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.

How many flights is the helicopter supposed to make?

5

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?

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.

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

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.

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

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

Page 15 of https://www.researchgate.net/publication/32...gy_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.

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.

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?

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 video 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.

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

Andy

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

https://en.wikipedia.org/wiki/Wright_Flyer#...s_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."

details of the 2nd flight LINK

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

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

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

Second flight completed:

https://pbs.twimg.com/media/EzlQd0QVUAMrEJN...&name=small
https://twitter.com/NASAJPL/status/13852281...3615239/photo/1

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.

Link to images in this MET range

*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.

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:

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).

Click to view attachment

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

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.

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.

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

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



2nd flight mp4 for full screen (does not work on mobile for me)

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 (does not animate on mobile for me)://http://bit.ly/2ndFlightLossless (do... mobile for me)

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)

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
Click to view attachment

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

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

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.

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

Birdsview! OMG

Click to view attachment

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.



Speed x3:

I would rather call it bumblebee's view.

Thorsten

Flight 3 planned for this Sunday! Wow! 50 m north and back to land!
https://mars.nasa.gov/technology/helicopter...rd-flight-test/

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

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
Click to view attachment

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?

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

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

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.

See this PDF: Mars Helicopter Technology Demonstrator "PDF LINK"
Click to view attachment

Wiki adds this:

thanks Paul!

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:
Click to view attachment
Ingenuity's already showing us how she can be useful!

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...

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".

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

John

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-ingen...n-third-flight/

The new image 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.