MGS in Trouble, Formerly: MGS in safe mode Options

[Guest_Analyst_*]

SWTB - Solar Array Wing tip brake?
SR - Switch ...??

[djellison]

Just for fun, probably highly inaccurate...if they DO do HiRISE imaging...I've seen figures of 100km smacked around which would be approx 10cm/pixel....so here's a couple of simulated views using ye-olde VRML model that's online if you google for it.

Doug

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[akuo]

You have to remember, MGS might be out of HiRise's focus at 100km. Though the focus is adjustable, I don't know if its this much adjustable, and whether they would do a major adjust right at the beginning of the PSP.

Should still look pretty good.

[djellison]

Two more of whatever those things were...followed by two SCGNT :

CODE

  mi2128 94 SRSWTB 2006-314T19:29:16.4 2006-314T19:29:56.3 Radiated
  mi2128 94 SRSWTB 2006-314T20:09:08.8 2006-314T20:09:48.7 Radiated
  mi2177 94 SCGCNT 2006-314T21:26:58.4 2006-314T21:27:38.3 Radiated
  mi2177 94 SCGCNT 2006-314T22:07:39.4 2006-314T22:08:19.3 Radiated

Doug

[tuvas]

Doug,

Where do you get that kind of info? Just curious...

Anyways, unless something drastic happens, it's looking more likely like JPL will have to take more drastic options to try and find MGS, feel free to use your imagination. Also note that everything public about the possibility of MRO photographic MGS mentions MRO, no specific instruments were mentioned.

[jamescanvin]

Have we gone past the 7 days out of contact yet?

It still seems likely to me that MGS is happily pointing her arrays at the sun and waiting for 7 days before attempting to contact Earth through the HGA, as she is programmed to do in safe mode.

[djellison]

http://mgsw3.jpl.nasa.gov/seq/MGS/rad/MGSradiation.log_nohdr

Doug

[Bubbinski]

Does this "radiation log" mean MGS is still alive?? Have they regained contact? Let's hope so!

[djellison]

It doesn't really tell us anything to be honest - it's guess work at best, but it's a list of the sequences being sent TO the spacecraft, not ones being recieved from it....and the same sequence being sent many times over would be suggestive (I would have thought) of an unresponsive spacecraft.

Lots more commands radiated overnight, including....

Reset a sun-angle timer to a different time.
that's looped a few times, and then

Turn on telementry modulation
Switch that to 10bps
then that gets looped a couple of times

They've radiated 50 commands in the last 24 hours.

Doug

[Guest_Analyst_*]

It's only guessing, and I guess they have not got telemetry back because almost every block of commands ends with "Turn on TWTA". Without a working TWTA you can't get telemetry.

Analyst

[djellison]

Well - we've had this loop of 5 commands

CODE

mi2148 94 CXSPG1 2006-315T04:00:33.3 2006-315T04:01:13.2 Radiated
  mi2149 94 CXSPG2 2006-315T04:01:31.3 2006-315T04:02:11.3 Radiated
  mi2150 94 TCM1MN 2006-315T04:02:31.4 2006-315T04:03:11.3 Radiated
  mi2151 94 TCM2MN 2006-315T04:03:47.4 2006-315T04:04:27.3 Radiated
  mi1523 94 STRPAN 2006-315T04:05:37.7 2006-315T04:06:17.7 Radiated

And it was run at.....

04:00
05:18
05:58
07:58
09:13
09:53
11:12
11:51
13:09
13:55

That's time gaps of... 78,50,120,75,40,79,39, 78 and 46 minutes. basically cycling between 80 ish and 50ish with one odd one ( perhaps a DSN handover) looks to me like they're trying at the two 'sides' of the orbit with 80ish mins being hte visible time and 40 mins being the occulted time.

Unfortunately, space.jpl.nasa.gov doesn't include Mars spacecraft in orbit, and http://mars1.jpl.nasa.gov/mgs/realtime/mgs1.jpg is very very broken
Doug

[Guest_Analyst_*]

There are small variations in this 5 command pattern lately.

Could it be that MGS is in a command loss routine, switching (by itself) between different hardware components with the goal to deselect a failed one and doing this until one of the commands sent here again and again comes through?

Analyst

[Bubbinski]

Yikes...thanks for the answers. Guess we'll be waiting for the Hirise picture of MGS to tell us more. If this truly is the end, then let's salute MGS for a decade of service over Mars and a job well done.

[djellison]

My best efforts in understanding what the sequences are is limited - but there are specific, multiple references to some of them...

CXSPG1 and 2 are "Set the modulation index for 10 bps data rate" on both Box Sides XSU1 and 2.
The XSU's are cross strap units for routing telemetry to the SSR's or Telecoms.

TCM1MN and TCM2MN turns telemetry modulation on for MOT 1 and 2
The MOT's are Mars Orbiter Transponders

STRPAN turns on the TWTA.

To try and put it all in to context - attached is an extract from http://mars.jpl.nasa.gov/mgs/pdf/SE012V1.PDF

I wish someone from the MGS team would do a HiBlog type effort The money just isn't around for good outreach with the older missions I guess.

Doug

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[mcaplinger]

I wish someone from the MGS team would do a HiBlog type effort The money just isn't around for good outreach with the older missions I guess.

So which did you want, good outreach or a HiBlog type effort?

Seriously, if somebody was blogging instead of working on recovering the spacecraft, I'd fire their ass.

You're doing just about as good a job with the radiation log as I could; I hope they don't yank it off the web. I am not empowered to discuss spacecraft operations publicly; inquiries have to be directed to JPL.

MGS is either power-positive right now, in which case we will get it back eventually, or it's not, in which case it's dead and gone. Not much else to explain.