Mars Perseverance Rover: Countdown to Impact | JPL Mars Helicopter

Here’s a sanitized version of the provided YouTube transcript:

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[Music] After traveling nearly 300 million miles at warp speed, NASA’s Perseverance spacecraft is closing in on its target: Mars. If all goes well, this roving space lab and the first-ever Martian helicopter will touch down on the red planet on February 18th, but not before facing the riskiest part of the mission.

[Music] A fiery entry, a harrowing high-wire act landing, and seven long minutes of silence. The rover will have landed, or it will have crashed, and we will not know until that signal gets back. One way or another, you’re going to be on the ground in seven minutes in search of signs that life once existed here long ago. Are we alone? I don’t think so. If we find ancient life on Mars, it really changes everything.

Perseverance countdown to impact: the desert plains of Isidis Planitia, thousands of square miles of sand, rocks, and whispering wind. The memory of a vast lake haunts this region, brooding in undisturbed silence for millions of years.

Four engine ignition, two, one, zero. The Perseverance rover began its journey seven months ago when it was launched atop an Atlas V rocket on July 30th, 2020, bound for Mars. The Atlas V is now supersonic. Making the launch window was fortuitous; we always launch at the optimal time when Earth and Mars are positioned just right to make that journey as short as possible. Earth and Mars’ orbits are elliptical and rarely align. Earth is closer to the sun, and Mars takes nearly two Earth years to make a full circuit. Astronomers call the moment of closest approach between the two planets “opposition.” This is the time to jump from one planet to the next. These launch windows happen once every two years. We’re seizing the opportunity with Perseverance, and it’s going to be a seven-month trip to Mars.

[Music] Perseverance is not the first rover to explore Mars. There have been four previous missions that have sent back amazing data and imagery to Earth. Everybody knows the story of how we landed on the moon and the first steps on the moon, but a lot of people don’t understand that there were robotic precursors to those Apollo missions, and they were very critical in paving the way for taking technologies to Mars and improving those technologies that are important for future human exploration.

The Pathfinder mission is the first; it lands in a cocoon of airbags in 1997. Its rover, Sojourner, is named after civil rights abolitionist Sojourner Truth. Its primary mission is to prove we can send robotic explorers to Mars safely. This first rover mission lasts 83 days. Twin rovers Spirit and Opportunity are next; these robotic geologists make a startling discovery: minerals that form only in the presence of water. The news headline captures the world’s attention: Mars was once a water planet like Earth. Curiosity, the largest rover, lands on Mars in 2012 and is still exploring Gale’s Crater, searching for evidence of microbial life.

Mars today is a cold, dry desert world. It’s a stark, windswept landscape of dust, sand, and spectacular rock formations. But if we look back in the past, Mars was once warmer, wetter, and even had lakes and rivers like we would recognize on the surface of Earth today. The key ingredients for the recipe of life are water, sunlight, and certain organic compounds like carbon, hydrogen, and nitrogen. The revelation about Mars and water gives new credibility to age-old questions. Before Spirit and Opportunity, the mantra was “follow the water,” and now we’ve been able to move beyond that. Now, instead of just following the water, we’re trying to understand what the chemistry of the water was. Was that water something that could have given rise to life? Why did the environment change so much on Mars that we once had liquid water and we don’t anymore? Perseverance may just help answer these questions.

As long as the carefully chosen landing site hosted water long ago, we have picked the landing site to be on the western edge of the Isidis Planitia impact basin, and we’re going right here to a place called Jezero Crater, which once, when Mars was warmer and wetter, hosted a lake—an environment very different from what we’re going to see when we land today. This ancient lake bed is the same size as Lake Tahoe in California. It’s an excellent place to look for possible Martian life because we already know that Jezero has rocks and minerals that could only form in water. The Jezero Crater site, if you look at it from space, is pretty obviously a delta. We think that Mars was habitable about four billion years ago, so the question is not just where was that life on Mars, but also where could it be preserved for four more billion years for us to find it later on Earth? Lakes are filled with living creatures; evidence of that life is preserved in the mud and sand deposited on the bottom of the lake. Could the same be true for Mars? The rover’s instruments will closely examine the ancient rocks of the bygone lake.

The dress rehearsal: a dry lake bed in Death Valley and geologic study in Australia—places that share an uncanny similarity to Martian geologic history. One of the most exciting things about the rocks that we’ll be exploring on Mars is that they date back to a period where we have the first evidence of fossil life on Earth, so about 3.5 billion years ago. These are exactly the age of the rocks that we’ll have accessible to us in Jezero. This is where the science team examines geology and tests their instruments. This rock is sandstone, not unlike a rock that we might actually find in Jezero Crater. We would be interested in sampling a rock like this to understand what each individual sand grain has to tell us about Mars and its evolution.

But first, the rover must get there safely. When Perseverance makes its final approach for landing, the most dangerous part of the mission begins: Entry, Descent, and Landing (EDL). One of the most exciting parts of getting to Mars is the landing sequence. It’s been said that the Mars atmosphere is too thin to be useful but too thick to ignore, meaning it heats the spacecraft up by friction but doesn’t slow it down. This is when the spacecraft and its protective aeroshell will attempt to enter the Martian atmosphere and perform a groundbreaking high-wire act landing. Entry, descent, and landing is all about getting the vehicle from the top of the atmosphere down to the bottom safely.

So we hit the atmosphere going about 12,000 to 13,000 miles per hour. Hit the atmosphere too shallow, and the vehicle skips off into space like a stone skipping over water. Hit the atmosphere too steep, and it burns up like a meteor. Friction from the air burns the heat shield with temperatures reaching 3,800 degrees Fahrenheit. So it’s heating up, heating up, heating up, and finally gets to a portion of the atmosphere where the atmosphere actually acts to slow down that spacecraft. That’s when the parachute deploys. It’s also one of the riskier parts of the mission; you don’t want that parachute to tear.

Then what happens is the radar starts to see where we are relative to the ground. The rover and its descent stage detach from the parachute. The descent stage is called a sky crane; it takes over the landing and fires its engines as it descends under its parachute. The rover takes pictures of the ground; its onboard computer rapidly compares the images with pictures stored in its database. This computer lines up features it sees in the new photos with features it sees from the cataloged photos. If the rover is descending toward dangerous ground, it can change direction and move toward a safer place to land. It slows, hovers, and then lowers the rover on the edge of this tether. When contact is sensed with the ground, the tether is cut, the descent stage flies away, and the rover falls what should be no more than a meter to hit the surface but gently.

For a few minutes, the spacecraft will not be able to communicate with Earth, but we’re going to have that period where it will have happened on Mars. The rover will have landed, or it will have crashed, and we will not know until that signal gets back. Those minutes of blackout are some of the most heart-pounding moments as you wait to see what happened with the spacecraft. For the science and engineering team, comprised of hundreds of people, over a decade of work comes down to seven nail-biting minutes. A lot of things have to go right in a space mission to get your spacecraft to Mars. One way or another, you’re going to be on the ground in seven minutes. All we can do is cross our fingers, hope for the best, and cheer on the crew that’s making the launch happen.

Perseverance is armed with a battery of seven instruments and 23 cameras that address questions about life in the past, present, and future. With two microphones on board, we will actually hear the first true sounds of Mars.

[Music] For the first time, we’re going to have that human sense on another planet. We never really heard our environment on Mars, and I think it’s going to be exciting to hear the entry, descent, and landing, the wheels turning on the surface of Mars. The rover will identify chemical elements in the Martian soil, as well as organics and minerals that may be signs of past microbial life. The latest in camera technology can capture features as small as a grain of salt. The Mars 2020 instruments are really well-suited to look for things that we call biosignatures, which are signs that ancient life might have been there in the past. If something ever lived here, Perseverance can find evidence of it. You can’t prove it until you actually can get down and get your nose in the dirt.

A drill shares the turret with the scientific instruments; the drill bores holes and extracts core samples. This is the system that allows us to take core samples of rocky material on the surface of Mars, carefully seal them in very sterile clean vessels for eventual return to Earth. Once the sample is collected, Perseverance stores the sample in a revolving chamber located inside the rover. This chamber is called the sample cache, and it has storage for 47 empty tubes. Here, the samples are hermetically sealed; no contaminants from the rover will ever enter the tubes, and nothing can escape them. In a mission first, these collection tubes will be the cleanest ever sent into space to ensure whatever microbes come back are Martian and not from Earth. The last thing NASA scientists want to do is contaminate Mars. At some point in the future, a site will be chosen where the sample cache will be deposited. This will become a depot. Perseverance will spend the rest of its mission bringing sample tubes to the depot. A future mission will collect the cache and bring the samples back to Earth. This makes Perseverance part one of a sample return mission.

I think we have a lot to learn, life or no life, about the evolution of our solar system and our planet by looking in depth at rocks brought back from Mars.

[Applause]

[Music] The array of cameras on Perseverance serves a multitude of purposes. The Mastcam-Z instrument consists of two fixed-focus but zoomable cameras that are mounted on either side of the rover’s mast, so they let us get a stereo view of the landscape, just as our eyes do. The Mastcam-Z is used for long-distance driving and infrared science, and the Navcams are used for autonomous navigation. Temperatures are well within our limits, so we’re ready to go. We’re going to come up and do Mastcam-Z. The cameras work the same way as human eyes, giving us a stereoscopic view of the landscape. Mastcam-Z is effectively our eyes on Mars in terms of reconnaissance and assessing what the terrain is doing. The Mastcam-Z is used to choose targets for a closer look and to get a sense of the terrain surrounding the rover.

What’s special, though, about the Mastcam cameras, in addition to imaging in visible light, is that they image out into the near-infrared wavelength ranges, and this near-infrared lets us get a compositional picture of when chemistry and mineralogy are changing in the rocks. The rover’s extensive camera package is not the only eyes on the mission. Probably the most exciting experiment of all is Perseverance’s companion, dubbed Ingenuity, the first-ever Martian helicopter. Within 30 days of landing, the rover will deploy an experimental new craft. What we’re then hoping to do is a series of flight tests—first maybe just up and hover, then maybe up a meter, then maybe up and up to a couple of tens of meters away. The helicopter has a camera, has two rotors, and we’re hoping to prove out this new technology that we can fly other spacecraft on Mars, collecting pictures from above.

From day one, this was the unwavering dream of our team: to get our helicopter launched to Mars so that we can get the opportunity to do the very first rotor-powered flight test in the actual environment of Mars. There are unusual challenges to powered flight on Mars; the air on Mars is indescribably thin—just one percent of the thickness of the atmosphere here on Earth—and Mars has a much lower gravity—just one-third that of Earth’s—meaning less lift is needed. So the first and foremost challenge is to make a vehicle that’s light enough to be lifted, and then the second is to generate lift. The rotor system has to spin very fast. You’ll also see that the blades themselves are much longer, and their configuration is different, and that’s because to take advantage of the minimal amount of lift that’s provided through Mars’ atmosphere, you have to have a much larger blade size for any given payload than you do on Earth.

Our experiment window is 30 Martian days, so we have planned up to five flights of incremental difficulty. Most of our flights will be at three to five meters height. We will be going horizontally again at a few meters per second, so our priority will be to get back engineering telemetry and not so much images, but I’m sure we’ll return a few because they’ll always look cool. But there’s one more challenge: with no human assistance and a lag in communication, Ingenuity will have to fly on its own autonomously. Ingenuity is going to scout ahead of the rover, hopefully demonstrating powered flight on another planet, which would be awesome and cool and open up a whole new suite of reconnaissance.

[Music] The rover not only sees like a human; it’s designed to test new tools for future human exploration. Mounted on the body of the rover is the Mars Oxygen In-Situ Resource Utilization Experiment, also known as MOXIE. MOXIE will synthesize oxygen out of the Martian atmosphere to create a gas that would be breathable by future humans on the surface. MOXIE is a demonstration of this technology. The Martian atmosphere is about 96% carbon dioxide. MOXIE is a test to see if we can process Martian air to make liquid oxygen for rocket fuel and for breathing. The idea comes from an exploration strategy of living off the land. If we make some of our supplies in situ rather than bringing everything from Earth, then we can reduce the cost of a human mission to Mars, paving the way for future missions.

But MOXIE’s not the last engineering test Perseverance has in store. The rover has a weather station that will keep track of wind, humidity, dust levels, and temperature. By studying the ways dust and water ice interact with solar radiation, this weather station analyzes conditions on the ground that help predict the weather on Mars. Perseverance also has sample fabric swatches mounted on one of its instruments—a critical test to see which fabrics hold up in the harsh Martian environment so that NASA can develop the safest spacesuits for future human explorers. Thanks to Perseverance, future explorers will wear the outfit best suited for prevailing weather conditions.

In spite of the pandemic, the challenges of getting to Mars, communicating with Earth, and flying in Martian air gives a whole new meaning to “perseverance.” You couldn’t name this mission any better. Since we’ve had to deal with the pandemic, when it hit, it was kind of like walking into a dark blind alley; you just didn’t know what was out in front of you. It took some faith to go forward and a determination to deal with whatever came your way, and I think that’s the definition of perseverance, right?

[Music] Mars beckons us, knowing that in the deep past, Mars may have once been an Earth-like world. If we find ancient life on Mars, it really changes everything. We have suddenly learned that the universe does not just have one planet with life, but that it had two. That’s tremendous. What are the implications of that? Did life on Mars somehow come from Earth, or is it an independent second genesis of life? Are we alone? I don’t think so—probably not. There are a lot of stars and planets out there, but finding life on Mars would be one of the first steps in that direction to really understanding how much life is out there in our universe. With Ingenuity and Perseverance, we may soon unlock the secrets of the red planet and a glimpse into our future.

[Music]

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