Telescopes Of The Future - The James Webb Space Telescope
No other telescope is as well known and has opened our eyes to the beauty of our universe as the Hubble space telescope. It brought us close to distant galaxies, showed us breathtaking images of cosmic nebulae of gas and dust and even images of exploding stars. Since 1990, the space telescope has orbited the earth 120,000 times and sent more than a million photos to Earth. But despite all his accomplishments, Hubble is getting on in years. But for all astronomy fans out there, here's the good news: a real construction boom is taking place worldwide - a whole new generation of supertelescopes that will allow us to look further and deeper into space and thus further back into time than ever before.
Already in less than nine months we are entering a new decade and the chances are excellent that in the coming decade we will not only see pictures in an unprecedented quality, but also our understanding and perception of the universe will expand significantly once again.
Let's start with the telescope, which is expected to be the first to be completed and which some of you may already know: the James Webb Space Telescope.
The technical challenges are enormous. Its six and a half meter mirror diameter and the even larger five sun shields make a complicated construction necessary to accommodate the space telescope on board an Ariane 5 rocket. This is one of the reasons for the delays and multiple postponements of the mission. Because if something goes wrong during deployment, it would be a real disaster for NASA.
Another challenge was the weight. If you had used mirrors comparable to the Hubble, the James Webb telescope would have become ten times heavier than it is today, far too heavy to take to its destination in space. To save weight the engineers used beryllium. This is a very light and at the same time solid material. The individual mirror elements were then vaporized with gold.
Maybe you're wondering how much gold you need for such a large surface? The answer is: amazingly little. For the whole mirror it was only 48 grams.
For comparison: a golf ball weighs about 46 grams.
If all goes well, the James Webb telescope will start into space on march 30, 2021 and will start working about six months later. It will not only be able to observe the first stars and galaxies, but also planetary systems in their formation phase.
Another task of the James Webb is to study the composition of atmospheres of exoplanets in an unprecedented accuracy and it will also search indicative for extraterrestrial life.