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Perseverance rover’s descent and touchdown on Mars [video]

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Re: Perseverance rover’s descent and touchdown on Mars [video]

#111

Post by joeyh »

ardy42 wrote: post #103
joeyh wrote: post #53

This was recorded by a computer running Linux, using ffmpeg. Embedded Intel system with fairly stock cameras. "the first open source linux box running on the surface of Mars" "thank you to the open source community for allowing us to use your amazing software" Per their press conference today, in the Q&A section. https://youtu.be/gYQwuYZbA6o?t=4025

> Per their press conference today, in the Q&A section. https://youtu.be/gYQwuYZbA6o?t=4025 What was the model? The recording was garbled, and all I could hear was "...we're using a commercial computer, an Intel ???? PC. It's running Linux...

https://link.springer.com/article/10.1007/s11214-020-00765-9 has details:

> The DSU is an off-the-shelf computer-on-module (CoM) from CompuLab Ltd with an Intel Atom processor and solid-state memory. The DSU runs the Linux operating system, along with additional software to communicate with the EDLCAM sensors, perform the EDL data collection sequence, manage the data storage and compress the collected data files. The DSU uses a high-density connector to provide connectivity to the high-speed USB3, USB2, gigabit ethernet and SATA interfaces.

> The main DSU is located inside the rover body. A second DSU, the descent stage DSU, is located on the descent stage. In both DSUs the CoM is connected to a custom electronics board that provides connectivity for all the USB devices. The two DSUs are almost identical to each other and communicate with each other through a gigabit ethernet link. The rover DSU includes a 480 GB solid-state flash memory drive (SSD) for data storage, provides a gigabit Ethernet link between both DSUs, and implements the high-speed serial communication protocol to communicate to the rover computer.

Re: Perseverance rover’s descent and touchdown on Mars [video]

#112

Post by frosted-flakes »

interestica wrote: post #71

Observations Open source bits and shout out: - The rover has an Intel-based PC running Linux. - The video is compressed using FFmpeg. - https://youtu.be/gYQwuYZbA6o?t=4027 Images and Video and Data! - 30GB of data. 23 000 images - https://youtu.be/gYQwuYZbA6o?t=562 Cam Fail on Descent: - 1 of 3 cameras failed when the mortar/parachute fired. - Some other items were damaged/disrupted during the firing as well – not de…

In future, please don't put prose in code blocks, particularly links. You have a lot of good info here, but it's hard to read and non-trivial to follow the links on mobile. Thanks.

Re: Perseverance rover’s descent and touchdown on Mars [video]

#113

Post by megablast »

GeorgeTirebiter wrote: post #105
geocrasher wrote: post #34

This may sound silly, but: The closest I've coming to building a "robot" was a simple little arduino kit. The kit was terrible, the parts defective, and you can imagine I was pretty sick of troubleshooting it after a time. These are things happening on my workbench with a small amount of automation code. I'd have been thrilled if it had just worked as designed. Now, take three robots. One is wheeled, one flies by rot…

What if you had $ 2.7B? Would that help? (I'm not suggesting Percy is anything but a near miracle; only that they did have at least some non-trivial resources.)

And a whole pile of experts who’ve done it before.

Re: Perseverance rover’s descent and touchdown on Mars [video]

#114

Post by jamiek88 »

croutonwagon wrote: post #110
AnotherGoodName wrote: post #89

Earlier quoted context omitted.

If only. >The minimum safe lower limit for the partial pressures of oxygen in a gas mixture is 0.16 bars (16 kPa) absolute. https://en.wikipedia.org/wiki/Partial_pressure If it was 20% that would be survivable with just an oxygen mask fwiw. Humans can go down to 16% atm pressure safely if they breathe 100% oxygen. The rest of the body can easily handle the pressure difference (1 full atm of pressure is equivalent to…

Uh....10 msw is roughly 2 atm. It’s an additional atmosphere. On top of...the one we live in at sea level. Also 100% O2 anything past about 4 msw will kill you. The MOD of pure o2 is 13 feet. Which is about 3.9 msw

Yeah I was about to reply something similar. Wouldn’t want to go diving with those assumptions!

Re: Perseverance rover’s descent and touchdown on Mars [video]

#115

Post by divbzero »

andyzweb wrote: post #109
GeorgeTirebiter wrote: post #105

Earlier quoted context omitted.

What if you had $ 2.7B? Would that help? (I'm not suggesting Percy is anything but a near miracle; only that they did have at least some non-trivial resources.)

Was that the budget for the whole thing? If that’s what it cost to put that thing up there why aren’t we doing this once a month.

… or at least once every 26 months or so. [1]

[1]: https://en.wikipedia.org/wiki/Exploration_of_Mars#Launch_win...

We sent 3 separate spacecraft to Mars during the most recent launch window. We’ll see how we do next time around.

Re: Perseverance rover’s descent and touchdown on Mars [video]

#116

Post by jamiek88 »

spookthesunset wrote: post #85
baggy_trough wrote: post #30

Earlier quoted context omitted.

If there was mass available to add something to the sky crane, you'd be better off putting that thing on the rover, since the rover has the plutonium power pack. I do feel a bit sorry for the crane as well though :)

This is what I was thinking. That sky crane has to be as barebones as can possibly be made. Every single bit of mass on it is something that could be better used elseware. Tradeoff of course is if you skimp on the mass too much you'll get an unreliable sky crane and the whole thing is a dud.

Sky crane will be used for seismic measurements with another vehicle picking up the waves from it slamming into mars firma on the other side of the planet so some use of it at least!

Re: Perseverance rover’s descent and touchdown on Mars [video]

#117

Post by systemvoltage »

midasuni wrote: post #93
netcraft wrote: post #7

So glad they've realized the value in allowing everyone to experience how hard these things are. So impressive, I can't wait to watch this video over and over. The inflation of the parachute is spectacular, and knowing how hard it is, and how hard it is to test on earth - its just incredible. And the skycrane was flawless - just so impressive how well it works. Too bad it flies off to crash and can't land gently some…

SpaceX broadcasts really raised the bar on what the public expect from space, and with it brought a lot of excitement. Great that scientific program is following in those footsteps.

Ehh...to be fair, Space exploration has always been an excitement for public ever since the Apollo days. NASA's PR team has been stellar for over 50 years in inspiring people around the world. Indeed, SpaceX upped the game for live broadcast.

Let's put it this way - if SpaceX didn't exist, I am sure Mars 2020 program would have had high resolution cameras and videos of the landing, along with all the excitement from the public. It's just inevitable as technology progresses. Keep in mind that social media wasn't a thing back then.

NASA/JPL and the Perseverence program isn't following anyone's footsteps here.

Re: Perseverance rover’s descent and touchdown on Mars [video]

#118

Post by jamiek88 »

soheil wrote: post #92

The way and the speed by which the sky crane moves away is just like any sci-fi movie, totally unreal [0] [0] https://youtu.be/4czjS9h4Fpg?t=188

Looks like from terminator 2 or something similar. I remarked to my wife that it looked full on sci fi.

Sky cranes on Mars, HD and 360video, microphones on an suv sized rover.... man... I love living in the future!

Re: Perseverance rover’s descent and touchdown on Mars [video]

#119

Post by systemvoltage »

tppiotrowski wrote: post #57

Can someone comment on why this is the first time I'm seeing videos from Mars versus previous missions. Did the memory write speeds increase, more sensitive CCD sensors, easier to send data back to Earth? I'm sure there must be some technological reason this wasn't done before because it's simply stunning...

It's not just cameras. What good is an 8K video taken on a rover but it can upload at 200 bits/sec?

The entire stack has improved. I suspect everything from radiation hardening, semiconductor manufacturing, CCD reliability and costs, image processors, colorometry, radio transmission, relay tech and orbiters, and not to mention the importance of great PR.

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