-bb] Tiangong Re-enetry on Heavens bove
You can see the live track of Taengong to re-enter in the next 24 hours
on
Just remember, as it suffers increased drag, it will speed up and be
ahead
of classic predictions.
But at least you can see when you are under the orbit as to whether it
is
worth going outside. I 'd go out several minutes before the prediction since we dont know how quickly they are updating the elements as it
speeds
up.
and even if it is daytime, you will see it if it comes in in your
area...
Bob _______________________________________________ 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 _______________________________________________ aprssig mailing list [email protected] http://www.tapr.org/mailman/listinfo/aprssig
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
participants (3)
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Greg D -
Robert Bruninga -
Roger