Voyage to dawn of time: The James Webb telescope looks like a giant honeycomb and next week will launch one million miles into space to get a glimpse of the Big Bang – and see the birth of our universe
- The ‘honeycomb’ is a golden mirror more than 21ft across- largest mirror on largest telescope sent into space
- Product took 25 years and cost nearly $10 billion (£7.6 billion) to build
- Will be sent into space next week but was dogged by delays and costs
Few objects sent into space have looked more outlandish than the James Webb Space Telescope.
The JWST has been compared to a giant slice of honeycomb balancing on a sheaf of silver wrappers. And in illustrations it certainly looks like something from an over-imaginative primary school science project.
But in reality, that ‘honeycomb’ is a golden mirror more than 21ft across — the largest mirror on the largest telescope ever sent into space — while the silver foil is a sunshield the size of a tennis court.
At 25 years and nearly $10 billion (£7.6 billion) in the making, it is the product of intensive research and design by 10,000 astrophysicists, engineers and chemists, many of them British, over the course of 40 million ‘build hours’.
It has also been dogged by delays and ballooning costs that swallowed up the budget of so many other projects, it has been called ‘the telescope that ate astronomy’.
But as it is the most powerful space observatory ever built and will allow us to peer back billions of years into the cosmic Dark Ages — almost to the Big Bang — and find the first light that ever shone in the Universe, astronomers hope it will be worth the wait.
The JWST has been compared to a giant slice of honeycomb balancing on a sheaf of silver wrappers. And in illustrations it certainly looks like something from an over-imaginative primary school science project
If all goes to plan, it will be launched on December 22 from Europe’s spaceport at Kourou in French Guiana.
Folded up like a piece of origami, it will be carried into space on an Ariane 5 rocket. Once in orbit a million miles from Earth, it will begin unfolding, then spend more than six months calibrating and testing its instruments.
When all is ready, it will beam down 458 gigabits of data a day for up to ten years, with its pictures picked up by large radio antennae worldwide and relayed to an operations centre in Baltimore.
The project, originally envisaged in the mid 1990s, was so ambitious that Nasa turned for help to the European Space Agency, of which the UK is a member, and its Canadian equivalent.
It is named after former Nasa administrator James E. Webb, who almost became a victim of ‘cancel culture’ this year. He was accused of being complicit in discrimination against gay and lesbian people in the 1960s and his name was retained only after an internal inquiry found no evidence to support the allegations.
Space telescopes allow scientists to get a clearer view of stars, planets and galaxies by circumventing Earth’s atmosphere. They are, in effect, time machines. Given how long light takes to reach Earth from deep space, the farther you look, the farther back in time you’re going.
All set: The James Webb ready for shipping to the launch site
Until now, scientists have had to rely on the Hubble Telescope, which has been in orbit since 1990. And it’s made some astounding discoveries, including the revelation that most galaxies have a black hole at their centre.
It has also captured spectacular images such as the so-called Pillars Of Creation, plumes of interstellar gas and dust forming stars in the Eagle Nebula, 7,000 light years from Earth.
But the new telescope has a field of view 15 times wider than Hubble, collects six times more light and is highly sensitive to infrared light.
By the time light emitted by the earliest stars or galaxies reaches a telescope on Earth, it is so stretched it arrives as infra-red, which is invisible to the naked eye.
To observe infra-red light the JWST must be kept very cold, so it will go much deeper into space than Hubble and maintain a tight orbit around a point where a balance of gravitational forces will allow it to stay in the same place — which is useful for communications with Mission Control.
Its sunshield divides the telescope into hot and cold sides. On the hot side are the solar panels that generate power for the control systems.On the cold side is the primary mirror, which has an instruments module that needs to be at minus 233c, so it will be kept chilled by a helium-powered refrigerator.
Some of the biggest unanswered questions about the Universe concern the early years after it was created in the ‘Big Bang’ 13.8 billion years ago. The JWST should be able to see light dating back at least 13.5 billion years.
When Hubble was launched, a single crooked mirror meant the pictures sent back at first were horribly blurred. A special trip by astronauts from the Space Shuttle was needed fix it.
The stargazers at Mission Control will be praying the James Webb doesn’t suffer a similar setback.
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