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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

#71
post #46

Does anyone know why they chose to send a helicopter and not some kind of plane or glider? I would've thought that a fixed-wing aircraft would have been simpler, lighter, faster and more efficient.

How many runways do you see on Mars

What if a glider separated prior to the initial main landing? I guess that would increase the risks around the landing.

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

#72

Earlier quoted context omitted.

In general the older nodes work better for radiation and other cosmic forces. https://en.m.wikipedia.org/wiki/Radiation_hardening That's why they don't use the latest and greatest in the space.

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.

While the chip/circuit design itself matters, it’s good to note that NASA will run several pieces of the same/similar hardware for fault tolerance in a component[1] as well as attempting to protect it. This isn’t bad, but I also think that design of the chips and circuits should come into play if it’s proven in testing to be affected by radiation, e.g. don’t use an RPi2 in a Xenon Flash testing lab.

[1]- https://science.nasa.gov/science-news/science-at-nasa/2005/1...

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

#73
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 most prolific operating systems the world has ever seen, but not just this world - there is a helicopter on Mars that is flying due to the seeds which I planted that day...”

What have you built?

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

#74

Earlier quoted context omitted.

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.

Reminds me of SpaceX or Erlang; build a process that handles errors rather than an error free process.

I mean its space. Any computer expected to be in space and do non completely trivial things have tons of mechanisms in place to survive computer issues.

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

#75

Earlier quoted context omitted.

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.

Many types of bit error are not recoverable without a full system reset. It isn't a matter of a simple "this bit in ram got corrupted", but more "this floating point unit has got into a state where it will not produce a result, and will therefore hang the entire processor". Therefore boot time becomes critical - if you end up rebooting due to bit errors multiple times per second, you can't afford to wait for Linux to…

Well I suppose they do not have to load all the kernels and drivers that Linux provides today.

I wonder how one could use micro kernels to further improve startup time and have a mini distributed OS/kernel for each component.

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

#76
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…

In general the older nodes work better for radiation and other cosmic forces. https://en.m.wikipedia.org/wiki/Radiation_hardening That's why they don't use the latest and greatest in the space.

Can't all of the radiation issues be mitigated with proper shielding of the electronics?

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

#77

Earlier quoted context omitted.

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.

Many types of bit error are not recoverable without a full system reset. It isn't a matter of a simple "this bit in ram got corrupted", but more "this floating point unit has got into a state where it will not produce a result, and will therefore hang the entire processor". Therefore boot time becomes critical - if you end up rebooting due to bit errors multiple times per second, you can't afford to wait for Linux to…

And that’s why it’s wise to have multiple systems running at the same time, if one errors you still hopefully have another online. There’s a reason airplanes and now cars are designed this way. I’m sure they’re working towards this too.

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

#78

Earlier quoted context omitted.

How many runways do you see on Mars

What if a glider separated prior to the initial main landing? I guess that would increase the risks around the landing.

I mean the point is to test a re-flyable vehicle. A single use glider would seem to defeat the point

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

#79
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…

It's nice that NASA isn't falling victim to not-invented-here. If a commodity part or protocol can do the job, no sense reimplementing it.

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

#80

Earlier quoted context omitted.

In general the older nodes work better for radiation and other cosmic forces. https://en.m.wikipedia.org/wiki/Radiation_hardening That's why they don't use the latest and greatest in the space.

Can't all of the radiation issues be mitigated with proper shielding of the electronics?

Yes, but the problem is that radiation shielding is heavy because it's typically made of lead.
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