Printable Version of Topic

Posted by: mars_armer Apr 4 2005, 02:38 PM

I just heard that Odyssey went into safe mode on Saturday. I haven't seen any official announcement yet.

One result is that MER is having to replan using direct to earth only. Current estimate is that Odyssey will not be able to support UHF relay until "mid-week at the earliest".

Posted by: djellison Apr 4 2005, 02:55 PM

Now that's bad news. I suppose they could bring MGS back into a relay role, but it would take about as long to write and uplink the commands for that as it will to fix odyssey - any URL's with news on this?

Doug

Posted by: MahFL Apr 4 2005, 03:25 PM

I was wondering why there were no new images since the 2nd April.

Posted by: Sunspot Apr 4 2005, 04:03 PM

Are they still able to command the rovers in the normal way, just not transmit large amounts of data? I suppose they've put off all driving and science activities until the problem is resolved?

Posted by: dot.dk Apr 4 2005, 04:18 PM

Why should they do that? Just send commands and downlink via direct to Earth sessions. And Why has MGS not been used for relay as much as Odessey?

Posted by: djellison Apr 4 2005, 04:21 PM

A typical rover day - roughtly - in local solar time....

10:00 - Wakeup
11:00 - Direct from Earth HGA uplink of days commands
11:30 - 5 min carrier only tone on LGA to confirm handover to new sequence (if driving at the same time, this is called a honk - and no, they've not observed a dopler from the rover driving )
11:40 - Sometimes a nap for a half an hour, or an hour.
15:00 - Sometimes an Odyssey Pass
16:00 - Sometimes an Odyssey Pass - usually one, sometimes 2 - about 90 mins apart
17:00 - Sleep
if deep sleep -thenskip straight thru to the following morning, otherwise
03:00 - 04:00 - same UHF as before, one or two, about 90 mins apart.

The bulk of the rovers activities occur between around 11:00 and 15:00. Very VERY little data gets downlinked via DTE on the HGA usually - as it's power inefficient compared to UHF ( on a Whrs / Mbit scale )

I imagine, without UHF passes - they might use an extended HGA pass in the morning and add some DTE after the uplink - and perhaps another short one in the afternoon to downlink housekeeping data for the day, and a very small ammount of science data - probably little more than thumbnails, and reduced navcam frames.

Doug

Posted by: Sunspot Apr 4 2005, 04:48 PM

I think they were planning 2 days of imaging at Viking Crater...did that get all the imaging data down?

The lack of any picture updates, even small thumbnails might imply they've decided to forgo any driving/science at the moment?

Posted by: tedstryk Apr 4 2005, 04:51 PM

Because the data volume that MGS can store and relay is a pittance compared to Odyssey.

Posted by: dot.dk Apr 4 2005, 05:01 PM

Can't wait for relay via MRO then hehe

Posted by: djellison Apr 4 2005, 06:22 PM

One 12 minute UHF pass with Odyssey = 184 Mbits
Typically done 2 times per sol, call it 300 Mbits.

300 Mbits at 8kbps DTE (on DSN antennae already scheduled for other missions) = 10.4 hrs. The most they could use the DTE for in a sol is a couple of hours, it takes a lot of power, and means that a single sols data would take perhaps 4 sols to downlink - during which time, the flash memory will have filled up - two fold

MGS uses the MOC buffer for UHF ops - and so it plays hell with scheduling of MGS ops - has to be planned quite well in advance. Odyssey was doing more than enough for relay ops - so MGS was turned back to mapping ops. They only uplink to MGS about 3 or 4 times a week - and the sequence to include fill-in UHF passes would take a week or so to write - so by the time they've written the sequences, uplinked them....Odyssey will be back on course

Doug

Posted by: mars_armer Apr 4 2005, 06:44 PM

Yes, the plan for the next few sols is to convert the morning 20-minute DTE to a 90-minute DTE. This only gives them 12.7 Mbits of downlink, of which the first 7 is engineering data. It also requires them to plan in restricted mode (relying on the previous morning's knowledge).

Since the hope is to get Odyssey relays restarted by the end of Wednesday, it doesn't make sense (yet) to try to get an MGS relay going.

And no, I haven't found a URL to confirm this information.

Posted by: dvandorn Apr 4 2005, 07:10 PM

Makes you appreciate why Squyres, in one Q&A session, said that his number one priority for "what to do different" on future missions is to have a bigger pipe for getting data back to Earth.

Heck -- my cable modem provides me 5 Megabits per *second*. At that rate, I can download 300 Megabits in about one minute.

How much coax cable would it take to set up the MERs with RoadRunner service, anyway...?



-the other Doug

Posted by: cIclops Apr 4 2005, 07:26 PM

About three times as much as it needs at conjunction

Make sure you get the heavy duty cable, it gets quite hot near the middle or use a longer run and route via Venus.

tip: twisted pair would be cheaper and lighter than coax and still work at 5 mb/s but it will need more repeaters to boost the signal.

Posted by: dot.dk Apr 4 2005, 07:28 PM

IF Odessey is crippled could they use Mars Express as a temporary solution?

I know it has relayed a few pictures, but can it relay as much as Odessey?

Posted by: djellison Apr 4 2005, 07:28 PM

I'll hold one end - and you start walking, stop when I give it two tugs so I can tie the next reel on, then get going when I give it three tugs.

That - or wait for MRO- with it's 4mbps downlink

I think MEX is about as able as Odyssey - and it would be a nice repayment of the Odyssey-Beagle 2 attempts - if Odyssey takes a few days longer that would be a very good idea - but with MARSIS antenna deployment due soon - would they be up for it?

Doug

Posted by: tedstryk Apr 4 2005, 08:27 PM

[/quote]

Makes you appreciate why Squyres, in one Q&A session, said that his number one priority for "what to do different" on future missions is to have a bigger pipe for getting data back to Earth.

Heck -- my cable modem provides me 5 Megabits per *second*. At that rate, I can download 300 Megabits in about one minute.

How much coax cable would it take to set up the MERs with RoadRunner service, anyway...?



-the other Doug

[/quote]

Problem is, by now the cables would be tangled up around the Sun, with tragic consequences

Posted by: alan Apr 4 2005, 08:36 PM

There have been three images (full resolution not thumbnails) added at exploratorium today. Does that mean its fixed now?

Posted by: mars_armer Apr 4 2005, 09:16 PM

No.

Posted by: dvandorn Apr 5 2005, 08:13 PM

I've done some extensive Googling, and can't find a single reference to Odyssey going into safe mode this last week. Nothing whatsoever at any of the NASA or JPL websites. The only thing Google picks up on search phrases "Odyssey" and "safe mode" are articles on the spacecraft being affected by the huge solar flares of a couple of years ago.

So, 1) does anyone know the real story and what the Odyssey team thinks might have happened, and 2) why the heck isn't *anyone* reporting on this?

-the other Doug

Posted by: cIclops Apr 5 2005, 08:50 PM

neither can I, perhaps it's in ultra safe top secret mode

"Never let the truth get in the way of a good story"

Posted by: mars_armer Apr 5 2005, 10:02 PM

The only reason I know anything is because of the impact on MER planning, and I haven't heard anything new since Monday morning. I'm wondering the same thing as you.

Posted by: slinted Apr 6 2005, 12:12 AM

Just a quick mention, with regards to the importance of Odyssey's use as a relay.

MGS did support some relay operations early on in the mission, but it appears that it is unable to do so right now.

http://mpfwww.jpl.nasa.gov/mgs/status/reports/msop-mgs.html

Back on July 21, 2004 in the above status report:

And, as of the last update, it is still in Beta-Supplement mode. So, if Odyssey can't downlink data to Earth, they lost the primary and at this point only alternative to DTE transmission from the rovers of images/data. Lets hope this gets fixed soon, this would be a huge blow to the revitalized rovers.

Posted by: djellison Apr 6 2005, 08:54 AM

Except for MEX

Doug

Posted by: Sunspot Apr 6 2005, 09:45 AM

Yikes....this is starting to sound REALLY bad for the MER mission. Without the Odyssey UHF link, the rovers are practically crippled. We're currently down to 1 or 2 pictures per day Im surpried there hasn't been an official statment from JPL on this too..

Posted by: djellison Apr 6 2005, 09:52 AM

I'm quite disgusted by the lack of information from JPL to be honest

I'm sure odyssey will be back up and relaying shortly - but that it's a 5 day old situation and we still have no proper news is a disgrace.

Then again - why would the break the 2 year 6 month tradition of not giving a single Mars Odyssey status update http://mars4.jpl.nasa.gov/odyssey/mission/status.html

If this is a bigger problem than just a small safing issue - then we're in trouble. I would hope that ESA would bend over BACKWARDS to assist with MEX given the enormous effort by JPL and MSSS in relaying and imaging attempts for Beagle 2.

Doug

Posted by: Sunspot Apr 6 2005, 10:02 AM

.....it seems the people that use and read this message board are the only ones aware of the problem outside NASA Quite a few news articles about the 18 month extension though......

Posted by: djellison Apr 6 2005, 10:14 AM

If anyone wants to poke around somewhere they probably shouldnt be...


http://mgsw3.jpl.nasa.gov/seq/odyseq.html

there might be something in there somewhere

I've got to spend the rest of the day on the wonderful M1 visiting Watford - but I'll be chasing this topic VERY hard tonight and sending emails to appropriate places.

I did find this though...

0790454015:3 2005-017T18:30:15 ci2905 d:/seq/copy_rw_failed_to_cmic RELATV 9F0664FD
0792456839:5 2005-040T22:50:36 ci2960 d:/seq/solar_array_cycle_05_040 RELATV 3D68978F
0792531971:6 2005-041T19:42:48 ci2980 d:/seq/mmc_fubar_mem_fill_05_041 RELATV 76242CDA
0792940586:3 2005-046T13:13:02 ci2982 d:/seq/themis_4w_htr_on RELATV 7BB8E9C9
0792982744:3 2005-047T00:55:40 ci2983 d:/seq/themis_4w_htr_off RELATV 7A0F71F
0794187466:3 2005-060T23:34:20 ci2977 d:/seq/dpt_init_124k_relay RELATV 5B60AB8E
0796506249:0 2005-087T19:40:39 ci2997 d:/seq/crc_check_file_seq_pt1 RELATV CF6DDCD5
0796584494:1 2005-088T17:24:44 ci2998 d:/seq/crc_check_file_seq_pt2 RELATV CCA359FA
0797013133:8 2005-093T16:28:43 ci2262 d:/seq/safe_mode_daily_diagnostics RELATV 47A47FFE
0797091539:9 2005-094T14:15:29 ci2262 d:/seq/safe_mode_daily_diagnostics RELATV 47A47FFE
0797188568:1 2005-095T17:12:37 ci3007 d:/seq/rexmit_050405_upgo RELATV 3C447CF7
0797189118:1 2005-095T17:21:47 ci2262 d:/seq/safe_mode_daily_diagnostics RELATV 47A47FFE
0797197803:1 2005-095T19:46:32 ci2698 d:/seq/heap_reinit RELATV 53EA825F
0797203805:1 2005-095T21:26:34 ci3005 d:/seq/map_sm_recovery_upgo RELATV 939F56E1

April 1st was DOY 91 - so that last uplink was, I believe, 21:26 April 5th - i.e. late last night.

Doug

Posted by: chris Apr 6 2005, 10:44 AM

Lets hope 'fubar' isn't the appropriate description.....

Posted by: djellison Apr 6 2005, 10:53 AM

Well - that would have been about Feb 10th

If they run spacecraft like most people write software or name 3d objects in animation - there's some comedy variables in there

Doug

Posted by: chris Apr 6 2005, 11:36 AM

Ah, I misunderstood the dates. I get it now.

And I would *never* use use "foo" as a placeholder in code

Posted by: OWW Apr 6 2005, 12:31 PM

Thanks Doug for that link. Look at this pdf on that same site:

http://mgsw3.jpl.nasa.gov/seq/M1O/SOE/cs054d.00.rsoe.pdf

05-095/21:39:47.3 (GMT): SAFEMODE_EXIT : Transitions the spacecraft to nominal mode if not already in nominal mode.

and then apparently deletes the recovery sequence:

05-095/23:50:47.9 (GMT): Deletes the designated file.: d:/seq/map_sm_recovery_upgo.rel

So, maybe Odyssey is recovering...

Posted by: djellison Apr 6 2005, 04:27 PM

Well - we were told Wednesday

Maybe tonights UHF passes will be nominal - and I imagine they will use every single UHF opportunity there is for the next few sols, even the poor ones, to get as much back as possible.

Doug

Posted by: alan Apr 6 2005, 09:15 PM

Twenty new navcams were added at exploratorium 15 minutes ago, a good sign?

Posted by: mars_armer Apr 6 2005, 09:33 PM

Yes, they are out of safe mode, and had their first chance for a relay from Spirit at about 4:45 PM local time. Looks like it was successful!

Good news. I never did hear what caused the safe mode.

Posted by: RedSky Apr 6 2005, 10:05 PM

Thanks for that link.... real interesting stuff there. I looked into the Radiation Log and found the frequency of command files sent to Odyssey each day this year. There was an especially interesting label of "FSW_OBJ_INITIAL". I created a little graph of files radiated by day... with the "Red" portion of the bars indiciating those INIT files. Seems like a lot of activity in the last few days to get out of safe mode with a lot of those INIT command files. Glad to hear things might be fixed!

Posted by: cIclops Apr 9 2005, 09:20 AM

Finally an "official" story from NASA about all this, not on the Mars Odyssey page of course but in the Spirit status report for April 8:

(Sol 446 is April 5, 2005)

"Sol 446:
Spirit and Opportunity use NASA's Mars Odyssey orbiter as their main communications link between Mars and Earth. On April 2, Odyssey entered "safe mode," which is a protective state a spacecraft automatically enters when onboard fault protection software instructs the spacecraft to disregard its onboard sequence of commands and wait for instructions from the ground. As a result, relay communication with the rovers was suspended, and Spirit did not receive any data from sols 444 and 445. With an unknown status of the rover after its drive, the Spirit team restricted rover operations to remote sensing.

Sol 447:
The Odyssey flight team scrambled to recover the orbiter, but it remained in a safe state, not yet available to support relay communications. Spirit received very little information from its "direct-to-earth" communications link, so the rover team planned another basic remote sensing sol, which generated little data.

Sol 448 (April 7, 2005):
Spirit performed additional remote sensing, including panoramic camera and navigation camera imaging. The Odyssey team brought the orbiter back on-line, the Spirit team received all imaging needed for continuing to drive, and team members are planning to drive on sol 449 with a new appreciation for their orbiting partner! The Odyssey team is investigating the cause behind the fault protection software sending the orbiter into safe mode."

http://marsrovers.jpl.nasa.gov/mission/status.html

Note there is no mention of the Odyssey safing in the earlier status reports for April 2, 3 or 4

Posted by: Sunspot Apr 9 2005, 11:38 AM

Either they didnt drive or the drive stalled as Spirit didnt move on Sol 449, maybe slippage again?