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The Mars Helicopter Is Online and Getting Ready to Fly

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Re: The Mars Helicopter Is Online and Getting Ready to Fly

#81

Post by kingo55 »

samstave wrote: post #73
birktj wrote: post #23

One of the things I find really cool about Ingenuity is how it is in large based on consumer hardware. The main processor is a Snapdragon 801 running Linux which communicates with Perseverance using the Zigbee protocol [1]. Perseverance on the other hand uses a RAD750 from 2001! If successful I hope this can lead to more modern hardware for these kinds of missions in general. [1] https://en.wikipedia.org/wiki/Ingenui…

If you were to build the exact same helicopter here based on those parts what would be the cost vs what’s the device on Mars cost? Also, I know plenty of solid engineers who I could build one thing based on that, obviously not taking atmosphere and G-forces into account to get there. Also Linus finally got his progeny to Mars. That’s a pretty cool accomplishment: “What have you built?” Well, I invented one of the mos…

It's not just atmosphere and g-forces. The cold temperatures mean the helicopter spends 2/3 of its battery power keeping the batteries and electronics from freezing.

Good rundown of how it was built: https://www.youtube.com/watch?v=GhsZUZmJvaM

Re: The Mars Helicopter Is Online and Getting Ready to Fly

#82

Post by lights0123 »

fuzzy2 wrote: post #33
birktj wrote: post #23

One of the things I find really cool about Ingenuity is how it is in large based on consumer hardware. The main processor is a Snapdragon 801 running Linux which communicates with Perseverance using the Zigbee protocol [1]. Perseverance on the other hand uses a RAD750 from 2001! If successful I hope this can lead to more modern hardware for these kinds of missions in general. [1] https://en.wikipedia.org/wiki/Ingenui…

The CPU will probably be destroyed by radiation before long. I'd guess the key factors here were weight, power draw, size and perhaps performance. A radiation-hardened CPU probably didn't fit the bill. It's also super expensive.

> perhaps performance

absolutely performance. Yes to the other three for sure, but the engineers reported that there was no way they were running flight control using image tracking on a 200MHz CPU.

Re: The Mars Helicopter Is Online and Getting Ready to Fly

#83

Post by m463 »

marcinzm wrote: post #37
birktj wrote: post #23

One of the things I find really cool about Ingenuity is how it is in large based on consumer hardware. The main processor is a Snapdragon 801 running Linux which communicates with Perseverance using the Zigbee protocol [1]. Perseverance on the other hand uses a RAD750 from 2001! If successful I hope this can lead to more modern hardware for these kinds of missions in general. [1] https://en.wikipedia.org/wiki/Ingenui…

As the name RAD750 indicates, that processor is designed to be radiation hardened which matters for longer missions. I doubt the Snapdragon 801 will survive as long or have as few errors but it also doesn't matter since Ingenuity isn't aimed for long term usage.

One thing that's not clear to me is what the radiation is like on mars. Mars has an atmosphere, but no magnetic field.

Is it like the situation high in earth's atmosphere (like using your ipad on a commercial flight), or would it be more like on the moon with no protection?

Re: The Mars Helicopter Is Online and Getting Ready to Fly

#84

Post by birktj »

marcinzm wrote: post #37
birktj wrote: post #23

One of the things I find really cool about Ingenuity is how it is in large based on consumer hardware. The main processor is a Snapdragon 801 running Linux which communicates with Perseverance using the Zigbee protocol [1]. Perseverance on the other hand uses a RAD750 from 2001! If successful I hope this can lead to more modern hardware for these kinds of missions in general. [1] https://en.wikipedia.org/wiki/Ingenui…

As the name RAD750 indicates, that processor is designed to be radiation hardened which matters for longer missions. I doubt the Snapdragon 801 will survive as long or have as few errors but it also doesn't matter since Ingenuity isn't aimed for long term usage.

What I imagine for long lived and high-cost missions is using some sort of co-processor setup with a radiation hardened processor and a faster and more modern processor. These rovers run a lot of computer vision algorithms and I believe more powerful hardware would be quite useful. They may already do something like this, however my understanding is that there is a lot of skepticism in integrating these less fault-tolerant processors. Ingenuity could help remove some of the skepticism and lead to more systems like this in the future.

Re: The Mars Helicopter Is Online and Getting Ready to Fly

#85

Post by _joel »

akiselev wrote: post #29
orev wrote: post #15

Earlier quoted context omitted.

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…

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.

Re: The Mars Helicopter Is Online and Getting Ready to Fly

#86

Post by upbeat_general »

laydn wrote: post #25

Why is nobody worried about the helicopter crashing to the rover and possibly destroying a science instrument? How far will the helicopter be from the rover?

I’m pretty sure this was one of the main criteria for building the helicopter since the -reject is not essential to the mission but is instead is a demonstration.

It’s probably also why they’re waiting to fly it so that the rover is a bit further away

Re: The Mars Helicopter Is Online and Getting Ready to Fly

#87

Post by shawnz »

laydn wrote: post #25

Why is nobody worried about the helicopter crashing to the rover and possibly destroying a science instrument? How far will the helicopter be from the rover?

The helicopter is itself also a science instrument. How do they prevent any of the instruments from destroying each other? Careful planning, I would guess

Re: The Mars Helicopter Is Online and Getting Ready to Fly

#88

Post by ejolto »

jessriedel wrote: post #67
Robotbeat wrote: post #50

Earlier quoted context omitted.

They work better primarily because they had previously invested in the tooling to rad-harden them and it’s really expensive to do that again one time for each mission; cheaper to rely on already-rad-hardened designs.

Doesn't radiation mostly cause random one-off errors rather than permanent defects? If so, then if the rad-harden stuff is 100x slower (which I think is approximately right?), it is almost certainly better to use error correction on non-rad-hardened hardware.

In addition to SEUs (single event upsets) which are bit flips, there are also the following Single Event Effects (See) that are destructive:

- Single Event Burnout, SEB

- Single Event Gate Rupture, SEGR

- Single Event Latch-up, SEL these can be recoverable

In addition there are also Total Ionizing Dose (TID) Effects https://radhome.gsfc.nasa.gov/radhome/tid.htm

Re: The Mars Helicopter Is Online and Getting Ready to Fly

#89

Post by ericbarrett »

Robotbeat wrote: post #51
marcinzm wrote: post #37

Earlier quoted context omitted.

As the name RAD750 indicates, that processor is designed to be radiation hardened which matters for longer missions. I doubt the Snapdragon 801 will survive as long or have as few errors but it also doesn't matter since Ingenuity isn't aimed for long term usage.

It’s less about longevity and more about reducing errors. Interestingly, Ingenuity has some sort of watchdog that can reset the Snapdragon in-flight fast enough to recover if there is an error.

A consumer chip is a lot more likely to be permanently damaged by a "silver bullet" cosmic ray, though. Rad-hard chips don't just have shielding, they can also have redundant circuits and modifications to the foundry process. That said, I'm sure Ingenuity's processor is fit to purpose.

Re: The Mars Helicopter Is Online and Getting Ready to Fly

#90

Post by _Microft »

hcrisp wrote: post #56
l2p wrote: post #35

Earlier quoted context omitted.

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/se…

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...

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