I had the afternoon off today, so I popped over to the National Air & Space Museum's Udvar-Hazy Center. I spent some time looking at their Mars Pathfinder display. Their Pathfinder is an engineering duplicate of the lander, and the Sojourner is "a nonworking model built by JPL for the NASM." One thing that struck me was that the ramps for Sojourner looked too narrow. It looks like there are metal guides that are about the same distance apart as the inside wheelbase dimensions, so they could act as a guide for Sojourner's wheels. However, there didn't seem to be enough width of material outboard of those guides on which Sojourner's wheels could safely travel or be supported. The only other thing I can figure is that the dimensions on these two display items don't match up.
Does anyone recall how that worked?
Here's a photo I snapped today, perhaps you can see what I mean.
http://i407.photobucket.com/albums/pp155/texwardo/Sojourner.jpg
http://mars.jpl.nasa.gov/MPF/ops/80911_full.jpg
From the tracks at the base of the ramp, this looks about the same as the museum display.
Phil
I guess the ramp material is stiffer than it looks!
Found the movie of the roll down the ramp - it does indeed use the metal guides and roll the wheels outside of them - that looked like a tougher steering challenge than I remember!
http://mars.jpl.nasa.gov/MPF/ops/rover_movie.gif
Looking at my image from the museum, it appears that the guide on the right side of the picture extends farther back onto the lander deck than the one on the left. That would have served to align the wheels and drive path as Sojourner first began moving.
http://trs-new.jpl.nasa.gov/dspace/handle/2014/23848 may be of interest.
Super, thanks for the link!
Returning to an older Sojourner thread... there's still lots of good stuff to do with that mission, and the images are available in the Planetary Image Atlas. I'm trying to reconstruct the rover route map. I hope nobody reading this was responsible for making the mission maps - cuz they are awful! Well, the polar one with tracks all around the lander looks good, but it's a simplification. and the other map that frequently made it into journals has all sorts of gaps caused by improved estimates of location from the end of one day to the start of the next.
Well, I guess I'll be cleaning it up myself. As a start I'm assembling daily composites of IMP rover documentation images like these. Sol 12 and Sol 23.
Phil
This is really cool! That reminds me, I am two thirds of the way though the rover black and white images, after which I will have the entire set of rover images done.
I've been working on a new map of the Pathfinder site. It's always hard to create a photomap from reprojected surface images, but here the spatial control is the HiRISE image, making it a bit more reliable than the contemporary mission maps.
Phil
You might want to use the Sojourner panorama from Sol 76 to fill in the area behind the rock garden.
I'm considering it, but much of it lies outside my area.
Phil
This is a part of the Sojourner route map I have compiled for my Mars Atlas. The background is from the Pathfinder panorama, projected as close as I can get it to fit the geometry of the HiRISE image. The routes, overnight stops and experiment locations are indicated. Labels like S2, A4, W3 refer to the various experiments which will be described in the text.
Phil
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