What is the “Perseverance” robot doing on Mars in 2022?
Arriving at Mars in February 2021, the rover Perseverance have so far explored Jezero Crater in detail and collected rock and soil samples from this area where life could have developed. Separately, NASA and the European Space Agency are planning the mission Mars Sample Return which aims to retrieve these samples and return them to Earth.
When it landed on Mars, the rover Perseverance brought on board a drill and 43 titanium tubes intended to collect cores of Martian rock and soil that we hope to study more thoroughly one day in our planet’s advanced laboratories.
Currently, 18 of the 43 tubes have been filled and sealed: among these 18 tubes, one contains air from the Martian atmosphere, the other two contain sand samples taken from the ground , and 15 include rock cores obtained from the Martian atmosphere. Jezero estuary.
The large crater, 49 kilometers in diameter, created by the impact of a meteorite, was, 3.5 billion years ago, filled with water and formed a lake like the one found here, in Canada, in ancient meteorite craters. Manicouagan, in Quebec, is a typical example. “There is a lake in the crater with a river coming from the west that flows through it and creates a large delta. Because a delta is formed very slowly by the deposition of successive layers of sediment, therefore it’s clear that the lake has been there for a very long time,” said Canadian Raymond Francis, deputy director of scientific operations for the mission. Perseverance.
What is the life span of this lake? What were the environmental conditions during the lake period? Is the lake permanent, intermittent, or even seasonal? “The geological and geochemical details of our samples will allow us to understand all of this,” said Francis, who holds a doctorate in planetary geology and computer engineering from the University of Western Ontario.
Analysis of samples taken from the bottom of the crater by onboard instruments Perseverance revealed last year that they are made of igneous (or magmatic) rocks altered by lake water, which changed the geochemistry and mineralogy of these rocks, the specialist said.
“In 2022, we will have finished exploring the crater floor. Then, we reached the front of the delta at the end of April, after a very fast crossing of the crater, the fastest a rover has ever reached. Perseverance traveled hundreds of meters per day using new automated navigation software that can analyze stereo images of the environment, find safe routes for the Rover, plan the route to follow, and do that planning on its own while the Rover wheels are spinning. All this is possible thanks to the fact that Perseverance is equipped with a more powerful computer than the one with which the two previous rovers were equipped. This automatic navigation system, called AUTONAV, is the most advanced ever used on another planet,” said Francis from NASA’s Jet Propulsion Laboratory in Pasadena, California.
In search of traces of life
Perseverance so the exploration of the delta started in 2022 and took some samples from the part that ends at the crater. In a few weeks, the rover will begin a new campaign of exploration and sampling over the delta, which is “a very complex terrain created by the river that dug many different furrows. It will be very interesting for scientists because we can see what materials the delta is made of, and thus we can determine whether its formation took place in one long event or in several successive stages,” said G Francis.
“The delta is a good place to look for traces of ancient life on Mars, because the deposition of thin layers of sediment during its formation allowed the physical and chemical traces of life to be well preserved,” he says.
Scientists did not expect to find mollusk shells as fossils, but rather layers of stromatolites formed by bacteria. The chemical traces of life must in turn take the form of an enrichment of certain isotopes of carbon, potassium and oxygen in particular, which are abundantly used by living beings.
the helicopter Intelligencewhich was developed and piloted at the beginning of the mission March 2020 of engineer Farah Alibay, is now working to survey the terrain before driving the rover there. “This allows us to identify areas in the delta that will be most interesting to explore Perseverance said Mr. Francis.
“Currently, it is winter in the northern hemisphere of Mars, where the Jezero crater and its delta are located. However, the helicopter is not designed to work in this season, so it is necessary to change the software and also to be faster spin the propellers because the atmosphere is thinner in winter. Additionally, all of its navigation algorithms assume that the ground is flat. So it will be a challenge to climb the delta, which also has a lot of relief,” underlined Mr. Francis.
The samples
Before taking a soil or rock sample, instruments aboard the rover perform terrain analyzes that help select the perfect spot to drill and retrieve Martian material. Perseverance is actually equipped with multispectral cameras, spectrometers in remote sensing mode and spectrometers mounted on its robotic arm that allow measurements very close to the target using X, ultraviolet and infrared rays.
In 2021 and 2022, almost all samples were taken in duplicate. “We took two samples of the same stone a few centimeters apart. This duplicate sample represents a backup in case Perseverance will no longer work when we go to get the samples to bring them back to Earth,” said Mr. Francis.
NASA and the European Space Agency are currently preparing the mission Mars Sample Return (MSR), predicting that a lander will arrive at the Red Planet in 2031 to retrieve samples. Since this lander will not be mobile, Perseverance will meet him and send him the sample tubes he has hidden inside him, using his robotic arm.
“But since this maneuver won’t happen for nearly a decade, the rover’s mechanical and robotic systems may be flawed and unable to deliver the scales. MSR said mr. Francis. Two alternative plans are therefore provided if such technical problems arise.
“If, in a few years, we realize that the system of Perseverance who is doing the mechanical transfer starts to have problems, we can decide to drop all the tubes it contains on the Martian soil so that they can be picked up during the MSR mission by two small robotic helicopters that will be carried by lander with him,” said Francis.
If worse, Perseverance suffers a catastrophic failure that prevents the samples it contains from being released into the soil, they will be lost forever. So in anticipation of an event that some samples are collected in duplicate, deposited on the Martian soil, where they will be recovered by two helicopters of MSR.
Since last December 16, the robot dropped on the surface of Mars 5 the 18 tubes that it filled and inserted into its body. Five other pipes will also be abandoned in the ground in February, each in a location clearly documented and archived. When the rover releases a tube, a camera located at the end of its robotic arm looks under the machine to see if the tube has indeed fallen to the ground and not rolled on the wheels of the vehicle’s wheels. Perseverancewhere it can be overwritten.
It is planned to leave on the surface of Mars 10 tubes containing a copy of 10 different samples. The rover will keep 33 other tubes inside it, 5 of which will be witnesses that will make it possible to check the level of cleanliness and contamination of the mechanical sampling system, until 2031, when, if everything goes well, will send this. on the lander MSR to be sent to Earth.
