An Atlas V rocket from the United Launch Alliance took off as scheduled at 7:50 am local time (11:50 GMT) from Cape Canaveral, Florida, in a clear sky, to embark on a journey of nearly seven months and nearly 480 million kilometres.

The first stage of the rocket fell off a few minutes later. NASA is now preparing for a second separation, from Earth's orbit, that will propel Perseverance on its path to Mars.

"With the launch of Perseverance, we begin another historic mission of exploration," said NASA Administrator Jim Bridenstine. "This amazing explorer's journey has already required the very best from all of us to get it to launch through these challenging times. Now we can look forward to its incredible science and to bringing samples of Mars home even as we advance human missions to the Red Planet. As a mission, as an agency, and as a country, we will persevere."

If all goes well, on February 18, 2021 Perseverance will be the fifth rover to make this journey since 1997.

All of the scout vehicles that have landed on Mars so far are American, but China launched its first rover to the red planet last week and is expected to arrive in May 2021.

Thus, Mars may simultaneously host three active rovers next year, along with the American Curiosity, which has traveled 23 km of the planet's surface since 2012.

Perseverance's primary mission will be to look for traces of past microbial life.

Scientists believe that more than 3 billion years ago the planet was warmer and covered with rivers and lakes, the ingredients necessary to make microbes emerge.