Dual Ariane launch with German research instruments
The Herschel and Planck space telescopes were successfully launched from the European spaceport in Kourou at 15:12 CEST today. The satellites were carried on their way to Lagrange point L2, around 1.5 million kilometres from the Earth, by an Ariane 5 ECA launch vehicle. The two infrared telescopes are carrying high-tech German research instruments, which are financed by the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR) using funds from the German Federal Ministry of Economics and Technology (Bundesministeriums für Wirtschaft und Technologie; BMWi). Herschel will study extremely cold objects in galaxies while Planck will use the cosmic background radiation to examine the primordial universe. German scientists have a significant degree of involvement in these ambitious European Space Agency (ESA) missions.
Herschel: next-generation infrared astronomy
Herschel is the first space observatory to cover the entire wavelength range of the far-infrared (FIR) including the sub-millimetre range (60 to 670 microns). Because Herschel will study some parts of this spectrum for the first time, astronomers are expecting a wealth of new discoveries. They will use far-reaching observations of the sky to study the formation and development of galaxies since the dawn of the Universe. In the process, the scientists want to investigate the physical and chemical processes that take place in the interstellar medium and obtain new knowledge about how stars are formed from molecular clouds. In addition, they want to use high-resolution spectroscopy to map the composition of the atmospheres and surfaces of comets and planets.
The telescope's main mirror has a diameter of 3.5 metres This makes Herschel the largest space telescope to date, being around one and a half times larger than Hubble. For weight reasons, the mirror is made from the ceramic material silicon carbide (SiC), which is being used for a mirror of this size for the first time.
In Germany, the Max Planck Institute for Extraterrestrial Physics (Max-Planck-Institut für extraterrestrische Physik; MPE) in Garching is involved in the development of PACS (Photodetector Array Camera and Spectrometer), one of Herschel’s three scientific payloads. A large part of the work was carried out on behalf of MPE by the companies Kayser-Threde GmbH (Munich) and ASTEQ Applied Space Techniques GmbH (Kelkheim). The Max Planck Institute for Astronomy (Max-Planck-Institut für Astronomie; MPIA) in Heidelberg has funded a tilting mirror that was manufactured by Carl Zeiss AG in Oberkochen. The University of Cologne is coordinating the German contributions to the Dutch-lead instrument HIFI (Heterodyne Instrument for the Far Infrared). In addition, the University of Cologne has developed a mixer element and the Acousto Optical Spectrometer (AOS). The electronics for the AOS were manufactured by the Max Planck Institute for Solar System Research (Max-Planck-Institut für Sonnensystemforschung; MPS) in Katlenburg-Lindau. The local oscillator subsystem was developed under the direction of the Max Planck Institute for Radio Astronomy (Max-Planck-Institut für Radioastronomie; MPIfR) in Bonn.
Planck: studying the cosmic background radiation
Planck will significantly improve measurements of the cosmic background radiation and create a map of the entire sky with an angular resolution better than 10 arcminutes. Differences in temperature of around one-millionth of a degree Celsius are also expected to be detectable. Using Planck, scientists hope to obtain fundamental contributions to current questions in cosmology: What did the early stages of our Universe look like? How did it develop to become what it is today? How will it develop in future?
Planck is carrying a telescope with a mirror surface of 1.5 × 1.75 metres and two instruments that detect microwave radiation in different frequency bands. In Germany, the Max Planck Institute for Astrophysics (Max-Planck-Institut für Astrophysik; MPA) in Garching is involved. Scientists from MPA developed the software for data processing and information exchange while the instruments were being built, wrote the simulation programmes required for testing the data processing routines and analysis of the observation data and are building a database to store the data after they have been processed.
Herschel and Planck overview
Large Lissajous orbit around Lagrange point L2, at a distance of approx. 1.2 to 1.8 million kilometres from the Earth