ESA builds biggest space telescope

In less than two years, the European Space Agency (ESA) will launch Herschel, the biggest ever space telescope. Built in Europe and named after the pioneering astronomers William and Caroline Herschel, it will be launched on board an Ariane 5 rocket.

The Herschel Space Telescope follows up the success of ESA’s Infrared Space Observatory, which was launched in 1995.

This time around, ESA will be able to look at regions of the infrared spectrum never explored before. Herschel has a mirror almost twice as big as that of the Hubble Space Telescope. This is made possible with new materials and by the fact that it will be dealing with long-wavelength radiation. As the universe is expanding, a bigger mirror will allow Herschel to pick up weak infrared signals from older events further out in the universe.

Yves Toulemont, Herschel Telescope Project Manager, EADS Astrium, said, “It’s not just a mirror we’re talking about, more like a piece of precision Swiss watch-making, covering a ceramic base tooled to a tolerance of one micron. All of Europe’s world-leading skills in lightweight resistant ceramics have been integrated into its construction. Hubble had a primary mirror two metres forty across, weighing one and a half tonnes. Ours is three metres fifty, but only weighs three hundred and fifty kilos.”

Professor Giovanni Bignami, Chairman of ESA’s Space Science Advisory Committee said, “We have wanted to conduct infrared astronomy for a long time, but it’s very difficult from the Earth as the water vapour in the atmosphere prevents this. This is why infrared telescopes have to be in satellites.”

Bignami went on to say, “Herschel goes into orbit in a year and a half, and it will be a real revolution. Its mirror is much larger than before, and it will be so sensitive that it will have the potential to penetrate into the heart of the unknown. It will probe a range of previously unexplored frequencies, which makes it a unique scientific experiment.”

Four months after its launch, the Herschel Space Telescope will be looking out at the universe from a point one and a half million kilometres from the Earth. It will spend the next 3 years providing scientists with pictures of the invisible universe, helping them to understand the chemistry at work in our own solar system, more than five billion years ago.

Bignami said, “Herschel can look for specific things, like the vibrations transmitted by molecules such as water, or more complex elements, like organic molecules. They are not in themselves proof of life, but in reality they are elements at the origins of life.