- On December 25, 2021 at 9:20 a.m. local time (1:20 p.m. CET), the James Webb Space Telescope, the largest space telescope of all time to date, took off from the spaceport of the European Space Agency on an Ariane 5 launcher.
- A total of four instruments are housed on James Webb. Two of them come from Europe and have German shares.
- The German Space Agency at DLR coordinates the German contributions for ESA and for an instrument in the national space program.
KOUROU, French Guiana (DLR PR) — James Webb Space Telescope – JWST for short – was launched from the European spaceport in Kourou (French Guiana) on its journey to Lagrange Point 2, 1.5 million kilometers away. James Webb is the largest and most expensive space telescope of all time, which has now started its long journey into the depths of space with an Ariane 5 upper stage ‘Made in Germany’. In addition, MIRI (Mid Infrared Iinstrument) and Near Infrared ( Near Infrared Spectrograph) – two of the four instruments on board – German parts: The near-infrared instrument NIRSpec was built by Airbus in Ottobrunn and Friedrichshafen. With this instrument, scientists from all over the world want to analyze the ‘hours of birth’ of the universe. NIRSpec is primarily intended to detect the radiation from the first galaxies that formed shortly after the Big Bang.
“The James Webb telescope will thus provide answers to previously unanswered questions and enable us to open doors to new questions,” explains Dr. Walther Pelzer, DLR board member and head of the German space agency at DLR, the scientific importance of the mission.
The German Space Agency controls the German contributions for the European Space Agency (ESA). Germany is currently the largest contributor here; Germany is contributing around 106.5 million euros to the James Webb mission as part of the ESA. Added to this are a further ten million euros for the MIRI instrument from the so-called National Space Program. DLR scientists are also hoping for JWST observation time to study exoplanets.
“With the new telescope, atmospheres around much smaller planets can be detected in the future than was previously possible,” says Prof. Dr. Heike Rauer, head of the DLR Institute for Planetary Research in Berlin-Adlershof . “The MIRI instrument is a well-suited tool for examining the gas envelopes of these particularly small celestial bodies.”
What Charles Darwin and the James Webb Space Telescope have in common
When Charles Darwin set off on the HMS Beagle 190 years ago – more precisely on December 27, 1831 – he did not yet know that his observations and findings would fundamentally change the world of science. Today we have at least an inkling of what riddles the James Webb Space Telescope could solve. But the most precise infrared telescope of all time has its sights set on the unknown:
“Like Charles Darwin, the James Webb space telescope also uses the finest observations to get to the bottom of evolution – not that of humans and nature, but of stars and planets. The telescope, with its huge, deployable main mirror 6.5 meters in diameter, looks extremely far back in time: ‘Shortly’ after the Big Bang around 13.8 billion years ago, the first galaxies shone light through the universe. Because of the rapid expansion of space, this only reaches us today as extremely weak thermal radiation. It is precisely this radiation that the telescope can capture – no matter how small it is, “explains Heinz Hammes, James Webb project manager at the German Space Agency at DLR.
JWST is a joint project of the space agencies NASA (USA), ESA (Europe) and CSA (Canada). It will cover a large infrared range and make this “ancient” thermal radiation visible. And since the infrared radiation is also visible through cold clouds of dust, even these obstacles for JWST disappear.
“So the telescope sees what has hitherto been hidden, because James Webb is the first to cool the mirror in a space telescope. You can receive signals that were previously hidden in the noise. But the telescope is not only concerned with the early history of the universe, it can also observe the formation of stars and planetary systems from special rings of gas and dust – the so-called protoplanetary disks – and examine planetary systems for their friendliness.”
Two European instruments with a large German component
NIRSpec is designed for the wavelength range from 0.6 to 5 micrometers and was built by Airbus in Ottobrunn and Friedrichshafen on behalf of ESA. For the first time ever, this instrument is intended to target spectra of up to 100 different observation targets simultaneously in a field of view of 3.4 by 3.6 arc minutes, making it ideal for spectroscopy of distant galaxies. One minute of arc corresponds roughly to the resolution of our eyes, whereby the full moon in the sky corresponds to an expansion of 32 minutes of arc. The main aim of NIRSpec is to detect the radiation from the first galaxies that formed in the early universe around 200 million years after the Big Bang, when space was still significantly different from its current state.
“NIRSpec will split the infrared light received by these celestial bodies into individual wavelengths and thereby provide scientists with important information on the distance, chemical composition, dynamic properties and age of these objects, as well as examine intergalactic space and its gases more closely. NIRSpec is an extremely versatile instrument that will also investigate the early phases of the formation of stars in our Milky Way and analyze the atmospheric properties of planets of other stars, with which the possibilities for extraterrestrial life can be better assessed, “explains project manager Heinz Hammes.
MIRI was built jointly by ESA and NASA. The detectors and the associated electronics come from the USA. Europe provides the optical and mechanical components of this instrument. While all other instruments observe in the near infrared range, MIRI is dedicated to the mid infrared range. The instrument has three 1024 by 1024 pixel detectors and covers the wavelength range from five to 28 micrometers. Due to the longer wavelength, the resolution is reduced to 0.19 arc minutes. However, MIRI has an angular resolution seven times higher than the Spitzer Space Telescope and is also around 50 times more sensitive. However, an active cooling circuit is necessary for this instrument, as the detectors must be cooled to six Kelvin with helium.
The instrument has different modes designed for different applications. The imaging mode is suitable for screening. The Coronography Mode can be used optimally for the examination of exoplanets due to various filters. In Medium Resolution Spectroscopy Mode the sky is observed with four different channels. By covering a very large wavelength range, this instrument is sensitive to both near and warm objects, such as objects in the Milky Way, but also to objects with a high redshift from the early days of the universe. Working on the project are NASA’s Jet Propulsion Laboratory and the Goddard Space Flight Center as well as a European consortium from 26 nations led by the Astronomy Technology Center in Edinburgh, which also includes the Max Planck Institute for Astronomy in Heidelberg and the University of Cologne.
James Webb – a major international project
Four instruments are integrated on the James Webb Space Telescope, which were set up by different consortia. A total of 14 different countries are involved in this huge project: the USA and Canada have been working together since 1996 and since 2003 also twelve European countries, represented by the ESA. In addition, ESA provides the launcher with an Ariane 5 ECA and participates in the operation of the Space Telescope Science Institute in Baltimore. For this purpose, the ESA receives a full partnership in the consortium and access to the observation time for all member states, similar to the current scientific predecessor project Hubble. This time is assessed and allocated by an independent body. The German Space Agency at DLR coordinates the German contributions to ESA. German contributions to the mission are also made Airbus, ArianeGroup, Hensoldt Optronics, IABG, that Max Planck Institute for Astronomy and the University of Cologne.