161–170 of 265 posts
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 would it take-off and land without runways? VTOL flying wing designs have been proposed. But the first step is demonstrating any powered flight at all, which means helicopter.
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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
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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…
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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.
How much more likely? Are the odds all that high over the mission duration?
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Not in python, maybe. Smartbombs have been doing the necessary image processing with much less processing power, on much less capable sensors, for a long time.
What. I dont understand how you can make this claim. Guided bombs are NOT using CV with optical cameras. They use lasers, GPS, and other non "fancy" techniques. I just don't get in what world you think military munitions are using CV for targeting bombs.
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The moon is not a planet.
I'd argue Mars is still the most impressive. Rockets in no atmosphere is easy. Floating on Venus is easy because it has more atmo than any other rocky planet. Figuring out something that works well in Mars' thin (but still there) atmosphere, especially a helicopter , is really impressive. The celestial body classification is just a cherry on top.
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Not in python, maybe. Smartbombs have been doing the necessary image processing with much less processing power, on much less capable sensors, for a long time.
Dunno about guided bombs, but cruise missiles have been using some pretty fascinating techniques to navigate before GPS was a thing. It's probably hard to find CPU specs, because they're defense technology.
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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.
One of the most significant obstacles for landing on Mars will continue to present problems for our heroic helicopter now that it is safely on the surface. The atmospheric pressure on the surface of Mars is only about 1% that of Earth. Does this also limit the use of parachutes on Mars, or require bigger canopies? I know that Perseverance had a parachute for part of the descent, but not the final landing sequence. II…
Both, but the main limit of a parachute is that our probes don’t go into orbit first but rather crash on Mars. So you enter the atmosphere at higher than orbital speeds. From orbit a parachute might be doable despite the relatively thin atmosphere. Stationary probes can use retro rockets to land because you don’t care about their stationary mass that much. For rovers it’s more tricky so you have to either use airbags…
>our probes don’t go into orbit first but rather crash on Mars.
I'm wondering why they don't go into orbit, and what extra complexities that introduces?
In the future are we anticipating Starship to go into orbit, or will it also directly "crash" ?