PIONEER chronology |
PIONEER chronology |
Guest_PhilCo126_* |
Jan 4 2008, 05:35 PM
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#1
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Just thought I would start a similar topic as the 'VOYAGER chronology' ... of course with nice diagrams
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Guest_PhilCo126_* |
Apr 9 2008, 04:59 PM
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#2
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Hundred days without reply in this interesting topic, so I'll post an add-on:
Pioneer 11 encounter with planet Saturn It was an important decision by NASA-Ames Research to perform a low-risk flyby of Saturn outside Saturn's rings the other Phil |
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Apr 18 2008, 05:05 AM
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#3
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Member Group: Members Posts: 340 Joined: 11-April 08 From: Sydney, Australia Member No.: 4093 |
I can offer the following chronology ... not mind-boggling, but at least something (apologies for the layout):
Pioneer 10 03 Mar 1972 (01:49) Launch 15 Jul 1972 Enters Asteroid Belt 03 Dec 1973 200,000 km Jupiter Fly-By 31 Mar 1997 End of science mission 27 Apr 2002 Last telemetry data received 23 Jan 2003 Last signal received 04 Mar 2006 Last attempt to acquire signal fails in 126,000 years No longer dominated by gravitational force of sun in 2 million years Aldebean Fly-By Pioneer 11 06 Apr 1973 (02:11) Launch 02 Dec 1974 34,000 km Jupiter Fly-By 01 Sep 1979 21,000 km Saturn Fly-By 30 Sep 1995 End of science mission 30 Nov 1995 Last signal received in 4 million years Lambda Aquilla Fly-By -------------------- |
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Apr 18 2008, 03:27 PM
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#4
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Member Group: Members Posts: 648 Joined: 9-May 05 From: Subotica Member No.: 384 |
in 2 million years Aldebean Fly-By I was just about to ask will it be a close flyby then I remembered that it does not carry a camera....so I guess no nice images.... -------------------- The scientist does not study nature because it is useful; he studies it because he delights in it, and he delights in it because it is beautiful.
Jules H. Poincare My "Astrophotos" gallery on flickr... |
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Apr 18 2008, 03:55 PM
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#5
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Senior Member Group: Admin Posts: 4763 Joined: 15-March 05 From: Glendale, AZ Member No.: 197 |
Pioneer 10 does have a camera.
-------------------- If Occam had heard my theory, things would be very different now.
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Guest_PhilCo126_* |
Apr 18 2008, 05:03 PM
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#6
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Indeed it was crucial to have a camera onboard, in fact a special instrument better known as " Imaging Photo-polarimeter "
It measured the faint glows in interplanetary space of the zodiacal light, the Gegenschein and it scanned the planets and moons... |
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Guest_PhilCo126_* |
Apr 18 2008, 05:44 PM
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#7
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The incredible Saturn flyby by Pioneer 11 in September 1979, next year 30 years ago!
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Apr 19 2008, 01:00 AM
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#8
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Merciless Robot Group: Admin Posts: 8784 Joined: 8-December 05 From: Los Angeles Member No.: 602 |
What a year 1979 was...V1 @ Jupiter in March, V2 there in July, and Pioneer @ Saturn in September. (On a personal note, I also got to see a total solar eclipse in February). I'll bet a lot of people got hooked on space that year.
-------------------- A few will take this knowledge and use this power of a dream realized as a force for change, an impetus for further discovery to make less ancient dreams real.
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Apr 19 2008, 01:26 AM
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#9
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Senior Member Group: Admin Posts: 4763 Joined: 15-March 05 From: Glendale, AZ Member No.: 197 |
I bought my first car in 1979.
-------------------- If Occam had heard my theory, things would be very different now.
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Apr 19 2008, 08:07 AM
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#10
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Founder Group: Chairman Posts: 14432 Joined: 8-February 04 Member No.: 1 |
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Apr 19 2008, 02:08 PM
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#11
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Merciless Robot Group: Admin Posts: 8784 Joined: 8-December 05 From: Los Angeles Member No.: 602 |
<grumble>...bloody young whippersnapper...</grumble>
<gloat>...nyah, nyah, Doug, me & EGD got to watch VL1, VL2, V1, V2, & P11 "live"!!! </gloat>... -------------------- A few will take this knowledge and use this power of a dream realized as a force for change, an impetus for further discovery to make less ancient dreams real.
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Apr 19 2008, 02:19 PM
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#12
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Interplanetary Dumpster Diver Group: Admin Posts: 4404 Joined: 17-February 04 From: Powell, TN Member No.: 33 |
The most important day of that year was the 24th of January. Far eclipsed the Voyager and Pioneer missions.
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Apr 19 2008, 03:13 PM
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#13
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Member Group: Members Posts: 813 Joined: 8-February 04 From: Arabia Terra Member No.: 12 |
I've just realized that New Horizons passing beyond the orbit of Saturn will be the first time in my life that a spacecraft has traversed this distance. In 1982 the Voyager encounters with Saturn were long past.
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Apr 19 2008, 03:28 PM
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#14
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Interplanetary Dumpster Diver Group: Admin Posts: 4404 Joined: 17-February 04 From: Powell, TN Member No.: 33 |
One exciting thing to think about. Pioneer flew by Saturn just before the 1979-1980 ring plane crossing. 28 years later, the 2009 ring plane crossing is identical. Voyager 1 flew by soon after in 1980, and Voyager 2 flew by in 1981, with the rings appearing much brighter because of the wider illumination angle. In a sense, that period was almost like having an orbiter make three gigantic orbits. The fact that Cassini will follow the exact same seasonal sequence over the next three or four years should make for some very interesting comparisons.
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Guest_PhilCo126_* |
Apr 19 2008, 04:59 PM
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#15
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That's an astronomer speaking ( Saturn's rings appear much narrower in 2008 & 2009 )
However for Pioneer 11's passage of Saturn, NASA had 2 options. They've chosen the safer trajectory. Those interested in the complete background story of selecting Pioneer 11's flyby option of Saturn, can turn to: Quest - The History of Spaceflight Quarterly ( Volume 7 number 4 - Spring 2000 ) Pathfinding the Rings: The Pioneer Saturn Trajectory Decision ( By Mark Wolverton ) |
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Apr 19 2008, 07:19 PM
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#16
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Interplanetary Dumpster Diver Group: Admin Posts: 4404 Joined: 17-February 04 From: Powell, TN Member No.: 33 |
( Saturn's rings appear much narrower in 2008 & 2009 ) No, it is exactly the same pass as the 1979-80 crossing. -------------------- |
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Apr 21 2008, 10:56 PM
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#17
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Member Group: Members Posts: 813 Joined: 29-December 05 From: NE Oh, USA Member No.: 627 |
Interesting to note that CASSINI XXM end trajectory will be quite similar to the INSIDE ring passage
rejected for PIONEER 11 at Saturn... http://planetary.org/blog/article/00001392/ The Perils of PIONEER 11 http://www.geocities.com/CapeCanaveral/Lau.../2099/9711.html "The more daring trajectory would take Pioneer inside the rings, with closest approach about halfway between the cloud tops and the innermost edge of the main rings. This was a relatively dangerous area, because there was known to be at least one faint ring inside the main ones. The estimated probability of spacecraft survival ranged from over 99% to under 1%, depending on whose ring-density model you believed. The payoff was a unique opportunity to observe Saturn and its magnetosphere up close, using an old spacecraft whose useful life was nearly over anyway. However, actually losing the spacecraft at the ring-plane crossing would considerably reduce the data return. After a long debate, the principal investigators who ran Pioneer's instruments voted 11 to 1 in favor of this "inside" mission. The more conservative "outside" plan specified two ring-plane crossings, both well outside the visible rings. The chosen distances for the crossings matched the flyby distance needed for Voyager 2 if it were to reach Uranus. The Voyager planners, given a unique and irreplaceable opportunity to visit two more planets, badly wanted to know if that distance presented any risks to their spacecraft. Such a flyby was also much safer for Pioneer, assuring Saturn data return after ring-plane crossing and also providing for a continued mission on into deep space. The final decision was made at NASA Headquarters: Using Pioneer as a pathfinder for the Voyager Uranus-Neptune mission was more important than getting maximum return from the Pioneer flyby alone. Pioneer would take the relatively safe "outside" trajectory. " In 1979, my son David turned two...... my daughter was a plan in waiting.... Craig |
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Apr 21 2008, 11:47 PM
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#18
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Member Group: Members Posts: 340 Joined: 11-April 08 From: Sydney, Australia Member No.: 4093 |
Pioneer would take the relatively safe "outside" trajectory. " Only to nearly crash into a then-unknown but photographed moon, possibly being Janus or Epimetheus -------------------- |
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Apr 22 2008, 08:44 PM
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#19
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Interplanetary Dumpster Diver Group: Admin Posts: 4404 Joined: 17-February 04 From: Powell, TN Member No.: 33 |
Only to nearly crash into a then-unknown but photographed moon, possibly being Janus or Epimetheus Well, ~2500 km isn't exactly the near miss it is often made out to be, but it still led to some nail-biting. -------------------- |
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Apr 23 2008, 07:00 AM
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#20
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Member Group: Members Posts: 340 Joined: 11-April 08 From: Sydney, Australia Member No.: 4093 |
Well, ~2500 km isn't exactly the near miss it is often made out to be, but it still led to some nail-biting. Any good reference on the latest analysis of that "encounter"? It would make a good line on my website. Just by looking at it, it remained the closest flyby of an outer-planet moon until Galileo's Io swing-by during its Jupiter orbit insertion. -------------------- |
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Apr 24 2008, 03:54 PM
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#21
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Special Cookie Group: Members Posts: 2168 Joined: 6-April 05 From: Sintra | Portugal Member No.: 228 |
What a year 1979 was... At least it gave the title to one of my 10 favourite musics ever... ...And I was about to go to school...those were the days... -------------------- "Ride, boldly ride," The shade replied, "If you seek for Eldorado!"
Edgar Alan Poe |
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Apr 24 2008, 04:08 PM
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#22
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Interplanetary Dumpster Diver Group: Admin Posts: 4404 Joined: 17-February 04 From: Powell, TN Member No.: 33 |
At least it gave the title to one of my 10 favourite musics ever... ...And I was about to go to school...those were the days... I love that song. -------------------- |
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Apr 24 2008, 04:25 PM
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#23
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Special Cookie Group: Members Posts: 2168 Joined: 6-April 05 From: Sintra | Portugal Member No.: 228 |
That's my Ted "Smashing" Stryk!
I sure need an extra top 10 only for them... -------------------- "Ride, boldly ride," The shade replied, "If you seek for Eldorado!"
Edgar Alan Poe |
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Apr 24 2008, 11:57 PM
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#24
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Merciless Robot Group: Admin Posts: 8784 Joined: 8-December 05 From: Los Angeles Member No.: 602 |
<dancing in my seat>...yeah, I love that song, too!
-------------------- A few will take this knowledge and use this power of a dream realized as a force for change, an impetus for further discovery to make less ancient dreams real.
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Guest_PhilCo126_* |
Dec 7 2008, 10:03 AM
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#25
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With the passed 35th anniversary of Pioneer 10 Jupiter flyby ( 03 Dec 1973 ) it's time to look forward to the 30th anniversary of the Pioneer 11 Saturn flyby ( 01 Sep 1979 ) as illustrated here:
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Guest_Enceladus75_* |
Dec 8 2008, 04:09 AM
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#26
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If I remember from reading an article years ago there was a proposal to fly Pioneer 11 through the Cassini Division of Saturn's rings as it was thought to be clear. Lucky they didn't because of course the Voyagers later found that it was by no means a clear division.
The historic Pioneer 10 flyby of Jupiter took place just over a year before I was born (and Pioneer 11 the month before) and for some reason in my mind the band Wings's song "Jet" seems to be a very appropriate number for the Pioneer 10 encounter.... Jet By Wings (1973) |
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Dec 8 2008, 06:30 PM
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#27
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Member Group: Members Posts: 378 Joined: 21-April 05 From: Portugal Member No.: 347 |
Here are two P10 images (A5 and A7) that I tried to correct for the planet's rotation and spacecraft motion. Still very rough, but I think that the relative positions of the cloud features are closer to reality, although there are still some scale issues.
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www.astrosurf.com/nunes |
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Mar 1 2009, 10:15 AM
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#28
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Junior Member Group: Members Posts: 45 Joined: 18-July 05 Member No.: 439 |
Well, a side question to Pioneer chronology...
In SP-446, Pioneer -- First to Jupiter, Saturn and Beyond, at p.79 one reads: On November 7, Pioneer crossed the orbit of Sinope, the outermost satellite of Jupiter. In the following few days, the spacecraft successively crossed the orbits of Pan (renamed Carame) and Andrastea (renamed Ananke). By November 21, Pioneer 11 had crossed the orbit of Hera (renamed Elara) at just over 11.75 million kilometers (7 million miles) from Jupiter; it later crossed the orbits of Demeter (renamed Lysithea) and Hestia (renamed Himalia). So what are those forgotten names for the satellites of Jupiter, what is the history behind? And what is "Pan (renamed Carame)" in the context of the 1974 flyby of Jupiter? And another quote from 1973: Early in the encounter, Pioneer crossed the orbit of Hades, first of Jupiter's four outer moons; the following day, it crossed the orbit of Pan. On November 11, it crossed Amdrastea's orbit. On November 22, eleven days later, Pioneer will reach and cross the orbits of the three middle moons, Demeter, Hera, and Hestia, located 11.3 million kilometers from Jupiter. On December 3, the day of encounter, the spacecraft will make its closest approach to all five of Jupiter's inner moons. Which one of the outer satellites is not mentioned? |
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Guest_PhilCo126_* |
Mar 1 2009, 06:34 PM
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#29
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Mar 3 2009, 08:12 PM
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#30
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Junior Member Group: Members Posts: 45 Joined: 18-July 05 Member No.: 439 |
No, PhilCo126. This reference does not contain the names in question. Of course, it's not a problem to find that names Hestia, Hera, Demeter, Andrastea, Pan, Poseidon, and Hades were given to the seven Jupiter moons, J VI through J XII, in 1955 and replaced in 1975 by the names we are used to see. I was asking about the story behind this short-lived nomenclature that was in official use during the Pioneer flybys. By the way, here in Russia I never heard of those old names earlier. Not because I was young in 1975 -- I've read a lot of books in astronomy which could contain them. |
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Mar 3 2009, 11:51 PM
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#31
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Newbie Group: Members Posts: 15 Joined: 28-November 08 From: Germany Member No.: 4498 |
Have a look at http://en.wikipedia.org/wiki/Naming_of_moons#Jupiter
The table lists the names proposed for Jupiter VI to Jupiter XIII from the 50s to 70s. The name Amalthea for Jupiter V was apparently proposed by Camille Flammarion shortly after its discovery in 1892. References 10 and 13 link to two Icarus papers that should discuss the nomenclature issues, but I can´t access them ringt now. |
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Mar 4 2009, 10:17 AM
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#32
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Junior Member Group: Members Posts: 45 Joined: 18-July 05 Member No.: 439 |
OK, speaking about chronology again. Here's the list of Pioneer 10 Jupiter flyby events (planned).
Times are evidently Spacecraft Event Time (SCET), UTC. 1973 Dec 03 Tp-14h 00m = 12:26 - Callisto, 1392300 km Tp-12h 30m = 13:56 - Ganymede, 446250 lm Tp-07h 00m = 19:26 - Europa, 321000 km Tp-03h 30m = 22:56 - Io, 357000 km 1973 Dec 04 Tp-00h 00m = 02:26:00 - Pericenter, H=130000 km Tp+00h 10m = 02:36 - Equator plane crossing Tp+00h 15m 45s = 02:41:45 - Io occultation entry Tp+00h 17m 16s = 02:43:16 - Io occultation exit Tp+01h 16m 25s = 03:42:25 - Jupiter occultation entry Tp+01h 49m 35s = 04:15:35 - Jupiter shadow entry Tp+02h 21m 21s = 04:47:21 - Jupiter occultation exit Tp+02h 41m = 05:07 - Jupiter shadow exit Note: for that day, ET = UTC + 44.184 sec, and ERT = SCET + 45 min 55 sec. |
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Mar 4 2009, 10:28 AM
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#33
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Junior Member Group: Members Posts: 45 Joined: 18-July 05 Member No.: 439 |
And here's the list of Pioneer 11 Jupiter flyby events (planned).
Times are evidently Spacecraft Event Time (SCET), UTC. 1974 Dec 03 Tp-21h 00m = 08:21 - Callisto, 786500 km Tp-07h 12m = 22:09 - Ganymede, 692300 km 1974 Dec 04 Tp-02h 10m = 03:11 - Io, 314000 km Tp-01h 06m = 04:15 - Europa, 586700 km Tp-00h 20m 58s = 05:00:21 - Jupiter shadow entry Tp-00h 20m 18s = 05:01:01 - Jupiter occultation entry Tp-00h 00m = 05:21:19 - Pericenter, H=42828 km Tp+00h 12m 33s = 05:33:52 - Jupiter shadow exit Tp+00h 21m 44s = 05:43:03 - Jupiter occultation exit Tp+01h 08m = 22:29 - Amalthea, 127500 km Note: for that day, ET = UTC + 45.184 sec, and ERT = SCET + 41 min 40 sec. |
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Mar 4 2009, 10:53 AM
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#34
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Junior Member Group: Members Posts: 45 Joined: 18-July 05 Member No.: 439 |
Finally, the Pioneer 11 flyby of Saturn events (planned).
Times are evidently Spacecraft Event Time (SCET), UTC. No possibility to calculate the planned pericenter time from these data. 1979 Aug 27 Tp-128h 32m = 08:02 - Phoebe, 9453000 km 1979 Aug 29 Tp-82h 29m = 06:05 - Iapetus, 1039000 km 1979 Aug 31 Tp-28h 03m = 12:31 - Hyperion, 674000 km 1979 Sep 01 Tp-01h 59m = 14:35 - Descending node Tp-01h 25m = 15:09 - Approach to rings from below Tp-00h 30m = 16:04 - Dione, 291100 km Tp-00h 07m = 16:27 - Dione, 291100 km Tp-00h 00m = 16:34 - Pericenter, H=21400 km Tp+00h 01m 30s = 16:35 - Saturn occultation entry Tp+00h 02m = 16:35:57 - Saturn shadow entry Tp+01h 20m = 17:53:32 - Saturn occultation exit Tp+01h 21m = 17:54:47 - Saturn shadow exit Tp+01h 31m = 18:05 - Departure fron rings Tp+01h 54m = 18:28 - Tethys, 331700 km Tp+01h 59m = 18:33 - Ascending node Tp+01h 59m = 18:33 - Enceladus, 225200 km Tp+06h 00m = 22:34 - Rhea, 341900 km 1979 Sep 02 Tp+25h 30m = 18:05 - Titan, 356000 km Note: for that day, ET = UTC + 50.184 sec, and ERT = SCET + 86 min 21 sec. |
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Guest_PhilCo126_* |
Apr 23 2009, 10:05 AM
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#35
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The decision to go for the "outside" option was taken in November 1977 so when did the Pioneer 11 controllers at NASA Ames Research Center made final adjustments to the trajectory?
March 1978? ... were there more adjustments later on? |
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Apr 23 2009, 06:42 PM
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#36
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Junior Member Group: Members Posts: 39 Joined: 26-March 09 From: Cornwall Member No.: 4697 |
According to my notes, there was a correction on 13 Jul 1978.
Can't find my source for this, but there was a NASA press release on 24 Jul that said that the final correction had been made. |
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Apr 23 2009, 07:43 PM
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#37
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Senior Member Group: Members Posts: 1729 Joined: 3-August 06 From: 43° 35' 53" N 1° 26' 35" E Member No.: 1004 |
Robotic Exploration of the Solar System part 1 (page 146): "the final trim maneuver on 13 July 1978 that set up the outer ring-plane crossing..."
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Apr 24 2009, 12:21 AM
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#38
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Member Group: Members Posts: 340 Joined: 11-April 08 From: Sydney, Australia Member No.: 4093 |
Thanks Liss & all other for these beautiful timelines. I have taken the liberty to include them in the timelines on my website for Pioneer 10 and Pioneer 11 ... please let me know if you object to that.
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Guest_PhilCo126_* |
Apr 24 2009, 06:40 AM
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#39
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That's a great website Daniel ... and "Welcome to UMSF.com" gwiz ...
I wonder if NASA Ames will celebrate the 30th anniversary of the Pioneer 11 ( Pioneer Saturn ) flyby of the ringed world. For an article on that subject I've found another 1970s Pioneer checkout photo, which I'll post in the Pioneer Hardware topic of the subforum |
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Apr 25 2009, 01:52 AM
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#40
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Member Group: Members Posts: 340 Joined: 11-April 08 From: Sydney, Australia Member No.: 4093 |
I wonder if NASA Ames will celebrate the 30th anniversary of the Pioneer 11 ( Pioneer Saturn ) flyby of the ringed world. I sent a Twitter message (tweet) to AMES with that question. They have just answered: don't know myself, but can ask around. ... EDIT 29/04: another tweet came back: "I asked our news chief here at Ames about the Pioneer but he is not aware of any celebrations.". Anyway, I will try to create a historic simulation for the flyby. -------------------- |
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Apr 29 2009, 08:59 AM
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#41
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Member Group: Members Posts: 340 Joined: 11-April 08 From: Sydney, Australia Member No.: 4093 |
Pioneer 11 30 years ago ... now showing on my website at http://tinyurl.com/c6vopp
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Apr 29 2009, 10:35 AM
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#42
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Senior Member Group: Members Posts: 2920 Joined: 14-February 06 From: Very close to the Pyrénées Mountains (France) Member No.: 682 |
I realy enjoy your website
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Apr 30 2009, 03:21 AM
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#43
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Member Group: Members Posts: 340 Joined: 11-April 08 From: Sydney, Australia Member No.: 4093 |
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). I will update my website in due course. -------------------- |
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Apr 30 2009, 04:35 PM
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#44
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Member Group: Members Posts: 340 Joined: 11-April 08 From: Sydney, Australia Member No.: 4093 |
I worked the Horizons system a bit more and get the following c/a times and distances. Most are pretty close to the timeline Liss provided, with the exception of Phoebe (arguably not a close approach in either scenario!). According to these numbers, the undiscovered near-miss moon would have been Epimetheus at a distance of 6676km ... or about 6 minutes 45 seconds, given their relative speed of 59,271km/h!
Disclaimer: Horizon states that the trajectory data are reconstructed to fit the observations and is thus probably not as accurate as trajectory data available for current missions. Nevertheless: CODE 1979-08-29 06:06:10 Iapetus closest approach (1,032,535km)
1979-08-29 11:53:33 Phoebe closest approach (13,713,574km) 1979-08-31 12:32:33 Hyperion closest approach (666,153km) 1979-09-01 14:50:55 Epimetheus closest approach (6,676km) 1979-09-01 15:59:30 Dione closest approach (291,556km) 1979-09-01 16:26:28 Mimas closest approach (104,263km) 1979-09-01 16:29:34 Saturn Flyby (altitude: 20,591km) 1979-09-01 16:51:11 Janus closest approach (228,988km) 1979-09-01 18:25:34 Tethys closest approach (329,197km) 1979-09-01 18:30:14 Enceladus closest approach (222,027km) 1979-09-01 22:15:27 Rhea closest approach (345,303km) 1979-09-02 18:00:33 Titan closest approach (362,962km) -------------------- |
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May 4 2009, 06:56 PM
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#45
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Junior Member Group: Members Posts: 45 Joined: 18-July 05 Member No.: 439 |
Thanks Liss & all other for these beautiful timelines. I have taken the liberty to include them in the timelines on my website for Pioneer 10 and Pioneer 11 ... please let me know if you object to that. No objections: essentially these are NASA timelines. |
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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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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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Lo-Fi Version | Time is now: 22nd May 2024 - 05:52 AM |
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