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The Mars Helicopter Is Online and Getting Ready to Fly

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101–110 of 265 posts

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

#101
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

No it is still attached to the rover.

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

#102
post #83

Earlier quoted context omitted.

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?

Between the two. 30 µSv per hour on the surface of Mars on average compared to 60 µSv on the Moon - compared to 5 µSv on a jet. Not friendly, but not too awful.

Or 0.5 per hour on Earth at sea level. That's only 2 orders of magnitude difference. Given that we don't expect radiation damage to be a major source of failures in Earthbound consumer or commercial electronics, it's a bit surprising it's such a big deal in space.

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

#103

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.

Yes, there's a flight qualified microsemi FPGA (a ProASIC, I think) that acts as a supervisor for the vehicle.

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

#105

Earlier quoted context omitted.

This is so cool, I didn‘t know about these yet and I‘d call myself a space buff... Speaking of flight and picking the nits here — looks like Wikipedia also isn‘t completely correct here: > It is planned to make the first powered flight on any planet beyond Earth ...arguably the first _powered_ flights were done by the sky cranes of Opportunity and Perseverance

> ...arguably the first _powered_ flights were done by the sky cranes of Opportunity and Perseverance Not the Apollo 11 lunar module? In contrast to the sky cranes it actually lifted off again.

The moon is not a planet.

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

#106

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…

Run 9 systems in parallel and reset the ones that give less common results or no results at all.

You still have 10% the surface area, power usage and weight and 10 times the speed of the radiation hardened ones.

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

#107

Earlier quoted context omitted.

Between the two. 30 µSv per hour on the surface of Mars on average compared to 60 µSv on the Moon - compared to 5 µSv on a jet. Not friendly, but not too awful.

Or 0.5 per hour on Earth at sea level. That's only 2 orders of magnitude difference. Given that we don't expect radiation damage to be a major source of failures in Earthbound consumer or commercial electronics, it's a bit surprising it's such a big deal in space.

yes but these chips having to function and survive on the way to the planet right? and they do all sorts of software updates etc during this time. Maybe we could shield them and that would be fine? or would that add to much extra weight

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

#108
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…

One of the fascinating things about space silicon is that NASA spends many years hardening specific processors to withstand the types of shocks and electromagnetic interference from space travel. These intensive processes mean that the equipment they can use is always 10-20 years behind the modern equivalents.

and yet they are fine with using a snapdragon arm processor on the helicopter?

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

#109
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.

Non-mobile link: https://en.wikipedia.org/wiki/Radiation_hardening

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

#110

Earlier quoted context omitted.

Between the two. 30 µSv per hour on the surface of Mars on average compared to 60 µSv on the Moon - compared to 5 µSv on a jet. Not friendly, but not too awful.

Or 0.5 per hour on Earth at sea level. That's only 2 orders of magnitude difference. Given that we don't expect radiation damage to be a major source of failures in Earthbound consumer or commercial electronics, it's a bit surprising it's such a big deal in space.

There are actually a lot of bit flips in Earthbound electronics due to lack of parity error checking. But those bit flips don't necessarily cause failures, or when they do it's impossible to determine the root cause.
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