- 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 desired, but expected
- https://youtu.be/gYQwuYZbA6o?t=615
Parachute + Secret Message:
- When packed, the parachute has the same density “as oak”.
- it trails at about 150 feet.
- The parachute pattern detail is intentional – sections to assist tracking different portions, etc.
- There appears to be some sort of secret message encoded in the parachute: “sometimes we leave messages in our work for others to find…give it a shot and show your work”
- https://youtu.be/gYQwuYZbA6o?t=1174
- see also https://twitter.com/lqqkout/status/1363982243010473986
Mic Fail on Descent:
- They did not get audio from the port-side EDL mic on descent due to a analog-to-digital comms malfunction
- specifically stated that it was not a hardware issue.
- https://youtu.be/gYQwuYZbA6o?t=3518
Other Descent Things + Sky Crane:
- The heatshield is aeodynamically stable and does not tumble/spin on ejection.
- No plumes from the ‘sky crane’ because the exhaust products of hydrazine are hydrogen and nitrogen.
- The only hint that the rockets are firing are the slight colour change due to the heat (pink tint).
- The photos/videos are the first views of the sky crane in action because it’s not something that can be tested on earth.
- The photos/videos from the sky crane looking down at the rover at transmitted to the rover via an ‘umbilical cable’
Comms and photo things:
- The High-gain antenna has only now been deployed. That’s the one that allows the high speed 2mbps rover-to-orbiter link.
- https://youtu.be/gYQwuYZbA6o?t=2039
- The data rate changes depending on the different orbiter being used.
- “return 500-900 megabits per pass” and 2-3 overflights per night.
- https://youtu.be/gYQwuYZbA6o?t=3928
- And some of the biggest data relays were via European/ESA Trace Gas orbiter.
- https://youtu.be/gYQwuYZbA6o?t=4097
The pieces:
- There’s a shot of all the pieces and their landing/crash sites as taken from orbit. Heat shield, perseverance, back shell, descent stage/sky crane, parachute.
- https://youtu.be/gYQwuYZbA6o?t=2251
Mic + Hardware things:
- There are two mics. One captured some audio on the surface. A gust of wind. (more interesting to me was the hum of the rover). It would be cool if the audio from the mics could be used to pair with the panoramic view to create spatial audio.
- https://youtu.be/gYQwuYZbA6o?t=2333
- Because the EDL mic is ‘off-the-shelf’ it is expected to fail quickly in the Mars environment. They have no immediate plans to use it for any kind of diagnostics during its lifetime.
- https://youtu.be/gYQwuYZbA6o?t=4215
Camera + Hardware things:
- The cameras used are off-the-shelf commercial hardware with some modifications. Purchased from Point Grey Research (which was acquired by FLIR Systems).
- Most interesting mod: they had to replace some materials that could off-gas in space/vacuum and potentially deposit on the detectors.
With all that, these press conferences are so weird. They still use a lot of acronyms. The setup is strange when there's no actual audience in front of them. They don't actually answer the questions from the press sometimes. They attempt to describe aspects of videos/images ("on the right you can see an antenna") instead of using technology to actually show. It's not quite clear who the audience is here: they're combining questions from kids and the press. It would be helpful if they annotated images. It would also be helpful to place the questions on screen (who has asked them). But, still so damn exciting.
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.
It's a lot better than last year, when code blocks didn't even wrap on mobile. The only formatting HN allows is paragraphs, italics, and code blocks, with auto-links. So you're forced to do lists as a bunch of paragraphs.
Were there any scientific utility to these payloads, or were they added in order to create some spacecraft porn? How much did the equipment for this weigh?
IIRC, a downward facing camera is useful for precisely locating the landing location, but I'm having trouble seeing a purpose for the upward facing camera besides getting cool sky-crane video.
There is an engineering use for it, and that is to the see all the dynamic behaviour that other sensors might not capture. This is rocket science and they do want to know how the landing went.
Open source bits and shout out:
Images and Video and Data! Cam Fail on Descent: Parachute + Secret Message: Mic Fail on Descent: Other Descent Things + Sky Crane: Comms and photo things: The pieces: Mic + Hardware things: Camera + Hardware things: With all that, these press conferences are so weird. They still use a lot of acronyms. The setup is strange when there's no actual audience in front of them. They don't actually answer the questions from the press sometimes. They attempt to describe aspects of videos/images ("on the right you can see an antenna") instead of using technology to actually show. It's not quite clear who the audience is here: they're combining questions from kids and the press. It would be helpful if they annotated images. It would also be helpful to place the questions on screen (who has asked them). But, still so damn exciting.//edit, formatting