NASA, Mars 2020, Nuclear power, Nuclear thermal rocket, Nuclear propulsion Curiosity's Trek Across Mars
Now known as perseverance. Now i was lucky enough to actually visit jpl twice and get to see uh, you know, perseverance getting built in the clean room. Obviously it was on the other side of a sheet of glass, but it was really cool to see this piece of piece of hardware. Getting ready to go to mars in many ways: it’s identical to mars science, laboratory, better known as curiosity, which landed back in 2012, using the sky crane system, the sky crane is something that seemed a little crazy at first, we would probably use the word kerbal, except That back in 2012, kerbal space program was only a year old and it hadn’t quite infected the psyche of everyone that was into space stuff. The reasoning behind this design is that you can’t build a parachute that is big enough to softly land, a vehicle of this size and mass. So you need rockets, but rockets kick up a lot of dirt, so the sky crane allows the vehicle to be set down carefully detached and the sky crane can then fly away to its well to its doom really and one of the things i’m most looking forward To is the fact that this process will be documented by a multitude of cameras and microphones, and so i actually want to go back to curiosity. This is the image sequence captured by the mars descent imager. It was a simple color. Camera you’ll see that i’ve corrected the shape of the frame to account for lens curvature.
It was dumping, jpeg images into an eight gigabyte buffer, so it could take just enough images to get through the landing. It would take images five times per second and it can compress those in real time it couldn’t take video, it couldn’t get audio, but this was amazing to see this back in 2012. It was the first time we’d really seen an automated spacecraft in somewhat real time. Performing a landing on mars, i say real time. These images came down days later, but when they were assembled, it was really exciting. So, to just put some orientation on this to the right here is north to the left is the center of gale crater that black area is sand dunes and the thing about gale crater is? It was probably filled with water and it contains lots of sedimentary features and you can see channels and shorelines now, we’re falling onto the parachute and about 1800 meters. Up from the surface, the parachute uh of the spacecraft will drop out and now it’s under rocket thrust, and you can actually see the vehicle banking to the the left and now it’s banking. Over and looking out to the right. This is just uh, basically nulling out its horizontal velocity, picking a landing site, and now we start to get close to the surface it’s slowing down and it will start deploying the vehicle so it’s, now less than 100 feet above the surface, less than 30 meters.
There come the wheels it’s now being lowered down towards the surface. You can’t see much because of the debris getting thrown up, but this is a lot less debris than would be thrown up if the rockets were attached to the vehicle itself and that’s good, because you don’t want stuff blowing about it would make uh. You know it would cause potentially cause damage to the rover and now it’s on the surface, that camera can still be used to look at stuff directly under the vehicle. Now i actually discovered something pretty cool while trying to clean this thing up and see this heat shield, this heat shield, you can actually follow all the way down. Now it obviously fades off into the distance and gets you very small, but it’s still very reflective, and it stands out, especially against the dark background of those dunes or when the angle is right and it catches the the light. This is the last time that i honestly say that i can see the heat shield uh it’s, just between those two creators. It catches the light for a few frames and you can see the pixels are just slightly brighter from there it’s only a few seconds before the thing actually hits the ground and we do actually see the impact there’s, a big black splash that appears, and unfortunately it Then moves out of frame, so we don’t get to see anything more after that. But actually, if you just ping pong the frames near the landing, then you actually can see the shadow coming up from the bottom, like from the seven o’clock mark and going in and out there’s black spots, where the shadow of the heat shield is just before it Hits it probably has zero scientific value knowing this, but i thought it was cool, they have the mars reconnaissance orbiter and it was able to take images off the site the next day, showing the landing site of the spacecraft.
The heat shield, the parachute, the aeroshell, the sky, crane, all that stuff was scattered out over the area over a few kilometers and during the landing they actually slewed the camera on the reconnaissance orbiter over to higher. You know higher angles so that they could actually catch the landing live and they they picked out the parachute the vehicle aren’t falling under the parachute. Now, of course, the mars reconnaissance orbiter takes a lot. You know strips of data, so this is part of a much larger image. There is the thing under the parachute there, but yeah. If you down here, this is actually where the landing occurred. So the camera is kind of looking down it’s, roughly 45 degree angle. It says 42 degrees, but the point is that it’s coming down at an angle, therefore, you can actually estimate that this is about two and a half kilometers up based upon the landing site being roughly here, stepping back a bit or stepping up a bit. This is what the crater uh gale crater looks like from orbit, and the curiosity landed in the top left region here, that’s the to the northwest uh. You can see the big long black sand dune area there zooming in a bit more. You can see the channel right in the top left the channel that flows in from the north and beyond that channel. You get an outflow area, a relatively flat area and on the left side of this dune area, you come to see a sort of gap where they plan to cross it onto mount sharp okay.
So here we have a 3d model based upon satellite data from the mars reconnaissance orbiter, and this shows the same landing site and you can see a lot of the same features that we saw. I mean, obviously you see that dune area, you can see these shorelines and actually, if you slide this way, you can see uh. This is obviously me sliding towards the north. This is a channel that flowed into gale crater. It forms this alluvial flan, so the landing site is roughly about here and one thing you couldn’t really tell from those cameras. Looking straight down was that there’s actually a lot of relief in the terrain. If you look and i pan downwards, you can actually see that to the south on the other side of this uh. These sand dunes is quite a substantial mountain. This is about five kilometers tall fifteen thousand feet, and this is where curiosity has been going for the last eight years or so slowly, making its way around these dunes uh. It basically headed down this way through this area. Here it had made a number of diversions and it’s going around this and going to be climbing up here and eventually hoping to head up here into that mountain and, as it goes up, the side of this mountain you’ve got to realize that this is geology. That’S been laid down by sediment so, as you go up, you’re going to younger and younger terrain features so you’re getting a sort of a geological history of mars and that’s very good because it can help you reconstruct the geological history of this planet, and this is What curiosity sees of mount sharp so it’s a large mound in the middle of gale crater? It was formed during the impact when you have a large enough of energy large enough scales.
The ground actually behaves like a liquid and it rebounds a little during the crater forming process, and that is what stood for billions of years and so there’s. All this geology up the side of the mountain that we want to investigate, but to get there they had to take a bit of a circuitous route. They had to initially go to the south west around all that black sand, so they could then turn and cut through a gap into the actual mountainous region. Now, of course, translating maps and images to an idea of what the uh you know mars is like is hard, which is why i find it great that there’s a few sites that nasa has gone and essentially constructed 3d environments, for this is um. This is dingle gap, yes, it’s named after an australian site there you go and it’s located where a bunch of sand dunes are so yeah. This is all running like literally running in my browser, so i’m, just dragging this around and lets me view various things what’s. You know if you want to figure out say what this looks like you just click on it puts a flag in it and you can actually see where that corresponds to in the various navigation cameras. They have a bunch of different sites in here, it’s, not a huge number. I guess it takes a lot of time to do all the photogrammetry. This is a standing looking at this very interesting wall.
Here and again, you can just click on it and find the various parts. This is the kimberly. These are all north office. So if you look uh sorry, if you look at the various points, this is still north of the sand dunes. If i zoom out and over there is the sand dunes still getting in our way, but again click and you shall see the various images by 2018. They were had crossed the dunes and were starting to climb the mountain and one of the first things they did was when they found a ridge. They turned around and took a complete panorama which showed where they had been all the places they had analyzed all the sites they had drilled, photographed and subject to you all the instruments that mars science laboratory brought with them and after seeing their opportunity, they found a Way to pick their way across the dunes being always mindful of how spirit ended up stuck in a sand trap before, ultimately, failing, of course, while crossing you’ve got some amazing photos of these sand dunes, like the patterns, there are pretty darn unreal, really glad that they Actually include the scaling on here i mean this is what happens when you leave sand to get blown around and have all the dynamics work on it’s black basalt based sand, um, which there may have been a whole lot more of this in the past? But even then you get these big uh dunes that are migrating across the bottom of the crater.
Now, obviously, curiosity has been sciencing the heck out of everywhere, as it traverses this landscape, and this image shows us all the sites that they took drill samples from – and one thing i want you to notice – is that the names are all sort of appropriate to each Other so as they move down, the themes are changing and right down the bottom. Those last two rows are all once they cross the dunes onto mount sharp. Those are all places in scotland, so they have basically decided once they crossed on to mount sharp. That is scotland and they’ve been there for the last thousand days, they’re now crossing into a new region which is going to have a french theme and so for climbing mount sharp they’re moving through a region right now, which is called the clay unit that’s, because it Has spectra that implies there were clay minerals here very interesting if you’re, of course, looking for ancient water they’re going to have to go up through this channel, that has been cut down the side of the mountain through the sulphate unit. Again, the evidence from orbit points to high sulfate levels in these rocks um, but yet this is a channel that has been cut through it by a water flow from higher up mount sharp down the side, and so this is great, because not only is it an Easier path, but it also has cut down through the layers giving access to geology which they might not be visible in other locations.
So as of right now, this is the most recent panorama that’s come down. This is from january and it’s still in the scottish region, but they’re now moving headed into the french region of mars, but um the vehicle is powered by a radioisotope thermoelectric generator. Its lifetime is limited. The plutonium that powers that has a half life of like 80 odd years and as this power decays they’re, going to have to start taking steps to reduce the power usage. It’S it’s, not just the rtg, because that charges, batteries and the batteries also degrade over time. So they have to take all this into account, but most likely this thing is going to have a limited life and it’s really a question of how far up it gets mount sharp before it has to take its leave.