The Mars 2020 Perseverance Rover will search for signs of ancient microbial life, which will advance NASA's quest to explore the past habitability of Mars.
Perseverance's PIXL at Work on Mars (Illustration) (2020)NASA
The rover has a drill to collect core samples of Martian rock and soil, then store them in sealed tubes for pickup by a future mission that would ferry them back to Earth for detailed analysis. Perseverance will also test technologies to help pave the way for future human exploration of Mars.
Mission Overview: NASA's Perseverance Mars Rover (2020)NASA
Searching for Ancient Life, Gathering Rocks and Soil
There are several ways that the mission helps pave the way for future human expeditions to Mars and demonstrates technologies that may be used in those endeavors. These include testing a method for producing oxygen from the Martian atmosphere, identifying other resources (such as subsurface water), improving landing techniques, and characterizing weather, dust, and other potential environmental conditions that could affect future astronauts living and working on Mars.
There are seven primary phases to the mission:
- Pre-launch Activities
- Entry, Descent, and Landing
- Instrument Checks and First Drive
- Surface Operations
In a clean room at NASA's Jet Propulsion Laboratory in Southern California, engineers observed the first driving test for NASA's Mars 2020 Perseverance rover on Dec. 17, 2019 (2019)NASA
The Perseverance rover is now on its way to Mars. It launched on July 30, 2020, at 4:50 a.m. PDT (7:50 a.m. EDT).
Perseverance launched on an Atlas V-541 rocket from Launch Complex 41 at Cape Canaveral Air Force Station, Florida. The Atlas V is one of the largest rockets available for interplanetary flight. This is the same type of rocket that launched the InSight and Curiosity to Mars. The launch vehicle was provided by United Launch Alliance, Centennial Colorado.
The cruise phase begins after the spacecraft separates from the rocket, soon after launch. The spacecraft departs Earth at a speed of about 24,600 mph (about 39,600 kph). The trip to Mars will take about seven months and about 300 million miles (480 million kilometers). During that journey, engineers have several opportunities to adjust the spacecraft’s flight path, to make sure its speed and direction are best for arrival at Jezero Crater on Mars. The first tweak to the spacecraft’s flight path happens about 15 days after launch.
The final 45 days leading up to the landing make up the approach phase. This phase primarily involves navigation activities and getting the spacecraft ready for Entry, Descent and Landing. This is when the final three trajectory correction maneuvers may be performed, if needed.
Entry, Descent, and Landing (EDL)
EDL is the shortest and most intense phase of the Mars 2020 mission. It begins when the spacecraft reaches the top of the Martian atmosphere, travelling nearly 12,500 miles per hour (20,000 kilometers per hour). It ends about seven minutes later, with Perseverance stationary on the Martian surface. To safely go from those speeds down to zero, in that short amount of time, while hitting a narrow target on the surface, requires “slamming on the brakes” in a very careful, creative and challenging way.
Landing on Mars is hard. Only about 40 percent of the missions ever sent to Mars – by any space agency - have been successful. Hundreds of things have to go just right during this nail-biting drop. What’s more, Perseverance has to handle everything by itself. During the landing, it takes more than 11 minutes to get a radio signal back from Mars, so by the time the mission team hears that the spacecraft has entered the atmosphere, in reality, the rover is already on the ground. So, Perseverance is designed to complete the entire EDL process by itself – autonomously.
Ten minutes before entering the atmosphere, the spacecraft sheds its cruise stage, which houses solar panels, radios, and fuel tanks used during its flight to Mars. Only the protective aeroshell – with rover and descent stage inside – makes the trip to the surface. Before entering the atmosphere, the vehicle fires small thrusters on the backshell to reorient itself and make sure the heat shield is facing forward for what comes next.
As the spacecraft enters the Martian atmosphere, the drag produced drastically slows it down – but these forces also heat it up dramatically. Peak heating occurs about 80 seconds after atmospheric entry, when the temperature at the external surface of the heat shield reaches about 2,370 degrees Fahrenheit (about 1,300 degrees Celsius). Safe in the aeroshell, however, the rover gets up to only about room temperature.
As it begins to descend through the atmosphere, the spacecraft encounters pockets of air that are more or less dense, which can nudge it off course. To compensate, it fires small thrusters on its backshell that adjust its angle and direction of lift. This “guided entry” technique helps the spacecraft stay on the path to its downrange target.
The heat shield slows the spacecraft to under 1,000 miles per hour (1,600 kilometers per hour). At that point, it’s safe to deploy the supersonic parachute. To nail the timing of this critical event, Perseverance uses a new technology – Range Trigger – to calculate its distance to the landing target and open the parachute at the ideal time to hit its mark. The parachute, which is 70.5 feet (21.5 meters) in diameter, deploys about 240 seconds after entry, at an altitude of about 7 miles (11 kilometers) and a velocity of about 940 mph (1,512 kph).
Zeroing in on Landing
Twenty seconds after parachute deployment, the heat shield separates and drops away. The rover is exposed to the atmosphere of Mars for the first time, and key cameras and instruments can begin to lock onto the fast-approaching surface below. Its landing radar bounces signals off the surface to figure out its altitude. Meanwhile, another new EDL technology – Terrain-Relative Navigation – kicks in.
Using a special camera to quickly identify features on the surface, the rover compares these to an onboard map to determine exactly where it’s heading. Mission team members have mapped in advance the safest areas of the landing zone. If Perseverance can tell that it’s headed for more hazardous terrain, it picks the safest spot it can reach and gets ready for the next dramatic step.
In the thin Martian atmosphere, the parachute is only able to slow the vehicle to about 200 miles per hour (320 kilometers per hour). To get to its safe touchdown speed, Perseverance must cut itself free of the parachute, and ride the rest of the way down using rockets.
Directly above the rover, inside the backshell, is the rocket-powered descent stage. Think of it as a kind of jetpack with eight engines pointed down at the ground. Once it’s about 6,900 feet (2,100 meters) above the surface, the rover separates from the backshell, and fires up the descent stage engines.
As the descent stage levels out and slows to its final descent speed of about 1.7 miles per hour (2.7 kilometers per hour), it initiates the “skycrane” maneuver. With about 12 seconds before touchdown, at about 66 feet (20 meters) above the surface, the descent stage lowers the rover on a set of cables about 21 feet (6.4 meters) long. Meanwhile, the rover unstows its mobility system, locking its legs and wheels into landing position.
As soon as the rover senses that its wheels have touched the ground, it quickly cuts the cables connecting it to the descent stage. This frees the descent stage to fly off to make its own uncontrolled landing on the surface, a safe distance away from Perseverance.
Perseverance Rover's Entry, Descent and Landing Profile (2021)NASA
Landing at Jezero Crater
The rover’s new home is Jezero Crater, a large impact crater about 28 miles wide (45 kilometers wide) just north of the Martian equator. Jezero once contained a lake, which scientists think is one of the most ideal places to find evidence of ancient microbial life. If life exists anywhere else in our solar system, chances are, it might be at Jezero Crater.
Jezero Crater, Mars 2020's Landing Site (2019)NASA
The main question Perseverance is trying to answer is: Was there ever ancient life on Mars? To answer that question, the rover will collect and store the most compelling rock and soil samples for return to Earth by a future mission. Once on Earth, scientists can use a variety of sophisticated instruments, many of them too large and bulky to transport to Mars, to help answer this question.
Mars 2020 Landing Site: Jezero Crater FlyoverNASA
Surface Operations: What Happens After Landing?
The surface operations phase is the time when the Perseverance rover conducts its scientific studies on Mars. After landing safely (Feb. 18, 2021), the rover has a primary mission span of at least one Martian year (687 Earth days).
While exploring Mars during surface operations, Perseverance:
Finds rocks that formed in, or were altered by, environments that could have supported microbial life in Mars’ ancient past (Objective A)...
Mars 2020 Collecting Sample (Artist's Concept) (2020)NASA
Finds rocks capable of preserving chemical traces of ancient life (biosignatures), if any existed (Objective B)...
NASA's Mars 2020 Rover Artist's Concept #5 (2017-11-17) by NASA/JPL-CaltechNASA
Drills core samples from about 30 promising rock and “soil” (regolith) targets and caches them on the Martian surface (Objective C)...
NASA's Mars 2020 Rover Artist's Concept #1 (2017-05-23) by NASA/JPL-CaltechNASA
Tests the ability to produce oxygen from the carbon-dioxide Martian atmosphere, in support of future human missions (Objective D).
Crazy Engineering: Making Oxygen on Mars with MOXIENASA
All address key astrobiology questions related to the potential of Mars as a place for life. The first three consider the possibility of past microbial life. Even if Perseverance does not discover any signs of past life, it paves the way for human life on Mars someday.
First Humans on Mars (Artist's Concept) (2019)NASA
To learn more and get involved with the Mars Perseverance Mission, visit: go.nasa.gov/mars2020toolkit