It will take about a month for the world’s most powerful telescope to reach a position in space, called Lagrange Point 2, where it will orbit the Sun in line with the Earth.
A European rocket, Ariane 5, successfully launched the $10 billion ‘time travel machine’ into space on Saturday from Europe's Spaceport in Kourou, French Guiana.
It had been in development by Nasa, the European Space Agency and the Canadian Space Agency for more than two decades and faced several delays.
The US space agency has made live tracking of the telescope available on its website.
US President Joe Biden congratulated Nasa on launching the telescope that is expected to create a revolution in astronomy, astrophysics and planetary science research.
“Congratulations Nasa and all who made today’s launch of the James Webb telescope possible,” he tweeted.
“Webb is a shining example of the power of what we can accomplish when we dream big. We've always known that this project would be a risky endeavour, but with big risk comes big rewards.”
Researchers all over the world are set to benefit from the telescope once it becomes operational next year.
It is 100 times more powerful than the Hubble Space Telescope, which has provided millions of images of planets, galaxies, nebulas and stars for 32 years.
The James Webb telescope would be able to see more than 13.5 billion light years away and capture data around the ‘birth of the universe’.
This will help researchers study the very first stars and galaxies that may have formed within the first few hundred million years of when the universe came into existence.
It will also study the atmospheres of planets, black holes, the evolution of stars and planetary systems.
Nasa administrator Bill Nelson said that the telescope would “help discover incredible things that we never imagined”.
“Now we have to realise there is still innumerable things that have to work perfectly. We know that in great reward, there is great risk, and that’s what this business is all about,” he said.
“That’s why we dare to explore. The James Webb Space Telescope is very much part of that exploration.
“It’s significant that we had the delays and it kept us all the way to today – Christmas Day.”
The telescope’s journey to Lagrange Point 2, which is 1.5 million kilometres away from Earth, has been smooth so far.
About 12.5 hours after launch, one course correction manoeuvre had already been performed successfully.
Nasa said there are three mid-course correction manoeuvres in total, with the first one being the most important and time-critical.
The telescope was named after James Webb, who led Nasa during the 1960s and was one of the architects of the Apollo moon programme.