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NASA's Perseverance rover sends stunning images

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Re: NASA's Perseverance rover sends stunning images

#331

Any sound clips released as of now? I heard they had a microphone on board unlike so many of the probes till now.

https://mars.nasa.gov/mars2020/participate/sounds/

Actually they sound some what underwhelming.

Re: NASA's Perseverance rover sends stunning images

#332

Earlier quoted context omitted.

Scott Manley mentioned in one of his recent videos about Perserverance that they have an FPGA on board the rad hardened PPC main cpu can offload tasks to, such computer vision based navigation during landing. 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 affecte…

You got me curious and I found a product listing with a rather amazing explanation of what they're doing for radiation-proofing. Radiation Performance > RTG4 FPGAs are immune to radiation-induced changes in configuration, due to the robustness of the flash cells used to connect and configure logic resources and routing tracks. No background scrubbing or reconfiguration of the FPGA is needed in order to mitigate chang…

Wow, a rad hard FPGA! Now that's something I didn't expect - thanks for digging this up! :)

Re: NASA's Perseverance rover sends stunning images

#333
post #214

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…

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).

For radiation-hardened semiconductors sometimes you use specialized processes like silicon-on-insulator. Even if you're using a more conventional process, you're probably using specialized upset-resistant gate designs and layout. And even your gate-level or HDL-level design might have changes to make it possible to detect and recover from some kinds of bitflips. It really affects the whole technology stack.

Re: NASA's Perseverance rover sends stunning images

#334
post #87

Stupid question maybe but like is there a reason the picture quality seems worse than a decent dslr photo? I'm so curious what that photo would look like, taken with an everyday camera, without the bizarre 'scientific' look of these shots.

Is it simply dusty/hazy? Some of the fuzzy photos remind me of the Sahara Desert when there was a little wind.

Dusty. Gives the sky a dull reddish color. Also makes Martian sunsets blue.

Re: NASA's Perseverance rover sends stunning images

#335
post #159

Earlier quoted context omitted.

From my layman's understanding, it's relayed via the orbiters. There are a few orbiters around Mars. NASA appears to have an arrangement with the ESA to upload data from the rovers to the ESA's orbiters, depending on whose orbiters are within line of sight at any given time. Then the orbiter sends the information back to Earth, which are received by NASA's Deep Space Network During the time when line of sight between…

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, humans built massive engineering projects, including the Pyramids, massive irrigation and earthwork systems, and tunnels, and bridges, domesticated wild animals, produced metals - including steel - out nothing but wood, water, and low grade ore, etc, etc.

They did not have internal combustion engines, or electricity, or the ability to machine parts to high tolerances, but ancient engineers cared deeply about efficiently transforming mechanical energy from one form to another.

Re: NASA's Perseverance rover sends stunning images

#337
post #181
post #87

Stupid question maybe but like is there a reason the picture quality seems worse than a decent dslr photo? I'm so curious what that photo would look like, taken with an everyday camera, without the bizarre 'scientific' look of these shots.

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.

One of the most beautiful and haunting things I've ever heard was a tape cassette that had EM signals recorded by Voyager transposed into human-audible sound domain somehow. It was like whale song of space.

Re: NASA's Perseverance rover sends stunning images

#338
post #87

Stupid question maybe but like is there a reason the picture quality seems worse than a decent dslr photo? I'm so curious what that photo would look like, taken with an everyday camera, without the bizarre 'scientific' look of these shots.

In some interviews with the mast cam engineers, they say they can capture higher resolution images later on. Maybe they were reducing the image size to get then transmitted quicker.

Re: NASA's Perseverance rover sends stunning images

#339

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…

I know the camera image compression happens on a x86 processor. Not sure if it is rad hardened. It would be okay if the processor is not doing critical work and can be power cycled due to a rare SEU failure. Also the same with the helicopter uses a mobile phone processor.

Also some of the components are not rated for long term use. The microphones they installed will probably fail due to extreme temperature cycling. The helicopter is expected to last only 4 uses and anything beyond that is a bonus.

Re: NASA's Perseverance rover sends stunning images

#340

Earlier quoted context omitted.

Oh see you did it now - opened up a vacuum about ancient tech. I'll start: https://en.wikipedia.org/wiki/Aeolipile

(The question as to how - and why or why not - we could go from the Aeolipile to full blown steam engines, I've always found fascinating ... ... what other things / proceses / materials / frame of mind made the steam engine possible vs. this. What made for an industrial revolution in the 1800's vs. the 1st century AD).-

One thing that severly hampered the romans was their number system.
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