Spirit - Still Alive - volume 2 - Page 4

Really good report on Spirit's situation. If nothing else the enforced stay has provided further evidence that Home Plate was a hydrothermal/vocanic area. It is a bit sad though that after all this time the extraction technique will be exactly what they were doing when they first got bogged.

[link]

RE: "...the extraction technique will be exactly what they were doing when they first got bogged." -- Serpens

I don;t know why you say that. Before they stopped, they tried driving backwards, in the same direction they were going, and they tried crabbing sidewards, downhill into the crater. I do not think they ever tried driving forward, in the direction they came from. I could swear I heard them say as much in the conference. The forward extraction drive, along the original tracks, looks like a new, previously untried maneuver to me.

Serpens is correct. The very last movement was forward.

See this 1891-1894 animation:

Er, is anyone interested in the Spirit images taken in the past few months? I have processed them but not posted most of them on Flickr.

Re: "The very last movement was forward."

But not straight forward. I'm guessing that was the last of a set of twisting maneuvers aimed at crabbing to the left, downhill.

In this very last movement, how big is it, and is there any idea about how stuck Spirit are in despite of last attempts to extraction? 1M$ question I suppose.

Thanks Hortonheardwho - that was the animation I was basing my statement on. It very clearly shows that they actually moved back along their entry track a reasonable distance. A repeat of the purgatory dune technique?

Re: "In this very last movement.... is there any idea about how stuck..." -- Mizar
At least one person on the team does not consider Spirit to be stuck. Also, concerning the stalled middle wheel, they have tested it without the stall reoccurring.

“I’m an optimist,” said Arvidson....“Back when we decided not to drive and do a stand down on Sol 1900, we were still making progress on the last drive until left middle wheel stalled. That’s why I say we’re not stuck, but mobility impaired.... I’m not sure we’ll get out though.”

This is the link to where I got the quote in my last post.

Concerning Hortonheardwho's animation: The wheels are turned in a different orientation in the before and after shots so it's hard to know how they were turned during the drive. The wheels are turned to the left at the end of the drive. They are currently turned straight back for the next drive and may possibly be turned to the right to counter any slippage down slope to the left.

"We'll start by steering the wheels straight and driving, though we may have to steer the wheels to the right to counter any downhill slip to the left," said Ashley Stroupe, a JPL rover driver...http://www.jpl.nasa.gov/freespirit/

This does not seem like a repeat of the sequence seen in Hortonheardwho's animation.

Thanks for a good answer centsworth_II, and lets hope this efforts will 'unstuck' Spirit.
If they can make use of the stalled middle wheel, the chances are far better for a success.

Driving planned today - in fact should be happening now:

02088 p1154.02 2 0 0 2 0 4 front_hazcam_idd_unstow_doc_pri15
02088 p1161.03 1 1 0 0 0 2 FHC_LEYE_PreDrive_IDD_sub_2bpp_pri_47
02088 p1162.02 1 1 0 0 0 2 FHC_LEYE_PostMI_IDD_sub_2bpp_pri_29
02088 p1162.02 1 1 0 0 0 2 FHC_LEYE_PostMI_IDD_sub_2bpp_pri_29
02088 p1214.05 2 0 0 2 0 4 front_hazcam_ultimate_4_bpp
02088 p1235.00 2 0 0 2 0 4 front_hazcam_0.5bpp_pri_18
02088 p1247.03 2 2 0 0 0 4 frHC_mega_cleatcam_half_2_bpp_pri_26
02088 p1254.00 2 0 0 2 0 4 front_hazcam_fault_pri15_4bpp
02088 p1314.00 2 0 0 2 0 4 rear_haz_ultimate_4bpp_pri15
02088 p1335.00 2 0 0 2 0 4 rear_hazcam_0.5_bpp_pri_18
02088 p1347.03 2 2 0 0 0 4 RearHC_mega_cleatcam_half_2_bpp_pri_26
02088 p1354.01 2 0 0 2 0 4 rear_haz_fault_pri15_4bpp
02088 p1806.03 2 0 0 2 0 4 navcam_1x1_visodom_LOCO_pri_28
02088 p1809.06 2 0 0 2 0 4 navcam_1x1_visodom_LOCO_pri_17
02088 p1809.06 0 0 0 0 0 0 navcam_idd_doc_1_bpp_pri_15
02088 p2128.01 3 3 0 0 1 7 pancam_cal_targ_L257
02088 p2142.08 3 3 0 0 1 7 pancam_left_middle_wheel_L257
02088 p2143.08 3 3 0 0 1 7 pancam_right_middle_wheel_L257
02088 p2601.03 4 2 0 0 2 8 pancam_tau_L78R48
02088 p2906.03 1 0 0 1 0 2 mi_cover_open_minloss2_LUT3_DN3000_crit
02088 p2906.03 1 0 0 1 0 2 mi_cover_open_minloss2_LUT3_DN3000_crit
02088 p2926.00 1 0 0 1 0 2 mi_open_minloss2_LUT3_DN3000_pri24
02088 Total 41 18 0 21 5 85

Planetary Blog

http://planetary.org/image/spirit_sol2079_2088_wheel_comparisons.gif

See the before & after animation from today's move. Is it my imagination or has the LF wheel moved fractionally higher?

From Nov 17, 2009 Free Spirit:

The preliminary results from the first extrication drive for Spirit on Sol 2088 (Nov. 17, 2009) indicate the rover stopped less than 1 second after it began, sensing more vehicle lateral tilt than permitted.

Yikes!

The permitted tilt was less than one degree, perhaps much less.

sol 2008-2088 ( Aug 27-Nov 17, 2009 ) left wheel animation:

It looks like the center wheel went up in less than 1/2 of a tread width turn. Perhaps rode up on a buried rock? If so, then a very good sign that the left center wheel should have traction against the rock.

And yes, the left front wheel rose a mm or so.

Well the left front wheel certainly rose a smidgeon. It would seem as if the left middle may have also also risen very slightly, unless this is just an effect of the rocker bogie movement due to the left rear sinking.

Since we are on the very edge of a crater filled with dust, maybe the sinking of the wheels will have been Spirit's salvation. She may have sunk enough to have wheel(s) on solid debris. Else why would the LF wheel, which is in the crater, have lifted?

sol 2088-2090 great escape animations.

Looking good!

I wonder if it makes sense to clear away the loose mound of soil in front of the left front wheel using the IDD arm. Might make the progress faster.

pk, how do you imagine the arm being used to move more than a few grams of soil?

> how do you imagine the arm being used to move more than a few grams of soil?

The rat brush, perhaps? Isn't a brush the correct tool to clean up a mess of spilled soil?

Hort - The first big question is whether moving the mound away off to the side would indeed help and if it would be worth it. The mound in front of the wheel presents a steep slope which the wheel is plowing through, rather than climbing out of.
If the answer is yes, then I was imagining using the side face of one of the instruments to scrape the soil off, with repeated motions. Like using one's arm to push things away.

Just a thought.