RUAG Space’s engineering and production capabilities will play a central role when the James Webb Space Telescope (JWST) is launched from the KourouSpaceport in French Guiana, scheduled for December 22, 2021. In addition to the payload fairing, separation system and on-board computer for the Ariane 5 launch vehicle, the company delivered the antennas for data transmission to Earth, the ground support equipment as well as three mechanisms for two of the telescope’s four scientific instruments.

The James Webb Space Telescope (JWST) – or short “Webb” – is the largest and most powerful space telescope ever built. The successor of the Hubble space telescope will be able to peer into the oldest, most distant areas of the universe to study some of the first stars and galaxies that formed after the Big Bang more than 13.5 billion years ago. The satellite has been developed under the leadership of NASA in cooperation with the European and the Canadian Space agencies. It is scheduled to be launched from the European spaceport in Kourou, French Guiana, on an Ariane 5 rocket on December 22, 2021.

Collaborative Effort to Change the Way We See Our World

For a quarter of a century, thousands of engineers and hundreds of scientists worldwide worked to make Webb a reality, along with over 300 universities, organizations, and companies from 29 U.S. states and 14 countries. Also, RUAG Space contributed to the mission with key technology from its sites worldwide. “Like no other mission, Webb demonstrates what the international space community is capable of. The revolutionary technology will study every phase of cosmic history – from our solar system to the most distant observable galaxies in the early universe. One hundred times more powerful than its predecessor, Hubble, the JWST will change the way we see our universe. We are proud to be part of this global collaborative effort that will help us understand ourselves, our solar system, and the history of our universe better than ever before,” emphasizes André Wall, CEO of RUAG International. “In addition to the payload fairing, the computer and the separation system for the Ariane 5 launcher, we had the honor of supplying the antenna for data transmission to Earth, the ground equipment and three mechanisms for two of the telescope’s four scientific instruments,” he continues. 


Making sure Webb’s data reach Earth

The communication antenna system that will transmit collected data from the telescope to Earth was developed and produced by RUAG Space in Gothenburg, Sweden. The system consists of two antennas, one of which is a 0.6 m diameter reflector made of carbon fiber composite that provides low weight and high precision at extreme temperatures. The second antenna is a small cup type antenna that provides a backup function in another frequency band. “All of the amazing science data from the telescope will pass through our antennas. Just imagine, for instance, if this turns out to be the missing puzzle piece to help us better understand dark matter,” says Anders Linder, head of RUAG Space’s global Satellites business unit.

Three Mechanisms for Webb’s Scientific Instruments

Furthermore, RUAG Space was responsible for three crucial mechanisms for two of the telescope’s four scientific instruments. Two high-precision mechanisms for the telescope’s “super eye” called NIRSpec were developed, built and tested by RUAG Space’s site in Vienna, Austria. This includes the mechanical support structures and special ball bearings of the two filter systems referred to as the instrument’s Filter Wheel Assembly. The 200-kilogram “super eye” – one of the two European contributions to the mission – can detect faintest infrared radiation from the most distant galaxies. Designed to observe 100 objects simultaneously, the NIRSpec will be the first spectrograph in space that has this remarkable multi-object capability.

An extremely versatile instrument, the second European instrument “MIRI” (Mid Infrared Range Instrument), will support all four of JWST’s science themes. The instrument’s Contamination Control Cover was developed by RUAG Space in Zurich, Switzerland, and delivered in 2008.
It will protect MIRI against external contamination during the cooldown phase of the tests and after the launch. Additionally, this cryo-mechanism acts as an optical shutter for the instrument to allow on-board calibration and to protect the detectors against bright objects. 
MIRI will help to see the first generations of galaxies born after the Big Bang.

Crucial Products for A Successful Launch

During assembly and before the JWST finally launches on board an Ariane 5 rocket, a rotating and tilting device developed and produced by RUAG Space in Vienna, enables engineers to work on the telescope from all sides. Depending on the requirements, the trolley moves the telescope to a vertical or horizontal position. RUAG Space has already delivered more than 80 so-called “multipurpose trolleys,” which can rotate and tilt a satellite, to customers in Europe and the United States.


The top of the Ariane 5 rocket is made of RUAG Space’s payload fairing. It protects the JWST during liftoff and its journey through the atmosphere. The 17-meter-high structure was produced at the company’s site in Emmen, Switzerland. The Webb’s sunshield – as big as a tennis court – was specially engineered to fold up and fit within the 5.4-meter diameter fairing. “Our fairing was custom-made for this precious payload,” says Holger Wentscher, who heads RUAG Space’s Launchers business unit. “New hardware ensures that venting ports around the base of the fairing remain fully open. This will minimize the shock of depressurization when the fairing is jettisoned away from the launch vehicle.” 

On its way into space, the launch vehicle is controlled by a RUAG Space on-board computer (“brain”). Once the payload reaches a certain height, the two halves of the payload fairing are separated and jettisoned from the launch vehicle. The corresponding separation system was manufactured by RUAG Space in Linköping, Sweden. At a later stage, this separation system (payload adapter) allows the JWST to be separated from the launch vehicle.

JWST: Studying the Beginning of Galaxies, Stars and Life

Named after James E. Webb, NASA Director between 1961 and 1968, the JWST will directly observe a part of space and time never seen before. Webb will gaze into the epoch when the very first stars and galaxies formed, over 13.5 billion years ago. Ultraviolet and visible light emitted by the very first luminous objects has been stretched or “redshifted” by the universe’s continual expansion and arrives today as infrared light. Webb is designed to “see” this infrared light with unprecedented resolution and sensitivity. The Webb has four scientific missions: finding the earliest stars and galaxies, understanding how galaxies evolved, observing the formation of new stars and solar systems, and scanning Earth’s neighboring planets for their chemical properties and signs of life. The main instrument of the JWST is an infrared telescope with a main reflector 6.5 meters in diameter. Unlike its predecessor Hubble, which observes the universe from a height of a few hundred kilometers above the Earth, the JWST will orbit around a point 1.5 million kilometers from the Earth. This will keep the spacecraft in the same relative position to the Sun and the Earth to keep the telescope’s temperature very low behind its large solar shield. This is necessary for the Webb’s sensitive instruments to function properly.


Picture 1: “All of the amazing science data from the telescope will be transferred to Earth via our antennas,” says Anders Linder, Senior Vice President Satellites at RUAG Space. Copyright: RUAG Space, Peter Nilsson. Download:

Picture 2: The James Webb Space Telescope is the largest and most complex space telescope ever built. Download images of the telescope:

Picture 3: In addition to the payload fairing, separation system and on-board computer for the Ariane 5 launch vehicle, the company delivered the antennas for data transmission to Earth, the ground support equipment as well as three mechanisms for two of the telescope’s scientific instruments. Download infograph:

Picture 4: Once in orbit the RUAG Space payload fairing is separated into two halves and jettisoned from the launch vehicle, thus permitting the later separation of the James Webb Telescope from the launcher. Copyright: ESA / D. Ducros. Download:


Media contacts RUAG Space:

RUAG Space, Philipp Bircher, Director Communications Space,, 
T: +41 7979 011 81

RUAG Space, Christian Thalmayr, Communications Manager,, 
T: +43 664 8874 7876

Media Contact RUAG International: 
Clemens Gähwiler, External Communication Manager, RUAG International,, T: +41 76 319 28 58


RUAG Space: Leading Supplier to the Space Industry

RUAG Space, headquartered in Zurich, Switzerland, is the leading supplier to the space industry in Europe with a growing presence in the USA. Around 1300 employees in six countries (Switzerland, Sweden, Austria, Germany, USA and Finland) develop and manufacture products for satellites and launch vehicles – for both the institutional and commercial space markets.

RUAG Space is part of RUAG International, a Swiss technology group with production sites in 14 countries, which is divided into four divisions: Space, Aerostructures, MRO International and Ammotec. RUAG International employs around 6,000 people.

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