The James Webb Space Telescope Mirror is seen during a media unveiling at NASA's Goddard Space Flight Center at Greenbelt, Maryland November 2, 2016. Photo: Xinhua

The much-delayed launch of the James Webb space telescope will go ahead on Friday, NASA and the company overseeing the launch confirmed on Saturday.

The project, begun in 1989, was originally expected to deploy the instrument - which will be the largest and most powerful telescope ever to be launched into space - in the early 2000s.

But multiple problems forced delays and a tripling of the telescope's original budget with a final price tag of nearly $10 billion.

The Webb telescope was built in the US and transported to its launch site in Kourou in French Guyana in 2021 with a planned date of departure of Saturday.

However, new problems have forced two delays.

"The James Webb Space Telescope is confirmed for the target launch date of December 24," tweeted launch company Arianespace, adding that it would go ahead at 12:20 GMT on Friday.

Confirming the launch date, NASA tweeted that the telescope was "encapsulated inside its @Ariane5 rocket fairing."

It follows in the footsteps of the legendary Hubble telescope but will be located much further from the sun. 

It is hoped that it will reveal what the universe looked like even closer to its birth nearly 14 billion years ago.

The new telescope is named after the late James E. Webb, who ran the fledgling NASA space agency for much of the 1960s.

AFP