Washington (AFP)

It should only last 40 seconds but will nonetheless be historic: the first flight of a motorized vehicle on another planet, which had been pushed back, could finally be attempted Monday by Ingenuity, the NASA helicopter, on Mars.

“There is only one first flight per planet,” enthuses MiMi Aung, helicopter project manager.

Ingenuity is a "scout," she added.

"NASA expects the first flight of its Ingenuity helicopter to take place no earlier than Monday, April 19," the agency said on Saturday.

The flight is expected to start around 3.30am (07.30am GMT), and NASA plans to broadcast live on the internet the reception of the first data, from 6.15am (10.15am GMT).

Originally scheduled for April 11, it was delayed due to a technical problem that arose during the testing of its rotors.

The winds remain the main uncertainty that could jeopardize the flight of this helicopter, which arrived on the Red Planet on February 18 aboard the Perseverance rover, from which it was then unhooked.

The operation is a real challenge, because the Martian air has a density equivalent to only 1% that of the Earth's atmosphere.

However, it is by pushing the air while turning that the propellers can lift weight.

On Mars, "there are just fewer molecules to push," MiMi Aung explained.

Even if the gravity is less there than on Earth, the NASA teams had to develop an ultralight machine (1.8 kg), whose blades will turn much faster than a standard helicopter, to hope for success.

With its four feet and two superimposed blades (1.2m long), it looks more like a large drone.

- Color video -

The operation will be the equivalent on Mars of the first flight of a motorized vehicle on Earth, in 1903, by the Wright brothers.

A piece of fabric from this aircraft that took off more than a century ago in North Carolina in the United States has even been placed on board Ingenuity.

The latter will not take any risk for his first attempt.

"We want the very first flight to be a safe flight," said Tim Canham, helicopter operations manager.

He will rise vertically to a height of three meters, an ascent that should take him six seconds.

Then it will hover for thirty seconds, during which it will simply pivot on itself in the direction of the rover, before descending.

It will receive its instructions from Earth a few hours before, but will then fly in autonomy, by analyzing its position in relation to the ground itself.

After the flight, the helicopter will transmit technical data to the rover on what it has achieved, which will in turn be sent to Earth.

Among this early data, there will be a black and white photo of the ground taken by Ingenuity directly below it when it is in the air.

The next day, once its batteries are recharged, the helicopter will transmit a color photo of the horizon, taken by its other camera.

But the most spectacular images should come from the Perseverance rover, placed for observation several meters away, and which must film the flight.

Shortly after this, video clips will be transmitted.

NASA teams are hoping one of them will show Ingenuity flying.

The complete video will be transmitted "during the following days," said Elsa Jensen, head of the rover's cameras.

"There will be surprises, and you'll learn them the same time we do. So let's all get the popcorn out!"

- "Take risks" -

Four outcomes are possible, MiMi Aung warned: full or partial success, missing data, or failure.

If successful, the second flight may take place no more than four days later.

Up to five flights in all are planned, of increasing difficulty.

NASA would like to be able to raise the helicopter up to 5 meters in height, then try to make it move sideways.

“The lifespan” of Ingenuity will be “determined by how it lands” each time, MiMi Aung explained.

Which means: if he succeeds in avoiding the crash.

“When we get to the 4th and 5th flight, we'll have fun,” she promised.

“We really want to push our vehicle to its limits” and “take risks”.

Whatever happens, after a maximum of a month, the Ingenuity experiment will stop, to let the Perseverance rover devote itself to its main task: to search for traces of ancient life on Mars.

© 2021 AFP