InSight, the latest Mars probe, aims to land on Monday and get to work: NPR

Mars receives a new visitor from Earth on Monday. If all goes well, a NASA probe named InSight will land near the Martian equator shortly before 3 pm. IS. Once it lands on Mars, it will stay in place. InSight is not a mobile. His mission is to stay at a place after landing and to study the interior of Mars from the surface of the planet.

But before he can carry out this mission, he must land safely. This means a slowdown of 12,300 mph at the entrance from the top of the Martian atmosphere – until a full ground stop six and a half minutes later.

"The landing is completely automatic and autonomous," said Rob Grover, leader of the entry, descent and landing team at the Jet Propulsion Laboratory in Pasadena, California. surface, "says Grover.

The reason why real-time control is impossible is that it takes about eight minutes for a radio signal to travel from Earth to Mars. As the landing sequence only takes six and a half minutes, the landing gear would already be on the ground by the time a signal from the Earth arrived.

This is what is supposed to happen: about 90 minutes before the atmosphere, mission managers send the latest tracking information to the probe, so that it knows where it is and how fast. They will also send last minute modifications to the probe software that controls the landing, based on estimates of the amount of dust in the Martian atmosphere.

Then the probe is to get rid of what is called the stage of the cruise. This is a part of the spacecraft needed only when InSight travels from Earth to Mars.

"We eject that from the vehicle seven minutes before we find ourselves at the top of the atmosphere," Grover said.

After that, the spacecraft rotates, so that its heat shield is oriented in the right direction.

When the probe enters the atmosphere, the air molecules that make up the Martian atmosphere hit the heat shield, causing its warming and slowing down of the craft.

"Believe it or not, 99% of the energy we receive from space is actually absorbed by the atmosphere," Grover said.

The heat shield acts for about three and a half minutes.

"The next big event is the deployment of paratroopers," said Grover. At this point, the probe travels faster than the speed of sound. InSight is therefore equipped with a special parachute designed for supersonic speeds.

Once the probe is about 4 miles above the surface, the radar will turn on. This will help you understand how the on-board navigation directs the aircraft, once the probe has detached the parachute and landed using rockets.

"The whole descent under the power of a rocket takes about 40 seconds," says Grover. "We have 12 small downhill engines clustered around the bottom of the LG that allow us to slow down the last mile."

Even if they can not do anything to help InSight on the way down, mission leaders should be able to track their progress.

"This will send data back in real time," says Grover, "and the MarCO spacecraft will help with that – by relaying the data."

MarCO is a small spaceship that flies to Mars with InSight.

"It's about the size of a cereal box," says Anne Marinan, system engineer for the MarCO team, one of the new generations of tiny satellites called cubesats.

"Cubesats was originally developed to give students easy access to space," says Marinan.

Cubesats are now used at NASA to test new technologies. In the case of MarCO, the new technology consists of communication equipment that will transmit InSight's telemetry data to the Earth.

Two almost identical MarCO spacecraft were launched with InSight last May and follow the probe on its flight to Mars.

"For starters, we're late," says Marinan, "but by the time InSight lands, we'll be beyond Mars." Unlike InSight, the MarCOO spacecraft continues to cross Mars in space. Once they have finished relaying InSight 's Landing Telemetry, their mission is complete.

If the MarCOs fail to relay telemetry, the data will also be stored by other NASA satellites orbiting Mars and sent to Earth after landing.

InSight arises in what seems to be a very boring part of Mars, known as Elysium Planitia. The chefs de mission wanted a boring place – they want the probe to remain silent. Its two main instruments, a sensitive seismometer and an underground temperature probe, will measure the tiny fluctuations of the interior of the planet.

To make precise measurements, these instruments should not be disturbed. If they work properly, scientists should have a better idea of ​​the internal structure of the red planet.

The mission is expected to last about two Earth years.