301–310 of 365 posts
This mission is an incredible achievement. The images are as advertised (stunning) and I'm sure all the sciences - and even art - will benefit from the data. What I find a little sad is that we seem incapable of doing this without leaving a particularly human signature wherever we go. We arrived on Mars with jets of pollution https://mars.nasa.gov/resources/25672/black-and-white-smoke-... followed by the dumping of t…
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It never ceases to impress me that we have the ability to do this sort of stuff. A couple thousand years ago, the height of technology was shooting something from a few hundred metres away with a bow and arrow, now we are landing machines on another planet and transmitting data back and forth through the solar system. Incredible.
A couple of thousand years ago is the peak of the Romans, so you're way off on your 'height' of technology at that time. Using bows and arrows as an example when you've got wonders of pretty advanced engineering like the Parthenon, plus they also had ballistae, chariots and catapults, so not the peak at all. Not only that, but even the bows were more advanced, composite bows much more powerful than simple ones made o…
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Yep, that’s the same reason why it runs on a PowerPC750 chip. They cost $200k+ for under 200Mhz on a 150-250 nm process, but can withstand up to 1,000,000 rads of radiation and function within extreme temperature ranges for decades. They have been proven to work in the harshest environments on prior missions, and the risk of an unproven processor is giant; a CPU failure could jeopardize the mission just as much as a…
Maybe a stupid question, but couldn’t they put there something “cutting-edge” next to the existing system? Then if that fails then whatever, the rest of the system is still functional as expected, but at least they know that in the future what they would need to change to be able to use the new technologies in that environment. Although I can imagine that even the smallest weight increase could cause issues, so proba…
Not sure what the long term plan is for that hardware - I guess they can just do stuff more slowly on the main CPU if it gets fried by radiation. Or maybe being an FPGA the can just isolate the radiation affected regions over time and use the rest ?
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Could you explain why such a processor is 1000x more expensive than a non-rugged one ? I mean, considering the future of earth, I'd certainly welcome a processor that could withstand a lifespan of decades (including the harsh "I'm going to unsolder it to put it in another device" environment).
The low demand definitely leads to higher prices but the other aspect is all of the additional testing involved for every chip. There's standard testing at every level of the manufacturing process and there will be further environmental testing at the package level. They will even run radiation tests on the wafer to characterize any quirks.
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My question is why was the “sound of Mars” release only 18 seconds long? Why not record hours of what it sounds like to be on another planet? Even the sound recordings from decades ago on (I think Titan) was only a short creepy clip. I understand it’s mostly going to be wind and interspliced with the robots sounds but I still don’t get how we don’t have hours of Mars already.
Perseverance is the first rover with microphones on Mars. This is why we don't have audios from prior missions.
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> easily shielded by essentially any solid material If that shield fails for any reason, including tampering, you're looking at the radiological contamination and likely deaths of everyone nearby at the very least.
Alpha sources outside the human body are of little health concern. You'd have to break it open and eat the plutonium inside for it to be a serious risk.
[1] https://en.wikipedia.org/wiki/Alexander_Litvinenko [2] https://en.wikipedia.org/wiki/Smoke_detector
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a glowing green sandwich covered in red sand. But seriously, this stuff is powering those voyager probes 40 years later. Which makes me ask: why do we have to send there technologies 10 billion miles away to make them work? Why can't my fridge be powered this way?
Why can't my fridge be powered this way The MMRTG is a cylinder 25" in diameter and 26" high, it's going to seriously impact space in your 'fridge. Plus it weighs nearly 100 lbs. It outputs around 100W of power, which might be enough for a small refrigerator, but it also emits around 2000W of thermal energy, so your kitchen's going to get a little warm (probably a good thing in the winter, not so much in summer). Tho…
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The helicopter hasn't flown yet - they put it down on the ground, and they're going to run it through a lot of remote checks before flying it. IIRC it's gonna be a month or two before first flight.
I would think with the wind and sand storms that it'd be dangerous leaving it exposed for a month before you even get to use it. Does the rover park on top of it during storms for minimal protection?
ref:https://ichef.bbci.co.uk/news/976/cpsprodpb/58BB/production/...
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Very low bandwidth, very low power, very long distance comms are really cool. The limiting factor tends to be the clock frequency precision - if you have precise enough clocks at both ends, there isn't anywhere in the universe you couldn't communicate with, as long as you're happy to go slow enough.
> there isn't anywhere in the universe you couldn't communicate with Right, assuming you are emitting infinite amount of photons, there are no obstructions, black holes and you ignore universe expansion and GR which can make your precise enough clocks go out of sync.
