Perseverance Rover To Land On Mars
NASA’s Mars Perseverance rover is scheduled to land on Mars shortly before 4 p.m. Eastern Time today. Back in July the rover blasted off from Cape Canaveral, Florida, atop a rocket. This morning, WAMC's Jim Levulis spoke with Kirsten Siebach, a professor at Rice University and a participating scientist on the Mars 2020 mission, about today’s landing and what the rover is meant to do once on the red plant.
Siebach: Perseverance Mars 2020 mission has been in cruise stage to Mars for the past seven months. It'll drop out of the cruise stage and then as it hits the top of the Martian atmosphere, there's a lot of friction from hitting that atmosphere. And so Perseverance will have a heat shield around it. And that'll look like a meteor streaking through the sky of Mars. And that'll slow it down some, but still going to be moving above the speed of sound, it starts out at over 12,000 miles per hour. And so it's still moving really fast when it deploys a parachute, we call it a supersonic parachute, because it actually deploys at greater than the speed of sound. It’s a very large parachute, and that'll help slow it down further, it'll be able to get rid of the heat shield that's been protecting it from that strong blast of heat, and lower on the parachute. Now the parachute helps. But again, the Mars atmosphere is just not thick enough to slow it down entirely. And so eventually, once it's closer to the ground, it'll drop away from the parachute. And at that point, basically, some jet packs will come on, it's got what we call a sky crane, it's got these little backpacks, and so it'll be a flying object there with jetpacks extending, and it will actually drop the Perseverance rover down on a tether. So Perseverance will be dangling below this sky crane was jetpacks, which will then go and lower Perseverance to the surface, and the tethers will break and the sky crane will go crash elsewhere on Mars and Perseverance will just have appeared on one spot on the surface.
Levulis: And if I understand it correctly, there will actually be a delay in terms of how the landing goes and those at NASA knowing what occurred.
Siebach: Yeah, so it takes about seven minutes to get from the top of the atmosphere that 12,000 some miles per hour to sitting on the ground. And the time delay for just the speed of light is to tell us what's happening on Mars is about 11 and a half minutes today. So that means we're hearing everything 11 and a half minutes after it's happened. And it only takes seven minutes to happen. So when we hear that Perseverance hits the top of the atmosphere, in fact, Perseverance will be on the ground in some condition. And we'll just be following along a few minutes after.
Levulis: And with that time difference there, if something goes wrong during the landing, are there options for aborting and trying again?
Siebach: There's nothing we can do from Earth to change anything that happens between when Perseverance hits the top of the atmosphere and is on the ground. Now we've preprogrammed a lot into the different components of the landing. And so one of the real boosts for this mission, one of the big improvements, and one of the things that made us able to land in a relatively challenging geological location is this new computer that we added to the sky crane to the part with the jetpacks at the end of the landing. And it's actually got pre-loaded images of what the surface looks like. So while it's flying to land Perseverance, it will be scanning the surface, and comparing that to the images that we already have of the surface that it's got loaded onboard. And some it’ll use those to avoid hazards and find the safest spot to land. So hopefully we've programmed enough of these safety checks onto the rover, it can do them without us.
Levulis: Wow. So you know a lot of folks see those simulations that NASA puts out and in a sense, this program, this mission is simulated.
Siebach: What we'll see today, most of us will be watching those simulated landings, we've constructed it that way. But we will have a lot of cameras, that we will in the end have video of landing and one new thing with this mission is that we'll also have audio of that landing sequence which I am really looking forward to hearing. And we'll hear that supersonic parachute deploy, we'll hear kind of the crunch as the rover wheels hit the surface and so those will come back a little bit later. It takes a little while before we will have the data capacity to send all of that information back. But eventually we'll have videos of the landing.
Levulis: And to the audio part, since this is a radio interview I'm particularly interested in that. Once the rover lands on Mars and is collecting data, what are we expected to hear?
Siebach: So we will probably hear a lot of the Mars wind. Mars has a very thin atmosphere but partially because of huge temperature changes between night and day that atmosphere is frequently moving around and so we'll probably hear the Mars wind. And otherwise, it'll probably be the mechanical parts of the rover. One of the instruments on the rover is a laser that can zap rocks up to maybe 20 feet away and zap them into a plasma. And so, you know, we may hear some version of those lasers zapping rocks and different mechanical parts onboard.
Levulis: This is incredible. And Perseverance we'll be collecting rock and soil samples over the course of the two Earth years it's expected to be on Mars, looking for some form of life. So how might this mission set the stage for human missions to Mars?
Siebach: We will be collecting some important data that will tell us about what the surface is like. But in addition to that, we have an instrument on board called Moxie. And that will actually be converting the carbon dioxide atmosphere of Mars into oxygen. And that's just really important to show we can do on Mars before we send humans. They'll really need that oxygen, both for breathing and for creating their fuel for their return journey.
Levulis: We talked about the video delay, but how can people watch the landing and follow the mission?
Siebach: Yes, please, people follow along. It's actually so much fun on any given day, you can see something that we've never seen before on Mars. You can follow along with this mission and the others at mars.nasa.gov and for today, you can follow on NASA TV, YouTube Live. We're streaming the landing on as many different sources as possible. So please follow along. It's also in Spanish language.