NASA's Perseverance rover sends stunning images • Hacker News Board

Re: NASA's Perseverance rover sends stunning images

#271

Post by cosmonaughty » Wed, Mar 03, 2021, 1:00 PM UTC

wiz21c wrote: post #265

enlyth wrote: post #260

Earlier quoted context omitted.

10/10 satire

yeah, but as someone not educated in those matters, could someone compare the "fake" computations from the comment to real ones ? So we could see how wrong they are...

Perfect example of Dunning Kreuger! To answer your question you could get a physics textbook. The numbers I provided you are the official numbers. 610 pascals, or 0.088% earth pressure. A stuffed bear with a normal parachute would hit the ground at terminal velocity with only 600 pascals of air buoyancy.

Re: NASA's Perseverance rover sends stunning images

#272

Post by darkr » Wed, Mar 03, 2021, 1:02 PM UTC

Cthulhu_ wrote: post #212

reilly3000 wrote: post #208

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…

Especially since hardware is generally designed for speed and performance instead of reliability. Didn't NASA use a lot of 486es for a long time for this same reason? But yeah. It's not a problem if a CPU gets buggy or dies in a datacenter with 10K similar ones, because of redundancy and a completely different approach to software workloads nowadays. I mean a lot of production systems barely even care what CPU they r…

> Didn't NASA use a lot of 486es for a long time for this same reason?

They were also using Amigas until ~2006 for various duties, including launch control.

Re: NASA's Perseverance rover sends stunning images

#273

Post by HenryBemis » Wed, Mar 03, 2021, 1:10 PM UTC

bregma wrote: post #252

dmurray wrote: post #245

Earlier quoted context omitted.

I for one look forward to Rover McRoverface in the 2022 launch window.

Marvin McMarsface is to take a close-up look at the Face On Mars in 2023 and then implant an Illudium Q-36 Explosive Space Modulator to eliminate Mars because it obstructs our view of Venus.

> I doubt a NASA suggestion box open to the internet will be very fruitful.

The two resectful and fun comments between 'this' comment and your comment.

I can imagine a Tumblr/Reddit re-post would be more fun, but-yes-not for the NASA suggestion box. They would have 1 diamond idea every 100k unusable ones.

I can imagine every gaming company would LOVE to have the original Mars sound in their games (e.g. "No Man's Sky").

Re: NASA's Perseverance rover sends stunning images

#274

Post by alpaca128 » Wed, Mar 03, 2021, 1:17 PM UTC

phonethrowaway wrote: post #112

gtm1260 wrote: 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.

speculation, but it's probably compressed before transmission to earth... for obvious reasons.

It would surprise me if they used lossy compression. However I once read about a space probe using a custom image compression and transmission format which does not require 100% data integrity for proper decoding. So if the transmission is cut off after 60% NASA will still be able to view whatever they received. I assume such methods are still applied.

Re: NASA's Perseverance rover sends stunning images

#275

Post by dredmorbius » Wed, Mar 03, 2021, 1:18 PM UTC

TeMPOraL wrote: post #222

dredmorbius wrote: post #68

Earlier quoted context omitted.

Similar, a gf capturing the evolution of our knowledge of Puto in somewhat less than a century: https://i0.wp.com/www.nasa.gov/sites/default/files/styles/fu...

Great. Sometimes it feels like there's little progress made in space exploration. But such a compilation is a good reminder that - yes, maybe it's a bit too slow for the impatient, but progress is being made, and it shows.

That period during the New Horizons mission where every new image represented a major advance in our quantum of knowledge of Pluto was absolutely remarkable.

The situation with Mars is different: the planet's close enough for reasonably good telescopic investigation from Earth, we've had landers on the planet for 50 years (the Soviet Mars 2 lander beat Viking by 5 years), high-resolution orbiters for ... nearly as long? And since 1996, rovers, which have transected paths of varying lengths exploring specific regions of the plant. We've got a very strong overview (something still not complete for Pluto --- New Horizons got detailed close views of only about 60% of the surface), and several very-high-detail pictures.

Astronomical time and distance are both huge relative to human scale. That we (or our robot agents) can cross the solar system in a decade or two is remarkable. A few months to Mars is nothing. The Earth was once as large or far larger (to us).

Re: NASA's Perseverance rover sends stunning images

#276

Post by velvetz » Wed, Mar 03, 2021, 1:21 PM UTC

reilly3000 wrote: post #208

Balgair wrote: post #113

Earlier quoted context omitted.

Generally, these cameras are many years out of date. They don't load up the rovers with the latest gear from today, but with the latest gear from when the design review process was closed. I don't know when that was for Perseverance, but it would not surprise me if that was a decade ago. The cameras are also not specifically designed for image capture, but for scientific study. In that they take images at a wider ran…

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 probably that’s the reason.

Re: NASA's Perseverance rover sends stunning images

#277

Post by snickms » Wed, Mar 03, 2021, 1:23 PM UTC

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 the two pieces of trash required to enable the landing.

For all the data we have gained, we have lost a pristine planet - which makes me wonder if we are doing this at the right time.

Re: NASA's Perseverance rover sends stunning images

#278

Post by moftz » Wed, Mar 03, 2021, 1:26 PM UTC

wiz21c wrote: post #214

reilly3000 wrote: post #208

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).

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.

Re: NASA's Perseverance rover sends stunning images

#279

Post by mmcconnell1618 » Wed, Mar 03, 2021, 1:35 PM UTC

whatever1 wrote: post #155

Anyone has insights on how data in such volumes can be transferred from Mars to Earth in the absence of a direct link? Do the intermediate nodes have gigabytes of available storage to emit data to the next available node once it becomes visible ?

Vint Cerf has been working with NASA for over a decade on a design for interplanetary internet. I work at Google and he shared a story about how the earlier rovers had radios that were overheating at higher bandwidth transmissions. A smart engineer noted that they had an X band radio on the rover and still had one in an orbiter around Mars. The rover could transmit at 128mbps over xband to the orbitter, which in turn had large antennas to transmit back to earth at 128mbps. I assume Perseverance supports more bandwidth but it may be limited by whatever equipment we have in orbit around Mars.

https://www.quantamagazine.org/vint-cerfs-plan-for-building-...

Re: NASA's Perseverance rover sends stunning images

#280

Post by wongarsu » Wed, Mar 03, 2021, 1:45 PM UTC

velvetz wrote: post #276

reilly3000 wrote: post #208

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…

Ingenuity (the Mars helicopter) has a much more modern processor that isn't particularly radiation hardened, and instead just restarts within milliseconds on any fault (fast enough to recover if it happens in flight). If Ingenuity does well I wouldn't be surprised to see a similar design in a future rover.