Mars2020 landing cameras |
Mars2020 landing cameras |
Aug 28 2016, 12:34 PM
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#31
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Senior Member Group: Members Posts: 2346 Joined: 7-December 12 Member No.: 6780 |
I don't think, that sound attenuation poses any significant issue on Mars on the meter scale, especially when relative humidity is very low.
With this calclulator for atmospheric absorption, for sound of 1000 Hz, I get 0.014 dB / m for 103 kPa at 0°C with 10% relative humidity, and 0.0255 dB / m for 0.6 kPa at -20°C with 1% relative humidity. Above 10 kHz, it may be going to become an issue on the meter scale. The microphone membrane, however, might be required to deal with reduced sound intensity, since the low-pressure atmosphere transports less sound energy for the same amplitude. |
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Oct 12 2016, 05:33 PM
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#32
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Member Group: Members Posts: 613 Joined: 23-February 07 From: Occasionally in Columbia, MD Member No.: 1764 |
I don't think, that sound attenuation poses any significant issue on Mars on the meter scale, The microphone membrane, however, might be required to deal with reduced since the low-pressure atmosphere transports less sound energy for the same amplitude. Yes, 6mb CO2 conveys sound quite happily over distances of a few meters. Here is some music played ('quite loud' in 1 bar air, but considerably quieter here at 6mb simply because a loudspeaker diaphragm displacement at a given speed produces a lower sound pressure level simply because the air density is lower, as you note). The sound is a bit distorted (ethereal, dare I say..?) because of reverberation/multipath between the parallel metal walls of the chamber (these were tests I did a couple of weeks ago at the Mars Environment simulation chamber in Aarhus, Denmark). There's also a lot of plant noise (electrical, rather than vibration/acoustic) http://www.lpl.arizona.edu/~rlorenz/oxygene_on_Mars.mp3 More details to be presented at the Mars Atmosphere workshop in Granada in January Ralph Lorenz |
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Sep 18 2020, 12:42 AM
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#33
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Member Group: Members Posts: 154 Joined: 8-June 04 Member No.: 80 |
I know this is an old thread, but I was wondering if the video from the EDL cameras will be compressed before being sent to Earth like the first images from Curiosity's MARDI camera were compressed as the bandwidth was limited in the early days after landing. Does anyone know if Mars Odyssey and MRO will be in position to receive signals from Perseverance on landing day?
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Sep 19 2020, 10:54 PM
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#34
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Senior Member Group: Members Posts: 2542 Joined: 13-September 05 Member No.: 497 |
Does anyone know if Mars Odyssey and MRO will be in position to receive signals from Perseverance on landing day? Regardless of phasing, there are typically two passes per day per orbiter (see https://trs.jpl.nasa.gov/handle/2014/44382 ) and MAVEN and perhaps TGO will also be available, but there's usually some uncertainty about the performance of early relay ops. From the April 2020 MRO status for MEPAG https://mepag.jpl.nasa.gov/meeting/2020-04/...202020_post.pdf QUOTE Cover mission critical events at Mars: Mars 2020 EDL in 2021 As for data return from the EDL cameras, that will probably be discussed in the pre-landing press kit and press conference. -------------------- Disclaimer: This post is based on public information only. Any opinions are my own.
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Sep 20 2020, 06:56 PM
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#35
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Member Group: Members Posts: 154 Joined: 8-June 04 Member No.: 80 |
Regardless of phasing, there are typically two passes per day per orbiter (see https://trs.jpl.nasa.gov/handle/2014/44382 ) and MAVEN and perhaps TGO will also be available, but there's usually some uncertainty about the performance of early relay ops. From the April 2020 MRO status for MEPAG https://mepag.jpl.nasa.gov/meeting/2020-04/...202020_post.pdf As for data return from the EDL cameras, that will probably be discussed in the pre-landing press kit and press conference. Thanks. |
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Dec 10 2020, 03:30 AM
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#36
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Senior Member Group: Members Posts: 2542 Joined: 13-September 05 Member No.: 497 |
A paper describing the engineering cameras on M2020, including the EDL cameras and the TRN camera, is now online at https://link.springer.com/article/10.1007/s11214-020-00765-9 (open access). Enjoy.
-------------------- Disclaimer: This post is based on public information only. Any opinions are my own.
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Dec 10 2020, 05:58 AM
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#37
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Member Group: Members Posts: 427 Joined: 18-September 17 Member No.: 8250 |
A paper describing the engineering cameras on M2020, including the EDL cameras and the TRN camera, is now online at https://link.springer.com/article/10.1007/s11214-020-00765-9 (open access). Enjoy. Thanks. Nice to see it will have microphones (obviously I haven't been paying enough attention).Playing with the OSIRIS-REx sample collection images, I was wishing it had a microphone (I'm assuming a mic mounted to the hull would pick up debris impacts). |
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Dec 10 2020, 03:32 PM
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#38
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Member Group: Members Posts: 291 Joined: 29-December 05 From: Ottawa, ON Member No.: 624 |
Thanks. That was a really good read.
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Dec 10 2020, 04:29 PM
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#39
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Senior Member Group: Members Posts: 2542 Joined: 13-September 05 Member No.: 497 |
That was a really good read. We weren't that happy with it, since it's a whole lot of different stuff roughly stitched together and sort of veers between topics. But it didn't make sense to write separate papers either and it gets the basics across. You'll note that the Gopros considered originally didn't make the cut, but I know nothing about what the story is with that -- all I worked on was LCAM. -------------------- Disclaimer: This post is based on public information only. Any opinions are my own.
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Dec 10 2020, 08:55 PM
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#40
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Solar System Cartographer Group: Members Posts: 10229 Joined: 5-April 05 From: Canada Member No.: 227 |
In answer to a question posed above about EDL data relay: MRO looks like it will be doing this.
MRO: Providing radar 3D subsurface mapping of ice deposits and imagery and spectroscopy of surface features and weather; also supporting landing site assessments. Developing “Bent Pipe Communications” in support of Mars 2020 landing. Will continue to serve as major relay asset for surface missions (Curiosity, InSight, Perseverance, ExoMars). This is from this recent report: https://www.lpi.usra.edu/pac/presentations/...0PACNov2020.pdf Phil -------------------- ... because the Solar System ain't gonna map itself.
Also to be found posting similar content on https://mastodon.social/@PhilStooke Maps for download (free PDF: https://upload.wikimedia.org/wikipedia/comm...Cartography.pdf NOTE: everything created by me which I post on UMSF is considered to be in the public domain (NOT CC, public domain) |
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Feb 17 2021, 06:11 AM
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#41
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Newbie Group: Members Posts: 18 Joined: 13-February 10 Member No.: 5222 |
A paper describing the engineering cameras on M2020, including the EDL cameras and the TRN camera, is now online at https://link.springer.com/article/10.1007/s11214-020-00765-9 (open access). Enjoy. Thanks Mike - great paper! And lo and behold - there are two USB3 hubs on the EDLCAM system; one on the aeroshell and one in the descent stage (Figure 28) |
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Feb 17 2021, 06:16 AM
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#42
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Newbie Group: Members Posts: 18 Joined: 13-February 10 Member No.: 5222 |
In answer to a question posed above about EDL data relay: MRO looks like it will be doing this. MRO: Providing radar 3D subsurface mapping of ice deposits and imagery and spectroscopy of surface features and weather; also supporting landing site assessments. Developing “Bent Pipe Communications” in support of Mars 2020 landing. Will continue to serve as major relay asset for surface missions (Curiosity, InSight, Perseverance, ExoMars). This is from this recent report: https://www.lpi.usra.edu/pac/presentations/...0PACNov2020.pdf Phil Also this: https://www.jpl.nasa.gov/news/the-mars-rela...rtian-explorers |
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Feb 17 2021, 07:25 PM
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#43
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Member Group: Members Posts: 447 Joined: 1-July 05 From: New York City Member No.: 424 |
Fascinating Wired article about Jason Achilles Mezilis, a rock musician and space enthusiast who successfully pitched to be hired as a consultant for the Perseverance microphone team. https://www.wired.com/story/musician-who-de...icrophone-mars/
Mezilis was recently selected as PI for an imaging system for moon landers, the Lunar ExoCam project. https://www.space.com/lunar-exocam-landing-...eo-moon-surface. Note for Mods: Previous discussion of Perseverance microphones is distributed among several existing threads, including this one. I chose this one because one of the microphones is designed to record EDL. There is a Tech, General and Imagery subforum for the MER mission.You might at some point consider setting up something similar for the Perseverance science and engineering instruments, so that information doesn’t get lost in what we hope will be a long series of narrative threads. This post has been edited by Tom Tamlyn: Feb 17 2021, 08:02 PM |
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Sep 8 2023, 01:20 PM
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#44
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Newbie Group: Members Posts: 9 Joined: 13-August 23 Member No.: 9270 |
Sorry if you guys already know this, but the EDL-Cams are actually still alive! The Rover Down look Camera seems to act as a MARDI succesor, however it takes images during drives. I Have no clue how they manage to transmit over 900 images on one day, probably using video compression. The capability to act fully independent seems to allow them to image while driving. The Rover uplook camera is also still alive and seems to act as skycams pal. I can't see much on the raw images, but if you edit the images togather you probably get better results. The Lander Vison system Camera shows no signs of activity however. The cameras seem to be reactivated around sol 700.
You can look at their images at the row images site, however you have to activate the "show movie frames" box for most of them to show up. If you have a very good internet connection I can also reccomend using this (https://areobrowser.com/#/mode=perseverance&instruments=ED) site to gat an overview and see rough video versions of the imagery. The Sol dates seem to only indicate the date of transmission and not when the images where taken, which is especially noticable for the RDC. I have found no NASA statement on the surprisingly long live of the cameras although I haven't looked very hard. Once again sorry If I just repeat old info. |
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