After the Hubble Space Telescope has ended its operational life the James Webb Space Telescope will replace it. This telescope is scheduled to be launched in 2014. This instrument is designed to detect the light from the very first galaxies in the universe. This light is in the infrared region of the spectrum. Other objectives of this project include investigating the assembly of galaxies, stellar and planetary origins and the origins of life.

One question that is often asked is how we can see the light from the first galaxies as it occurred a long time ago. The reason is that they are located very far away from us. For example it takes 10 billion years for the light of a galaxy which is 10 billion light years away to get to us. Therefore, we see the galaxy as it was 10 billion years ago. It is likely that the galaxy has no resemblance to how we see it now. It is only time travel that is not science fiction!

The James Webb Space Telescope has a mirror assembly that is 6.5 metres wide, as opposed Hubble’s 2.4m. The larger mirror will collect more light making dimmer objects visible. The telescope will be placed into an orbit 1.5 million kilometers from Earth in the direction away from the Sun. In this location it will orbit the Sun at the same rate as the Earth. It will take 3 months for the craft to travel from Earth to this point. Also, if something goes wrong with it it will not be possible to repair it.

As the telescope will be observing infrared radiation it most be kept cold or it will emit infrared radiation making observations difficult, if not impossible. To achieve this the telescope will have a heat shield the size of a tennis court. The operating temperature of the instrument will be -225 Celsius or approximately 48 Celsius above absolute zero.

This is a video showing an animation of the James Webb Space Telescope being unfolded once it is in position. For more information you can go to the James Webb Space Telescope website.

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