You can also watch an EDL visualization in your browser: https://eyes.nasa.gov/apps/mars2020/#/home
And read about how it will use Terrain Relative Navigation to find a safe landing spot: https://www.jpl.nasa.gov/news/a-neil-armstrong-for-mars-land...
Perseverance is phenomenally complex, its Sample Caching System alone contains 3,000+ parts and two robotic arms. So exited for all the sciencing this nuclear-powered, sample-drilling, laser-zapping behemoth can do when it joins its friends on the only planet (known) to be inhabited solely by robots.
Edit: Percy is about to release its two 77 kg Cruise Mass Balance Devices (is this what NASA calls 'weights'?) to setup the right lift-to-drag ratio for entry. Mars InSight will be listening for the 14,000 km/hr impacts of these weights, providing useful calibration data. We wrote about this in this week's issue of our space-related newsletter, Orbital Index - https://orbitalindex.com/archive/2021-02-17-Issue-104/
It turns out that they took 640lbs (!) of weight to mars to be tossed off at various points during EDL. The video is worth watching if you'd like some more of the nitty-gritty behind the process: https://www.youtube.com/watch?v=W0NakShgbHY
Note: that's 290kg in NASA units
And knowing the difference is an important part of rocket science:
https://www.simscale.com/blog/2017/12/nasa-mars-climate-orbi...
Great video! I am also surprised by the fact that they bring that much mass just to jettison. In theory they could mounted some of the useful mass on a slider/rail system to achieve the necessary adjustment to the mass distribution without dropping mass overall, but apparently it wasn't worth the complexity/volume cost.
I'm sort of surprised we don't yet have ML powered "de-accent-ization". His french accent isn't hard to understand at normal speed, but when I set it to 1.5x or 2x speed it becomes hard to decipher in a way native speakers usually are not. If there was just a button (for him or me) to hit to tweak the sounds a bit to reduce the accent, I bet this problem would go away.
Iâm amazed that people still say things like âde-accentâ as if there was such a thing as âno accentâ. You are asking for a button that makes his French accent more like your own. Itâs a separate thing from native vs. non-native speakers - there are plenty of native English speakers with accents that you would also find challenging.
I, for one, would be uncomfortable with AI removing my accent. I understand it's for other people to understand me better - and I am fine with AI-generated subtitles - but altering the way I speak would reduce the amount of "me" in ways I'm not fully ok with.
No need to have a fancy all-new ML algorithm - stick a text-to-speech output on the auto-generated video subtitles and you can set it to whatever language you like.
If the speech recognition / subtitling algorithm can't understand the nuances of the language, that's going to be a problem anyway... accented pronunciation is so multidimensional, you're pretty much going to have to transcribe syllables/phonemes first...
I was hoping someone would link this video, it describes the various phases with a ton of details that.
Some of the other videos on this channel are just as in-depth: the ones about the plumes/exhaust of rocket engines as well as star occlusions are incredibly detailed.
Thanks for introducing me to the French Space Guy! I am hooked.
> Cruise Mass Balance Devices
They put those in to make the probe seem higher-quality. They got the idea from Beats headphones.
Just to set the record a bit straighter and ruin your joke, those pics of beats with weights were knockoff beats from the flea market not real.
Reporting on that: https://gizmodo.com/are-beats-headphones-really-designed-to-...
We were doing that at Meraki back in the early 2010s (it turned out they were also useful as a heat sink and, because the metal was exposed to air, a radiator). Pretty sure Meraki got the idea from some Apple product or other.
Speaking of Meraki, I had an awful experience with those devices. Basically we were in building with TONS of other wifi networks around and Meraki network just went crazy from time to time until we fine tune it down to the channel for each AP. I mean, for something you pay $$$ to buy the devices and $$$ each month for the subscription is a pretty poor experience.
Nortel and itâs predeccessors bell northern telecom used to put weights in the handsets so they had a nice feel to them.
> is this what NASA calls 'weights'?
Well no, the Cruise Mass Balance Devices are intended to Balance the Mass of the spaceship during Cruise conditions. That these Devices are single-part and constructed out of a single chunk of metal each should not be construed as merely being 'weights'. :)
What I'm getting from this, is that you can use weights to balance the mass of the spaceship during cruise conditions.
Actually more like that you can eject weights to intentionally un-balance the mass of a spaceship so it'll glide rather than falling straight down.
Atmospheric drag force center of drag and center of gravity to line up on a same axis, which force the craft to fly slightly sideways if spacecraft isn't perfectly balanced. Done carefully, it leads to direction of flight being slightly sideways, which is awkward but basically same as having lift towards that direction. Add roll control thrusters into the mix, and you get a really crude glider, with fixed pitch force, zero yaw control and barely controllable roll. With JPL-class engineering, such a spacecraft will be capable of actively correcting landing location.
Ships do this all the time (ballast), and anybody who's ever flown on a light aircraft or helicopter also knows the importance a pilot places on weight distribution.
I guess what's surprising is that they needed that much weight (140+kg seems like a lot?) and couldn't redistribute existing componentry; guess the knapsack algorithm wasn't good enough, or that they just couldn't break up enough pieces?
And yes, Cruise Mass Balance Devices sounds like the type of name a tired engineer would come up with to convince upper management...lol
Surely you mean: "What I'm getting from this, is that you can use devices to balance the mass of the spaceship during cruise conditions"...j/k
Maybe they have both, and needed a name to distinguish the ejectable weights from the non-ejectable weights?
Got it. Fancy weights.
Also, InSight's SEIS seismometer is a true marvel: "We have been able to detect, at about 10 hertz, displacement of the ground of the order of less than 5 picometersâŚwhich is a fraction of the size of an atom." â https://eos.org/features/a-modern-manual-for-marsquake-monit...
LIGO puts this shame with 10^11 better sensitivity.
At sensitivity/gram insight wins. Per dollar probably not.
It's a great achievement with some really interesting work done on the landing algorithms with terrain recognition and it seemed to have worked exceptionally well.
Looking forward for the next landing in May of the Chinese rover and all the science these robots will produce. Also, the test of Ingenuity, the helicopter, will be very interesting to watch, that could really pave the way for a different exploration style in the future.
And finally, maybe the next transfer window will already see some Starships, that would really change everything.
Early starships got me thinking: given the high likelihood of a failed starship landing, and maybe having the ability to send one before fully engineering a payloadâŚ
What would you ballast a starship with for the practice missions?
Useful materials which might survive a RUD and aim for someplace near a likely landing zone? If you crash the parts of a milling machine, a lathe, some tooling, some assorted metals stock, and a bunch of assorted wire, well sure you just cleared out a machine shop auction, but maybe there comes a day when an early Mars colony would be thrilled to go clean up your âlandingâ site.
Solar cells Would not handle a rud. But Just fill the entire thing with solar cells. If they want to produce methane and co2 on Mars they will need lots of power.
Soil? Though not sure it is prudent to potentially spread active biological material all over a pristine (eco)system.
Mars soil is usable for plants. Or should be at least. So no need to bring soil from earth.
Why not work on some very small machines that can mine and refine materials to make more of themselves?
Because "refine" really means "melt at temperatures ranging from 500 to 4000 degrees celsisu and then extract via various mechanical processes and/or using various reactants which often require gigantic plants to produce and are highly unstable".
Basically all of the history of science until 200 years ago was figuring out "mine and extract" and the course of civilization is very much linked with the price & quality of metal structures they could produce. But it's gotten so good we take it for granted.
However that is because of gigantic plants situated in specific areas where energy is cheap that do this thing at an amazing scale.
Aluminum is cheap as chips, except that it used to be more expensive than platinum (and at a much higher impurity ratio than the stuff we use for baking or for making cheap cases).
Heck, gold is "a thing" because we could purify and mold it without bringing it to a melting point and it was, for a very long time, the only metal available to us to do anything with, way before the bronze age.
And the problem with the refinement process is that you can't really "be smart" about it, reaching very high temperatures is one of those things you can't really scale down in an efficient way. You'd have to propel 100,000 tons of factory to mars in order to efficiently refine anything remotely close to the metals we had access to 100 years ago.
Which is not to touch on the mining bit, that is in itself very complicated (see how slowly and shallowly rovers are currently able to drill).
Are there workarounds for this? Maybe, I don't think anyone knows them though, they are not the kind of thing that's within easy reach. Maybe if we happen to stumble upon large reserves of bismuth or lead or gallium or mercury close to the surface of Mars, and build a whole branch of engineering around using those to build machinery... ? But my limited knowledge of geophysics and geology tells me that finding those in large amounts is very unlikely.
For reference, if you take an oven, that can reach, say, 450 degrees celsius (home) and up to 700 (industrial). Those aren't enough to refine any "useful" metal (e.g. iron) and building them requires materials that were produced at 1500+ degrees.
IANAChemist/IANAMaterialScientist/IANABlacksmith though, so take with a spoon of salt.
Donât litter Mars Elon. Stick your landing. LOL.
Ingenuity is maybe the most interesting and coolest advance for space travel. The idea of a remote drone to explore Mars is just rad! I can totally nerd out about that!
A great video where the host visits the drone, interviews its makers, and goes over the cool technical aspects of it and its mission: https://m.youtube.com/watch?v=GhsZUZmJvaM
You may be interested in dragonfly then: https://www.nasa.gov/dragonfly
More about Ingenuity https://spectrum.ieee.org/automaton/aerospace/robotic-explor... and it's source code https://github.com/nasa/fprime
That is not Ingenuity's source code, that's the software framework used to link the various software modules. It's generic to any mission / instrument.
The Nasa person they have helping narrate what's going on is so genuinely happy the landing went well. It made me kinda tear up. It's infectious just how excited all these people are about this project. Also, I was a bit worried he was going to pass out. 10/10, would watch again (and probably will with my kids)
The audible whew from one of the crew members after maximum deceleration when the telemetry re-established was heart-rending. Years of work, and there's nothing anyone here can do eleven light-minutes away; it was either going to work or one of the thousands of things that had to happen correctly wasn't going to happen.
Everything happened correctly. :)
This guy? https://www.youtube.com/watch?v=gm0b_ijaYMQ&t=1h41m36s
That is Rob Manning, an absolute legend! Here is an interview with him from a few years back: https://solarsystem.nasa.gov/people/2280/rob-manning/
He also wrote this great book: https://www.amazon.com/Mars-Rover-Curiosity-Curiositys-Engin...
I love the fact that you could hear people saying things like "yes yes yes YES YES!" in the background as data came in. Like you say, very infectious
First surface photo is in too!
NASA is making the raw images of everything available:
Today's images are from Sol 0. Zero-based counting rules.
You can see what this page looked like for Curiousity at https://mars.nasa.gov/msl/multimedia/images/?page=0&per_page...
Can't wait till they start posting raw images :)
Thanks for that! I just found this especially awesome shot of Curiosity: https://mars.nasa.gov/resources/21929/curiositys-dusty-selfi...
It's very high res. You can see the holes/damage on the wheels -- Perseverance will have new wheels because of it. And also, won't have the 'morse code spelling' on the wheels either. It's amazing that this kind of damage/wear couldn't have been predicted in tests. The amount of dust that has settled on top in what appears to be predictable channels is also interesting.
Looks like they have more than 300 000 images on the raw site: https://mars.nasa.gov/msl/multimedia/raw-images/?order=sol+d...
N00b question: why is it black & white?
Other posters have pointed out that it's the hazard avoidance camera, but they haven't said why the hazard avoidance camera is black and white.
When you do computer vision, the first step you do is convert your color image into a black and white image, and run your CV algorithms on the black and white image. This is because when you're looking at objects and shapes and stuff, it's contrast that tells you where the boundaries between things are. This is true even in a human world of human objects, which tend to be many colored. It's even more true on Mars where basically everything is varying shades of orange. So having color doesn't help a whole lot, and you also have to do the additional step of converting the color image to black and white, which takes CPU power and adds latency. Remember, the purpose is hazard avoidance- latency is bad.
Additionally, color camera sensors aren't actually color sensors. They're black and white sensors. In front of every pixel on the black and white sensor is a filter that is either red, green, or blue. Pixels are grouped into sets of four, and there are two pixels with green filters, one pixel with a blue filter, and one filter with a red filter. (sometimes one of the green filters is omitted, giving red, green, blue, and b&w, or sometimes one of the green filters is a filter that allows IR, or something like that.) So if you have a 16MP camera, the camera has 8M green, 4M red, and 4M blue pixels. This means two things; first of all, if you just wanted a black and white image in the first place, a color sensor gives less detail than the equivalent black and white sensor, and second, you need to do additional processing to convert the raw output from the sensor into an image that's usable for anything. The additional processing adds latency.
Just as a heads up, the HazCams on Perseverance are in fact in color (Source: https://link.springer.com/article/10.1007/s11214-020-00765-9 - "The Mars 2020 Navcams and Hazcams offer three primary improvements over MER and MSL. The first improvement is an upgrade to a detector with 3-channel, red/green/blue (RGB) color capability that will enable better contextual imaging capabilities than the previous engineering cameras, which only had a black/white capability.") Your observations are correct though - the stereo precision is important, so there was additional analysis of the stereo depth computation to make sure it wouldn't cause an issue.
Thank you for the explanation. That was highly interesting. Does anyone else know if the human eye does perceive color directly? Is this at all technically possible? And if yes, why aren't we doing it with cameras?
The world is a complicated place, Hobbes.[1]
The lower "HazCams" hazard avoidance cameras (which captured those initial photos) are there to detect hazards (rocks, trenches, etc.). They are stereoscopic, lightweight, and high resolution.
My guess is that using color sensors would have either increased the 3D mapping precision or added weight/power/bandwidth requirements, or otherwise been less robust in that environment.
Those cameras were also pre-deployed for the landing phase and likely transmit more quickly due to the lower data information. The other cameras were shielded for the landing phase.
The navigation and other cameras are in color, and I expect we'll be seeing better images shortly.
[1] This comes to mind whenever a question like that is asked: http://4.bp.blogspot.com/-CWM1zDcmWXs/TroD0VsX4WI/AAAAAAAAAV...
> My guess is that using color sensors would have either increased the 3D mapping precision or added weight/power/bandwidth requirements, or otherwise been less robust in that environment.
I think you meant to say decreased? In which case I think you would be correct! Camera pixels are made up of these things called photosites which don't by themselves record color, only brightness. In order to record color information, the photosites are placed behind a Bayer filter[1], which effectively reduces the resolution of the camera by 3, because in order to get the color of a pixel you need its red, green and blue component. Bayer filters also frequently have a small blurring filter in front of them to make sure that nearby photosites with different color filters get the information they need.
If you're looking for the highest resolution image possible, black and white is the way to go!
FYI - the HazCams on Perseverance are in fact in color (this is new, they were black and white on Curiosity)! Stereo precision was a concern based on the switch to color sensors, so there was some algorithmic work done to make sure it wouldn't cause an issue. (Source: https://link.springer.com/article/10.1007/s11214-020-00765-9 - "The Mars 2020 Navcams and Hazcams offer three primary improvements over MER and MSL. The first improvement is an upgrade to a detector with 3-channel, red/green/blue (RGB) color capability that will enable better contextual imaging capabilities than the previous engineering cameras, which only had a black/white capability.")
And by "increased" I meant the "decreased" kind...
Just an enthusiast, no real answers, but here's a guess:
These are hazard cameras, designed to be inputs into the guidance algorithms on board. It might make sense for such a camera to be B/W to reduce on board processing required. There's also a glass cover on them, and a lot of dust from the landing, so that may be obscuring true color if the cameras do in fact take color images.
Also they may have just transmitted a lower quality B/W image to get something back to Earth quickly, since higher res images take longer to uplink.
It's from a hazard camera, which is not used for main photography. Better images will come soon.
Worth noting that these first pictures are sent in the first seconds after touchdown, you can even still see the dust in the air from the landing (even if it was craned down to reduce dust). It also explains the very low resolution in general, they want to get confirmation ASAP, no time for high quality high resolution images.
The shadow features are fantastic!
Greetings from Jezero Crater! Really doesn't look alien. RLike the high mesa of New Mexico sans flora ;)
Watching the live feed was a blast. When they said they received the exact landing coordinates I was extremely curious to see it plotted vs their targeted landing zone, but unfortunately they haven't shown it yet. However, I could audibly hear an engineer in the background say "Oof, well, we'll take it!"
Anyone seen anything about the precise location yet?
https://twitter.com/jccwrt/status/1362514739671298051
> UNOFFICIAL but it looks like Percy landed right on the edge of the Mafic Floor Unit, with older (probably sedimentary) rocks that were buried by it only a short drive away.
In one of the previous threads about Mars missions, one of the comments was how we have gotten to the ability of "land it close enough, and we'll drive the rest of the way". Seems pretty accurate for this mission.
Seeing the engineers and scientists celebrating the successful landing was one the best things I've seen in a LONG while. Very live affirming and inspiring to me!
Is part of the joy that they now have secure jobs for years to come?
I think it's mostly the joy that their past decade or two of work wasn't wasted.
Most common assumption by outsiders is that they're happy that their many years of effort came to fruition, but I think a big part of is that they will be working on this mission for the foreseeable future as you point out. They get to tell their kids I worked on this mission, it was successful and then we made the rover do X, Y and Z in the next few years.
Maybe but for me I think it would the joy of completing such a massive task so well. They literally just achieved something that no one else in history has.
It is the fifth rover... But still super impressive feat, with years of detailed planning. I boogles my mind thinking about all the bits of engineering put together to make this happen.
I canât wait to see what it sends back. Always celebrate your successes.
I wouldn't be surprised if a lot of the engineers who worked on EDL move on to other projects in the coming weeks
Clean feed here - https://www.youtube.com/watch?v=kPrbJ63qUc4
EDIT: Congrats to the team! Great success
Reading you 5 by 5. Thank you.
Shout out to the team member with the "This is fine" plush dog on their desk.
The dog is a fine addition to any meeting.
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