What time is the James Webb Telescope launch? How to watch live and everything you need to know

Nasa will be launching the James Webb Space Telescope on Christmas Day.

The launch of the craft has been long-awaited due to numerous delays. Last Tuesday, Nasa announced that upper-high level wind could force the rocket launching the telescope off-course on its initial launch date – 24 December – and so delayed the launch until the day after.

These last-minute snags come after years of delays and cost overruns for Webb, the biggest and most powerful science observatory ever built for space.

“There are over 300 things, any one of which goes wrong, it is not a good day," Nasa Administrator Bill Nelson said. "So the whole thing has got to work perfectly.”

Viewers will be able to watch the lift-off on Saturday, 25 December 2021 at 12:20pm GMT (4:20am PT / 7:20am ET) on Nasa’s website.

The James Webb Space Telescope will soar from French Guiana on South America’s north-eastern coast, aboard a European Ariane rocket. Launch managers will meet again.

The $10 billion infrared observatory is considered the successor to the Hubble Space Telescope, in orbit since 1990.

During a news conference Tuesday, NASA officials said the rocket and telescope were in good shape, and that the only lingering, though tolerable, problem was an intermittent communication relay between the two. The issue earlier forced a two-day delay; a clamp that inadvertently jolted the telescope at the launch site had prompted a four-day slip.

Compared to the Hubble Space Telescope, Webb will be able to provide “an entirely new perspective on the universe that will be just as awe-inspiring,” said Nikole Lewis, deputy director of Cornell University’s Carl Sagan Institute.

Webb will attempt to look back in time 13.7 billion years, a mere 100 million years after the universe-forming Big Bang as the original stars were taking shape. Scientists are eager to see how closely, if at all, these initial galaxies resemble our modern day Milky Way.

Additional reporting by Associated Press