MESSENGER News Thread, news, updates and discussion |
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MESSENGER News Thread, news, updates and discussion |
 Oct 24 2006, 12:40 AM
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#121
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Member  Group: Members Posts: 540 Joined: 17-November 05 From: Oklahoma Member No.: 557  |
Yes, the emphasis on the second flyby would seem to be more toward reducing speed relative to the sun. The spacecraft will always be seen from the sun as moving eastward, giving a counterclockwise orbit as viewed from north to south. But Venus flinging it back will significantly reduce the spacecraft speed as seen from the sun (and microscopically increase the speed of Venus).
On the website space.jpl.nasa.gov you can see the approach (and departure) of Messenger in a broader scene up to a point. That point is 3:40 UTC on the 24th, with a sudden shift to a Venus centered approach line rather than sun centered for both planet and spacecraft. It will only show one snapshot at a given time at five minute intervals, but repeated entries will show the two closing in on each other. Chose "MESSENGER" as seen from "above" with a selection of "60 degrees" field of view (make sure the field of view option is clicked) on this website and you'll see what I'm talking about. Just about nine hours to go ... |
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Oct 24 2006, 02:41 PM
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#122
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Senior Member Group: Members Posts: 1636 Joined: 9-May 05 From: Lima, Peru Member No.: 385 |
By now, I haven't found any internet refresh news. Let suppose that the flyby have occured today at around 4:30 am at EDT time.
How was the Venus 1 fly-by? Rodolfo |
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Oct 24 2006, 02:44 PM
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#123
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Founder Group: Chairman Posts: 14432 Joined: 8-February 04 Member No.: 1 |
How could we possibly know? Venus, like Mars, is in conjunction. That is the reason there was no science planned for Messenger during this flyby - the spacecraft is totally out of touch.
Doug |
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Oct 24 2006, 03:09 PM
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#124
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 Junior Member Group: Members Posts: 90 Joined: 20-April 05 Member No.: 289 |
Why no science?
Surely Messanger could be programmed for observations well in advance for the flyby - even if it was unable to transmit the results until sometime aftwards? Would this not be at least an opportunity to test run some of the instruments ahead of the eventual rendezvous with Mercury? |
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Oct 24 2006, 03:20 PM
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#125
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Founder Group: Chairman Posts: 14432 Joined: 8-February 04 Member No.: 1 |
There will be further chances to test the instruments out - but one could ask the same question of MGS, ODY and MRO at Mars during conjunction....why no science.
#1 reason - while you're out of touch you want the spacecraft to be as quiet as possible, so minimising the chance of anything going wrong and causing a safe event which may consume prop etc. doug |
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Oct 24 2006, 03:20 PM
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#126
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Solar System Cartographer Group: Members Posts: 10172 Joined: 5-April 05 From: Canada Member No.: 227 |
Why no science?
The question has been asked many times. Simply put, if you can't communicate with the spacecraft and the encounter is not the main focus of the mission, you can't afford to conduct complex operations. If anything goes wrong and the spacecraft enters safe mode you can't go to work on it, and the potential for fatal errors is too high. And... there's a second chance to do some Venus science later. Phil -------------------- ... because the Solar System ain't gonna map itself.
Also to be found posting similar content on https://mastodon.social/@PhilStooke Maps for download (free PD: https://upload.wikimedia.org/wikipedia/comm...Cartography.pdf NOTE: everything created by me which I post on UMSF is considered to be in the public domain (NOT CC, public domain) |
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Oct 24 2006, 04:49 PM
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#127
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Senior Member Group: Members Posts: 1636 Joined: 9-May 05 From: Lima, Peru Member No.: 385 |
QUOTE (Phil Stooke @ Oct 24 2006, 10:20 AM)  Why no science? And... there's a second chance to do some Venus science later. Yes, at June 6, 2007 Messenger will have coordinations with VEX to conduct many science observations. It is a matter of time. This second flyby is a very important since Messenger will jump from Venusian orbit into to Mercurian orbit. Rodolfo |
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| Guest_Sunspot_* |
Oct 24 2006, 05:23 PM
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#128
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Guests |
But MRO IS making daily observations during the conjunction period.
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Oct 24 2006, 06:37 PM
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#129
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Founder Group: Chairman Posts: 14432 Joined: 8-February 04 Member No.: 1 |
Only a very limited ammount with two instruments in a steady orbit. To sequence fly-by observations is a much mroe involved and intensive operation. If Messenger does some Mag observations during this flyby, then that would be analogous to the MARCI/MCS obs of MRO during conjunction.
Doug |
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Oct 24 2006, 10:04 PM
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#130
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Founder Group: Chairman Posts: 14432 Joined: 8-February 04 Member No.: 1 |
Bloody hell :
MESSENGER swung by Venus at 8:34 UTC (4:34 a.m. EDT), according to mission operators at the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Md. About 18 minutes after the approach, an anticipated solar eclipse cut off communication between Earth and the spacecraft. Contact was reestablished at 14:15 UTC (10:15 a.m. EDT) through NASA's Deep Space Network, and the team is collecting data to assess MESSENGER's performance during the flyby. |
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Oct 25 2006, 04:24 AM
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#131
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 Merciless Robot Group: Admin Posts: 8784 Joined: 8-December 05 From: Los Angeles Member No.: 602 |
 ...Doug, I assume "bloody hell" means "HELL yeah!" in American slang...I hope this is good news, although it seems a bit guarded... 
-------------------- 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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Oct 25 2006, 06:08 AM
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#132
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 Member Group: Members Posts: 103 Joined: 12-February 05 From: Utah Member No.: 167 |
I just saw something in the Florida Today "Flame Trench" blog that Messenger had an unexpected computer reset. I hope it's nothing serious.
-------------------- - My signature idea machine is busted right now.
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Oct 25 2006, 06:13 AM
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#133
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Member Group: Members Posts: 599 Joined: 26-August 05 Member No.: 476 |
Bloody hell! And that is NOT HELL yeah!
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Oct 25 2006, 07:08 AM
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#134
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 Senior Member Group: Members Posts: 3648 Joined: 1-October 05 From: Croatia Member No.: 523 |
Update on the flyby: MESSENGER Completes Venus Flyby.
There's also an image of Venus taken by MDIS from 16.5 million km. -------------------- |
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Oct 27 2006, 01:26 AM
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#135
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Merciless Robot Group: Admin Posts: 8784 Joined: 8-December 05 From: Los Angeles Member No.: 602 |
Rog on the "BH", Doug & Mchan...just didn't see any reference to the anomaly in Doug's post, so I got confused.
In fact, I can't find any mention of this on Google News or on the Messenger website, which is kind of worrisome. I hope this doesn't mean that anomaly recovery has been interrupted by superior conjunction. Anybody have an update? -------------------- 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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