World’s most advanced space telescope set to launch on Christmas Eve

The $10 billion James Webb Space Telescope will capture the universe in its infancy

Nasa's James Webb Space Telescope will give astronomers a peek into the early universe. All photos: Nasa

An artist's impression of the telescope in space. It will detect stars and galaxies 13.5 billion light years away, capturing light sources and studying formation of galaxies

It is hoped the telescope will show us what the universe was like 100 to 250 million years after its birth

The James Webb Space Telescope has 18 primary mirrors that are built together in the shape of a honeycomb

It is the world's most powerful telescope. Its mirrors are 100 times more powerful than its predecessor, the Hubble Space Telescope

The $10 billion telescope is the size of school bus. It had to fold up to fit inside the launch rocket

A European rocket, Ariane 5, launched the $10 billion ‘time travel machine’ from Europe's spaceport in Kourou, French Guiana

After 20 years in the making, the James Webb Space Telescope is finally set for launch.

On Christmas Eve, the $10 billion space observatory will lift-off on a European Ariane 5 rocket from a spaceport near Kourou in French Guiana, South America.

The telescope will be capable of looking back 13.5 billion years to see the first stars and galaxies of the universe and search for signs of life.

It has been in development by US and European space agencies for two decades and faced several delays.

After several launch delays this year alone, a date of December 22 was set, but technical issues pushed it to December 24 at 4.20pm Gulf Standard Time.

The team discovered a faulty data cable between the telescope and launch pad equipment at the spaceport, which was causing communication issues between the two.

The problem was resolved and the launch was back on. Dozens of engineers and scientists will be working through the holidays to make the launch a success.

“For us this is a historic moment that took 20 years to come. What we have not understood is what happened about 13.5 billion years ago, when a universe that was largely made out of protons and helium turned into something that made galaxies for the first time,” Thomas Zurbuchen, science mission directorate associate administrator for Nasa, said at a space conference held in Dubai earlier this year.

“That’s what we’re going to observe. It’ll be like looking at baby pictures of that universe.”

What’s special about this telescope?

Once operational, the James Webb Space Telescope would be 100 times more powerful than the Hubble Space Telescope, which for 31 years has made countless discoveries and provided millions of images of planets, galaxies, nebulas and stars.

It would be placed in a different orbit than the Hubble and much further out in space, allowing it to see greater distances.

That position in space is known as a Lagrange point, meaning it will follow Earth around the Sun

This strategic location would enable it to see further in space than any other telescope. It would detect some of the first galaxies, study the atmospheres of exoplanets, or planets outside of the Solar System, and search for any oxygen present.

How will it see back in time?

To study the early universe, the telescope will be able to see 13.5 billion light years away, meaning it will see 13.5 billion years back in time.

Telescopes are described as ‘time-travel machines’ because they observe distant objects. The light from these objects take years to travel to Earth, so the telescope sees the object at the moment it released the light.

Mirrors are an important component. On the James Webb Space Telescope, 18 primary mirrors are built together in the shape of a honeycomb that measures 6.5 metres in diameter – six times bigger in area than Hubble’s.

To help reflect infrared light more efficiently, the mirror is covered with a thin coating of gold.

The mirror will be kept at a temperature of minus 233°C to shield it from the Sun. It has a five-layer sunshield that is the size of a tennis court, which makes the heat from the Sun more than a million times weaker.

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