[X] My Assistant

[stewjack]

Now that we know where we are going, I thought we could use a topic about our future route. I hope that a few images will get the rover rolling - downhill.

READY START

BACKGROUND
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From Steve Squyres Misson Update
Octoberber 4, 2005

Extending eastward from the summit of Husband Hill is a broad ridge that we've named Haskin Ridge. It trends ENE from the summit, does a little dog-leg to the right, and then trends ESE for a bit. Right at the dog-leg there's a pretty steep step, which we're not certain we can get down. So we're going to descend the upper portion of the ridge, right to where the step is, and assess the situation. If we can see a safe route, then we'll continue down onto the lower portion of Haskin Ridge.
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My Image of Haskin Ridge
I tried to get the best image of Haskin ridge that was available, and this is a crop from a true color TIFF summit panorama, located on the the Cornell Pancam web site. I converted the tif file to a gif file to save some download time.

Warning : File Size : 1.7 MB
Cornell True Color Pan of Haskin Ridge

Reference
WEB page of Husband Hill Summit Panorama
Warning: File Size : 80 MB !!!!
Preliminary Spirit Pancam of "Husband Hill Summit" Panorama

Jack

PS If you can't see the "steep step" that Squyres mentions - try this orbital image. I believe that the "steep step" is the dark shadow cutting across the ridge that is located directly under the word CRATER. I think that it is also visible in the true color pancam image, but it is less obvious.

Orbital View of Husband Hill and Basin

[sattrackpro]

Tesheiner,
I think you are right. The only place where Spirit can cross that step is where you painted the route and a little bit more to the right.
jvandriel

I hope you are BOTH right - but, James may have a point - there could be a rather sudden drop off that isn't quite so easy to see in these photos - yet...

It is possible that line he draws goes all the way across the pan... the big question is - is there any drop-off at all. What I'd like to see - is what does it look like further to the right...

There looks to be an easy and smooth descent to the floor of Gusev to the left, once down this 'step' - then a drive-around, to get back to home plate.

[RNeuhaus]

Just been looking at the images from Sol 637 again (yestersol) (no 638 yet  ) and noticed how close to the top edge of the frame the horizon is in the front hazcam shots, Spirit is at quite an angle already.

Looking at Front and rear hazcams from the summit I think the curve of the horizon should get to about 200 pixels of the top of the hazcam frames on level ground (at the summit height above the planes). On Sol 637 there is only ~35 pixels to the top, with 0.12 degrees per pixel that means Spirit is tilted forward ~20 degrees already.
James

James,

I am interested on your technique to measure the slope. How do you count the pixels from the picture? I cannot see every pixel from the picture. How do you now about the measurement of 0.12 degree per pixel?

Rodolfo

[Tesheiner]

I hope you are BOTH right - but, James may have a point - there could be a rather sudden drop off that isn't quite so easy to see in these photos - yet...

It is possible that line he draws goes all the way across the pan...  the big question is - is there any drop-off at all.  What I'd like to see - is what does it look like further to the right...

There looks to be an easy and smooth descent to the floor of Gusev to the left, once down this 'step' - then a drive-around, to get back to home plate.

Sattrackpro,

The line plotted by James was made by measuring distance (by parallax) to known points before and after the line. Maybe you can't see a sudden drop on a single picture, but you can actually "see" it by checking both L&R images (in 3D).

The path I painted on my previous post has no such discontinuity. What does it mean? That the distance smoothly increases on the whole path; there is no sudden jump on the measured distance, meaning that there is no step.

[RNeuhaus]

The attached picture is my path recommendation. Avoid whenever as possible to pass over the stones (they make more problems with slipping and unstabilizing by the difference of height). Prefer to go down over the sandy land.

I have traced two paths : the yellow's one is possible but much dangerous and the blue's one is the best.

Rodolfo

P.S.I learned that the pancam pictures are the best ones to study the land. Navcam pictures showed me a false impresion of land surface. Even better if it is analghphy?? in combination with bearing of red and blue eyeglass.

Attached thumbnail(s)

 

[Tesheiner]

...  and the blue's one is the best.

Rodolfo, take a look at the discussion about the "step" on this same thread.

[RNeuhaus]

Rodolfo, take a look at the discussion about the "step" on this same thread. 

What thread? . Remember, that the MER ladies are capable to incline as much as 45 degree but only up to 30 degree as safety margin. When I goes down on a big dunes (above than 100 meters), my truck can behave very well on slope of 30 degree without any problems of control (use a very slow rpm engine as a brake). However, the Haskin Ridge has more stones so it must go with more care in touching as less as possible on them.

Rodolfo

Attached thumbnail(s)

 

[Burmese]

Looking back, the rover tracks look very peculiar.

http://qt.exploratorium.edu/mars/spirit/re...00P1312L0M1.JPG

Why all the scuffling back and forth every foot of the way? It's as if the rover is practicing a side-slip method for edging downhill on a steep slope.

[RNeuhaus]

Yes, I think it so.

I seems that this is not a good practice since it increases the risks to loose the stability. The wheels must be on straight line on the gravity for a better traction control.

I see that Spirit is not experiencing much slippage. She went on the right way where there are fewer stones.

Rodolfo

[Tesheiner]

Burmese,

Looking that picture and also taking into account Spirit was driving three days in a row (including today) while Oppy was driving four days in a row (today too), I must ask:

What were those guys at JPL smoking this week?

[odave]

Using jvandriel's navcam panorama and the usual MOC image, it seems to me that there are enough unique features visible to derive Spirit's current location on the ridge:



But I'm not sure how to transfer the angles. Any of you pros care to try?

[Burmese]

When Spirit 1st started to climb the hills, they modified the autonomous driving program such that if the rover detected slip over a certain threshold, it's 1st reaction would be to change direction slightly and attempt to 'tack' up the slope. Perhaps they will apply the same algorithm for going downslope, with the slip threshold reversed, but this current slope doesn't seem to be the sort to induce any slip at all yet.

[RNeuhaus]

When Spirit 1st started to climb the hills, they modified the autonomous driving program such that if the rover detected slip over a certain threshold, it's 1st reaction would be to change direction slightly and attempt to 'tack' up the slope. 

That algorithm is sure good. It applies the same to the off road which is to steer on the both sides when the wheels starts to slip.

Rodolfo

[stewjack]

[B]Watch that first step![/B}

An Animated gif for the 3D challenged
The big step is close to the bottom of the image - don't miss it.

Haskin Ridge Flicker
File size 500 Kb

[attachment=1923:attachment]

[jamescanvin]

Wait a minute, James!
Did you get those pictures directly from the pancam tracking web? How?

Edit: Sometime ago I was playing with that "display_jpeg" button on the webpage with no results. Any trick?

I discoved this some time ago, last time we had a major outage at JPL and Expl (when the Tracking site was first found) I have mentioned it in this forum somewhere.

The trick is, do you see that big button titled "Table of All Images From All Sols"? (Just below the select sols box) well give it a click...

Then find the seqence you want and click on the link in the "Seq.Ver.Iter" column and hey presto you should get some 200 x 200 thumbnails.

James

[Guest_Sunspot_*]

[B]Watch that first step![/B}

An Animated gif for the 3D challenged
The big step is close to the bottom of the image - don't miss it.

Haskin Ridge Flicker
File size 500 Kb

[attachment=1923:attachment]

Ahhhhhhh so that's the step lol .. couldn't make it out until now.

.. another drive by the way

http://qt.exploratorium.edu/mars/spirit/fo...00P1214R0M1.JPG