Astronomers in suspense as $ 10 billion James Webb telescope prepares to take off | James Webb Space Telescope

Final checks and refueling are underway for the launch of the James Webb Space Telescope, a flagship NASA mission that aims to observe worlds beyond the solar system and the first stars and galaxies that lit up the cosmos.

If all goes according to plan, the $ 10bn (£ 7.4bn) observatory will become the largest and most powerful telescope ever to launch into space when it takes off at 12:20 p.m. British, on Christmas Day aboard an Ariane 5 rocket from the European Space Agency spaceport. in Kourou, French Guiana.

It took more than 30 years to design, design and build the telescope and the project was beset by delays, cost overruns, redesigns and technical issues that postponed the launch until later than this week.

“I am both excited and nervous,” said Professor Martin Barstow, chairman of the Space Telescope Institute Council and director of strategic partnerships at Space Park Leicester. “It’s exciting to think that after such a long time we could possibly send this telescope into space. But I’m nervous because we all know that no matter how good the rocket is, there are risks involved in getting there, and a lot of things have to go perfectly in order for us to have a functioning telescope.

At the heart of Webb is a 6.5-meter primary mirror that will allow the telescope to observe the faint glow of some of the oldest and most distant objects in the universe. Because the universe is expanding, the light emitted by stars and galaxies stretches during its travel, which means that the glow of the first stars is “redshifted” in longer wavelengths. long infrared light.

Unlike the Hubble Space Telescope, which orbits the Earth, Webb will orbit the sun. It’s heading to a place called L2, or Lagrange’s second point, a million kilometers from Earth. Here, gravitational forces will allow the telescope to observe the sky in the infrared domain, with the Earth and the sun behind.

Webb’s main mirror is so large that it needs to be folded up for launch and unfolded during the month-long trip to L2. Along the way, the telescope will also deploy a tennis court-sized sun visor to help shield the telescope from the sun’s rays.

“We want it to be really cold and the space not to be that cold,” Barstow said. “There is a lot of infrared coming from the Earth and the Sun that will heat things up. Cooling everything takes a long time.

Beyond observing the first stars and galaxies, Webb will observe alien worlds crossing the faces of their stars and measure how infrared light is absorbed in the atmospheres of the planets. This will provide clues to atmospheric chemistry and potentially favorable conditions for life.

“In terms of science, this is going to be transformational,” Barstow said. “It is quite simply the largest and most sensitive telescope ever to be in space. It was designed to trace the ancient history of the universe and to understand the formation of the first stars and galaxies. And it’s about us. It’s about how we came to be and our place in the universe.

If Webb makes it to L2 unharmed, mission scientists will spend an additional five months checking the telescope’s systems and making sure they are functioning properly before taking data in early summer.

“I just want it to be there and to work,” added Barstow. “There are thousands of astronomers waiting to use this telescope. It is important to remember that this is a huge business. There will be a lot of people in the world biting their nails tomorrow. “