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View Full Version : Communication Problem on Sol 119 -- what did that say?



John Dlugosz
2004-May-05, 09:21 PM
I was reading This update (http://www.spacedaily.com/news/mars-mers-04zzzzh.html) and was hoping someone could translate. It's written using all the jargon of the people working there, with no explaination for the lay reader.

EFossa
2004-May-05, 09:46 PM
I was reading This update (http://www.spacedaily.com/news/mars-mers-04zzzzh.html) and was hoping someone could translate. It's written using all the jargon of the people working there, with no explaination for the lay reader.

I have to be honest I have no idea lol.

However, watching yesterdays flight directors update it seems they transmitted Spirits daily operational schedule at the wrong bit rate so the rover didnt receive it. The latest update says Spirit is fine and drove the remaining 30m to "Lahonton Crater" on Sol 120

http://www.jpl.nasa.gov/mer2004/flight-director/index.cfm

ToSeek
2004-May-06, 02:55 AM
We attempted to uplink our daily loads as planned, but we received the off-nominal beep at 10 LSTA.

Spirit indicated a problem via a signal at 10 local standard time.

Investigation revealed that we uplinked at 500 bps, but the comm window was a 1K bps window. So the sol 119 master sequence load never made it on board.

They sent the instructions for the day of Sol 119 at 500 bits per second, but the rover was expecting them at 1kbps, so they didn't get through.

The ramification of this was that Spirit would stay awake until 12:00 LSTA and then shutdown for the day. To add insult to injury, we did not execute our e0010 daily mod comm. window sequence.

Part of the instructions for the day that didn't get uplinked were to modify the spacecraft's communications plans, so those didn't "take", either.

On sol 119 we had a 13:05 afternoon MGS pass communication window scheduled as well as a 14:10 to 15:00 DTE pass scheduled. Spirit would have shutdown at noon and awoken at 12:58 to support the MGS pass. The spacecraft would then have stayed awake through the 14:00 - 15:00 DTE because it would have been solar groovy.

So we would have: 1. Not executed sol 119 as planned 2. Supported two afternoon communication sessions that we did not need, including 50 minutes of SSPA powered on time 3. Not slept through the afternoon as was the default run out plan 4. Substantially depleted our batteries

If they hadn't done anything, Spirit would have made pointless efforts to communicate with MGS and Directly To Earth and would have powered up its transmitter (Solid-State Power Amplifier) unnecessarily, using up a significant chunk of battery power without accomplishing anything.

With the help of TDL (Chris Lewicki) and SIE (Sharon Laubach) and ACE (Bill Currie) we created and uplinked a standalone ae0010 mod comm window SCMF with its accompanying real-time activate command. This sequence deleted the afternoon MGS and DTE comm windows on sol 119.

They created a new command sequence to cancel the unnecessary attempts to communicate. (TDL = flight director, SIE = command sequence guru, ACE = communications guru.)

We also created and uplinked the real-time delete ae0010 sequence command to clean up after ourselves. We completed command radiation with about five minutes to spare, so the commands should execute before the spacecraft shuts down at noon.

The commands were transmitted in time.

We also got the real-time stop comm command ready and the ACE will uplink it once at 15 bps to be received by the spacecraft at 14:06, during the prep time for the afternoon comm window, and once more at 1000 bps to be received by the spacecraft at 14:15 during the comm window. This last action is just a backup in case we did not get the mod comm window sequence up earlier.

They arranged to send the cancel communications commands in real-time as well, just in case the sequence uploaded in advance didn't work for some reason.

Some other notes for the uplink planning team, we have not performed data management activities since sol 117. DM pulled their sequence just before uplink on sol 118 and you know what happened on sol 119. Also Spirit has only one more morning DFE comm window, on sol 120, loaded.

Spirit only knows about one more chance to communicate directly with Earth.

We had reviewed and bundled a new strategic comm window load, ae0050, that would have loaded comm windows through sol 127, and it have been executed on sol 119 but it did not make it. So there is added urgency to get it up on sol 120.

So we really, really want to tell it when it can send and receive data for the next few days really soon.

A quick note on the uplink data rate, when we switched to HGA uplink sessions, we were initially told to stay at 500 bps to ensure adequate margin on the uplink. The latest strategic comm window delivery (sol 121 - 127) has the morning uplink rate set to 1K bps.

There is some confusion over whether the high-gain antennas will support 500 bps or 1kbps.

I requested that the TDL question Telecom and verify that in-fact there is sufficient margin to uplink at 1K bps. The answer was 1K bps uplink is fine. So we expected the uplink rate to increase from 500 on sol 120, to 1000 bps on sol 121. Also adding to the confusion, we have not had a complete downlinked comm window data product dump since sol 115.

They will support 1kbps. Another issue: we haven't confirmed the spacecraft's onboard communications schedule data (not sure if this is the schedule or feedback on how well the uploads have gone) in a while.

As it turns out sol 118's uplink data rate was 500 bps, sol 119's data rate was 1K bps, sol 120's data rate is 500 bps, and sols 121 and on will be 1K bps. We should avoid data rate oscillations in the future.

Make up your minds and stop playing with my head!

Another point is that even through the comm window was set to 1K bps, we only had a 34 meter DSN antenna this morning and our ACE doesn't believe that a 34 meter dish can support 1K bps uplink.

Even if the spacecraft can support the higher 1k rate, if we get a small antenna on Earth, it may not be able to.

carolyn
2004-May-06, 05:50 AM
wow! i'm impressed =D>

where on earth did you learn to do that? (or is it a gift :D )

Do you translate Hubbish too?

Maksutov
2004-May-06, 11:17 AM
wow! i'm impressed =D>

where on earth did you learn to do that? (or is it a gift :D )

Do you translate Hubbish too?

Don't know about "To Seek" but I believe the BA can translate Hubbish. He was involved in Hubbish things for a number of years. :)

Irishman
2004-May-06, 03:10 PM
Maksutov, I think he means HUb'ish. HUb' is a poster around here who for various reason posts in something akin to gibberish. Through years of interaction, a few people have managed to make sense out of what he posts. It is definitely a special talent.

He was not referring to Hubble (the HST).

Amadeus
2004-May-06, 03:58 PM
Maksutov, I think he means HUb'ish. HUb' is a poster around here who for various reason posts in something akin to gibberish. Through years of interaction, a few people have managed to make sense out of what he posts. It is definitely a special talent.

He was not referring to Hubble (the HST).

I do find Hub's posts interesting and always try to wrap my puny mortal brain round the text.

carolyn
2004-May-06, 08:00 PM
Maksutov, I think he means HUb'ish. HUb' is a poster around here who for various reason posts in something akin to gibberish. Through years of interaction, a few people have managed to make sense out of what he posts. It is definitely a special talent.

He was not referring to Hubble (the HST).

Oi! who are you calling a 'he'! :roll: :-s

ToSeek
2004-May-06, 08:36 PM
wow! i'm impressed =D>

where on earth did you learn to do that? (or is it a gift :D )



Twenty years of supporting NASA control centers and ground stations helps a little (and even then I was still making educated guesses!). ;)

carolyn
2004-May-07, 05:56 AM
wow! i'm impressed =D>

where on earth did you learn to do that? (or is it a gift :D )



Twenty years of supporting NASA control centers and ground stations helps a little (and even then I was still making educated guesses!). ;)

yup, that'll do it.

What an interesting job :)

Irishman
2004-May-07, 05:38 PM
carolyn said:

Oi! who are you calling a 'he'!

Uh, my finger slipped on the "s". Yeah, that's it.

Deepest apologies for failing to pay close attention to who said what. #-o

carolyn
2004-May-07, 05:48 PM
carolyn said:

Oi! who are you calling a 'he'!

Uh, my finger slipped on the "s". Yeah, that's it.

Deepest apologies for failing to pay close attention to who said what. #-o

[-X :D