PIONEER chronology |
PIONEER chronology |
May 4 2009, 07:58 PM
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#46
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Junior Member Group: Members Posts: 45 Joined: 18-July 05 Member No.: 439 |
After consulting JPL's NSSDC and Horizons websites, it seems that Saturn closest approach was at 01 Sep 1979 16:29:34 UTC at an altitude of 20,591 km (using a Saturn radius of 60,268 km). Umm, in http://trs-new.jpl.nasa.gov/dspace/bitstre...5/1/03-0282.pdf actual TCA is given as 16:30:34. |
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May 7 2009, 02:28 AM
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#47
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Member Group: Members Posts: 340 Joined: 11-April 08 From: Sydney, Australia Member No.: 4093 |
Pioneer 11 had a fairly close flyby of Atlas at 45,960km on 1 Sep 1979 15:06:32. To put it into perspective ... Cassini got closer to Atlas only once so far AFAIK!
Umm, in http://trs-new.jpl.nasa.gov/dspace/bitstre...5/1/03-0282.pdf actual TCA is given as 16:30:34. I suspect that time is ET, which converts to 16:29:44 UTC. That's just 10 seconds off the times in Horizons. And at the time of C/A, the altitude doesnt change much so I'd take both times as being "equal enough" :-) -------------------- |
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Guest_PhilCo126_* |
Jun 17 2009, 03:38 PM
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#48
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Guests |
We're ready for the upcoming 30th anniversary of the Pioneer 11 - Saturn flyby:
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Jun 17 2009, 11:18 PM
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#49
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Member Group: Members Posts: 340 Joined: 11-April 08 From: Sydney, Australia Member No.: 4093 |
Beautiful! And we're nearly there, 75 days and 57 million km to go ... historic realtime simulation (well, 30 years "late")
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Jul 22 2009, 01:39 PM
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#50
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Junior Member Group: Members Posts: 45 Joined: 18-July 05 Member No.: 439 |
QUOTE (Liss) Umm, in http://trs-new.jpl.nasa.gov/dspace/bitstre...5/1/03-0282.pdf actual TCA is given as 16:30:34. I suspect that time is ET, which converts to 16:29:44 UTC. That's just 10 seconds off the times in Horizons. And at the time of C/A, the altitude doesnt change much so I'd take both times as being "equal enough" :-) The really strange thing is that NASA Release 79-108 issued August 22, 1979, lists all the events of Pioneer 11 Saturn encounter of September 1 against the TCA time of 18:00 UTC ERT = 16:34 UTC SCET, even if DSN Progress Report 42-53 lists the future TCA as 17:56 UTC ERT = 16:30 UTC SCET which fits nicely with post-flyby estimates. I cannot understand why NASA was off by four minutes just 10 days before the event. |
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Apr 9 2020, 10:09 PM
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#51
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Junior Member Group: Members Posts: 45 Joined: 18-July 05 Member No.: 439 |
I suspect that time is ET, which converts to 16:29:44 UTC. That's just 10 seconds off the times in Horizons. And at the time of C/A, the altitude doesnt change much so I'd take both times as being "equal enough" :-) No it's not correct. Null et al. in https://ui.adsabs.harvard.edu/abs/1981AJ.....86..456N said Pioneer 11 CA was at 16:31:24 ET (spacecraft time). It fits with 16:30:34 UTC as listed by Campbell and Anderson (1989) and Jacobson (2003). . Also, there was an error in my list of Pioneer 11 Jupiter timeline. Unfortunately it did it to Wiki. Tp+01h 08m = 22:29 - Amalthea, 127500 km should read Tp+01h 08m = 06:29 - Amalthea, 127500 km . And of course, in Pioneer 11 Saturn timeline Tp-00h 30m = 16:04 - Dione, 291100 km Tp-00h 07m = 16:27 - Dione, 291100 km should read Tp-00h 30m = 16:04 - Dione, 291100 km Tp-00h 07m = 16:27 - Mimas, 104210 km |
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