On Saturday, the world’s most powerful space telescope was put into orbit, heading for an outpost 1.5 million kilometers (930,000 miles) from Earth, after several delays caused by technical glitches.

The James Webb Space Telescope, some three decades and billions of dollars in the works, left Earth locked in its Ariane 5 rocket from the Kourou Space Center in French Guiana.

“What an incredible day. It really is Christmas,” said Thomas Zurbuchen, chief of science missions for NASA, who, along with European and Canadian space agencies, ESA and ACS, built the telescope.

ESA chief Josef Aschbacher said he was “very happy to say that we put the spacecraft into orbit very precisely … that Ariane 5 performed extremely well”.

This was the key, as putting the spacecraft into orbit saves the fuel the telescope will need to reach its final destination and perform well afterwards.

It is expected to take him a month to reach his remote destination.

It should return new clues that will help scientists better understand the origins of the Universe and Earth-like planets beyond our solar system.

Named after a former NASA director, Webb is following in the footsteps of the legendary Hubble – but intends to show humans what the Universe looked like even closer to its birth almost 14 billion years ago. .

Speaking on social media, Project Webb co-founder John Mather described the telescope’s unprecedented sensitivity.

“#JWST can see the thermal signature of a bumblebee at a distance from the Moon,” he said.

All this power is needed to detect the faint glow that was emitted billions of years ago by the very first galaxies to exist and the first forming stars.

US President Joe Biden congratulated NASA and Team Webb on the launch, saying on Twitter that the telescope “is a shining example of the power of what we can accomplish when we dream big.”

“Exceptional measures”

The telescope is unmatched in size and complexity.

Its mirror measures 6.5 meters (21 feet) in diameter – three times the size of Hubble’s mirror – and is made up of 18 hexagonal sections.

It’s so big it had to be bent to fit into the rocket.

This maneuver was laser guided, with NASA imposing strict isolation measures to limit any contact with the telescope’s mirrors from particles or even human respiration.

Once the rockets have carried Webb 120 kilometers, the craft’s protective nose, called the “fairing”, will be cleared to lighten the load.

To protect the delicate instrument from pressure changes at this point, rocket builder Arianespace installed a custom decompression system.

“Exceptional measures for an exceptional customer,” said an official of the European Space Agency in Kourou on Thursday.

Once at his station, the challenge will be to fully deploy the mirror and a sun shade the size of a tennis court.

This dauntingly complex process will take two weeks and must be flawless for Webb to function properly.

Its orbit will be much further away than Hubble, which has been 600 kilometers above Earth since 1990.

The location of Webb’s orbit is called Lagrange Point 2 and was chosen in part because it will keep the Earth, Sun, and Moon on the same side of its solar shield.

Webb is expected to officially go live in June.