Printable Version of Topic

Click here to view this topic in its original format

Unmanned Spaceflight.com _ Spirit _ Spirit now living longer than Viking 2

Posted by: OWW Aug 11 2007, 09:44 AM

Today is a historic day...eh Sol.
Sol 1281 is the sol that Spirit will beat Viking 2.
Yes, that's right, today a solar powered vehicle beat a Nuke in longevity!

I say a celebration is in order!

Posted by: Zvezdichko Aug 11 2007, 12:00 PM

Today is a big day for Martian exploration. Spirit is on its 1281 sol. Viking 2 was turned off on the very same sol because of a battery failure

Posted by: abalone Aug 11 2007, 12:15 PM

QUOTE (Zvezdichko @ Aug 11 2007, 10:00 PM)

Today is a big day for Martian exploration. Spirit is on its 1281 sol. Viking 2 was turned off on the very same sol because of a battery failure

What kind of batteries did the landers have, the orbiters are quoted as having wet cell NiCads. We have come a long way since then.

Posted by: Zvezdichko Aug 11 2007, 12:20 PM

According to wikipedia info:

QUOTE

Power was provided by two radioisotope thermal generator (RTG) units containing plutonium-238 affixed to opposite sides of the lander base and covered by wind screens. Each generator was 28 cm tall, 58 cm in diameter, had a mass of 13.6 kg and provided 30 W continuous power at 4.4 volts. Four wet cell sealed nickel-cadmium 8 A·h, 28-volt rechargeable batteries were also onboard to handle peak power loads.

I personally don't believe that at least one of the rovers will live longer than Viking 1 ( the other lander ).

Posted by: abalone Aug 11 2007, 12:26 PM

Thanx for that info, all seems good except this has got to be a typing error, how did they manage to run 1960's electronics on 60W, must be a zero missing

QUOTE

Each generator was 28 cm tall, 58 cm in diameter, had a mass of 13.6 kg and provided 30 W continuous power at 4.4 volts.

Must be correct, 35W maximum as quoted here
http://en.wikipedia.org/wiki/Radioisotope_thermoelectric_generator

Posted by: Steve Aug 11 2007, 02:06 PM

30 W for each of two RPGs comes to 1440 Watt hours per day. Spirit and Oppie together never reached that level.

Steve

Posted by: Rob Pinnegar Aug 11 2007, 04:14 PM

QUOTE (Zvezdichko @ Aug 11 2007, 06:20 AM)

I personally don't believe that at least one of the rovers will live longer than Viking 1 ( the other lander ).

Depends on what you mean by "live". Certainly they might not be able to keep moving for two or three more years. However, even if their wheels fail, they still might be able to act as stationary "weather stations".

Posted by: ustrax Aug 11 2007, 04:59 PM

QUOTE (OWW @ Aug 11 2007, 10:44 AM)

I say a celebration is in order!

ULTREYA ET SUS EIA SPIRIT!!!!
Undoubtfuly!
Abyss or no abyss this is, to me, the biggest of missions...
We have crossed the desert, w have climbed the mountain, we have descended the mountain...
Man...Spirit is just...BEYOND!

Posted by: Ant103 Aug 12 2007, 05:00 PM

It's a great day.

But, don't forget that the battery failure was due to very low temperatures who have made some charge and discharge, during the second winter that VL2 had through. Utopia Planitia winter is colder than Meridiani or Gusev. Now, imagine you put one of the rovers on this site, I don't believe that they can survive to the winter (lower sun and lower temperature : remember frost during some sols).

Posted by: edstrick Aug 13 2007, 07:41 AM

I believe the Viking's battery failures were due to age and not cold. Remember, the landers had large amounts of waste heat available from the radioisotope power generators. I don't remember anything about thermal control in detail, but that heat was available to keep the important insides warm.

Posted by: djellison Aug 13 2007, 10:46 AM

GO SPIRIT
BEAT VIKING

Posted by: tty Aug 13 2007, 08:11 PM

[Sigh] Contrary to popular belief Vikings did NOT have horns on their helmets.

Posted by: Shaka Aug 13 2007, 08:23 PM

(sigh) Obviously you never attended a Minnesota Vikings game.

Posted by: djellison Aug 13 2007, 09:47 PM

QUOTE (tty @ Aug 13 2007, 09:11 PM)

Vikings did NOT have horns on their helmets.

But the Viking engineers and scientists did on landing night.

Doug

Posted by: dvandorn Aug 14 2007, 03:19 AM

QUOTE (Shaka @ Aug 13 2007, 03:23 PM)

(sigh) Obviously you never attended a Minnesota Vikings game.

I was about to say "Just try telling that to several hundred thousand of my fellow Minnesotans," but you beat me to the punch, Shaka...

-the other Doug

Posted by: CosmicRocker Aug 14 2007, 03:51 AM

There are more, gradually improving tau measurements on Dr. Lemmon's http://www.lpl.arizona.edu/~lemmon/mer_dd.html. He also notes that Happy VL2 Day for Spirit was sol 1282.

QUOTE

*) Sol 1282 : Happy VL2 day to Spirit! By completing sol 1282, Spirit surpassed Viking Lander 2 for longevity on Mars. VL2 operated from sol 0 to 1280; Spirit's mission counts from sol 1.

Posted by: .dk Aug 14 2007, 01:44 PM

And Spirit has now surpassed the 100k image mark

http://marsrover.nasa.gov/gallery/all/spirit.html

Posted by: alan Aug 14 2007, 08:27 PM

QUOTE (Zvezdichko @ Aug 11 2007, 07:20 AM)

According to wikipedia info:
I personally don't believe that at least one of the rovers will live longer than Viking 1 ( the other lander ).

How many sols did Viking 1 last?

Posted by: jamescanvin Aug 14 2007, 09:42 PM

QUOTE (alan @ Aug 14 2007, 09:27 PM)

How many sols did Viking 1 last?

2245

Still a way to go...

Ha! I admit didn't remember the exact number of sols off hand so i looked on Wikipedia. I then went back and looked at what reference they had, only to find it links to a http://www.unmannedspaceflight.com/index.php?showtopic=3217, where I gave the answer last time!

Posted by: nprev Aug 15 2007, 12:20 AM

The WWW thus becomes a loop (dare I say an orbit?) around UMSFers! Now, here's my plan...

Posted by: CosmicRocker Aug 15 2007, 04:16 AM

That's an interesting story, James, to find a reference linked back to yourself here. In my experience, the UMSF forum frequently floats to the top of the list when I google space topics of interest to me.

Posted by: djellison Aug 15 2007, 07:57 AM

Quite often I'll be researching for a talk, and googling for a subject - only to find myself linked into UMSF again... 'NO...I KNOW that bit already!'

Doug

Posted by: Oersted Aug 20 2007, 08:59 PM

Regression:
See: Regression

Posted by: climber Aug 25 2007, 10:17 AM

QUOTE (jamescanvin @ Aug 14 2007, 11:42 PM)

2245

To be fair, we can also consider the sum of V1+V2 to be compared to the sum Spirit+Oppy so, it'll be less than another 500 sols for the MERS to beat the VIKINGS.
Any MERS in Minnesota ?

Posted by: fredk Aug 25 2007, 03:56 PM

Colourful tribute to the occasion http://marsrovers.jpl.nasa.gov/gallery/press/spirit/20070823a.html

Posted by: jamescanvin Sep 2 2007, 10:35 AM

It's now the afternoon of B1282 and so Oppy outlives Viking 2 as well.

Roll on A1774/B1754 (I think) to break the combined sols mark.

James

Posted by: PhilCo126 Sep 16 2007, 09:19 AM

The Viking spacecraft hardware:

Viking 1: Launched 20 August 1975
Viking 1 lander:
Touch down: 20 July 1976
Shut down: mid November 1982
Viking 1 orbiter powered down on 17 August 1980 (1400 orbits)

Viking2: Launched 9 September 1975
Viking 2 lander:
Touch down: 3 September 1976
Shut down: mid April 1980
Viking 2 orbiter powered down on 25 July 1978 (706 orbits)

See my avatar to see how engineers were dreaming to drive around in a Viking 3 rover

Posted by: dvandorn Sep 16 2007, 02:45 PM

QUOTE (jamescanvin @ Sep 2 2007, 05:35 AM)

Roll on A1774/B1754 (I think) to break the combined sols mark.

My first reaction to that statement was "Gods, that's another 500 sols!" My second reaction to it is "Gee -- only another 500 sols?"

-the other Doug

Posted by: climber Oct 8 2007, 08:04 PM

Yesterday, Today or Tomorrow, depending if you live in New Zealand or Hawaii , MER will get to 4 Martian years roving on Mars

Posted by: monitorlizard Oct 10 2007, 01:24 AM

These rovers are incredible. I propose we change Spirit's name to Old Faithful and Opportunity's to Slightly-Less-Old Faithful.