After seven months of journey, the Al-Amal probe placed itself in orbit around Mars on Tuesday, making the United Arab Emirates (UAE), at the origin of the adventure, the first nation in the Arab world to complete a interplanetary travel. Launched from Tanegashima, Japan, on July 19, the one also called Hope (“Hope” in English) covered 493 million kilometers before this key stage, the orbital insertion, which began around 4:43 p.m. French. After half an hour of anguish, faces lit up at the Mohammed bin Rashad Space Center in Dubai, where loud applause erupted.
For the initiates, it is a modest but nevertheless interesting mission which begins. “This will be the first time that we will be able to monitor the Martian atmosphere permanently,” enthuses Christian Mazelle, of the Institute for Research in Astrophysics and Planetology (Irap). It’s like a weather station on Mars. “
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The insertion maneuver, as delicate as it was decisive, lasted precisely 27 minutes, during which Hope had to brake considerably (from 121,000 km / h to approximately 18,000 km / h), otherwise the probe would have continued its journey in the solar system. In space, no disc brakes: the machines must turn on their engines to slow down. It is estimated that half of the fuel must have been consumed during this operation. “There have been failures in the past, so there is always a bit of suspense with the orbiting,” comments François Forget, researcher at the Dynamic Meteorology Laboratory (LMD), who contributes to the mission. When we go into orbit around Mars, we pass behind the planet, seen from Earth. So we lose contact at some point. When the probe reappears on the other side, it is very impressive. “
Before adopting a cruise orbit within two months, Hope will approach very close to the planet’s surface (1,000 km), move very far (49,380 km) and test its instruments. In this arsenal, nothing but very classic: a camera and two spectrometers to probe the different layers of the Martian atmosphere. “What is clever is to use a new orbit, underlines François Forget. Until now, all the probes we have placed around Mars have worked in low orbit, staying close to the planet. To take pictures, that’s what it takes. But we still had our noses on the planet, we only observed one slice at a time. We lacked a more general view, to know how the clouds evolve, how the temperature behaves, throughout the day. “
During the scientific mission which could last until 2025, the altitude will oscillate between 20,000 and 43,000 kilometers. “At 20,000 km, we are spinning at about the same speed as Mars. For a dozen hours, the probe will be over the same spot. She will watch everything that happens. If a dust storm breaks out, we will be able to observe all the stages of development, ”explains François Forget. “At the end of 12 hours, it will climb back up to 43,000 km. At that time, Mars will turn under the probe. And then, when she comes back down, she’ll explore a new place. At the end of four orbits, every nine days or so, we will have observed all of Mars and, at all local times. We will have at all points information on what he spends at each hour of a typical day of a given season. “
Hope could in particular make it possible to know more about the origin of the Martian atmospheric escape. Why are the gases that surround the planet, once provided with a much denser envelope, pack up? Several phenomena are known, such as the influence of the solar wind, of the flow of particles which “peel” the highest gaseous layers. But other causes are being studied in the lower parts of the atmosphere. Hope’s infrared spectrometer will allow you to watch variations over the entire height and track leaks. “It will be very motivating to simultaneously watch what is happening below and what is happening above,” says François Forget.
By becoming the fifth nation to reach the red planet, the United Arab Emirates, which aims to establish a human colony there in a century, enter the circle of space nations. “The Emiratis did not only want to make a technological demonstration, to say: we are able to send a satellite around Mars. They also wanted it to have scientific interest. It’s very complementary to what the other Martian missions do, ”says Christian Mazelle, who works on NASA’s Maven mission, Hope’s big sister. “They developed technical means, they designed the satellite in Dubai, but there were a lot of close collaborations with the Americans. “
The Emirati team is praised for the partnerships established: “The Mars Emirates mission has benefited from incredible support from the international scientific community, including in France”, welcomes Omran Sharaf, director of the Emirates project. Mars Mission to the Mohammed bin Rashid Space Center. Hope’s first data will be shared with scientists around the world starting in September.
Original article by : www.leparisien.fr