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?

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.

New topic created.

https://trs.jpl.nasa.gov/bitstream/handle/2...L%2317-6243.pdf

Some interesting info in https://trs.jpl.nasa.gov/bitstream/handle/2...L%2318-3381.pdf -- stuff in JPL TRS is circa 2018 so might be out of date though.

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 Like you say though these projections could be outdated.

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

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.

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

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.

Perserverance Underbelly Watson

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.

https://www.jpl.nasa.gov/news/press_kits/ma...ion/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

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.

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?

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.

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.

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....

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.

Click to view attachment

https://mars.nasa.gov/resources/25530/mars-...ding-press-kit/

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.]

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.

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....)

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/Publication...AA2018_0023.pdf

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.

The NASA Radioisotope Power Systems web pages have a very detailed 3d model 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 lzf compressed PLY format, for which there is a parser to extract triangles, normals and colors. This seems to be generated by a JPL protospace system which in turns uses Hololens for AR.

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

Click to view attachment
NASA/JPL-Caltech

An animated gif showing the testing of the deployment sequence:

Click to view attachment
NASA/JPL-Caltech/Lockheed Martin

https://www.jpl.nasa.gov/news/nasa-to-host-...icopter-flights

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

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/13...8641884160?s=20

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.

Not Mars but Nevada.

https://youtu.be/ojZeso5tVYk

Debris shield dropped.
Click to view attachment

From other points of view:

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

Percy is such a litterbug.

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

Click to view attachment

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.

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

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.

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

https://mars.nasa.gov/system/resources/deta...A24494-1200.jpg

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

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

Airfield & Flight Zone with simulated rover & helicopter for scale.

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?

https://www.jpl.nasa.gov/news/press_kits/ma...g_press_kit.pdf

Thanks.

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.

GIF - Helicopter 'Launch Lock' unlatched

Rotated / Cropped SHERLOC frames from Sols 35 & 36
Click to view attachment

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.

https://mars.nasa.gov/mars2020-raw-images/p...00LUJ01_800.jpg
Ingenuity drops down a bit, getting ready...
Phil

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.

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.