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NASA's Perseverance rover sends stunning images

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Re: NASA's Perseverance rover sends stunning images

#281

Earlier quoted context omitted.

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…

They did this exact thing with the helicopter — it's using a Snapdragon SoC that runs Linux.

Re: NASA's Perseverance rover sends stunning images

#282

Earlier quoted context omitted.

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…

But now you’ve added weight and need to remove something else.

As a tangent, I remember a talk from Grady Booch where he put software cost in terms of mass that needed to be added to your rocket. So every new feature cost weight by requiring more chips and more fuel.

Re: NASA's Perseverance rover sends stunning images

#283

What are the "dark spot anomalies" that appear to be floating in the air in some images (1, 2)? Dust on the camera lens? I've never looked at any rover images so I assume someone knows. Also, whay are the images fairly low resolution compared to a phones camera. Does it have to do with image data transmission error? Finally (then I'll shut up), when do we get to see the stereo images? I want to see these on my Vive.…

Same question. Where are the stereo images?

Re: NASA's Perseverance rover sends stunning images

#284

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…

I have an opposite view of this.

Cosmos and Mars, Sun whatever else was there long before us an will be still there long after us. From cosmic point of view humanity does not matter much.

From that 1000ft view humans and whatever we built is natural and not different than colony of ants. We are just sand grains that will be crushed when next big asteroid comes by.

Having pristine planet like Mars has no value besides human point of view "I want". Let alone planets are not pristine they are bombarded with space trash like asteroids all the time :)

Why do we use such anthropocentric view? It makes any difference if there is parachute on Mars? Pollution? Well we defined pollution because it is something we want to get rid of because it makes us sick. There is much more bad things for humans in space than you can count.

Re: NASA's Perseverance rover sends stunning images

#286
post #285

Mars surface looks pretty much like Earth surface :)

Wait until we get images of cliffs of Echus Chasma, the crater of Pavonis Mons or the view over Valles Marineris....

Edit: I know Perseverance isn't going to those places, but something/someone will eventually....

Re: NASA's Perseverance rover sends stunning images

#287

Earlier quoted context omitted.

According to the below, The Perseverance could potentially give you a dose of 210 milligram in an accident. That’s not as much as I’d have thought, though would make getting the milk from the nuclear fridge a little hazardous. https://mars.nasa.gov/mars2020/spacecraft/rover/electrical-p...

Galen Windsor and his colleagues worked elbow deep in plutonium and uranium for years. None of them ever got sick. There are some old Galen Windsor videos on YouTube. He traveled around the country eating uranium in front of his students and audience. The EPA of his day had hissy fits. Great stuff!

Eating unprocessed uranium order that isn't giving off very much radiation is a bit different. It just passes out of his body without bioaccumulating.

Source for the claim he worked around plutonium "elbow deep" please.

Re: NASA's Perseverance rover sends stunning images

#290
post #20

I remember a recent article on HN about being able to receive signals from Tianwen-1 with a homemade satellite dish - is it possible to receive these pictures over radio with the right equipment, or do they come down encrypted?

I would think encryption would slow down the transmission rate. So most likely are sent in the clear

I'm not saying they are encrypted but I thought that encryption is a close cousin to compression - that it generally doesn't add overhead.
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