Rover Nasa Mars: Key Questions About Perseverance

Thursday, NASA’s Perseverance rover successfully lands on Mars after a journey from Earth of almost seven months. Here we answer some common questions about the mission.

The Perseverance rover touched down on the Martian surface at 8:55 p.m. GMT (3:55 p.m. ET) on Thursday, February 18.

The robot is designed to look for signs of past microbial life, if it ever existed. This is the first NASA mission to directly hunt these “biosignatures” since the Viking missions in the 1970s.

The rover will collect rock and soil samples, enclose them in tubes, and leave them on the planet’s surface to be returned to Earth at a later date. Perseverance will also study the geology of the Red Planet and test how astronauts on future missions to Mars could produce oxygen from CO2 in the atmosphere. This oxygen could be used for respiration and rocket propellant.

In addition, a drone-type helicopter will be deployed to demonstrate the first powered flight to Mars. Perseverance will explore Jezero Crater, near the planet’s equator, for at least one Martian year (approximately 687 Earth days).

Perseverance launched on July 30, 2020 from Cape Canaveral, Florida. The one-ton, car-sized rover drove through the space enclosed in a protective shell made up of two parts: a tapered rear shell and a heat shield.

The aeroshell was connected to a cruise stage that fired thrusters to keep the spacecraft on track, ensuring it arrived on Mars at the right place for landing.

After traveling 470 million km from Earth, the spacecraft crisscrossed the Martian atmosphere. During this stage, its heat shield had to withstand temperatures as high as 2,100 ° C (3,800 ° F).

When about 11 km (7 mi) above the ground, the spacecraft deployed a parachute, slowing the heaviest payload in Mars exploration history to a speed of Mach 1 , 7 (2099 km / h; 1304 mph) to approximately 320 km / h (200 mph).

The heat shield then detached from the rear shell, and for a short time the rover – which was attached to a descent stage – fell freely to the ground.

Eight retrorockets on the descent stage then fired, making it possible to perform the “sky crane” maneuver. Perseverance was slowly lowered onto three nylon ropes and an “umbilical cord”. When the rover’s wheels touched the ground, the attachments were severed and the descent stage flew to a safe distance.

The rover’s landing site, Jezero Crater, is a 49 km (30 mi) wide impact depression just north of the equator of Mars. Over 3.5 billion years ago, scientists believe, river channels flowed over the Jezero Wall to form a lake.

The Large Bowl is also home to one of the best-preserved Martian examples of a delta, a sedimentary structure that forms when rivers enter open bodies of water and deposit rocks, sand, and – potentially – organic carbon. in layers.

The microbes could have lived in the crater when the water was there. Jezero keeps a record of important geological processes such as impact craters and volcanism, as well as the action of water. The study of its rocks will allow us to understand how the planet has evolved over time.

The Jezero Fan Delta is one of the main targets of the search for signs of past life. Scientists also see carbonate minerals deposited around the crater shore like the ring of a tub. When carbonates precipitate out of water, they can trap things in it, including evidence of life.

“We will be looking for biosignatures – patterns, textures or substances that require the influence of life to form,” says Katie Stack Morgan, associate scientist for the project.

We don’t know what Martian biosignatures might look like, but ancient Earth could provide clues. A trace of the early life of our planet can be found in stromatolites, rocks originally formed by the growth of layers after layers of bacteria. If similar structures exist on Mars, scientists could combine measurements from different instruments to assess the likelihood of a biological origin.

Today, Mars is cold and dry, with a thin atmosphere that exposes the surface to harmful levels of cosmic radiation. But billions of years ago the planet seemed to have been wetter, with a thicker atmosphere. Multiple lines of evidence, such as the presence of mudstones and sedimentary bands, show that there was once liquid water on the surface.

This is important because water is an essential ingredient for all life on Earth. Curiosity has also found organic molecules preserved in sedimentary rocks three billion years old. Although tempting, it is not clear whether these organic materials retain a record of ancient life, were their food, or have nothing to do with biological processes.

Perseverance carries an advanced payload of scientific instruments to gather information about the geology, atmosphere, environmental conditions, and potential biosignatures of Mars:

Ingenuity is a 1.8 kg (4 lb) helicopter that will fly to Mars strapped to Perseverance’s belly. NASA wants to demonstrate powered flight in the thin atmosphere of Mars. The gravity of the Red Planet is lower (about a third of that of Earth), but its atmosphere is only 1% of Earth’s density. This makes it more difficult to generate the lift needed to lift off the ground.

Equipped with two counter-rotating blades, the autonomous helicopter can take color images with a 13-megapixel camera, the same type commonly found in smartphones. Rotorcraft could be a useful way to explore other worlds: Flying vehicles travel faster than ground rovers and can reach areas inaccessible to wheeled vehicles.

Persistence is very similar to its predecessor Curiosity in terms of the overall design, but there are some key differences. In addition to the new science payload, Perseverance has a larger “hand,” or turret, at the end of its robotic arm to hold a suite of heavier tools, including a core drill.

The system designed to cache samples is also a new feature. The engineers redesigned the rover’s wheels to make them more resistant to wear and tear. The wheels of Curiosity sustained damage while rolling over sharp, pointy rocks.

The rover’s sample caching system is made up of three robotic elements. Most prominent is the 2.1m (7ft) long five-joint robotic arm, which is bolted to the frame. A rotary hammer drill on the arm turret is capable of cutting out intact cores from Martian rock. These carrots – about the size of a piece of chalk – go into a sample tube. The robot’s main arm then places the filled tube on a mechanism at the front of the rover called the bit carousel.

This mechanism, reminiscent of a 1960s slide projector, moves the tube inside the mobile where a smaller 0.5 m (1.6 ft) long sample handling arm (also called the T. rex arm) grabs it. An image is taken before the tube is hermetically sealed and placed in a storage medium. He is driven on the rover until the team finds a suitable place to drop him off.

For decades, scientists have wanted to deliver samples of Martian rocks and soil to Earth for study in the laboratory. Here, scientists could study the samples with instruments too large and too complex to be sent to Mars. By leaving rock and soil samples on the surface in sealed tubes, Perseverance will lay the groundwork for this to happen.

As part of the program known as the Mars Sample Return, a separate mission will be sent to land on Mars to retrieve the tubes using a “fetch” rover. A robotic arm will then transfer the tubes from the fetch rover into a rocket called the Mars Ascent Vehicle (MAV). The ascension vehicle projects the samples into Martian orbit where they are captured by an orbiter. This orbiter will then deliver the sample containers to Earth, possibly by 2031.