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NASA's Perseverance rover sends stunning images

bbc.com

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Re: NASA's Perseverance rover sends stunning images

#21

they don't look all that stunning to me.

What do you want before you'll call it "stunning"? Beaches with women in bikinis? Those are stunning for the amount of detail they show of the surface of another planet.

Microbes in bikinis, please

Re: NASA's Perseverance rover sends stunning images

#22
post #15
post #5

Earlier quoted context omitted.

Thanks for having the courage to make this comment. While beauty is in the eye of the beholder, it’s not like these are mind bending technicolor panoramas. They look like every other picture of Mars we’ve seen since the first pictures of Mars decades ago. At some point someone needs to ask why we’re spending billions on more pictures of Mars and answering deep questions like “Is Mars soil 36.7 or 36.8% silicon?”

This project will cost $2.8 billion…over the 10-year life of the project. https://en.wikipedia.org/wiki/Mars_2020 In government terms? That is nothing. We’ll burn that much on defective F-35 fighters in a year. And we are not “just” assessing the mineral content of the soil—not even close. https://mars.nasa.gov/mars2020/mission/science/ (If you’re that offended by the cost, I will Venmo you the 0.1 cents per year thi…

You triggered the fuck out of me. The saving grace of the Joint Strike Jobs program is that maybe 1% of the people learned what to do next time.

Re: NASA's Perseverance rover sends stunning images

#24

Does anyone know what type of data compression is being used to transmit these images? There's been huge progress since the last rover.

They use the same kind of compression as the last mission. JP2, I believe. https://en.wikipedia.org/wiki/JPEG_2000

I'm not sure that data compression has progressed that much since Curiosity in 2012 or Insight in 2018. There have been some formats that have improved compression at the expense of large amounts of memory or processing power, but neither of those are abundant on a rad-hardened processor. Neither is electricity. Neither are the toolchains to process such images very widespread or as well understood.

Re: NASA's Perseverance rover sends stunning images

#25
post #19

Does anyone know what type of data compression is being used to transmit these images? There's been huge progress since the last rover.

I'm speculating here, but I think these images are transmitted in some kind of raw format, or close to it, making them more resilient to data corruption. Compressed images will incur greater data loss when compressed, compared to raw images where you might lose a few image blocks at a time.

They compress them but transmit with forward error correction. They do have the ability to retransmit if the images are too damaged.

Totally uncompressed images are not a very efficient way to transmit images if you want to ensure they're scientifically accurate.

Re: NASA's Perseverance rover sends stunning images

#26
post #5

they don't look all that stunning to me.

Thanks for having the courage to make this comment. While beauty is in the eye of the beholder, it’s not like these are mind bending technicolor panoramas. They look like every other picture of Mars we’ve seen since the first pictures of Mars decades ago. At some point someone needs to ask why we’re spending billions on more pictures of Mars and answering deep questions like “Is Mars soil 36.7 or 36.8% silicon?”

Why? Because missions like these contribute to our understanding of extraterrestrial worlds, like Mars. The data collected will help with future space travel and potential settlement.

Re: NASA's Perseverance rover sends stunning images

#27

How close was the rover to its intended landing spot?

Nailed it - https://www.jpl.nasa.gov/images/avoiding-hazards-at-jezero-c...

(A little more complicated than that of course. If I understand correctly, anything in blue was a candidate landing spot that it was free to select from. I'm pretty sure the header image is an artistic crop :) )

Re: NASA's Perseverance rover sends stunning images

#28

Does anyone know what type of data compression is being used to transmit these images? There's been huge progress since the last rover.

They use the same kind of compression as the last mission. JP2, I believe. https://en.wikipedia.org/wiki/JPEG_2000 I'm not sure that data compression has progressed that much since Curiosity in 2012 or Insight in 2018. There have been some formats that have improved compression at the expense of large amounts of memory or processing power, but neither of those are abundant on a rad-hardened processor. Neither is elec…

Any idea how much storage it has? I would think it'd have to be TBs to store all these images, logs, and other data for years while making sure they have enough memory so that they're not limited and if the rover stays there for longer than intended.

Re: NASA's Perseverance rover sends stunning images

#30

Does anyone know what type of data compression is being used to transmit these images? There's been huge progress since the last rover.

They use the same kind of compression as the last mission. JP2, I believe. https://en.wikipedia.org/wiki/JPEG_2000 I'm not sure that data compression has progressed that much since Curiosity in 2012 or Insight in 2018. There have been some formats that have improved compression at the expense of large amounts of memory or processing power, but neither of those are abundant on a rad-hardened processor. Neither is elec…

One of the obvious constraints is that for science reasons they transmit each image in a lossless format, so we're up against the limits of what a lossless image compressor can do.

If there were a future mission's requirement to send back lossy images first, and CPU power was significant, something like AVIF or JPEG-XL would likely be a candidate.

https://netflixtechblog.com/avif-for-next-generation-image-c...

ICER appears to be what they're using now for lossless: https://en.wikipedia.org/wiki/ICER

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