SOFIA - the observatory above the clouds

Airborne observatory SOFIA provides astronomers with a new window into space

If you want to reach for the stars, you have to lift off. This could be the motto of SOFIA, a jumbo jet which has been converted into an observatory. On board it carries a 2.7-metre telescope, which the researchers use to observe the birthplaces of distant suns, galactic molecular clouds or the envelopes of planets in the infrared as they fly above Earth’s disturbing atmosphere at an altitude of 15 kilometres.

The balance between heating and cooling processes, on the other hand, regulates the temperature of the interstellar medium, thereby controlling the initial conditions for the formation of new stars. Such processes occur at low temperatures – way below minus 200 degrees Celsius – and can thus only be followed in the infrared. The researchers are therefore concentrating on the birth of stars and planets. SOFIA will be able to follow such cosmic delivery rooms in our galaxy and also in neighbouring galaxies with an accuracy never achieved before.

To operate at optimum performance, the observatory must have absolute calm; even the slightest vibrations would ruin any measurement. So the engineers developed a system to insulate against vibrations which is made of air springs, silicon-filled damping elements and high-tech control electronics. This mechanically decouples the plane from the telescope.

The astronomers work in the area in front of the pressure bulkhead and between the wings. And 1st class has been replaced with space for guest observers and teachers, students or journalists. This is how it came about that in the night before 15 July there were two German teachers on board for the first time. Wolfgang Viesser from Christoph-Probst Gymnasium in Munich and Jörg Trebs from Thomas Mann Oberschule in Berlin were able to experience at close hand how the scientists used GREAT to scrutinise L1157, a newly forming star in the Draco constellation.

The jumbo jet is based in Palmdale near Los Angeles. SOFIA will also take off from Christchurch in New Zealand and from Stuttgart airport on its cosmic excursions.

Project partners

SOFIA
The Stratospheric Observatory for Infrared Astronomy is a joint project between the German Aerospace Center (DLR) and the US American space agency NASA. The German funding is provided by the Federal Ministry of Economics and Technology, the State of Baden-Württemberg and the University of Stuttgart. The German SOFIA Institute (DSI) is also based at this university, which coordinates the scientific operation from the German side; the Universities Space Research Association (USRA) is responsible for the American operation. The DLR commissioned the construction of SOFIA’s heart, the 2.7-metre telescope.

GREAT
The German Receiver for Astronomy at Terahertz Frequencies was developed by scientists at the Max Planck Institute for Radio Astronomy and the University of Cologne, in collaboration with colleagues from the Max Planck Institute for Solar System Research and the DLR Institute of Planetary Research. The instrument was financed by the participating institutes and also the Max Planck Society, the German Research Association (DFG) and the DLR.