Hello, travel? The human object sent farthest out into the Universe has just shown signs of life after 24 billion kilometers.

©NASA/AFP

Atlantico: What were the main technical challenges we had to overcome? restore contact with the Voyager 1 probe after a long loss of contact?

Anna Alter: Everything in this story is a test. The Voyager 1 and Voyager 2 probes are a challenge in themselves, and it is not certain that humanity today, with its economic management, would provide itself with the means to cope with something similar. When I was a student at the Meudon Observatory, I had the opportunity to work as assistant professor André Braic, who was Monsieur Voyager of France, and he very enthusiastically told us about this project, as expensive as it was ambitious, which had no other goal, in addition to expanding knowledge by flying over the giant planets of our solar system.

Two twin probes were launched in 1977, less than a month apart: Voyager 2 on August 20, Voyager 1 on September 5, and both, like bottles in the sea, carry an optimistic message to “attention.” aliens to tell them in case they miraculously spot someone near their home, “hello, we are here in the Universe, men and women with a scientific culture, but not only… We also do literature, painting, cinema , music, filming on the third planet from our star. A hellish challenge to the mind, ours and that which would have developed under other heavens to such an extent that it was capable of understanding the Golden Disc engraved by us.

For 46 years now, Voyager 1 and Voyager 2 have been floating together in space and have long crossed the boundaries of our system, the Sun no longer has any influence on them, they are free as air, finally, so to speak, because where are they? not a bit…We keep in touch from a distance as long as we can so that they send us information about the unknown distant lands that they cross, only from time to time we lose contact and the task is to make a diagnosis from a very distant distance, in this case from about 24 billion kilometers, so we have no more news. Voyager 1 sent garbled signals for months as if it was suffering from senility, and concerned NASA engineers eventually said it was a problem with the chip. They managed to isolate the faulty part, this is more than a challenge, an exploit, since for each command you have to wait for a response for more than 40 hours, the round trip time is at the speed of light and you have to deploy a lot of patience in the azure to carry out the orders of the earth… The job is done , communication has just been restored and clear signals are understood.

How have images taken by the Voyager probes affected our understanding and perception of the planets of the solar system, especially Jupiter, Saturn, Uranus and Neptune?

Everything we know in detail about Jupiter, Saturn, Uranus and Neptune was given to us by the Voyager probes. From the Great Red Spot on the former’s belly and its complex functioning to the invisible rings of the Earth, including its atmosphere, the volcanism of its moon Io and the striated surface of Europa. From the structure of the rings of the second and the atmosphere of its Titan. From the mint-colored surfaces to the water of the last two, the most distant… The Voyager probes have taken turns giving us an accurate view of the giant worlds, which all wear more or less thin rings, we don’t really know why.

What impact did Voyager 1’s iconic photographs of Earth, especially the one taken on February 14, 1990, have on humanity’s collective consciousness of our place in the universe?

This photograph of the Earth seen from the sky, taken over six billion kilometers away, was a shock, a wonderful lesson in humility, our planet was just a pale blue dot, and that is how this historical photo was christened! This is to this day the most distant photograph of our globe…

What new opportunities are being opened up by current technological advances for space exploration beyond the achievements of the Voyager probes?

The solar system is worth traveling to, and no technology, no matter how advanced, can replace real interplanetary travel. Like the Voyager spacecraft, which, with the help of devices half a century ago, never gave equal results… We have never gone so far, so well, it is a giant… Instead of remaining with both feet in one hoof on the ground, we must move on. and go on new selfless space adventures. Knowledge for the sake of long-term knowledge…