NASA detailed on Wednesday how it will bring about 30 samples of Martian rocks to Earth by 2033, a plan that now includes sending two new helicopters to the Red Planet.
The Perseverance rover, which landed on Mars a year and a half ago, has already collected 11 rock samples.
But bringing them to Earth so they can be studied in depth for traces of ancient life turns out to be a complex mission that requires several steps.
Until now, NASA had planned to send another rover to Mars, which would store the samples collected by Perseverance to take them to a lander. In that module, in turn, there would be a mini-rocket ready to place the samples in orbit around the Red Planet in 2031.
However, NASA has decided that the second rover will not exist. Instead, Perseverance itself, which has shown good performance, will approach the rocket, called the Mars Ascent Vehicle.
The samples will be retrieved from Perseverance using a robotic arm built by the European Space Agency (ESA) and integrated into the lander, as previously planned.
But as a precaution, a workaround has been provided in case Perseverance is immobilized.
The lander, which is expected to lift off from Earth in the summer of 2028 and reach Mars in the mid-2030s, will have two small helicopters attached to it, in addition to the mini-rocket and robotic arm.
There is already a helicopter on Mars, called Ingenuity. Its performance exceeded all expectations: it performed 29 flights instead of the five initially planned.
The two new helicopters will be slightly heavier, equipped with wheels to move on the ground and a small arm that will allow them to collect samples, which can weigh up to 150 grams.
In this case, the samples would be dropped by Perseverance on the ground, retrieved by helicopters, and deposited on the lander in a few days.
There, samples would also be collected by the robotic arm, which can extend up to two meters, to be placed on the mini-rocket.
The samples will then be transferred to a previously positioned orbiter around Mars, which is scheduled to lift off from Earth in 2027.
Once the payload is recovered, this orbiter will return to Earth to land in the Utah desert in 2033.
Perseverance has a total of 43 tubes for storing samples. It will soon deposit a dozen on Martian soil to form an emergency stockpile. The other 30 will be destined to be recovered.
