IPB

Welcome Guest ( Log In | Register )

18 Pages V  « < 2 3 4 5 6 > »   
Reply to this topicStart new topic
MGS in Trouble, Formerly: MGS in safe mode
ElkGroveDan
post Nov 12 2006, 03:58 AM
Post #46


Senior Member
****

Group: Admin
Posts: 4763
Joined: 15-March 05
From: Glendale, AZ
Member No.: 197



Thanks for weighing in Mike. Anything you can share with us as events transpire would be appreciated. Even just a quick posting of an emoticon when you get some news.


--------------------
If Occam had heard my theory, things would be very different now.
Go to the top of the page
 
+Quote Post
climber
post Nov 12 2006, 10:46 AM
Post #47


Senior Member
****

Group: Members
Posts: 2917
Joined: 14-February 06
From: Very close to the Pyrénées Mountains (France)
Member No.: 682



I think I get the point from Mike and had not doubt they try the maximum.
Nevertheless, I'd like also to point out how badly needed are Doug's updates. Once you're on UMSF, you realise that you're not alone to consider Spacecrafts as an entity you're familiar with. They're not "persons" but they're no longer inert objects, they definitively have a kind of soul.
So, when something go wrong, you WANT to know and since the Internet exist you can actualy try to look for news...and soon you realise that the best place is here, at UMSF. This is because all of us share the same passion for the adventure/exploration AND because we know that some of us are ABLE to find the place where the information is.
OK, we only talk to MGS with no reply so far and, as Mike says, it's either power positive or not, but knowing what JPL does is badly needed. Just think about how we'll be the day when the first rover will not show anymore. Are you gona give up the first day or switch to the other one and try to forget? I don't think so, and I'm sure the new trait called "xxx doesn't respond anymore" will have more hit everyday than all the other traits of UMSF and this will be untill JPL Officialy give up.
Thanks again Doug for your dedication and thanks to Mike to give us your insider view. I back you guys.


--------------------
Go to the top of the page
 
+Quote Post
djellison
post Nov 12 2006, 10:59 AM
Post #48


Founder
****

Group: Chairman
Posts: 14431
Joined: 8-February 04
Member No.: 1



Well - reading the logs from overnight - there were about four hours of a different commanding sequence which included two references to the HGA (I can't see the sequences defined anywhere unfortunately) but since then - it's been the same CXSPG1, CXSPG2,TCM1MN,TCM2MN, STRPAN. If I had to guess a diagnosis - I'd say that they tried something different (perhaps based on predicts of spacecraft attitude) , had no results, and then resorted to the baseline sequencing.

Thanks for the input Mike - as with all such things the longer we know nothing the worse the situation seems.

Doug
Go to the top of the page
 
+Quote Post
diane
post Nov 12 2006, 02:01 PM
Post #49


Member
***

Group: Members
Posts: 100
Joined: 20-May 06
Member No.: 780



Keeping in mind that SOHO was out of service for more than a year, let's keep in mind that many things are still possible.

http://sohowww.nascom.nasa.gov/operations/Recovery/
Go to the top of the page
 
+Quote Post
djellison
post Nov 12 2006, 06:14 PM
Post #50


Founder
****

Group: Chairman
Posts: 14431
Joined: 8-February 04
Member No.: 1



Well - no updates to the log for 14 hours....most likely reason being that the script that adds things to the log is either broken, or intentionally turned off.

Doug
Go to the top of the page
 
+Quote Post
Guest_Sunspot_*
post Nov 12 2006, 06:27 PM
Post #51





Guests






Maybe they don't want people to know what they're doing blink.gif blink.gif wink.gif
Go to the top of the page
 
+Quote Post
djellison
post Nov 12 2006, 06:37 PM
Post #52


Founder
****

Group: Chairman
Posts: 14431
Joined: 8-February 04
Member No.: 1



Well - I found http://mgsw3.jpl.nasa.gov/seq/ which includes lots of similar info just by googling for "UHF Relay" - I can't believe that JPL would unintentionally allow that information to be out and about and so easy to find - indeed some parts are marked as being removed due to ITAR......but then it wouldn't be the first time that JPL would have let something be online that shouldn't have been. It wouldn't be beyond belief to have JPL stop updates going to that site because they didn't want people ( i.e. me ) reading it.

Doug
Go to the top of the page
 
+Quote Post
nprev
post Nov 12 2006, 10:44 PM
Post #53


Merciless Robot
****

Group: Admin
Posts: 8783
Joined: 8-December 05
From: Los Angeles
Member No.: 602



Just out of curiosity, what is MGS' consumable status? Reason I ask is that I hope it isn't burning fuel trying to reacquire Earth if that turns out not to be the appropriate course of action. sad.gif


--------------------
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.
Go to the top of the page
 
+Quote Post
djellison
post Nov 12 2006, 11:04 PM
Post #54


Founder
****

Group: Chairman
Posts: 14431
Joined: 8-February 04
Member No.: 1



http://www.unmannedspaceflight.com/lofiver...x.php/t902.html

"As of 05-153 (06/02/05) MGS fuel consumption is 3.3 g/day, with 9.15 kg of usable fuel remaining. At this consumption rate, the usable fuel will support operations into 2013."


Doug
Go to the top of the page
 
+Quote Post
nprev
post Nov 12 2006, 11:25 PM
Post #55


Merciless Robot
****

Group: Admin
Posts: 8783
Joined: 8-December 05
From: Los Angeles
Member No.: 602



Much better than I'd hoped....thanks, Doug! smile.gif


--------------------
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.
Go to the top of the page
 
+Quote Post
Norm Hartnett
post Nov 12 2006, 11:45 PM
Post #56


Junior Member
**

Group: Members
Posts: 70
Joined: 12-November 06
Member No.: 1354



QUOTE (diane @ Nov 12 2006, 06:01 AM) *
Keeping in mind that SOHO was out of service for more than a year, let's keep in mind that many things are still possible.

http://sohowww.nascom.nasa.gov/operations/Recovery/


Lets not forget that this craft managed aerobraking with a busted wing, this bird is tough and the team backing her is the best.

Thanks very much for this site. I am usually hanging out at NASAspaceflight.com arguing about the VSE but when I heard about MGS having having problems I was very happy to find this site. For some reason MGS has always been one of my favorite birds, courage in the face of adversity or something I guess. I am drinking coffee out of my authentic JPL MGS mug and thinking good thoughts.
Go to the top of the page
 
+Quote Post
mcaplinger
post Nov 13 2006, 01:03 AM
Post #57


Senior Member
****

Group: Members
Posts: 2502
Joined: 13-September 05
Member No.: 497



QUOTE (djellison @ Nov 12 2006, 04:04 PM) *
"As of 05-153 (06/02/05) MGS fuel consumption is 3.3 g/day...

Unfortunately this is in the normal mapping attitude. In nearly all safe mode orientations it won't apply, and in some safe modes, it uses thruster control instead of reaction wheel control and will consume fuel even faster. But we are still talking fairly low consumption rates; it's not like it's spinning wildly about looking for Earth. Its normal response to faults is to get the solar arrays pointed at the sun and then spin slowly about the sun line, awaiting commands. There are a few complicating factors: first, the whole problem started with a stuck solar array (one of two); second, the spacecraft goes into solar and Earth eclipse on every orbit; and third, the low-gain transmitter antennas are both up on the articulated HGA electronics box, so there are some orientations of the HGA that could block one or the other of the LGTs from view from Earth. The low-gain receivers are down on the body of the spacecraft and do not articulate.

Compiled from public sources: see http://pds-geosciences.wustl.edu/missions/...og/insthost.txt and http://klabs.org/richcontent/Reports/Failu...erver_11_93.pdf


--------------------
Disclaimer: This post is based on public information only. Any opinions are my own.
Go to the top of the page
 
+Quote Post
nprev
post Nov 13 2006, 01:54 AM
Post #58


Merciless Robot
****

Group: Admin
Posts: 8783
Joined: 8-December 05
From: Los Angeles
Member No.: 602



Hmm...okay, thanks very much for the elucidation, M.

Is it possible that the array is stuck in such a fashion that it's interfering with the HGA in between eclipse periods? I assume that MGS maintains inertial lock with respect to Mars nadir duing normal ops. If this scenario was true, then we might catch a break in a week or two due to the relative orbital motion between Earth & Mars (maybe longer...I think that we're in the middle of that long, slow distant "catch-up" phase between the two orbits).


--------------------
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.
Go to the top of the page
 
+Quote Post
mcaplinger
post Nov 13 2006, 03:01 AM
Post #59


Senior Member
****

Group: Members
Posts: 2502
Joined: 13-September 05
Member No.: 497



QUOTE (nprev @ Nov 12 2006, 06:54 PM) *
Is it possible that the array is stuck in such a fashion that it's interfering with the HGA in between eclipse periods? I assume that MGS maintains inertial lock with respect to Mars nadir duing normal ops.

With an array stuck I think MGS would immediately leave the nadir-fixed orientation, since the array would be unable to track the sun, as it would need to do. Unfortunately I don't know too much about the safing mode that is entered with a stuck SA gimbal; for example, what pointing of the HGA is commanded in that mode.
(Most of what I know is left over from Mars Observer, and the HGA never got deployed on that mission.)


--------------------
Disclaimer: This post is based on public information only. Any opinions are my own.
Go to the top of the page
 
+Quote Post
nprev
post Nov 13 2006, 07:04 AM
Post #60


Merciless Robot
****

Group: Admin
Posts: 8783
Joined: 8-December 05
From: Los Angeles
Member No.: 602



I see. That sounds like a potentially much more serious situation, then; hopefully, it's entirely notional.


--------------------
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.
Go to the top of the page
 
+Quote Post

18 Pages V  « < 2 3 4 5 6 > » 
Reply to this topicStart new topic

 



RSS Lo-Fi Version Time is now: 19th March 2024 - 05:55 AM
RULES AND GUIDELINES
Please read the Forum Rules and Guidelines before posting.

IMAGE COPYRIGHT
Images posted on UnmannedSpaceflight.com may be copyrighted. Do not reproduce without permission. Read here for further information on space images and copyright.

OPINIONS AND MODERATION
Opinions expressed on UnmannedSpaceflight.com are those of the individual posters and do not necessarily reflect the opinions of UnmannedSpaceflight.com or The Planetary Society. The all-volunteer UnmannedSpaceflight.com moderation team is wholly independent of The Planetary Society. The Planetary Society has no influence over decisions made by the UnmannedSpaceflight.com moderators.
SUPPORT THE FORUM
Unmannedspaceflight.com is funded by the Planetary Society. Please consider supporting our work and many other projects by donating to the Society or becoming a member.