I am setting up a new thread now for the early drives and continued checkout. Post in here as we start our traverse, sol 14 and on.

Phil

Nice!

Do we have any roadmaps for where the rover will be headed yet or is that something we will get in the weeks ahead after the helicopter

Hi Steve. They just had a press conference and image release on the mission website which includes this:

https://mars.nasa.gov/resources/25700/the-r...r-perseverance/

They will decide soon which of the two paths to take, but they seemed to prefer the clockwise path out of the landing area. Later it meets up with the nominal path through the delta.

Phil

I have updated my interactive map using an EDL rover down look image with an animation of the first drive, estimated from closely analyzing the animation shown during the press conference:

https://bit.ly/PercyMAP

Here is a map of the current location (ca. 4590880.87, 1093294.80, -2569.90, Equirectangular Mars 2000 Sphere projection):



I think it is pretty close. Rover should be to scale.

[edit] Ah, I see that Phil came up earlier pretty much with the same route. Should have noticed earlier. Anyways, glad it was not a case famous last worlds.

The counter-clockwise route is a little shorter (~5km to delta front). The potential for science targets on the clockwise route seems like a better option even though it adds another km or so to reach the main delta. For instance, the isolated delta remnant would be reached in about 5km and it could be very useful to understanding delta formation and erosion.

They could have used different colours for the first part, I thought the blue and purple were the same colour when I watched the news briefing.

Why did they make the tread pattern curved and not just a straight line ?

Been wondering about that too. To make them stronger than straight lines would? Curiosity's were more like the design in most tires, but then inverted; raised rims instead of grooves.

I found the answer :

"Extensive testing in the Mars Yard at NASA's Jet Propulsion Laboratory, which built the rover and manages operations, has shown these treads better withstand the pressure from sharp rocks and grip just as well or better than Curiosity's when driving on sand."

https://www.nasa.gov/feature/nasas-persever...-and-air-brakes

Another Sol, another drive (sol 15 Navcam - raw)
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I found as much; but nothing on straight vs curved specifically, only in comparison with the pattern on Curie's wheels.

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I made this map to show the two paths presented at yesterday's conference, my sense is that they'll decide fairly soon. Exciting times are ahead! The blue route is shorter (~4.6km, >23 sols drive) and safer, whereas the purple route is longer (~6.4km, >32 sols drive) but more scientifically interesting. The estimated times are based on the (aspirational?) 200m per sol that Percy has been designed to reach, of course in reality there'll be scientific stops that will greatly lengthen the journey.

Personally, I am a fan of the purple route, it covers a greater diversity of geological terrains and gets a good close-up look at the amazing stratigraphy on the isolated delta butte.

“But perhaps the most visible change is in the grousers. They are ten percent taller and run across the width of the wheel in a near straight line. It’s got a slight curvature to it to help give some strength to it,” says JPL engineer Patrick DeGrosse.

https://www.sciencefriday.com/segments/to-b...s-test-on-mars/

Test wheel victims and survivors:

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Ah. Thanks .

You'd think the Blue path would be more interesting with a large crater and the heat shield not far off the path that I'm certain the engineers would like to have a peek at.

In the telecon yesterday they made clear that they will be staying away from any EDL hardware for contamination reasons.
We'd all like to see it, but Oppy's encounter was a confluence of circumstances. All the hardware was visible as soon as they left Eagle crater, the heat shield was right on the traverse path from Endurance crater, and there were far fewer concerns about close proximity negatively affecting the science mission.

Look on the bright size; Mastcam-Z allows imaging at a distance with much more detail (if local topography allows), so no need to get super-close.

Yes for sure
But also, like many, I would like a visit to see (even from a distance) the colorful parachute and its backshell.
This would be a great opportunity for Education & Public Outreach and would offer the public great memorable pictures to see.
And we will not have other opportunities to take such impressive pictures for decades to come
Click to view attachment

That Percy wheel looks pretty good for doing 60Km.

It seems Perseverance is now roughly 30 metres NNE of Octavia E. Butler site : the blue path is maybe already the chosen path.

I think here is approximately the location of Perseverance after sol 15 drive, marked in a sol 11 left mastcam Z image.
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Picture taken by Navcam Right on sol 15 showing tracks left by tosol drive.

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Why are they avoiding the area directly to the west?

Alan, maybe they want to avoid sand dunes traverse ?

From the MRO images, it seems like there is room between the ripples to maneuver (it's not a solid field like what Curiosity had to go around to reach Mount Sharp), but presumably the team does not want to take even a small risk at this stage of the mission.

Looks like they're sticking to the "Smooth Unit" and avoiding the "Fractured Unit".

Click to view attachment

Definitely a "Blue" fan too. The crater is like an amphitheater with a view into the layer underlying the main delta. Also smoother driving and will let them make faster progress. I'd love to see photos of the heat shield in its new forever home even from a distance - good test of the zoom cams.

This is not the main traverse - they are looking for a place to drop the Belly Pan (which protected Ingenuity from the landing event), and will then return to a smooth area near the landing site to do the helicopter tests. Only after that will the main traverse begin.

Phil

In the absence of Navcam panoramas for each location I am using rather rough Hazcam reprojections to find the points to plot on the map. Here are the sol 14 and sol 15 images.

I think Erwan's site is very good.

Phil

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Thank you Phi for your comment ; and there is also an helicopter...

I have updated my interactive map based on EDL downlook at

http://bit.ly/PercyMAP

with an animation showing the traverse. It is based on geojson path data from the Where is the rover page. The azimuth of the rover is following the path. That means that the first 150 degree turn is not represented.

The way point geojson from the web page has additional yaw orientation data and shows for the current position a yaw of 88 degrees which I think corresponds to the front being pointed to the east. Is that what the latest camera images show ? Was there some turning in place on the final position of the last drive ?

[edit] The answer was yes. But the traverse continued more on a 72 track. I updated again http://bit.ly/PercyMAP .

Sol 16, another drive L-Navcam looking back at the latest set of wheel tracks on Mars...
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after the last sol 16 drive, Perseverance seems to be located here (marked on a mastcam Z sol 11 image)
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Looks like the rover took a right turn during its Sol 16 drive:

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https://mars.nasa.gov/mars2020/mission/where-is-the-rover/

If you've noticed the weird donut-shaped raw images on the Skycam, here is a great link on how it works.

https://www.hou.usra.edu/meetings/lpsc2020/eposter/2282.pdf

New helicopter thread established.

I am still trying to understand the Navcam geometry well enough to make panoramas. I put together a very simple one for sol 16 - horizon tier only - at low resolution. It's not perfect (not good enough to post) but good enough to make a circular view to check the sol 16 location on a HiRISE image. Only 5 Navcams are needed for a full panorama like this. It will be nice to see proper panoramas from our experts.

Phil

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Phil, it is good enough to refine the previous location i gave for sol 16 drive
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Odometer

https://mars.nasa.gov/mmgis-maps/M20/Layers...0_traverse.json

has the traverse geojson data which are used on the Where is Perseverance ? map.

The json data also include distances traveled per leg. In addition, it is possible to determine travel distance by measuring along the provided coordinates. Here is a table:



All in meters. There is a small difference and I am not sure why. In any case, total travel sofar is 70m to 72m.

Has it been decided where to send the rover on a north or south route?

No. Helicopter operations come before the main traverse.

Phil

Andreas,

Nice link for the traverse path JSON. Many thanks

I notice your animated traverse that you show elevation of the terrain around the rover.

Perseverance elevation data is not available in the M20 interactive map geojson files, so I was wondering if you are aware of any external links to the other M20 traverse values such as pitch, roll etc values and especially elevation at each coordinate change that is made available in the Curiosity Rover interactive map geojson files?
Elevation is not hugely interesting in this near flat plain, but it will be of great interest as the rover begins to climb onto the delta and beyond. Any links would be very welcome.

regards,

Paul

The Where is the rover map uses a few more geojson files, see http://www.unmannedspaceflight.com/index.p...st&p=250647 . The way points geojson has yaw, pitch roll data.

I just learned about the PDS PLACES database: http://www.unmannedspaceflight.com/index.p...st&p=250716

I think the geojson comes directly from there. There should be elevation (or Z data) but it is not provided in the geojson. I use the 1m HiRISE mosaic DEM linked from: https://astrogeology.usgs.gov/search/map/Ma...tTs0_lon0_first for querying elevation.

The DEM and the imagery should be very well co-registered. In my animated traverse due to slight 3d perspective viewing the rover appears a little offset from the traverse since it is offset above ground level. If the geojson included elevation, I could use that as well.

Regarding the odometer data, the distances from the geojson may be straight from the rover, using wheel rotations although the coordinates may also be straight from the rover (with subsequent conversion to latitude/longitude). I used projected, equirectangular coordinates to measure distances which is strictly speaking not quite correct but probably still ok at 18 degrees latitude. In any case, it could not explain a >1m discrepancy in distances. Perhaps the geojson distance is the straight line distance between way points, not along the path but this is inconsistent with the last leg which is almost perfectly straight and has the largest difference.

The Sol 17 raw images are online. There's a lot of images of the robotic arm.

Here's a good image of the business end of the arm, the coring drill, framed by a Martian landscape:

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Looks like we have arrived at a candidate Helipad. This posted on social media.



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The arm got a workout for each axis. Click to animate:

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has a color equalize for each frame (the blueish sky is not real).

Here is MEDIA SkyCam
Sol 16, 8 AM Local
There is dust on the lens (and some hot pixels)

(animated gif)
Click to view attachment

(and is that Wall-E peeking in ...)

And in this deeper exposure taken at a similar time we can see the sun through the neutral-density annulus:
https://mars.nasa.gov/mars2020-raw-images/p...5_0000LUJ01.png

This is an illustration of the map offset mentioned earlier. The color HiRISE image with the route map from the website registered to it. The third panel shows them superimposed. The map's starting location is too close to the drifts behind the rover and should be moved roughly 3 m southeast (north is at the top, except I registered the map to HiRISE when I should have done the reverse, so north is really a bit clockwise from the top).

Phil

Click to view attachment

http://bit.ly/PercyCOORDs (from http://www.unmannedspaceflight.com/index.p...t&p=250266)

shows the landing location as I had read it from the online map right when it was shown first, and the actual landing location imaged from orbit. The online map coordinates then showed as

77.45081, 18.44468

This now seems different and corrected on the online map, and they show as, and the geojson has them as:

77.45088572, 18.44462715

But, and I would confirm Phil, this is still a little offset from what the registered HiRISE of the landed rover shows. For me it comes out at

77.4508882°E, 18.4446394°N , CRS: EPSG 104971 - Mars 2000 (Sphere)

The differences are small but I think real and indicate some kind of positioning/registration mismatches.

On the other hand subsequent way point locations from the geojson look really close to what navcam imaging reveals, relative to close boulders. But I did not attempt any direct comparisons for those.

I just noticed that when you let the cursor roll over the traverse on the 'where is the rover' map, it pops up with the length of the drive. I don't know if I just missed that before or if it's new. Roll over the site and you get the sol on which the rover reached that point - it has done that since the landing. If that works for Curiosity as well, it makes up for the loss of drive distance which Paul was concerned about.

Phil