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Posted by: Art Martin Mar 7 2021, 04:35 PM

I'm putting this in the Early Drives category because I believe that one of the primary purposes of these first drives is to find a spot for the helicopter.

Is anyone else wondering like I am just what the terrain needs to look like to set the helicopter down? It sure looks to me that the areas we're in right now are largely free of obstacles for flying and landing with no large rocks. Unless you go for some completely sand covered spot I'm not sure you're going to find any areas any more pristine. Does anybody have any info about what type of zone they are exactly looking for? Since the helicopter is not really designed to be used for investigation of terrain but more as just a proof of concept of flight, I would imagine the choice of area would be wide open and flat.

Here's what I've got so far about upcoming events.

1. The helicopter below the rover limits ground clearance so it is vital that the helicopter phase be early in the drives so the rover is not limited in mobility.

2. The main purpose of the helicopter is proof of concept of Mars flight so the emphasis is not using it for exploration/route planning/research photography but merely that we can sustain flight - take off, fly autonomously, and land safely.

3. Once deposited on the surface, it will take a number of days of check outs prior to the first real flight.

Should we create a new topic that is discussion about the helicopter?

Posted by: mcaplinger Mar 7 2021, 06:35 PM

You could, but at this point, it would likely have nothing in it but speculation from those who don't know and silent frustration from those who know but can't say.

All of your observations are completely accurate as far as I know.

Posted by: nprev Mar 7 2021, 06:37 PM

New topic created.

Posted by: mcaplinger Mar 7 2021, 07:56 PM

https://trs.jpl.nasa.gov/bitstream/handle/2014/46229/CL%2317-6243.pdf

Posted by: mcaplinger Mar 7 2021, 08:33 PM

Some interesting info in https://trs.jpl.nasa.gov/bitstream/handle/2014/50175/CL%2318-3381.pdf -- stuff in JPL TRS is circa 2018 so might be out of date though.

Posted by: Art Martin Mar 8 2021, 06:26 PM

Fascinating stuff. From what I read there could be (after all primary mission objectives are met) a flight to land at a new parking place up to 500m away. Like you say though these projections could be outdated.

Posted by: Pando Mar 8 2021, 08:54 PM

Great info there. One thing that caught my eye was the future use of a helicopter as "Fetcher":

Posted by: Art Martin Mar 9 2021, 02:20 PM

According to a post on Twitter the rover has moved to an area where drop off may occur. I was looking at the images and GIF's of them testing the range of motion of the arm and I'll bet that it will be used to take photos of the underbelly as the pan is dropped off and the helicopter unfolded and deployed. Sherlock should get it's first real workout.

Posted by: Explorer1 Mar 12 2021, 03:00 AM

Helicopter lecture starting now:
https://www.youtube.com/watch?v=DoLYqFB6kVY

Posted by: Art Martin Mar 12 2021, 02:58 PM

Well my suspicions were confirmed as we got the first Watson pictures of the underbelly of the rover today. With the timing of that press conference about the helicopter my guess is the dropping of the pan is very likely happening very soon.

Edit: This got me to learn some debayering techniques so here's the image.

https://flic.kr/p/2kKiqSQhttps://flic.kr/p/2kKiqSQ

Posted by: Art Martin Mar 13 2021, 05:23 PM

I had no idea about the cover for the sample extraction system so I was obviously premature with thinking the cover for Ingenuity would be the next thing removed. Thrilled with the underbelly panoramas and animations of that drop. My question to anyone more familiar with the operations is will the rover now move away from that dropped cover before ejecting Ingenuity's cover or can they both be dropped in the same place. I would think that they'd be concerned Ingenuity's cover might roll over the other one and limit ground clearance. If so, I imagine the next step after full checkouts and photos of the sample retrieval system would be a short drive to be clear of the first cover drop to set up the next.

Posted by: mcaplinger Mar 13 2021, 05:56 PM

https://www.jpl.nasa.gov/news/press_kits/mars_2020/ingenuity/landing/mission/spacecraft/

I'm not sure if the timetable in the press kit still holds, but this suggests that the heli debris shield drop won't happen soon, considering that https://mars.nasa.gov/mars2020/spacecraft/rover/body/ said

Posted by: Art Martin Mar 14 2021, 05:43 AM

Thanks for the reply.

I remember certainly that discussion about the 60 days before deployment when they really had no clue what their landing area would look like but I also remember in the detailed explanation that the 60 days may be required to find an adequate flat spot free of obstacles to deploy it. We saw Twitter posts just this last week that seemed to indicate they've found that spot. I also remember someone being asked about it in early press conferences and saying that as long as the helicopter is tucked under the rover, the ground clearance was affected limiting where the rover might potentially drive so I would think getting the helicopter demo "over with" is truly in the best interest of the primary science mission. It is probably wishful thinking on my part to believe that 60 days is a fluid number and put out there to dampen expectations and impatience. The Twitter posts and the recent news conference/seminar concentrating on Ingenuity's operations seem to be doing exactly the opposite for the public of getting the excitement and anticipation going. We'll find out soon. In the end nobody should be disappointed with the timetables the rover team follow and I fully trust their judgment.

Until we begin getting regular mission updates, speculation on timings or drive directions is really all we have. With MSL they'll put in their update a basic calendar of upcoming events such as drilling and sampling or drives all subject to change of course due to days with missed communications or aborted actions. So far we're finding out about Perseverance's events after the fact although the raw images are coming down in real time giving wonderful hints. It's been amazing so far.

Posted by: Mogster Mar 14 2021, 09:17 AM

A planned 5 flights have been mentioned previously.

Is that a hard limit or as with the rovers will they continue operations until they can’t fly anymore?

Posted by: Art Martin Mar 14 2021, 04:04 PM

This has some speculation in it. We have not had any specific answers about your question that I can think of from Ingenuity's team.

Ingenuity cannot communicate directly from Earth, requires commands from the rover to receive it's programming for flights so, if the cold doesn't kill it from batteries not getting fully charged and operating heaters, the only possible scenario I can see where it can continue flying, since the engineers are going to want to move the rover and test its long drive capabilities, would be for those extra flights to be follow flights (or flying to a the rover's planned destination) where the helicopter ends up in the near vicinity of the rover. I cannot imagine, if it's still working perfectly after the initial flights, that they'd simply leave it to die but there could be data constraints as well. Ultimately, once that test is done, all of the emphasis goes to the science operations. Now, if some follow command takes nearly no time preparing it and the data to send it and receive the day's images from it are small data volumes then it might be around for awhile. I would bet any flights beyond the 5 are going to be far more risky in nature if it happens. What you probably wouldn't see though is a flight that could result in Ingenuity failing over the top of the rover.

Posted by: Art Martin Mar 14 2021, 04:24 PM

Here's some comments I found on the Ingenuity press kit regarding the 60 days that had been used earlier and more info about the 5 flights. Bolding is by me.

"Once a suitable site to deploy the helicopter is found, the rover’s Mars Helicopter Delivery System will shed the landing cover, rotate the helicopter to a legs-down configuration, and gently drop Ingenuity on the surface in the first few months after landing. Throughout the helicopter’s commissioning and flight test campaign, the rover will assist in communications back and forth from Earth. The rover team also plans to collect some images of Ingenuity."

That seems to indicate that the deployment and test could occur at any time up to 60 days.

"Ingenuity will attempt up to five test flights within a 30-Martian-day (31-Earth-day) demonstration window."

That's fascinating that they believe Ingenuity has the potential to last up to 30 SOLs. If tests go well I'm sure those 5 will get done as early in that window as possible to ensure that any early failures from the cold nights don't limit the number done. If you get them all done in a couple of weeks and the thing is still going strong I can't believe there's not the potential for extending past 5.

Posted by: Art Martin Mar 14 2021, 05:39 PM

An update. Just saw an answer to a Twitter post from the "rover" asking when deployment would be and it said there'd be a couple of weeks of system testing first. When in doubt, ask the source....

Posted by: Marvin Mar 14 2021, 05:53 PM

Ingenuity has a 13 MP color camera and 0.5 MP black and white navigation camera.

So along with images of the terrain from altitude, I hope we get some images of Perseverance from Ingenuity as well.



https://mars.nasa.gov/resources/25530/mars-helicopter-ingenuity-landing-press-kit/

Posted by: mcaplinger Mar 14 2021, 06:07 PM

If you read the press kit, you'll see that for safety reasons the helicopter never gets anywhere close to the rover (130ish meters), so this is not very likely, considering that the max altitude is stated as 5 meters.

[edit: I don't know how wide the FOV of the "horizon facing" color camera is or how it's pointed, so maybe there is some possibility it can catch the rover.]

Posted by: nprev Mar 14 2021, 07:38 PM

Per the press kit the expected effective radio range is 1000m, so I wonder if the Ingenuity XM plan is to send her out ahead of the expected rover path as a scout after accomplishing the core tech demo objectives as a follow-on operational utility test. Not sure how much that might slow down Perseverance, though, which has its own minimum mission objectives to meet.

Posted by: Explorer1 Mar 14 2021, 08:06 PM

Even if relaying to and from the rover has no negative effects on the science mission, in terms of data and planning time, the availability of personnel (and funding!) is another potential bottleneck on further flights.
But I just don't see a perfectly functional independent spacecraft being abandoned just like that (think of the negative PR alone! People grow attached to these things....)

Posted by: Marvin Mar 14 2021, 08:22 PM

The safety of the rover must be the primary consideration.

I found the following for the Ingenuity color camera, called RTE:

"Return-to-Earth (RTE) Camera. This is a rolling shutter, high-resolution 4208 by 3120 pixel sensor (Sony IMX214) with a Bayer color filter array mated with an O-film optics module. This camera has a FOV of 47 deg(horizontal) by 47 deg (vertical) with an average IFOV of 0.26 mRad/pixel...pointed approximately 22 deg below the horizon"

https://rotorcraft.arc.nasa.gov/Publications/files/Balaram_AIAA2018_0023.pdf

Posted by: fredk Mar 14 2021, 09:39 PM

There seems to be an error in that document, unless the camera has weird optics that compress horizontally to give a bad aspect ratio.

Anyway, those specs give a rover size of something on the order of 100 pixels at 130 metres. So if it's in the FOV, we'll see something.

Posted by: Andreas Plesch Mar 15 2021, 02:11 AM

The https://rps.nasa.gov/ web pages have a https://rps.nasa.gov/resources/3D-viewer/ of the rover.

It looks like a full engineering drawing and if you look at the belly has both Ingenuity stowed away in its protective shell and also the sampling system cover which was just dropped unceremoniously.

This gave me a much better understanding of the current location and orientation of the helicopter.

Looking at the web page in detail, it looks like the 3d model is fbx converted to https://github.com/McSimp/lzfjs/ compressed PLY format, for which there is a parser to extract triangles, normals and colors. This seems to be generated by a JPL https://www.cloudsasha.com/#/protospace/ system which in turns uses Hololens for AR.

Posted by: Marvin Mar 15 2021, 12:59 PM

Here's an image of the helicopter attached to the rover at the Kennedy Space Center on April 6, 2020:


NASA/JPL-Caltech

An animated gif showing the testing of the deployment sequence:


NASA/JPL-Caltech/Lockheed Martin

Posted by: Explorer1 Mar 17 2021, 08:38 PM

https://www.jpl.nasa.gov/news/nasa-to-host-briefing-to-preview-first-mars-helicopter-flights

Telecon on March 23rd about the chosen flight location. Looks like the first week of April for flight.

Posted by: Art Martin Mar 19 2021, 09:05 PM

This just came up on Twitter. Things seem to pointing to a few days drive to the selected site and dropping the protective cover. Then about a week of deployment activities.

https://twitter.com/NASAPersevere/status/1372986848641884160?s=20

Posted by: MrNatural Mar 20 2021, 09:52 AM

I wonder how much of a dust cloud it will kick up and how much that will interfere with its imagery. I guess we will find out, but I am not setting my expectations too high.

Posted by: Mogster Mar 20 2021, 01:06 PM

Not Mars but Nevada.

https://youtu.be/ojZeso5tVYk

Posted by: mcaplinger Mar 21 2021, 07:35 PM

Debris shield dropped.

Posted by: neo56 Mar 21 2021, 08:39 PM

From other points of view:

https://flic.kr/p/2kMXrwU

https://flic.kr/p/2kMXrvw

Posted by: rlorenz Mar 21 2021, 08:51 PM

Not much - the downwash velocity is not that high compared to the dust lifting windspeed.

This might be behind a paywall for you, but there's an analysis here
https://doi.org/10.1016/j.aeolia.2020.100653

Posted by: alan Mar 21 2021, 11:55 PM

Percy is such a litterbug.

Posted by: neo56 Mar 22 2021, 07:44 PM

Animation made with WATSON mosaics taken on sols 21 & 30.

Posted by: CryptoEngineer Mar 23 2021, 02:44 PM

That's cool!

Question: Does anyone know what the components are which move in the undercarriage, on the left and right sides, much closer than the debris cover? They also seem to move a panel crossing the width of the undercarriage between them.

Posted by: Phil Stooke Mar 23 2021, 04:05 PM

Those things are parts of the Belly Pan which was dropped earlier. This is an animation made with views before the belly pan was dropped and after the debris shield was dropped, not simply before and after the debris shield was dropped.

Phil

Posted by: Explorer1 Mar 23 2021, 04:37 PM

T - 1 hour to a preview of the flight: https://www.youtube.com/watch?v=WK5YXZIIEKU

I'd hazard a guess that they've found a good site for the flights.

Posted by: Art Martin Mar 23 2021, 06:41 PM

They have indeed. Very close to the original landing spot. There were maps during the presentation.

https://mars.nasa.gov/system/resources/detail_files/25744_PIA24494-1200.jpg

Posted by: MrNatural Mar 24 2021, 09:53 PM

Is the launch point going to be in one of the scour marks from the descent stage's engines? Might be less dusty....

Posted by: MahFL Mar 24 2021, 10:55 PM

Looks like it's just outside the blast zone, maybe some dust was blown.

Posted by: Sean Mar 25 2021, 12:33 AM

Airfield & Flight Zone with simulated rover & helicopter for scale.
https://flic.kr/p/2kGKfWS

Posted by: pioneer Mar 26 2021, 10:29 PM

I hear Ingenuity's window of operation will last about 30 days. When does the 30 days start? Is it on April 8, the tentative first day of flight?

Posted by: mcaplinger Mar 26 2021, 11:23 PM

https://www.jpl.nasa.gov/news/press_kits/mars_2020/download/ingenuity_landing_press_kit.pdf

Posted by: pioneer Mar 26 2021, 11:48 PM

Thanks.

Posted by: Art Martin Mar 27 2021, 02:00 PM

Lots of new images down of the underbelly and Ingenuity as well as pans of the surrounding area. I'd say we are truly at the final helicopter drop location.

Posted by: PaulH51 Mar 28 2021, 02:59 AM

GIF - Helicopter 'Launch Lock' unlatched

Rotated / Cropped SHERLOC frames from Sols 35 & 36

Posted by: rlorenz Mar 28 2021, 03:13 PM

Unlikely, IMHO. Helicopters do not scale up well.

Beyond the obvious thrust challenge in the thin Martian atmosphere (i.e. classic momentum theory, and the Mach/Reynolds aerodynamic issues common to all aeronautics), there are some other rotorcraft-specific issues that actually are rather challenging for Ingenuity that one only confronts when one gets into the real details of design and test.

First is heat transfer. The thin atmosphere gives almost no cooling. The Ingenuity motors have parts made of beryllium to act as a heatsink, but even then I think overheating is actually the limiting factor on fliight duration, not battery energy.

Second is aeroelasticity. There's a similarity parameter called the Lock Number (that I hadnt heard of until I started working with rotor people on Dragonfly) that is important in assessing the structural damping of blade flexing. Again, the thin atmosphere is the problem, it provides no damping so blade oscillations can build up.

Both of these issues get worse as you scale up. So at the NIAC / Powerpoint / student-final-year-project level, yes you can mock out neat-looking hexacopters and stuff in the 10-20 kg range and they look like they should fly, but once you really start poking into the thermal and mechanical design, I bet even those would not work out.

Posted by: Phil Stooke Mar 28 2021, 09:23 PM

https://mars.nasa.gov/mars2020-raw-images/pub/ods/surface/sol/00037/ids/edr/browse/shrlc/SIF_0037_0670231425_148EBY_N0031392SRLC07000_0000LUJ01_800.jpg
Ingenuity drops down a bit, getting ready...
Phil

Posted by: fredk Mar 29 2021, 05:04 PM

That's interesting, and surprizing. Since the rotors must produce comparable downward thrust on Mars as on Earth (to within an order of magnitude, anyway, considering the lower gravity), via a much greater rotor velocity, I might've guessed that the cooling effect of that air would be comparable too. I guess that means that thrust doesn't scale the same as conductive cooling with air density.

Posted by: Mogster Mar 29 2021, 05:21 PM

I remember cooling being a serious issue for the Apollo LRV. Everything was always ridiculously cold and at risk but then as soon as it started to operate it’d get so hot it’d be close to melting...

Interesting issues to overcome when more performance is needed from possibly human carrying vehicles on the Moon or Mars.

Posted by: mcaplinger Mar 29 2021, 06:50 PM

Can't speak to exactly how they're modeling it, but my own experience with R/C helicopters of similar scale suggests that rotor downwash is a pretty ineffective way of cooling the motors on Earth, and nothing about the Mars helicopter suggests anything different. Take a look at figure 6 in https://trs.jpl.nasa.gov/bitstream/handle/2014/48631/CL%2318-4405.pdf which shows the propulsion motors getting up to something like 85C worst-case. Of course, the range is extremely wide, suggesting that the thermal analysis is very conservative, as they usually are.

Posted by: PaulH51 Mar 29 2021, 10:14 PM

Another step closer (sol 38)

Posted by: Sean Mar 30 2021, 12:08 AM

Almost there...

Posted by: Marvin Mar 30 2021, 12:36 AM

It's getting exciting!

Here's what Flights 1 - 3 might look like:

https://www.hou.usra.edu/meetings/lpsc2020/pdf/2096.pdf

Posted by: neo56 Mar 30 2021, 07:45 PM

Animation of Ingenuity deployment from sols 35 to 38.

Posted by: PaulH51 Mar 31 2021, 01:24 AM

Looking good with all 4 legs deployed on sol 39 (processed & cropped)

Posted by: rlorenz Mar 31 2021, 02:59 AM

Thrust goes as rho * V squared. So for a given thrust and disk area, Martian density 50x less means the downwash has to be 7x faster

Power goes as rho * V cubed. So to generate that thrust we have to put 7x more power through the motor

But the heat transport goes as something like rho * V, so we have 7x less heat removal for a given temperature difference.


Now of course the disk loading of Ingenuity is a factor of a few less than typical small terrestrial drones, to make these effects a bit more manageable (and keep the rotor tips subsonic, etc.) but you can see the scaling really points to overheating being an issue for sustained operation at low density

Posted by: djellison Mar 31 2021, 04:35 AM

So what you're saying is...Dragonfly has it easy

Posted by: Bill Harris Mar 31 2021, 05:24 AM

One could assume that "technology will find a way", but this may have hit a wall in this case. R/C helicopters use brushless motors as standard, which have the windings on the stationary periphery of the motor and the rotating core of the motor containing a magnet array. The windings could be cooled via a circulating fluid or by coupling to a large heatsink, but the problem will be cooling that core magnet array. Typically that is force-air cooled, but that wi'll be impossibly difficult with the thin Mars atmosphere.

Posted by: htspace Mar 31 2021, 11:59 AM

Wow!

Posted by: MarkL Mar 31 2021, 04:55 PM

[quote name='neo56' date='Mar 30 2021, 08:45 PM' post='251285']
Animation of Ingenuity deployment from sols 35 to 38.



Thank you! I would imagine they have taken video of each phase of the deployment which would be show smooth rotation of the various components. Is this just wishful thinking? The cameras can shoot at 10 fps and it would makes sense to have such a video.
Mark

Posted by: mcaplinger Mar 31 2021, 05:22 PM

WATSON can only run at 1/4 the video rate of MCZ (like MAHLI on MSL.)

From "Curiosity’s Mars Hand Lens Imager (MAHLI) Investigation" https://link.springer.com/article/10.1007/s11214-012-9910-4 -- "For a 720p format video, the maximum rate is ∼1.9 frames per second."

Posted by: djellison Mar 31 2021, 06:18 PM

There are pyrotechnic devices being fired during these steps. You don't want science cameras pointed at pyro devices when they're going off.

Posted by: mcaplinger Mar 31 2021, 07:09 PM

Good point. I thought this was all non-pyrotechnic, but based on https://www.compositesworld.com/news/nasa-ingenuity-mars-helicopter-prepares-for-first-flight you're correct, there was a pyro involved.

Posted by: stevesliva Mar 31 2021, 07:19 PM

One begins to expect Ingenuity to deploy something below itself as well...

Posted by: djellison Mar 31 2021, 07:42 PM

Looking at the CAD file posted to https://rps.nasa.gov/3D-viewer/ it looks like there's definitely some involved in the chopper - shield deploy for sure, and at least some others around the interface to the rover.

Posted by: neo56 Mar 31 2021, 07:58 PM

Animation updated with sol 39 mosaic:

Posted by: fredk Mar 31 2021, 08:18 PM

Maybe it's https://en.wikipedia.org/wiki/Turtles_all_the_way_down

Posted by: Marz Apr 2 2021, 03:21 PM

April 11th is the expected first flight attempt, with data on April 12th:

https://www.space.com/ingenuity-mars-helicopter-flight-delayed-april-11

Posted by: PaulH51 Apr 3 2021, 03:47 AM

New Helicopter blog entry https://mars.nasa.gov/technology/helicopter/status/288/its-cold-on-mars/ (dated April 02, 2021)
Written by Bob Balaram, Chief Engineer for the Mars Helicopter Project at NASA's Jet Propulsion Laboratory

Posted by: Marvin Apr 3 2021, 02:05 PM

That's a great 3D viewer. I tried to find out more about this using public domain sources.

If you look at this image from Lockheed Martin Space, I think I see three pyrotechnic valves associated with the helicopter deployment:



From what I can ascertain from open sources they were used to:
1. Release the helicopter shield
2. Release a locking mechanism holding the helicopter to the rover
3. Release the arm to begin rotating the helicopter to the upright position

The final attachment of the helicopter to the rover seems to me to be a non-explosive spring loaded release mechanism activated by a current. That's the cylinder with a "Z" on it. This is the last electrical connection between the rover and helicopter.

These are my best guesses, most of the detailed engineering specs are behind paywalls.

Here is the original source to the Lockheed Martin image:
https://www.flickr.com/photos/lockheedmartin/50024052807/in/photostream/

Posted by: Art Martin Apr 4 2021, 01:17 AM

Just saw this on Twitter:

https://pbs.twimg.com/media/EyF2yf7WUAMSUdR?format=jpg&name=medium

Posted by: nprev Apr 4 2021, 01:20 AM

Upright & on the regolith.

Posted by: Explorer1 Apr 4 2021, 02:30 AM

And lapping up the sun's rays too! Terrific accomplishment, those last few cm.....

Posted by: Phil Stooke Apr 4 2021, 03:02 AM

The two Hazcam images projected to help locate the new position for the map.
Phil

Posted by: MahFL Apr 4 2021, 04:00 AM

Whoot !

Posted by: neo56 Apr 4 2021, 08:25 AM

A bit of image processing on this first photo of Ingenuity on its own on the surface of Mars.

https://flic.kr/p/2kR1udS

Posted by: Marvin Apr 4 2021, 11:44 AM

Good drop! I read somewhere there was a contingency to try to use the robotic arm to right it, if it had toppled.

The helicopter was fully charged before the drop, but I think I'm already seeing the "sticky dust™" on the solar panel. I don't know if this will impact the helicopter mission in any way.

Posted by: Sean Apr 4 2021, 12:23 PM

Survive The Night

Posted by: Explorer1 Apr 4 2021, 01:50 PM

It was a question during a press conference (specifically if the arm could be used if there was a problem during landing); the answer was if tipped over, it would be so damaged as to not fly anymore. In any case, the robot arm has no manipulator for that purpose.

Posted by: John Moore Apr 4 2021, 02:47 PM

Assuming all goes well for the eventual lift-off, I wonder will the manoeuvre generate a dust cloud around it so as to obscure camera-recording of it by Percy?

Whatever occurs, it's still a great achievement...congrats to the team.

John

Posted by: HSchirmer Apr 4 2021, 03:28 PM

Agreed!
Does this mean we get Martian air density data that allows future rovers to include a "leaf blower" to blow the dust off, and a bunch of detailed belly spectrometers to identify what minerals they're driving over?

Posted by: Art Martin Apr 4 2021, 08:17 PM

There's a number of images that I thought we'd see before the one of the rover fully backed away from Ingenuity. I would have thought they took images of steps such as the disconnect of the helicopter and its drop below the rover. Also possible images of the drive away from it. Perhaps they are still coming down and the importance was dropping it and moving quickly away to start the solar cells charging and ensuring it was all clear. I guess there was no possibility of video of the drop. Just once I'd like to see an object hitting the surface in the reduced gravity. I suppose we'll see that during the flights although it will be a power on landing.

Posted by: Art Martin Apr 4 2021, 08:20 PM

I believe before the first flight there are a couple of motor tests where the rotors will turn but be below take off speeds. Those may kick up some dust and remove it prior to the actual flight.

Posted by: fredk Apr 4 2021, 11:25 PM

See http://www.unmannedspaceflight.com/index.php?showtopic=8610&st=30&p=251113&#entry251113 for an answer to that.

Posted by: phase4 Apr 4 2021, 11:39 PM

here's an attempt to make an anaglyph of a L-R rear hazcam pair.
view with caution

https://flic.kr/p/2kR5W7c

Posted by: Sean Apr 5 2021, 02:29 AM

Sol 44 Navcam Left

Posted by: nprev Apr 5 2021, 02:52 AM

Yikes. Do I see dust on the arrays already...?

Posted by: Art Martin Apr 5 2021, 03:18 AM

Not sure where dust would have come from to have got to the top of Ingenuity. The cover was still on during landing and early roving and the rover didn't go very far after removing it with the solar panel vertical during that time until unfolding and deployment. Sure a drop of a few inches didn't kick up a bunch of dust. I'm certain they drove the rover away slowly. We'd really need a zoomed in shot to confirm that is actually some dust coating and not just different coloration of the panels.

Posted by: nprev Apr 5 2021, 03:24 AM

Agreed, of course. Definitely do not want to be right here.

Posted by: Art Martin Apr 5 2021, 03:31 AM

An anaglyph of the Nav Cam shots.

https://flic.kr/p/2kRdb43https://flic.kr/p/2kRdb43

Posted by: eliBonora Apr 5 2021, 05:23 AM

Hazcam panorama

https://flic.kr/p/2kR28Ms

Posted by: djellison Apr 5 2021, 05:31 AM

4 NCAM subframes each at 2x2 downsampled. I suspect this is the res we will see most of the time for drive direction Navcam images.

Posted by: fredk Apr 5 2021, 05:33 AM

One possibility is that we're seeing some reflected skylight on the solar panels.

I couldn't find whether the navcam sensors include IR cutoff filters. There shouldn't be any real need to include them, since colour accuracy isn't too important for the navcams and sensitivity is a plus. If they don't have IR filters, another idea is that the panels may look quite different in the IR.

Also the Martian soil is fairly dark, so these exposures make the helicopter look unusually bright.

Posted by: mcaplinger Apr 5 2021, 06:00 AM

https://link.springer.com/article/10.1007/s11214-020-00765-9

Posted by: neo56 Apr 5 2021, 10:01 AM

A mosaic of 2 Hazcam Left pictures taken on sol 43 and a Navcam Left picture taken on sol 44:

https://flic.kr/p/2kRfpJL

https://flic.kr/p/2kResXz

Posted by: Marvin Apr 5 2021, 10:55 AM

When it was still attached, there was a gap between the solar panel and the bottom of the rover, so dust could have been deposited by the wind. But looking at the latest images, most of the panel seems clear. Probably more than enough to charge the battery.

Posted by: Andreas Plesch Apr 5 2021, 04:15 PM

https://bit.ly/PercyMAP has been updated to show the latest drives, Ingenuity at its current position but exercising its rotors 4m up in the air, a closer default view, and with more links from recent way points. Also, the 3d scene code was simplified a bit.

Posted by: ChrisC Apr 5 2021, 06:29 PM

Could you add a "help" button that displays a paragraph of text or something that provides a basic explanation of how to use this? It looks truly excellent, if only I could figure out to move around, or do whatever is possible with it.

EDIT: OK, I found this earlier post which is a great start:


I think a lot of people will have trouble with the middle-mouse drag. Most hardware interfaces are lacking that capability (laptop touchpads, trackballs, mice with scroll wheels, etc.). Is there a reason that you didn't use left-click drag?

Scroll-to-zoom sense seems backwards to me, but I'll be happy to be shouted down on that.

Is there a way to tilt the scene? Your mention of "3D" implies yes but ... OH MAN I just clicked "overlook"! Wow! Yes! Add that to the help text!

Posted by: Art Martin Apr 5 2021, 07:16 PM

A new update showed up on the rover website that even includes the first image taken by Ingenuity of the ground below it as it was deployed.

https://mars.nasa.gov/news/8906/nasas-mars-helicopter-survives-first-cold-martian-night-on-its-own/

“This is the first time that Ingenuity has been on its own on the surface of Mars,” said MiMi Aung, Ingenuity project manager at NASA’s Jet Propulsion Laboratory in Southern California. “But we now have confirmation that we have the right insulation, the right heaters, and enough energy in its battery to survive the cold night, which is a big win for the team. We’re excited to continue to prepare Ingenuity for its first flight test.”

Posted by: James Sorenson Apr 5 2021, 07:41 PM

There is plenty of slots cut and a gap of atleased 3 or 4 millimeters all around the debris shield. I'm thinking that dust on the panel was blown in through these gaps and slots during landing. There was a significant amount of dust and small pebbles at the bottom of the shield after it was dropped, which I can only fathom being blown in during EDL.

Posted by: Explorer1 Apr 5 2021, 08:10 PM

At the live Q and A today team members said the panels are getting all the power they need. No need to worry more than usual!

Posted by: James Sorenson Apr 5 2021, 08:15 PM

Nope, I'm not worried. Just pointing that out. 🙂

Posted by: Marvin Apr 5 2021, 08:43 PM

Here's an image taken from Ingenuity on April 3:

https://mars.nasa.gov/news/8906/nasas-mars-helicopter-survives-first-cold-martian-night-on-its-own/

Posted by: Marvin Apr 5 2021, 09:24 PM

There was also dust at the bottom of the belly pan when it was dropped:



This was cropped from one of http://www.unmannedspaceflight.com/index.php?s=&showtopic=8608&view=findpost&p=250929

There may have been dust blown into certain areas during EDL.

My only concerns would be:

1. Was the rover or helicopter damaged?
Doesn't look like it.

2. Could there be contamination of the cache system?
Unlikely, since the tubes are sealed. Besides it's still stuff from Mars.

3. Is there a better way to land a rover this size?
I don't think so.

Posted by: Andreas Plesch Apr 5 2021, 09:29 PM

It is time to do that when I have a chance.
Although the touch interface should work pretty well, the content is probably too heavy for most mobile devices. Chromebooks may work.
Thanks for giving this a try !

Posted by: ChrisC Apr 6 2021, 03:28 AM

Here's that Q+A event: https://www.youtube.com/watch?v=PcpI8-S5ZE8

Great to see MiMi Aung again! We hadn't seen her since landing and I was beginning to worry.

Posted by: neo56 Apr 6 2021, 08:07 PM

Anaglyphs of Ingenuity made with Navcam pictures taken on sol 44.

https://flic.kr/p/2kRtRXk

https://flic.kr/p/2kRu2aS

Posted by: fredk Apr 7 2021, 04:31 AM

Stunning watson and ZCAM images of Ingenuity down:
https://mars.nasa.gov/mars2020-raw-images/pub/ods/surface/sol/00046/ids/edr/browse/shrlc/SI1_0046_0671022109_238ECM_N0031416SRLC07021_000085J01.png
https://mars.nasa.gov/system/downloadable_items/45939_1-PIA24547-Mastcam-Z-Gives-Ingenuity-a-Close-up.jpg

Posted by: Sean Apr 7 2021, 06:21 AM

Commencing pre flight check
https://flic.kr/p/2kRyknH

Prepare For Take Off
https://flic.kr/p/2kRASsD

M20_00046 Watson

Posted by: PaulH51 Apr 7 2021, 09:32 AM

Strange how the Mastcam-Z image is still not on the public server

Posted by: Marvin Apr 7 2021, 11:30 AM

It's interesting how that dust/sand is mostly on one side of the helicopter's solar panel.

I wonder if the orange cable bundle acted as a windbreak, causing the deposition on one side of the panel:

Not a big deal, the helicopter is getting more than enough power.

Posted by: fredk Apr 7 2021, 02:32 PM

With MSL mastcam the policy was to delay the images 24 hours before they appear on the public "raw" site, as I recall. We were told the policy was the same with M20.

Posted by: PaulH51 Apr 7 2021, 03:15 PM

Maybe the M2020 pipeline is still suffering from set up issues. That Mastcam is one of the sol 45 images, it was released across social media and as a photojournal entry but here we are on sol 47 and it's still not in the raw image server. Hopefully they can smooth out any kinks in the pipeline to the raw image server

Posted by: MahFL Apr 8 2021, 10:53 AM

Some thumbnails came down showing a rotor blade movement.

Posted by: Marvin Apr 8 2021, 11:45 AM

Perseverance made a large move Eastward this last Sol:

It may be moving towards the https://www.jpl.nasa.gov/images/van-zyl-overlook, from where it will watch Ingenuity take flight:



NASA/JPL have scheduled a Pre-Flight tomorrow and a "Live Broadcast: Mars Helicopter First Test Flight Results" on April 12 12:30 a.m. PDT / 3:30 a.m. EDT.

https://mars.nasa.gov/technology/helicopter/#Watch-Online

Posted by: marswiggle Apr 8 2021, 11:51 AM

Ingenuity in a close-up anaglyph, adjusted and sharpened for convenient viewing.

Posted by: Ant103 Apr 8 2021, 01:01 PM

MastcamZ @110mm portrait of Ingenuity. I had to focus stack two frames to avoid depth of field.

https://db-prods.net/marsroversimages/Perseverance/2021/Sol45_MastcamZ.jpg

Posted by: neo56 Apr 8 2021, 04:07 PM

Animation of two Mastcam-Z pictures taken on sol 47. Spinning tests are beginning!

Posted by: eliBonora Apr 8 2021, 04:39 PM

Here our anaglyph version

https://flic.kr/p/2kRMBpM

Posted by: MahFL Apr 9 2021, 09:26 AM

Looks like the rotor blades are now unlocked.

Posted by: neo56 Apr 9 2021, 10:13 AM

Perseverance rover is now at Van Zyl Overlook viewpoint at 30 m from Van Zyl Overlook viewpoint.
GIF made using Mastcam-Z Left and Right pictures at 110mm focal length (sol 48).

https://flic.kr/p/2kS34xS

Posted by: PaulH51 Apr 9 2021, 11:29 AM

Simple GIF I assembled with 9 selected thumbnails from 60 thumbnails I found on the image server (these were the only frames that featured activity)
I believe this shows the 50 RPM rotor spin-up, I assume the next test will be the 2400RPM run, prior to the big day.

Posted by: Marvin Apr 9 2021, 05:43 PM

Some quick notes from today's pre-flight briefing regarding Ingenuity:

- It is getting enough energy to charge its battery, and should have enough energy for the first flight
- It will lift 4m straight up, then rotate towards the rover and take a picture (and maybe image the rover)
- The rover's ZCAM will attempt to take images and video of the helicopter in flight

https://www.youtube.com/watch?v=9C_IyUdKKXI

Posted by: djellison Apr 9 2021, 07:00 PM

I heard 3m.

Importantly for this crowd - there was a strong commitment to keeping the flow of raw images going - and a shout out to the creations people like those in this community are making.

Posted by: Marvin Apr 9 2021, 07:32 PM

Yep, it was 3m. I think when she said the helicopter weighs 4 lbs, the 4 stuck in my head.

I totally agree that the image processing people make this site what it is. The panoramas they create are just jaw dropping. My image processing skills and software are crude at best, so I plan to take a break from posting. But I will be enjoying the wonderful vistas about to unfold.

Posted by: PaulH51 Apr 10 2021, 12:03 PM

Sol 49 Mastcam spin up GIF (2400RPM?) Very low res, but we can see some movement of the rotors (maybe there is motion blur at the selected shutter speed?)

Posted by: MoreInput Apr 10 2021, 01:18 PM

Just found a very good documentation about the helicopter plans of NASA the next time on Youtube in German: https://www.youtube.com/watch?v=CSEiLLzh34Q

It gives a very comprehensive overview what NASA wants to do with Ingenuity the next days. It also views the flight zone for the helicopter.
The flight zone will be about 90 meters, the start zone about 10x10 meters.
It will fly about 90 seconds, and with a max height of 5 m.

Posted by: Tom Tamlyn Apr 10 2021, 06:02 PM

I'm guessing that the results of this sol's high speed rotation test will start to arrive on earth between 11:00 pm and midnight Pacific time. Does that sound right? I was counting back ~40 minutes from the predicted time for the first flight results Sunday evening.

Edit: This post was incorrect to start with and has now been completely overtaken by events. I suggest that the mods delete it.

Posted by: nprev Apr 10 2021, 06:23 PM

https://mars.nasa.gov/technology/helicopter/status/291/mars-helicopter-flight-delayed-to-no-earlier-than-april-14/?fbclid=IwAR18ljCeS4zOjOZk9Xq6vm9S7v5CB_LbI9GPtHg-87iHYNUf_f0eaVrjJWM. Looks like a minor software glitch.

Posted by: ChrisC Apr 10 2021, 07:44 PM

I deleted the Facebook tracking garbage in the link above. Key quote:

Posted by: Olympusmonsuk Apr 11 2021, 05:38 PM

Looks like we will have to be patient for the test flight.

NASA Mars 2020 blog.

Based on data from the Ingenuity Mars helicopter that arrived late Friday night, NASA has chosen to reschedule the Ingenuity Mars Helicopter’s first experimental flight to no earlier than April 14.

During a high-speed spin test of the rotors on Friday, the command sequence controlling the test ended early due to a “watchdog” timer expiration. This occurred as it was trying to transition the flight computer from ‘Pre-Flight’ to ‘Flight’ mode. The helicopter is safe and healthy and communicated its full telemetry set to Earth.

The watchdog timer oversees the command sequence and alerts the system to any potential issues. It helps the system stay safe by not proceeding if an issue is observed and worked as planned.

The helicopter team is reviewing telemetry to diagnose and understand the issue. Following that, they will reschedule the full-speed test.

Posted by: Hungry4info Apr 11 2021, 10:20 PM

Does anyone have a link to the two images presented in the 09 Apr press conference? The down-looking engineering camera and the forward-facing colour image?

Posted by: Phil Stooke Apr 11 2021, 10:55 PM

Not yet but they should be up soon.
Phil

Posted by: Art Martin Apr 12 2021, 11:46 PM

We just had an update of what's going on with the software glitch they experienced during the high speed blade test. Apparently they will upload a software fix and do a full reboot and testing so the first flight date is "fluid". Here's the link for the story. https://mars.nasa.gov/technology/helicopter/status/290/work-progresses-toward-ingenuity-s-first-flight-on-mars

Posted by: Explorer1 Apr 12 2021, 11:50 PM

Already a a full week is gone; if the 30 days demonstration time is a hard limit before Perseverance has to continue its science mission, some later planned flights probably won't happened?

Posted by: MahFL Apr 13 2021, 12:45 AM

They only need one flight.

Posted by: Explorer1 Apr 13 2021, 12:57 AM

True, and and whatever time they need to do it is irreplaceable. Just hoping the "fluid" timelines get nailed down eventually.

Posted by: neo56 Apr 14 2021, 08:36 PM

A video taken by Mastcam-Z Left on sol 47 when the blades were unlocked. The frames arrived today, here is a GIF:

I had to squeeze the pictures definition to fit with the max upload size, https://www.flickr.com/photos/thomasappere/51115841364/in/dateposted-public/.

Posted by: Greenish Apr 15 2021, 02:18 AM

It seems to me both rotors are spinning in same direction - and upper one is wrong direction for lift.
I hope that is not the firmware issue! If so, would raise some fairly fundamental questions...

Posted by: PaulH51 Apr 15 2021, 02:32 AM

Both blades had to be spun in the same direction to unlock them. See this on Twitter: https://twitter.com/exploreplanets/status/1382430765095346179

Posted by: Greenish Apr 15 2021, 03:26 AM

Makes sense now, thanks.

Posted by: MarkL Apr 15 2021, 01:59 PM

There are a lot of video compression artifacts in that full size video.

Posted by: djellison Apr 15 2021, 03:22 PM

Have you compared it to the original images?
https://mars.nasa.gov/mars2020-raw-images/pub/ods/surface/sol/00047/ids/edr/browse/zcam/ZL0_0047_0671111103_660ECV_N0031416ZCAM05001_110050J01.png

Posted by: Blue Sky Apr 15 2021, 05:45 PM

While a "watchdog" timeout can mean that a tolerance was set too tight, it can also mean a hardware failure, such as a movement limit switch not being hit when it should have. Some of these errors can be worked around remotely, but others can't. We dopn't know what the exact timeout was.

Posted by: djellison Apr 15 2021, 08:27 PM

https://twitter.com/NASA/status/1382399592449314816

That series of QnA explained what happened. It wasn't a hardware failure.

Posted by: ChrisC Apr 16 2021, 03:37 AM

Those Q+A video snippets were actually very useful! Good questions, good answers. Thanks!

Posted by: MarkL Apr 16 2021, 03:24 PM

Blocky. Highly compressed. Not sure why - is it distance to Ingenuity?

Posted by: djellison Apr 16 2021, 04:09 PM

Because it's highly compressed.

Posted by: Explorer1 Apr 17 2021, 03:43 AM

Full speed spin test went well!
https://mars.nasa.gov/technology/helicopter/status/292/working-the-challenge-two-paths-to-first-flight-on-mars/

Posted by: neo56 Apr 17 2021, 05:52 PM

I processed the Mastcam-Z Left video of the high speed test of April 10th which ended prematurely.

https://www.flickr.com/photos/thomasappere/51121184944/in/dateposted-public/

Posted by: Thorsten Denk Apr 17 2021, 06:53 PM

First flight will (might) be Monday morning!
https://www.nasa.gov/press-release/nasa-to-attempt-first-controlled-flight-on-mars-as-soon-as-monday

Thorsten

Posted by: MarkL Apr 17 2021, 10:01 PM

Droll Doug. I love a good tautology. But there must be a reason why these images are so compressed when other are not. that is what I was getting at. No known reason is I guess the answer I am seeking.

Posted by: fredk Apr 17 2021, 10:37 PM

You can see from the filenames that these were jpeg compressed onboard at quality 50. Presumably they didn't want to have the huge downlink volume of so many uncompressed or lower compression video frames, and decided that for this purpose the quality was enough.

Posted by: mcaplinger Apr 18 2021, 01:44 AM

When returning realtime-compressed video, 16 1280x720 frames have to fit in 2 Mbytes, so you can do the math about how much compression you can use. https://mastcamz.asu.edu/cameras/tech-specs/

Posted by: MahFL Apr 19 2021, 07:30 AM

Ingenuity should be airborne right about now.

Posted by: Andreas Plesch Apr 19 2021, 10:35 AM

The Nasa coverage said data will be received any minute now.

Posted by: Andreas Plesch Apr 19 2021, 10:53 AM

success !

Posted by: serpens Apr 19 2021, 10:57 AM

That flight sequence was amazing.

Posted by: Explorer1 Apr 19 2021, 10:58 AM

Congratulations, and what an image of the shadow and Perseverance tracks!
Edit: and now the two color photos from the rover!

Posted by: pac56 Apr 19 2021, 11:07 AM

Flight video as seen from Perseverance on Youtube (time 40:55)
https://www.youtube.com/watch?v=p1KolyCqICI

Posted by: JTN Apr 19 2021, 11:33 AM

Tweets of the images/video from the livestream:

• https://twitter.com/NASAJPL/status/1384101674650722310
• https://twitter.com/NASAPersevere/status/1384104815567855626

Haven't noticed a press release yet, maybe we'll not get that until the in-depth presser later?

Posted by: Andreas Plesch Apr 19 2021, 11:42 AM

https://www.youtube.com/watch?v=p1KolyCqICI&t=2309s

has the altimetry plot. The change in altitude to the hover appears to be very close to 3m. The duration of the hover appears to be around 40s if I read the scale correctly. Ascend and descend take less than a few seconds, perhaps one second.

https://www.youtube.com/watch?v=p1KolyCqICI&t=2525s has the image sequence.

Posted by: MarkL Apr 19 2021, 01:05 PM

Makes sense. There were a lot of very clear images of the airfoils, then these so I figured something was different.

Just watched the Ingenuity first flight full frames from ZL. Incredible. Go download them! The hover and yaw rotation is distinctly visible. This clearly sets the stage for a drone mission with ground support and opens up a lot of the planet for further discovery.

115 seconds.

0672089482.269 to
0672089597.207

(*edit - from the altimetry plot, looks like airfoil rotation started at about 089425 and ended at 089580. Interesting the altimeter seems to have adjusted itself )



A few of the ascent (27 sec) and descent (22 sec) frames are missing. Maybe they are saving them to make the full presser video.

https://rkinnett.github.io/roverpics/?mars2020&sol58&filter=0672089

*edit2: As you scroll through the video stills of the flight, there are some compression artifacts, of course. These are not entirely random it seems. You can see what appear to be columns of refracted warming atmosphere rising to the top of the image (descending if you reverse the scroll) which are emphasized by the artifacts the compression algorithm produced. If that is the case, it demonstrates a great deal of thermal interaction between the very thin atmosphere and the ground.

Posted by: AndyG Apr 19 2021, 04:51 PM

Wow for the shadow picture. I'm curious about the 'shutter' speed, and can't find a relevant answer.

Andy

Posted by: MarkL Apr 19 2021, 05:12 PM

They might answer that at the presser coming up in an hour. Put the question on Twitter with the #MarsHelicopter hashtag. I will too and they might pick it up.

The shutter speed of the Ingenuity camera must be incredibly fast to capture a clear shadow of the airfoils while they rotate 360 degrees in 24 ms (66 μs / degree). If you allow 5 degrees of rotation without visible blurring, that would be .333 ms of shutter open time. 1/3000 s.

Posted by: MahFL Apr 19 2021, 05:16 PM

30 frames per second for the helicopter nav cam.

Posted by: Andreas Plesch Apr 19 2021, 05:22 PM

A quick mp4 from the frames, cropped and scaled x2:

https://user-images.githubusercontent.com/6171115/115275898-60c4f000-a110-11eb-86ab-66ffe263906f.mp4

workflow:

get frames from roverpics and wget

import as layers in gimp

use Filters - Animation - Playback to check

crop

export as webp (slow but hopefully higher quality then indexed gif)

for smaller file size use some web converter to convert to mp4


and a small gif for convenience (wait a bit for the spin up), 200ms per frame:

Posted by: djellison Apr 19 2021, 05:23 PM

Frame rate ≠ exposure.

https://www.researchgate.net/publication/322311208_Mars_Helicopter_Technology_Demonstrator suggests.....

• Navigation (NAV) Camera. This is a global-shutter, nadir pointed grayscale 640 by 480 pixel sensor (Omnivision OV7251) mounted to a Sunny optics module. It has a field-of-view (FOV) of 133 deg (horizontal) by 100 deg (vertical) with an average Instantaneous Field-of-view (IFOV) of 3.6 mRad/pixel, and is capable of acquiring images at 10 frames/sec. Visual features are extracted from the images and tracked from frame to frame to provide a velocity estimate

Posted by: MarkL Apr 19 2021, 05:28 PM

A useful article is at -

Particularly check the comments - estimated 1/30,000 s:

https://www.dpreview.com/news/4722643046/nasa-ingenuity-mars-helicopter-has-transmitted-back-images-of-its-historic-first-flight-on-mars

(May be wrong based on my rough math above - I came up with 1/3000 s)

Posted by: john_s Apr 19 2021, 06:14 PM

In the shadow picture, why the heck is the shadow of the body/solar panel and legs black, but the shadow of the rotor blades is a lighter tone? The blades don't appear to be translucent.

John

Posted by: MarkL Apr 19 2021, 06:18 PM

Mimi just played the entire video showing all the missing frames. Wow, and they are on the Raw server now. It looks like they hit the raw server as fast as they could have.

Posted by: Explorer1 Apr 19 2021, 06:24 PM

Watching the press conference now; looks like it was indeed some dust on the panel, that has now been taken off, and is now getting more power than before!

Posted by: MahFL Apr 19 2021, 06:45 PM

Because the blades are moving at 2500 rpm.

Posted by: Tom Tamlyn Apr 19 2021, 06:53 PM

From this thread: https://twitter.com/sdamico/status/1384205372668350465

I was going to suggest that the high blade speed resulted in dark photons falling over the side, but I didn't dare.

Posted by: Pando Apr 19 2021, 07:14 PM

Full flight video:

https://youtu.be/wMnOo2zcjXA

Posted by: fredk Apr 19 2021, 07:32 PM

I estimated very roughly 1/4000s to 1/6000s based on the new https://mars.nasa.gov/system/downloadable_items/45995_3E-ncam_flight10000003.jpeg which shows the blurring more clearly.

Yeah, that's a short exposure for Mars, but the low resolution of 640x480 will help to keep noise down.

Posted by: john_s Apr 19 2021, 07:36 PM

The blade shadow edges are almost sharp, so RPM can't be the primary reason. I'm happy with the additional low-gain integration explanation, though.

John

Posted by: fredk Apr 19 2021, 08:13 PM

Ingenuity hovering in the air: navcam anaglyph:

and cross-eyed:

Very rough colour tweak, otherwise no processing.

Posted by: fredk Apr 19 2021, 11:52 PM

Some differences in the ground surrounding Ingenuity are visible after the flight - the ground behind and especially to the right got darker, presumably due to dust blown by the blades. Here's a before-and-after gif:

And the stretched difference of the two frames:

Posted by: Brian Swift Apr 20 2021, 01:00 AM

Congrats to you and team Mike, great work on taking Ingenuity video.
Any chance you'll eventually do a write up on the work that was needed to squeeze this video out of the Mastcam imaging system?
Also, did the project ever request a proposal to develop upgraded electronics for higher frame rates?

Posted by: rlorenz Apr 20 2021, 01:35 AM

Hi John !

Great observation, took me a few seconds to figure out.

remember this was a pretty low-altitude shot, so the rotors are appreciably higher off the ground than the body (box). So, while both items block the direct solar beam, hence forming shadows, the shadow under the box sees a lot less scattered light from the Martian sky (bigger solid angle obstruction for each point) and so is pretty dark. The rotors obstruct a lot less of the sky as seen from each little patch of the shadow, and so the scattered light fills in the rotor shadows more, hence the lower contrast.

Ralph

Posted by: john_s Apr 20 2021, 01:54 AM

Hi Ralph-

Thought of that, but the rectangular solar panel is higher still and has a black shadow. So no.

John

Posted by: mcaplinger Apr 20 2021, 01:54 AM

This video rate has been a part of the Mastcam design all the way back to MSL (and was used for the MSL MARDI descent video, although there we had the flash space to store the images in raw form and read them out with compression later.) Though I'll acknowledge that there's not a huge amount of detail about it in https://link.springer.com/article/10.1007/s11214-020-00755-x ("Compressed color videos: Bayer pattern interpolated, 8-bit companded, lossy JPEG-compressed images concatenated into 16-frame motion-JPEG GOPs")

If JPL had wanted better video, they could have added another EDLcam I suppose, at some unknown cost delta (putting it on the RSM would have been prohibitive, I suspect, so it would have been fixed-pointing.)

Posted by: Andreas Plesch Apr 20 2021, 04:27 AM

I made animations from cropped raw frames, from most 'raw' (webp) to most compressed (mp4).

https://i.ibb.co/7XYY2L2/first-flight.webp

gif:


https://user-images.githubusercontent.com/6171115/115329825-e2dd0500-a160-11eb-9eb9-5af0e4b6c05c.mp4

Posted by: Brian Swift Apr 20 2021, 06:49 AM

Thanks Mike. I was having trouble figuring out how it got the video data rates over an 8-MBit/s LVDS link, which is the highest link rate mentioned at https://mastcamz.asu.edu/cameras/tech-specs/
However, from "J.F. Bell III et al", I see the link from camera head to DEA can run at up to 120Mbps which would yield a roughly the video frame rate.

Just curious, is the Actel FPGA re-programable?

Posted by: Andreas Plesch Apr 20 2021, 12:52 PM

Another animation (655 frames), slightly smoothed, and color stretched:



as mp4 for full screen:

https://user-images.githubusercontent.com/6171115/115397201-d6ce6300-a1b3-11eb-8349-bc9a1d3bb34d.mp4

workflow:

crop layers in gimp
use gmic to gently smooth all layers
use gmic to convert layers to tiles
color process
convert tiles back to layers
save as .xcf
use ezgif.com to convert to gif, optimize to under 10MB
use ezgif.com to convert to webp, 100% quality, convert to mp4, optionally resize

Posted by: MarkL Apr 20 2021, 02:03 PM

Thank you (!) Andreas. These GIFs are just great.

As a general question, is there any likelihood of getting clearer uncompressed images down at some point? Being the first flight and all it would be good to have the best possible video of it.

There is no trace of dust at all in the downwash which is remarkable. I guess that was predictable, but still surprising - JPL and the heli-team was also surprised it seems.

When we see so much dust raised in the atmosphere of Mars, it seems there should have been at least some kicked up by Ingenuity on take-off.

This seems to suggest that atmospheric mass has little connection to dust events on Mars. If a highly efficient chopper airfoil revolving 40 times a second over a dust-bed can't raise any dust , it is highly unlikely a gentle Martian breeze could. There is just not enough gas mass to move the dust mass. This experiment has proven that. Yet there are sand dunes and evidence of aeolian erosion all over the place. It's mystifying how all this sand and dust got moved around, and also a puzzle as to how the massive dust events maintain momentum in such a thin atmosphere. Perhaps over a very extended time horizon compared to what we are used to here, millimeters at a time over a billion years.

So dust storms and dust devils seem to be predominantly thermal events, just like thunderstorms on Earth - not that this was unknown, but certainly this video adds weight to the idea that the thermal regime of the atmosphere (vs. atmospheric mass) is the main climate driver on Mars. I always had the idea that a good blow on Mars would create a dust devil or cloud of dust but Ingenuity put paid to that.

Getting video down from Perseverance is already helping us visualize these thermoclines much more precisely as compression artifacts from atmospheric refraction. Could this be a good argument to put better video cameras on future rovers? Better processing power and new codecs (ie. AV1) give us high quality video at lower bitrates so we could perhaps even get HD video clips from Mars at 30 fps in the not too distant future. That is an exciting prospect. The improvements in imaging from MER to MSL to Mars2000 seem to be exponential and is there good reason to expect that to continue?

What do you think Mike? Could a 25 gram 4K cots camera make it into the Mars pipeline anytime soon? We can dream can't we?

Posted by: Andreas Plesch Apr 20 2021, 02:37 PM

Thanks, for me it was also worth learning how to generate such animations from frames (although there may be better tools for that).

The compression artefacts are in the raw png, perhaps a function of necessary local video processing during recording due to storage constraints. Random example:

https://mars.nasa.gov/mars2020-raw-images/pub/ods/surface/sol/00058/ids/edr/browse/zcam/ZR0_0058_0672089547_074ECV_N0032046ZCAM05032_034050J01.png

So the only chance for higher quality may be from still images. Perhaps zcam can record video and still images simultaneously ? Seems unlikely.

I noticed that the timestamps on the images are often 149 ms apart, not 150 ms.

I suppose it is still possible that the launch area just has a thin regolith layer, with the dust fraction having been blasted away during rover landing which was pretty close, and perhaps initial spin tests.

Posted by: mcaplinger Apr 20 2021, 02:57 PM

Somebody has to pay for it. EDLcam DDC was 2Kx1500 and 140 grams not counting the processing unit. It's fairly hard to build a camera with decent optics that weighs 25 grams, at least for any definition of decent that I would use. Putting stuff up on the mast is very difficult. Doing things without interfering with the science mission is also difficult. EDLcam didn't have to deal with either of those problems.

Posted by: ElkGroveDan Apr 20 2021, 03:20 PM

Too bad it didn't land near InSight - they could buzz right over and clean her off.

Posted by: djellison Apr 20 2021, 03:26 PM

In the raw images - even without processing - there is a large downwash at takeoff and landing. It's subtle - but it's there.

Posted by: serpens Apr 20 2021, 03:26 PM

Not really. Sand dunes on Mars do migrate, albeit slowly. This was first demonstrated by MRO in 2011 and Spirit took some nice images of sand ripples migrating during the first dust storm. The ground where Ingenuity was dropped seems pretty dust free. More of a desert pavement. I wonder what the downwash velocity would be with counter rotating blades, given the light weight and low atmospheric density. Not overmuch it would seem.

Posted by: MarkL Apr 20 2021, 04:40 PM

If its cots, the acquisition cost would be minimal. No doubt the integration cost would be quite high though. I have in mind (most would agree its a pretty decent camera for what it does - likely under 25g) something like:


https://www.dpreview.com/files/p/articles/2369895109/ifixit-iphone-12-pro-max-camera-array.jpeg
.

That could be put on any part of the rover, mast, arm or landing hardware. Perhaps even replace the NavCams. You would just need the processing power to support it which again, could be cots. Ingenuity demonstrates cots components can work in planetary mission environments.

I acknowledge it may not fit within the risk envelope you guys have to work in though. But what amazing science results it would provide.

Posted by: fredk Apr 20 2021, 04:50 PM

It wasn't http://www.unmannedspaceflight.com/index.php?showtopic=8610&st=30&p=251113&#entry251113

We've seen wind move dust many times on Mars - that's what kept the MER rovers going, after all!

Is it clear we're not just seeing nothing more than varying compression artifacts, rather than thermal currents in the air?

Posted by: djellison Apr 20 2021, 04:57 PM

You would still have to run power and comms cables up to it ( which on the RSM or arm is very very non trivial ) as well as survival heaters.

And then you have to get the data back to Earth - which is also non-trivial.

Posted by: fredk Apr 20 2021, 05:24 PM

MCZ doesn't do interframe video processing as such - it just encodes a sequence of still images as regular jpeg files (and bundles them up into groups of 16 frames). But they have to fit those 16 into 2MB (to fit the 8Mbps data rate) which means they have to use heavy jpeg compression (quality 50).

Posted by: Andreas Plesch Apr 20 2021, 06:54 PM

Thanks for the explanation. That explains seeing jpeg compression artefacts in pngs. Presumably the 16 frames get compressed together and are then split out as single frames (in the camera or later).

Posted by: MarkL Apr 20 2021, 07:01 PM

That makes perfect sense. And I know the imaging teams are pushing to get the maximum performance from the cameras.

My underlying point is that these new requirements (capturing motion either of the atmosphere or the helicopter) ought to motivate getting improved video technology on future missions. We have very capable, incredibly cheap, light and energy efficient camera subsystems available off the shelf now so perhaps those should be looked at for possible integration into future missions. If helicopters are now in the future exploration toolbox, it seems those platforms would be ideal for these types of cameras.

Posted by: anticitizen2 Apr 20 2021, 08:29 PM

shouldnt this go in a future hardware thread, not the thread on ingenuity operations.

there is a lot of noise getting added with incorrect image analysis/design suggestions that requires corrections from multiple people every time.
mods please delete whatever you decide, its just getting frustrating trying to keep up with actual ingenuity information

Posted by: MarkL Apr 20 2021, 09:32 PM

Its relevant to Ingenuity imaging AC. Don't let it frustrate you - not good for longevity lol. Just skip it. Its not like there's a sea of messages to sift through and there is a lull in hard news about the chopper.

No problem if folks want to discuss further in another thread.

Posted by: alan Apr 20 2021, 11:51 PM

How many flights is the helicopter supposed to make?

Posted by: djellison Apr 21 2021, 12:00 AM

5

Posted by: testguru Apr 21 2021, 12:12 AM

A few questions:
1. How far away can the rover be from Ingenuity and still do reliable communications?
2. After the one month of flight tests if Ingenuity is still flight ready why not have it tag along with the rover to scout out the terrain ahead?

Seems a shame to go though all that engineering effort to put a drone on Mars and then abandon it because it takes too much effort to continue using it. Is there anything useful it can do with its cameras that would be helpful to the rover mission?

Posted by: Pando Apr 21 2021, 12:44 AM

I don't think they will just abandon the helicopter once the 5 tries are done as long as it's is still in a good working condition and within a comm range of the rover. There are plenty of flight tests that they can try after the primary flight objectives are over.

However, once the rover needs to get moving it may start impeding rover's driving progress, and the helicopter's viability becomes limited in a rougher terrain where it just can't land safely.

Posted by: Explorer1 Apr 21 2021, 01:51 AM

MiMi Aung said at the press conference that they will go very aggressively towards the end of the allocated period. She seemed to be hinting that will be perfectly fine with testing to destruction and Ingenuity ending up in pieces (without saying so explicitly, of course!). Engineering tests are all about gathering data, especially extreme conditions at the limits of a vehicles rating.

Also, official versions of the dust cloud enhanced video have been released (this forum\'s denizens are quick on the draw, as usual):
https://www.youtube.com/watch?v=lMMPBNzp0Dg

Posted by: MarkL Apr 21 2021, 01:51 AM

If I was on the heli-team I'd be begging to extend the mission though - it could be a useful scout or could survey craters or delta remnants. But it sounds from the presser like MiMi wants to fly it till it crashes. What a great scientist!

What about finishing the test flight campaign by landing in an area near the delta close to where the rover will be in 100 sols and check in on it periodically? It might be challenging for it to stay warm and it would need to be truly autonomous, awaiting radio contact from base. It has a good sized antenna so I imagine the useable radio range would be on the order of hundreds of meters line-of-sight if it is using a cellphone radio/modem. Just testing the range and performance of the radio on Mars would yield useful additional information for future missions.

However it's probably all wishful thinking as the rest of the mission will undoubtedly have hard timelines to adhere to and they will not want to deviate too much by adding chopper duties to the work plans.

Posted by: MarkL Apr 21 2021, 01:54 AM

What he said ... (similar thought posted simultaneously lol)

Posted by: serpens Apr 21 2021, 02:00 AM

The helo is a minimal capability technology demonstrator and I would question whether it has any utility whatsoever for the actual mission.

Posted by: djellison Apr 21 2021, 03:23 AM

Page 15 of https://www.researchgate.net/publication/322311208_Mars_Helicopter_Technology_Demonstrator says

The link is designed to relay data at over-the-air rates of 20 kbps or 250 kbps over distances of up to 1000 m.



If flight 5 ends successfully I wouldn't be surprised to see an adventurous flight 6 out in some direction ahead of the rovers path and maybe again beyond that - but chopper ops are not free for Perseverance. Chopper flights = time and data volume taken away from Perseverance doing its own science, and it incurs planning complexity overhead that I'm sure they'll be glad to be done with once they get into full arm and sample caching checkouts.

Posted by: JRehling Apr 21 2021, 05:12 AM

The tiny chopper has blades located above the ground, blowing down. The speed would drop off rapidly with distance from the blades.

Martian dust devils have speeds of up to 46 m/s, operating over a huge vertical column, including at ground level.

And dust/sand can migrate at ground level, sliding along, without needing to go strongly vertical.

It's not surprising that a little helicopter would kick up little dust compared to a regional/planetary event or local events that persist over time.

Posted by: MarkL Apr 21 2021, 02:53 PM

To achieve lift, the speed would need to remain fairly consistent over that short distance. The airfoils have been modeled and designed to ensure that happens. If all the flow spilled off the tips and outward there would be insufficient lift.

What I am getting at is the Ingenuity experiment seems to lend credence to the idea that Mars dust events are predominantly thermal phenomena and not caused by the mass of the atmosphere interacting with dust. Heat seems to raise the dust similarly to how heat raises water from the oceans to the atmosphere on Earth. The atmosphere keeps it in suspension like cream in coffee but it is moved due to regional or local temperature variations which could be more pronounced in a very thin atmosphere - at least that is the theory. I always had the impression that Martian wind could create sandstorms like we observe on earth, but it really can't, it seems. A person standing on Mars in the middle of a dust event wouldn't ever "feel" wind. They would just see dust surrounding them and rising up. I think none of this is new at all. Its just that we now have more proof that dust storms come from heat rather than "wind". This is the first time we have had a good look at the mechanics of the Martian atmosphere at ground level.

The dust-enhancement videos were very interesting. JPL was also surprised at how little dust there was so they cranked up the signal and it really worked! Is that all dust or is it compressed atmosphere causing refraction?

Posted by: Deimos Apr 21 2021, 03:34 PM

Heat does not directly move the dust in any significant way. Winds, ultimately driven by heat when there are no helicopters around, move the dust. There is also some discussion of suction helping in dust devils, as opposed to winds over the surface. The dust that stays in the atmosphere is small enough that both turbulence and molecular forces help in its suspension (the coffee analogy isn't too bad, but the evaporation analogy fails).

The lesson from the https://photojournal.jpl.nasa.gov/archive/PIA24589_timer.mp4 showing dust lifting is ... there was dust lifting. Most dust devil imagery is processed similarly. Some dust devils are visible with no special processing at dusty sites. These dust devils have 10s to 100s of seconds of life pulling dust up. At Gusev, we saw dust devils explode in brightness when they crossed a dust-filled "hollow". The dustiness of the source matters, as does the lifetime of dust collecting. The Heli dust just got picked up and was blown away, so it is no surprise it remained optically thin. (Also, no refraction was involved, the densities are such that even extreme angles would produce no observable effect.)

If there, you wouldn't get Watneyed, but the winds can be noticeable. Anyone who has used ratios to find dust devils has likely seen the little horizon shifts that happen from time to time--the rover attitude can change by 10s of microradians in response to winds. MERs seemed better at that than Curiosity, and I think InSight has done it too. Winds that can do that wouldn't knock you down, but they have some significant force. The winds certainly move sand--you see it in dust devils (look for the ones with a "skirt" at the bottom), rover decks, dune/ripple motion, and a scientific paper here and there.

Posted by: AndyG Apr 21 2021, 06:25 PM

I kind of hope not! She deserves a top spot in some future Martian Smithsonian!

Andy

Posted by: djellison Apr 21 2021, 07:04 PM

It's worth noting - the Wright Flyer didn't end its flight test campaign with grace either

https://en.wikipedia.org/wiki/Wright_Flyer#Flight_trials_at_Kitty_Hawk

"Taking turns, the Wrights made four brief, low-altitude flights that day. The flight paths were all essentially straight; turns were not attempted. Each flight ended in a bumpy and unintended "landing." The last flight, by Wilbur, was 852 feet (260 m) in 59 seconds, much longer than each of the three previous flights of 120, 175 and 200 feet (37, 53 and 61 m). The landing broke the front elevator supports, which the Wrights hoped to repair for a possible four-mile (6 km) flight to Kitty Hawk village. Soon after, a heavy gust picked up the Flyer and tumbled it end over end, damaging it beyond any hope of quick repair.[3] It was never flown again."

Posted by: PaulH51 Apr 22 2021, 01:44 AM

details of the 2nd flight https://mars.nasa.gov/technology/helicopter/status/294/were-getting-ready-for-ingenuitys-second-flight/

Posted by: Tom Tamlyn Apr 22 2021, 03:20 AM

Posted by: Explorer1 Apr 22 2021, 04:13 AM

Speaking of phenomenal imagery; Mastcam-Z Video is up! Shows only takeoff and landing, but still, wow!

https://www.youtube.com/watch?v=LtTv1rUixiY

Posted by: fredk Apr 22 2021, 04:41 AM

The previous video was mastcam-Z right, at 34mm, so I guess this is mastcam-Z left at the long end.

Posted by: Andreas Plesch Apr 22 2021, 01:59 PM

Second flight completed:

https://pbs.twimg.com/media/EzlQd0QVUAMrEJN?format=jpg&name=small
https://twitter.com/NASAJPL/status/1385228111323615239/photo/1

Posted by: MarkL Apr 22 2021, 02:18 PM

Some thumbs are down. Looks like it did get to a greater altitude. I did not see any sign of translation in the thumbs but evidently it was another huge success.

Take-off: 0672355850
Descent: 0672355902

52 seconds. The thumbnails are cropped and do not show Ingenuity on the ground.

https://rkinnett.github.io/roverpics/?mars2020&sol61&filter=0672355&sort=date

*edit - Flawless flight - the hover and yaw rotation is gorgeous.

Since posting, the image firehose is wide open and the full images make Ingenuity look oh so pretty ...

It is absolutely stunning to see something you never thought you'd witness in near real time. It's an incredible accomplishment, built on decades of infrastructure development - launches, orbiters, the DSN, fiber data backbones, microprocessor and image sensor improvements, tens of billions in taxpayer investment and true grit on the part of the engineers and scientists.

Posted by: neo56 Apr 22 2021, 02:30 PM

As we wait for the first color pictures taken by Ingenuity, here is a colorization I made of the black-and-white picture taken by its navigation camera during this second flight:

https://flic.kr/p/2kUpspj

Posted by: neo56 Apr 22 2021, 02:45 PM

A comparison of two Mastcam-Z Right pictures taken during 1st and 2nd flights, clearly showing the difference of maximum altitude reached by Ingenuity (sorry, I left the caption in french).

Posted by: MarkL Apr 22 2021, 03:40 PM

Here is a GIF showing displacement of Ingenuity between takeoff and landing. The navigation seems extremely accurate. Within cms.

Posted by: MarkL Apr 22 2021, 03:50 PM

One more showing what seems to be the translation maneuver from 0672355865 to 0672355868. The pitch adjustments are evident but it is hard to detect motion as it moving more or less within the Z-cam - chopper plane.

Posted by: neo56 Apr 22 2021, 03:51 PM

Video made with 206 frames taken by Mastcam-Z Right camera. We clearly see Ingenuity rotating by 90° then again 90° clockwise, then moving towards Perseverance rover.

https://flic.kr/p/2kUowqg

Posted by: john_s Apr 22 2021, 07:29 PM

Awesome! The movement towards the rover near the end isn't too obvious in the image of Ingenuity itself, but is clearly seen in the shifted position of the shadow on the ground.

John

Posted by: Andreas Plesch Apr 22 2021, 09:09 PM

Here a cropped gif and mp4 with image magick enhancement and time stamps [updated]:



https://user-images.githubusercontent.com/6171115/115798206-b06f1a00-a3a3-11eb-8ea6-0842c4ca9729.mp4

workflow:
wget -i png_urls.dat
convert -delay 149x1000 label/0672355* -enhance -gravity South -annotate +0+10 '%f' -quality 100 ani4.mp4 &
ezgif.com: crop mp4 and convert/optimize gif

And here the png frames as lossless webp animation for best preservation:

http://bit.ly/2ndFlightLossless

Use browser zoom to enlarge.

workflow:
load pngs as layers in gimp (unfortunately image magick does not support multiframe webp)
export as webp: lossless, 149ms delay
find free host for large webp: generic static site host (surge, others) seemed best

And a left navcam sequence (10x speed up)

Posted by: Phil Stooke Apr 22 2021, 09:12 PM

Great stuff. Here is a comparison of the ground position of Ingenuity on sols 55, 58 and 61, before and after the first flight and after the second flight. The rotation of the helicopter is shown by the distinctive footpad with the loop on it (what is that? - part of the attachment to the rover?), which moves roughly 90 degrees during each flight. The second landing is a few cm further to the right (north) than the original position.
Phil

Posted by: Steve G Apr 23 2021, 03:38 PM

Is there any ability to use the microphone(s) to record sound for the test flights?

Posted by: rob66 Apr 23 2021, 03:48 PM

It was spoken about during the last press call (in the Q&A). It's intended for a future flight to record from Percy.

Posted by: Art Martin Apr 23 2021, 06:53 PM

Basically, if I remember right, the answer was that it was unsure if the operation of that microphone might add electronic noise to control transmissions so that risk will be added only after the 3 main designated flights.

Posted by: fredk Apr 23 2021, 07:33 PM

That's right - that question was asked on one of the video Q&A sessions.

Posted by: phase4 Apr 23 2021, 08:46 PM

Birdsview! OMG

Posted by: neo56 Apr 23 2021, 09:13 PM

The first color picture taken by Ingenuity is crazy!
Update on the Ingenuity second flight video, with 370 Mastcam-Z Right frames. We clearly see the 3 rotations and translations backward and forward, particularly by looking at the shadow.

https://flic.kr/p/2kUtwh8

Speed x3:
https://flic.kr/p/2kUtLBL

Posted by: Thorsten Denk Apr 23 2021, 10:10 PM

I would rather call it bumblebee's view.

Thorsten

Posted by: Explorer1 Apr 23 2021, 11:10 PM

Flight 3 planned for this Sunday! Wow! 50 m north and back to land!
https://mars.nasa.gov/technology/helicopter/status/295/we-are-prepping-for-ingenuitys-third-flight-test/

They might actually cram in all five flights, despite the lost week! !

Posted by: Phil Stooke Apr 23 2021, 11:32 PM

I increased the contrast in the new Flight 2 image - quite a spectacular view and it will be great to see new images taken at a distance of terrain we don't know so well.
Phil

Posted by: pioneer Apr 23 2021, 11:51 PM

I couldn't find any raw images from Ingenuity on the raw images page at https://mars.nasa.gov/mars2020/multimedia/raw-images/. Will any raw images from Ingenuity be placed there?

Posted by: Phil Stooke Apr 23 2021, 11:57 PM

Yes, they will be added, probably soon. New cameras are still popping up on that page.
Phil

Posted by: PDP8E Apr 24 2021, 09:55 PM

Quick question (sorry if it's a repeat., I did look around a bit)
What is the purpose of the 'horns' on the rotor blades (see below)

the only thing I can think of is to ward off the dust from the motor assembly during the flight?

Posted by: PDP8E Apr 24 2021, 11:18 PM

oh boy... I did something 2nd that I should have done 1st
I asked somebody who knows something about helicopters! (thanks Harry J.)
actually, Harry knows model helicopters
He believes the 'horns' are aerodynamic 'Chinese Weights'.
It counteracts the dreaded 'Tennis Racket Effect' (!?!)
basically, the rotating blade is prone to forces that want it to twist/flip (I am a little hazy here)
It is all about rotating forces, centripetal forces, and such.
A well-designed weight will lessen the actuator force required to change the pitch of the blade.
and seeing that this blade is whizzing at 2500+ rpm makes it more crucial.

Not sure I understand exactly what is going on here, but Harry is sure.

Posted by: PaulH51 Apr 24 2021, 11:21 PM

See this PDF: Mars Helicopter Technology Demonstrator "https://www.researchgate.net/publication/322311208_Mars_Helicopter_Technology_Demonstrator"


Wiki adds this:

Posted by: PDP8E Apr 24 2021, 11:38 PM

thanks Paul!

Posted by: fredk Apr 25 2021, 12:18 AM

By fluke the tiny bit of horizon we can see in the helicopter view has revealed a bit of the far SE rim that we couldn't see from ground level. (Ie the local horizon dropped a bit when we climbed the 5 metres.) Here's a comparison of that airborn shot with a navcam view from sol 35, at the dropoff location, with some features identified:

Ingenuity's already showing us how she can be useful!

Posted by: rlorenz Apr 25 2021, 01:47 AM

I heard that it may be due to the fact that the camera does not have a physical shutter. The storage area on the chip has some light leak, and given that the actual exposure time is so short, the signal due to leak * readout time is significant. This leak dilutes the contrast of nonpersistent shadows (i.e. the blade) but not shadows that are constant during the readout time...

Posted by: mcaplinger Apr 25 2021, 02:45 AM

Yes, this was described in post #175 upthread and a link in that post. The camera has some residual response even after the electronic global shutter is "closed".

Posted by: john_s Apr 25 2021, 03:55 AM

Nice! Turning your composite on its side gives some funky and rather extreme stereo.

John

Posted by: Art Martin Apr 25 2021, 03:08 PM

I'm seeing some indication on Twitter that the 3rd flight was successful and they are waiting for data transfer now.

This just showed up on the rover page.

https://mars.nasa.gov/news/8930/nasas-ingenuity-mars-helicopter-flies-faster-farther-on-third-flight/

Posted by: fredk Apr 25 2021, 06:10 PM

The https://mars.nasa.gov/resources/25849/the-third-color-image-taken-by-ingenuity/ from the 2nd flight confirms this - the horizon clearly shows heavy barrel distortion. The FOV is around 47 deg, so comparable to roughly 33mm on a full-frame sensor, which isn't nearly as wide as typical fisheys. I guess these optics were chosen to minimize weight/size.

Posted by: neo56 Apr 25 2021, 07:17 PM

The 3 color pictures taken by RTE camera aboard Ingenuity can be stitched together in a panorama. There is strong parallax between each pictures hence the tilted horizon on the left but still, it was nice to stitch a panorama taken from an altitude of 5m on Mars!

https://flic.kr/p/2kUYaKa

Posted by: Phil Stooke Apr 25 2021, 07:56 PM

My hero! That's great.
Phil

Posted by: Explorer1 Apr 25 2021, 09:48 PM

https://www.youtube.com/watch?v=kNx9hcrUpww
No comment!

Posted by: Steve G Apr 25 2021, 10:47 PM

Alas the stationary camera. Where is Ed Fendell when you need him?

Posted by: mcaplinger Apr 25 2021, 11:59 PM

Don't you think we would move it if we could?

Posted by: Steve G Apr 26 2021, 12:58 AM

I was saying it in jest, but couldn't they program the camera to follow it?

Posted by: djellison Apr 26 2021, 02:56 AM

You answer is right here Steve

Posted by: Phil Stooke Apr 26 2021, 03:03 AM

This is Neo56's mosaic of images in a very rough reprojection. A very respectable map could be made of any area where pictures like these were taken.

Phil

Posted by: mcaplinger Apr 26 2021, 03:22 AM

No.

Can't say more, but here are a few technical terms: motor controllers, spread-spectrum radio, EMI.

Posted by: djellison Apr 26 2021, 03:25 AM

Also clock drift. Wouldn't even know when to slew.

Posted by: mcaplinger Apr 26 2021, 03:31 AM

Not 100% clear that's true, but since slewing wasn't an option anyway, we didn't spend a lot of time digging into it.

Posted by: Tom Tamlyn Apr 26 2021, 03:38 AM

https://trs.jpl.nasa.gov/bitstream/handle/2014/43244/12-3587_A1b.pdf

Here's an interesting 2012 paper titled The Effects of Clock Drift on the Mars Exploration Rovers. This sentence was an eyeopener: "When Spirit landed on Mars, its clock drift was about 10 seconds."

Posted by: Explorer1 Apr 26 2021, 04:20 AM

There's no capability to track an object in flight because there's no need; Ingenuity sends telemetry for the entire duration of the sorties, and there's nothing else moving on the surface that would need to be tracked (except the dust devils, which aren't exactly part of the primary mission and the other cameras have been catching just fine).

Be patient Steve! I wouldn't be surprised if the fetch rover designers are thinking of how to capture the MAV liftoff. It's a tricky problem. Even the Apollo missions took multiple attempts to track the ascent stage lifting off from the Moon, and that was with barely any light-speed lag.

Posted by: Phil Stooke Apr 26 2021, 07:02 AM

Here's a comparison of Ingenuity locations before and after each flight, following on from the one I posted earlier. After flight 3 the landing was to the left of the initial position, and further back into the image, corresponding to about 1 footpad envelope (i.e. rectangle defined by the footpads) SW of the initial deployment site. I didn't expect such well-controlled landings.

Phil

Posted by: Dig Apr 26 2021, 09:18 AM

I understand that the camera cannot pan and follow the movement of the Ingenuity in flight, but I do not understand why the rover was not moved to a more favorable angle that would allow it to record the entire flight.

I want to think that there are more images, from other cameras, and that have not yet been downloaded, that show the entire flight. I would be surprised if that important part of the flight had not been recorded, where the Ingenuity has to decelerate, hover, turn and go back in the opposite direction. I understand that it is an important phase of testing.

On the other hand, I am surprised that no more high resolution color images have been taken or displayed from "Ingenuity". So far we have only seen three images, but I suppose they have taken more.
Another thing that also surprises me is that we have not yet seen an image of "Perseverance" taken from "Ingenuity". Of course, it would be one of the images of the mission.

There are still images to download and more test flights. I hope that now that the project has achieved all its main engineering objectives, it will surprise us with something else.

Posted by: neo56 Apr 26 2021, 10:20 AM

Mosaic of 3 pictures taken by Navcam Left camera during the 3rd flight of Ingenuity. The helicopter is visible on each of the 3 pictures.

https://flic.kr/p/2kV3PLg

Posted by: Dig Apr 26 2021, 11:10 AM

Excellent Thomas!

Comparing the images of the panorama that you just published, with the video that has been published by the team from the images captured by the Mastcam-Z, it is possible that we will see a video of the complete flight from the images of the Navcam and showing a much larger area.
Have to wait...

Posted by: Explorer1 Apr 26 2021, 01:11 PM

The cameras both point down (the colour one is at a bit of an angle, so it can catch parts of the horizon), and since they cannot fly near the rover, it is very difficult to get it in frame. Possibly if they just flew straight up to maximum altitude it might be possible at the top of the flight to squeeze it into the frame, but I don't know height is one of the things they are testing on the last two flights.

Posted by: Andreas Plesch Apr 26 2021, 02:03 PM

It may be also possible but probably difficult to execute to take the picture with the rover in a tilted orientation, presumably flying backwards, away from the rover. Sofar the pictures have been taken from a more stationary position, but exposure duration may allow also a moving camera.

Posted by: MarkL Apr 26 2021, 02:20 PM

Agreed. How awesome it would be to get a nice clear video of the entire flight.

The engineers must be getting all the flight data they need from the sensors on board though. Visual evidence of the flight having occurred is a bonus but it is not the heart of the data from their perspective.

The imaging devices we send to Mars are highly overdeveloped yet under-powered because that is just the way we do things when it comes to space - step by step, timidly (and very expensively). That careful but plodding progress has achieved a lot of science by not failing during missions.

My hope is that engineers are already building much more modern camera systems into their mission designs and may be encouraged by companies like SpaceX to think more bravely about risk, at least in terms of sensors which, if they fail, don't destroy the mission. The ability to create 4K 120fps video, compressed on the fly in HEVC is in the palms of our hands (or pockets) now and very cheap. The R&D has been done by Samsung and Apple for us.

I know I have made this point before so I won't do that again but the idea of having a high quality video of the second helicopter to fly on Mars is just too tasty a dream of mine not to mention it and maybe advocate for it.

Posted by: MarkL Apr 26 2021, 02:31 PM

One would assume that flight software could very precisely align the clocks of both vehicles without any adjustments to either by using NTP. This should enable synching to within milliseconds. There may be other synching issues if the helicopter has to make its own decisions about when to take off, how fast to fly and how it navigates.

Posted by: MarkL Apr 26 2021, 02:36 PM

As much as we may gripe about getting more and better videos (I am among the biggest gripers sorry to say), Ingenuity has surpassed all expectations and really set our collective imagination soaring. How far could we take powered flight on Mars? Right now, it is hard to conceive of limits.

Posted by: Pando Apr 26 2021, 03:18 PM

Interesting. Did the slight shift in position after the first flight happen because the first image of the "home" position couldn't be acquired until after the craft was already in the air? Subsequent landings nailed the position.

EDIT: Nevermind, the shift was after the 3rd flight, not the first. It's Monday.

Posted by: mcaplinger Apr 26 2021, 03:25 PM

I can't go into all of the constraints on timing and parallel operations we have for helicopter imaging, but suffice it to say that I think we are doing as well as we can within all of them. If people are still disappointed, oh well.

The helicopter sends extensive telemetry about its performance and the rover imaging is just a "nice to have".

Maybe we could move any discussion about future missions and capabilities elsewhere. And I rather resent the use of terms like "timid", "plodding", etc. Newer members might want to review Rule 2.6.

Posted by: chris Apr 26 2021, 05:09 PM

I think what's being done is AMAZING. Thank you.

Posted by: Sean Apr 26 2021, 07:31 PM

This aspect of the mission has been nothing short of fantastic... kudos to everyone involved and every wee scrap of data is much appreciated.

Posted by: rlorenz Apr 27 2021, 01:48 AM

Not to rain on the parade, but it is easy to conceive of limits. While I predict many upcoming powerpoint presentations that will profess to indicate the feasibility of scaled-up Mars helicopters, and possibly even address the basics of disk loading and specific power, I expect that once you get into the details, the issues of aeroelasticity and motor heat rejection will show anything more than a factor of 2 or 3 more massive or longer-endurance than Ingenuity to be impractical.

Posted by: MahFL Apr 27 2021, 02:06 AM

The, I think lead engineer, said 25Kg was feasible and design studies have already started.

Posted by: MarkL Apr 27 2021, 01:43 PM

The limits I am finding difficult to conceive are geographic. Flight opens up vast areas of Mars for exploration and surveying in cm detail. Exploration does not require enormous helicopters. I'm certainly not thinking of people "getting to the chopper" and zooming around Mars any time soon.

Before Ingenuity, folks conceived of many limits of flying on Mars. So many in fact it was thought impossible to achieve. This experiment has shown us limits may often be misconceived and impede research.

Independence of rotorcraft on Mars will always be somewhat tenuous as they cannot carry all the communication gear or power generation that a rover platform can, or retain sufficient onboard power for extended flight. They would likely have to operate in tandem with one or more rovers or LTA platforms.

I suspect the main constraint to scaling up the design is battery capacity which likely does not scale linearly with lift (ie. rotor size). Present battery technology is not as energy dense as it will be in the future but better batteries will open up ever more possibilities. Better processors and AI will give even greater independence. That is likely to be an area where significant advances can be made in the near future. So I stand by my comment and the parade continues into the sunshine. LOL.

Posted by: MarkL Apr 27 2021, 02:04 PM

Not meant in any pejorative sense. What your imaging team has accomplished is nothing short of incredible. You are returning thousands of wonderful images from Mars for all of us to enjoy. You got your hardware there successfully and it is more than sufficient. Plodding is good. Timid is good. When billions are at stake you can't go crashing through a mission.

My comment was intended to be more generic - we proceed stepwise and very very carefully into space like toddlers and that has produced excellent insight and got us where we are. We try not to blow things up too much. It may be time to look at risk differently though in the exploration of space. Take a few more chances in order to get greater rewards. You guys are the pioneers. Don't get me wrong. You're blazing the trail for what comes next, which will hopefully leverage the most advanced image processing technology we have available, even only as a tech demo.

Posted by: Explorer1 Apr 28 2021, 02:52 AM

Eating my words from last page:

https://www.jpl.nasa.gov/images/ingenuity-spots-perseverance-from-the-air

Posted by: fredk Apr 28 2021, 03:51 AM

Yep, the barrel distortion worked to our advantage to squeeze the rover into the corner. Insanely cool to see her like this!

Posted by: fredk Apr 28 2021, 04:30 AM

Based on the image, I make Ingenuity's location at just over 50 metres north of the deployment spot, roughly where the arrowed white dot that I've added to Phil's map is:

Posted by: neo56 Apr 28 2021, 12:44 PM

Picture taken by RTE camera on 3rd flight straightened and vignetting corrected.

https://flic.kr/p/2kVrceR

https://flic.kr/p/2kVnHEj

https://flic.kr/p/2kVvaDB

Posted by: MarkL Apr 28 2021, 01:52 PM

Lovely. Thank you Thomas.

Posted by: MarT Apr 28 2021, 07:52 PM

Hi!

This is my take on the third flight RTE image with Perseverance. I was unable to create a pleasing result with attempting to correct the deformations on the whole image. I must be missing something. It is 47x47 degree FOV, with an approx 22° tilt. But I am unable to get the horizon correct without creating a "valley", which is not there. So I just concentrated on the colors, noise, vignetting and contrast. After that I did what I could with the distortions and cropped it all to Perseverance.

Posted by: Art Martin Apr 28 2021, 11:01 PM

This just got posted to the rover website.

https://mars.nasa.gov/news/8933/with-goals-met-nasa-to-push-envelope-with-ingenuity-mars-helicopter/

Posted by: Andreas Plesch Apr 29 2021, 01:06 AM

Going south for 133m, eg. outside the designated flight zone into terra incognita.

Here is quick map of the path from the description, in orange, taken rather literally as flying exactly south:

The arrow is at 84m where Ingenuity will start collecting navigation images every 1.2m, the distance between the dots.

And a perspective of the general flight path area from above the current location of the rover, with 4x exaggerated terrain:



The target area is about 1m higher in elevation than the air field, a difference the rotorcraft could adjust to if maintaining a certain flight height above ground is an objective.

Posted by: vikingmars Apr 29 2021, 08:52 AM

It could be great from an EPO perspective if they could take pictures of the SkyCrane crash site and/or the parachute and its backshell from above (even from a distance)

Posted by: MarT Apr 29 2021, 06:57 PM

Ingenuity - flight nr.3 in 3D

SBS and anaglyph available depending on the device. Taken on Sol 64 with the Mastcam-Z L and R cameras.

https://www.youtube.com/watch?v=_Xbq-rUwxMk

Posted by: Art Martin Apr 29 2021, 07:07 PM

I just read on Twitter where the 4th flight did not get off the ground. No real details.

Posted by: ChrisC Apr 29 2021, 07:09 PM

NASA JPL Twitter update as of about 2:40pm ET:

https://twitter.com/NASAJPL/status/1387842380427001857

Posted by: Marz Apr 29 2021, 09:35 PM

flight mode software issue strikes again?
https://www.businessinsider.com/nasa-ingenuity-helicopter-failed-lift-off-ambitious-fourth-flight-2021-4

Posted by: ChrisC Apr 29 2021, 09:49 PM

LOL, go to the source instead of the re-reporter advertising impression mills!

from https://twitter.com/NASAJPL/status/1387877961445953539

Further info:

from https://mars.nasa.gov/technology/helicopter/status/296/mars-helicopters-flight-four-rescheduled/
(same as the go.nasa.gov link provided in tweet)

Note that the rescheduled press conference will occur about an hour after flight #4 first results come down, so obviously they'll talk about / show those results in the presser.

Posted by: Andreas Plesch Apr 29 2021, 10:02 PM

There is also a sol 67 movie frame sequence of a close up, perhaps a test recording. There is no movement of any part of the helicopter.

Analysis of the timestamps show deltas between frames from 67ms to 73ms, with a somewhat systematic increase through the recording. This is about 14-15 frames/second, and faster than the 149ms for flight 2.

Here is a (not very interesting) gif with time stamps of the left ZCAM, close up:



And a full uncompressed animation as webp:

https://mars2020.surge.sh/ZL0_0067_ECV_N0032208ZCAM05050_110050J04.webp

There is a simultaneous frame sequence of a wider view with the right ZCAM. It has timestamp delta of about 141ms with some 7s to 15s gaps in frames which are not yet available or not recorded.



https://mars2020.surge.sh/ZR0_0067_N0032208ZCAM05050_026050J04.webp

Nothing seems to move anywhere.

Posted by: Andreas Plesch Apr 29 2021, 11:18 PM

The sol 68 right and left frame sequences of flight which is still to come have frame deltas between 141ms and 145ms.

right:



https://mars2020.surge.sh/ZR0_0068_N0032208ZCAM05053_026050J01.webp

left:



https://mars2020.surge.sh/ZL0_0068_N0032208ZCAM05053_026050J01.webp

Posted by: Explorer1 Apr 30 2021, 03:32 PM

Briefing on now: https://www.youtube.com/watch?v=BAlXe-U0ws4

Posted by: Andreas Plesch Apr 30 2021, 07:59 PM

Success of the 4th flight on sol 69. In the air and going south at 12:34:13 as captured by Perseverance, and then safely returned. Here back at its air field at 13.30 :

https://mars.nasa.gov/mars2020/multimedia/raw-images/ZL0_0069_0673069601_694ECM_N0032208ZCAM05054_110085J

The plan was for a 2 minute flight.

It looks like the landing drifted towards the dune to the east. Here a map of the estimated landing positions:

Perhaps one leg dipped into sand a bit.

Posted by: pioneer Apr 30 2021, 10:37 PM

That would be great. Does anyone know if that will happen?

Posted by: Explorer1 May 1 2021, 12:19 AM

I watched the press conference, it seems the primary use will be scouting for the rover and imaging terrain/geological features not accessible from the ground. Since the current drive path is planned to the southwest, and the EDL hardware is not in that direction, I doubt imagery will be possible. When they turn north towards the delta, perhaps, but Ingenuity would have to be seriously long lasting for that. The press release also mentions that conjunction will be coming up towards the end of summer, and that may be a time to end operations, if there hasn't bee a hardware failure by that point.

If a failure happens to Ingenuity (during flight or failing to survive the Martian night), maybe that might be worth detouring to inspect, though...