Some Statistics for Spirit & Oppy, As the journey continues on Mars Options

[fredk]

Thanks for clarifying that, PDP! It would be interesting though to know how many frames have been sundial/sun/odometry. I could imagine writing a script that jumps through the jpl jpeg pages and counts them up. (Not downloading each image, of course.) Odometry would be easy - just add up the navcam subframes downsampled frames (match "EDN" in filename). Sun/sundial could be done by matching on the img width and height attributes...

[climber]

We all know that odometry means weels turn and not real kilometers and that the sun dials can't be stealed by the Martians without been seen since they are shot so many times . Well, I didn't ear that the MER sun pictures are used by Soho's team either.

Anyway I like the milestone 25 kilometres, 250.000 pictures, 4000 sols, 6 martian years coming along nearly altogether at the same time.

[fredk]

The more I think about it the more useful it would be to do a thorough count of images. One other use would be to find all the images that appear on exploratorium but not on the jpl gallery pages. Has anyone else noticed that there are images missing from the jpl pages? For example, these images are not on the jpl pages:
http://qt.exploratorium.edu/mars/opportuni...ARP1979R0M1.JPG
http://qt.exploratorium.edu/mars/opportuni...B8P2544L7M1.JPG
http://qt.exploratorium.edu/mars/spirit/fo...E5P1110L0M1.JPG
http://qt.exploratorium.edu/mars/spirit/pa...E5P2550L7M1.JPG
(these are from sols 1961 and 1972 (Oppy) and 1990 (Spirit)).

These were all released on August 9th and 11th on exploratorium, but never made it to the jpl gallery, obviously because of some glitch (August 10th images are missing too). But it would be good to have a list of all such missing gallery images, even though the images are public at exploratorium. The jpl gallery is a great, easy way to look for old images from some particular sol.

[Deimos]

I figured I'd check the stats myself. This is based on images downlinked, excluding multiple versions, and doesn't rely on the image browsing sites, but I cannot vouch for absolute completeness. I also am ignoring thumbnails and looking only at the EFF, ESF, and EDN types. I see a total of 120,604 Spirit images, 124,728 Opportunity images, for 245k images. That adds up to 261 Gbits (2.5% of which is from thumbnails and engineering/calibration data) as downlinked. Image number by camera (A/B) is: Pancam 78,929/80,972; MI 5,824/5,996; engineering--the rest. Among Pancam, 8,806/13,298 are of the Sun or sky; 16,482/15,739 are of the cal targets (aka sundial). Those two categories add up to <4% of total Pancam bits downlinked. The rovers have taken over 300,000 images (147,166/160,573); the difference between these numbers and the first set comes from images taken but deleted on board (e.g., some empty dust devil movies) or taken only in thumbnail form (or maybe some missed in my count?). By type, Pancam images are mostly EFF or ESF (like Sun and sundial), MI are almost all EFF, and engineering images are mostly EFF or EDN (like autonav).

* The numbers are as of mid-day (UTC) 15 Sept. 2009 (probably sols 2026/2006 PM downlink).

[edit: fixed Mbits to Gbits. What's 3 orders of magnitude among friends...]

[PDP8E]

Hey Deimos,

I was finishing up my lunch and doodling how to approach an Exploratorium count with a perl and shell script when your posting came across the wires! Thanks for the independent numbers. You rock!

[fredk]

Agreed, very cool to have those numbers, thanks Deimos. Roughly a third of all pancam frames are sun/sky/sundial. (Should the total volume be perhaps Gbits rather than Mbits?)

[briv1016]

With this latest week of drives, the combined driving distance of Spirit and Opportunity is now 26.62 km which beats the Apollo 16 rover driving distance of 26.55 km.

Just for reference:

Vehical / Distance

Lunokhod 2 / 37.00 km
Apollo 17 rover / 35.89 km
Apollo 15 rover / 27.76 km
Apollo 16 rover / 26.55 km
Opportunity (2056) / 18.89 km
Lunokhod 1 / 10.50 km
Spirit (2076) / 7.73 km
Sojourner / ?

[climber]

Interesting figures indeed.

We've now (last status nov 5th) roved 6209m since Victoria which added nearly 50% more odometry since there (started at 12678m).

[Guest_PhilCo126_*]

I believe that Sojourner (the little rover that could...) drove a total distance of about 110 meters... longest drive during one sol was about 7 meters? How far am I off ?

[Hungry4info]

The total distance will never be known. After Pathfinder died, contact between Sojourner and Pathfinder ceased. Sojourner was programmed such that if this ever happened (like if Sojourner wandered behind a rock or something), to circle Pathfinder, trying to establish contact. This would continue until either Sojourner re-established contact, or died.

Pathfinder died, so contact was probably never re-established. Sojourner spent the rest of its days, unattended to by anyone or anything, circling its lifeless companion, trying desperately to contact it. All in vain.

[djellison]

Actually - we can be fairly confident about how far Sojourner got after pathfinder died, as there's a fairly convincing identification via HiRISE of Sojourners location. We had an entire thread here about it- a pool of where we thought Sojourner would be

[Hungry4info]

Sojourner has been found? I thought its location remained unknown =o. Apparently I didn't keep up with it.

And how did you resolve the issue of not knowing how many times Sojourner circled Pathfinder?

[djellison]

It's fairly clear from the location that it drove from its last know position, in a straight line partially back towards the lander, and stopped.

In a perfect world - it would have circled the lander. But the pathfinder landing site was far from a perfect world.

post 70+ in this thread - http://www.unmannedspaceflight.com/index.p...irise&st=60

[climber]

On november 20th total Sols was 4160.
If one devides 900M$ by 4160x84600 (Number of second per Earth day), he'll find that costs of 1 rover second hit 2.5$.
Nominal mission was above 52$

[Deimos]

Keep in mind that the whole 'Bambi circling its dead mother' imagery was always more poetic than predictive. The code said to return to the lander; the result of certain keep-outs was that circling would occur on perfect terrain. But where Sojourner was on sol 83, Ender was on the most likely first direction. That is significant because Ender & Wedge almost ended Sojourner's travels much earlier, with a rover driver threatening to turn off all safety checks and command enough wheel turns to grind the rock to dust if that's what it took to move again. That terrain, the best entrance to the Rock Garden, was nearly non-navigable. An unattended rover with fault protections (tilt, etc) on had zero chance of passage. (My guess in '97 was right against Ender--wouldn't have won the pool, but close.)

Note that Sojourner got stuck somewhere around 6x nominal mission. The response to both Opportunity and Spirit being stuck has been much more cautious, despite being even further "past warranty". I think the real explanation is a somewhat different culture (despite a similar cast & crew); equally, though, it is clear that the MERs each had more future potential from continued roving, compared to Sojourner with the Rock Garden abandoned.

Also, I have 7 m (sol) and 104 m (mission--before the last couple m) for Sojourner.