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Comment by jefft255 | Hacker News Reader

I am incredibly excited for this. Can believe how nervous the control engineers must be for this. Not sure what quality of the footage to expect from this.

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I was also excited about it, however an article critical of various points of Mars 2020 damped this quite a bit [1 (in German)]: Does the drone actually have any scientific relevance? I'm even doubtful it answers relevant engineering questions. I mean, it was tested in a pressure chamber already simulating mars atmosphere and gravity, we know it will work. The only question seems to be: Will it fail because of some engineering oversight or hardware failure, or not? There seem to be no scientific sensors on it at all. This 'commodity hardware test' could also be done with just the processor and monitoring, without the helicopter part. Looking at it like this it seems like mostly a toy or PR stunt, but one that takes $80M and space on the rover away from scientific projects.

[1] https://www.golem.de/news/perseverance-diese-marsmission-hat...

I do not agree at all that it is not useful but even if true the PR in itself is likely worth it, both for getting more attention to NASA (IE. budgeting) and for sparking ideas and dreams.

I'll gladly change my mind, what is it useful for?

On your other point, I'm sure many people find it fascinating and are inspired. However a young geologist or biologist might not be inspired to start a career at NASA. Another point the author of the article above makes it that in the ~2 hours of live coverage, 6 seconds were spent discussing the rovers instruments. As for budget, this is also dangerous; after all, if the next funding round comes along, anyone who does not like NASA can have an easy argument that the $80M on the helicopter are wasted and did not produce any knowledge about Mars or the universe.

It's useful (if it doesn't die) for scouting. From above, it will have a better look at the terrain, helping mission control do path planning and terrain/risk assessment. I have no information telling me that's going to happen, but this is my fairly educated guess as to how the drone could be used.

Ok, that could be a use for it. They do have satellite images, but I guess those are much lower resolution and a better satellite would probably be orders of magnitude more expensive.

Sadly, this helicopter won't record any footage, it is only meant to test flight control and to proof that the idea will work for future missions. There is a interesting Veritasium episode (youtube) that talks about this (interviewing the actual designer from the JPL). The only footage will be from Perseverance filming the flight.

This is not correct, there are multiple downward facing cameras [a]:

1) 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.

2) Return-to-Earth (RTE) Camera. This is a rolling shutter, high-resolution 4208 by 3120 pixel sensor (Sony IMX 214) 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.

[a]https://trs.jpl.nasa.gov/bitstream/handle/2014/46229/CL%2317...

Shouldn't that be a Return-to-Mars (RTM) Camera?

No, it is going to record images meant to be returned to Earth. See section "Sensors" on page 13 in

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

But aren't those cameras just for navigation and won't record or stream any footage?

Edit: spelling

One of the stated goals is to use of the drone to scout interesting places for other drones. In theory I guess it could take that decision without sharing the source images, but that seems a bit far fetched. You'd want to study them in ridiculous detail.

Are you suuuuure about that?

> Its payload is a high resolution downward-looking camera for navigation, landing, and science surveying of the terrain, and a communication system to relay data to the Perseverance rover.

(From Wikipedia)

Also: https://mars.nasa.gov/resources/25526/bottom-of-ingenuity-ma...

I'm pretty sure the point of the helicopter, other than to test powered flight, is to capture frames.

It does have cameras.

https://mars.nasa.gov/resources/25526/bottom-of-ingenuity-ma...

Wow, that’s disappointing. I’m surprised they couldn’t squeeze a basic mobile phone camera module on there just for the sake of it.

The problem isn't the camera, it's the uplink to Perseverance and all the other parts required for a usable camera. They're using Zigbee [1] to communicate with the Rover at 200 kbps and the solar panel recharging the batteries also have to power heaters to keep the electronics alive - there's no hardware connection between the two for data or power exchange AFAICT. The drone is already so heavy that it can only stay aloft for 90 seconds to a few minutes between charges so between the extra battery, lens, better antenna and RF module, etc. it'd require a redesign of the entire mission.

[1] https://rotorcraft.arc.nasa.gov/Publications/files/Balaram_A... - page 15

It's not that heavy, relatively speaking, it has to spin the rotors a lot faster to gain altitude in 1% atmosphere of Earth, hence the shorter flight time.

I suspect it's to save power. Even mobile phone cameras are very power hungry.

I had initially assumed that they would be using it for aerial photos to improve navigation decisions. Kind of sad if not.

There absolutely are cameras on board, and yes they are used for navigation.

My original question relates more to bandwidth, storage and processing limitation which may mean that we won’t see high quality 30 FPS video.

The Snapdragon CPU has plenty of power for JPEG encoding and likely even hardware accelerated encoders. The 640x480 8bpp navcam images could be entirely usable at a fairly lossy 40:1 compression ratio which ends up about about 8KB per frame, for a 90s flight recording at 10fps that's only about 7.2MB to record the whole flight. It would take a little under 5 minutes to send that back to the rover at 200kbps. The color high resolution camera isn't set up for high frame rate recording IIRC so that was never an option.

High quality 30fps video was never really an option but it's entirely possible/likely to get navcam video after a flight. The Snapdragon is also fast enough to do intraframe compression codec (even h.264) for the navcam video to be able to stream it live back to the rover for relaying back to Earth later like was done with the landing imagery.

The nature of Perseverance relaying through orbiters for high speed uplink to Earth was always going to preclude "live" video from any instrument. The only data important enough for "live" transmission is vehicle telemetry and even then that's only available for the portion of a sol (Martian sidereal day) that Earth is visible from the rover.

I think the rover is at least going to film the flight, but agree a camera in it would have been dope.

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