New James Webb space telescope launches with Austro technology

With the "James Webb Space Telescope" (JWST), after several launch delays, the largest and most powerful telescope ever put into space is to set off "no earlier than 24 December".
The James Webb Space Telescope is ready for launch. (ESA/CNES/Arianespace)

The space agencies of Europe, the USA and Canada want to learn more about the early universe and alien planets with the device, which will cost over ten billion dollars (about 8.82 billion euros). Austro researchers and a space company from Vienna are involved in the project.

The telescope is to take off on board a European Ariane 5 rocket from the Kourou spaceport in French Guyana. However, unlike its famous predecessor, the Hubble telescope, which has been in use for more than 30 years, it will not be at an altitude of 500 kilometres above the Earth, but an impressive 1.5 million kilometres out in space. There are five points in the solar system - called Lagrange points - where the gravitational forces of the Sun and Earth cancel each other out, explained Günther Hasinger, Director of Science at the European Space Agency (ESA), in the summer. The destination is one of them, the orbit is then 1.5 million kilometres further away from the sun than that of the earth.

With our home planet and the sun behind us and protected from thermal radiation by the 21-metre solar shield, the instruments can then begin their measurements in different infrared wave ranges. But it will take about four weeks after the launch for the telescope to get there. There have been several postponements around the take-off of the launch vehicle. Originally, the launch was scheduled for October 2018.

Looking back into space shortly after the Big Bang

Researchers want to use the high-tech telescope to learn more about the origins of the universe. They hope to look back into the universe shortly after the Big Bang 13.8 billion years ago. The heart of the device is the mirror with a diameter of 6.5 metres. This makes the James Webb Telescope the largest reflecting telescope in space.

Measurements are then taken with a variety of instruments such as cameras and spectrographs. Both in one is the "Mid Infrared Instrument" (MIRI), in the development of which astrophysicist Manuel Güdel from the University of Vienna played a leading role from 2003. This is also a kind of virtual laboratory in space with which thermal radiation from gas and microscopically small dust can be detected. The data can be used to draw conclusions about molecules in space and to study the composition of fine dust in the universe.

On the one hand, "comprehensive spectra of planetary atmospheres will be recorded, which have never been recorded in this quality before", says Güdel. Ultimately, particularly precise information about the composition of planetary atmospheres can then be obtained. It is hoped that this will provide new insights into what conditions might be like on planets outside our solar system (exoplanets).

Contribution to the characterisation of exoplanets

"With extensive model calculations, one can further model these spectra and thus also determine other physical properties of the atmospheres. In this way, Webb is contributing to the characterisation of exoplanets in a previously impossible depth. Our goal will be to better understand how life-friendly planets like Earth can come into being in the universe at all," explained the Viennese astrophysicist.

To do this, the researchers are using MIRI to look into the nursery of planetary systems, so to speak, the protoplanetary disks. These gas disks are the size of an entire solar system and orbit a star. Planets are formed from this cosmic accumulation of material. At the end of such a process, a system like ours can emerge. "With appropriate models, we can explore the structure of these disks and thus their role in planet formation," says Güdel. In any case, it has never been possible to look into all phases of planet formation in such detail as MIRI promises.

But Austrian experts were also involved in the heart of the new observatory: The Viennese space company RUAG Space supplied two high-precision mechanisms for the "super eye" called "NIRSpec" (Near Infrared Spectrograph), one of the three main instruments of the telescope. This can detect up to 100 celestial bodies such as galaxies or stars simultaneously. It can look even deeper into space and provide images of distant celestial bodies than "Hubble". The instrument has a mass of around 200 kilograms and will operate in space at a temperature of minus 238 degrees Celsius.

Most precise ball bearing in all of Europe

The Vienna-based company supplied equipment that enables the precise mounting and rotation of a filter wheel and a grid wheel of the "eye". "The mechanism's ball bearing is the most precise in all of Europe," said RUAG Space Austria managing director Andreas Buhl.

During the final assembly of the telescope on Earth, red-white-red technology was also in use: the rotary tilting device to be able to turn and tilt the space observatory also comes from the Viennese company, which also supplied the thermal insulation for the telescope's large communication antenna.