Case study

MIRI/James Webb Space Telescope (JWST)

The telescope will study the first stars and galaxies and examine the physical and chemical properties of solar systems.

Artist impression of the James Webb space telecope.

An artist's illustration of the James Webb space telescope. Credit: ESA.

Mission facts

The UK leads the European Consortium to build the Mid InfraRed Instrument (MIRI) for NASA’s James Webb Space Telescope. Webb is a collaboration between ESA, NASA and the Canadian Space Agency, due for launch in 2021 as the replacement for the Hubble Space Telescope.

The UK provided the scientific leadership on MIRI and the instrument design and managed the overall project. The UK was also responsible for the overall construction of the instrument and the quality control to ensure that MIRI would operate as intended and cope with the harsh conditions of space.

MIRI was built for ESA by a European Consortium of 10 countries, led by Principal Investigator Prof Gillian Wright at the Edinburgh Astronomy Technology Centre. The European Consortium works in partnership with a team at NASA’s Jet Propulsion Lab, who have contributed the detectors and cryo-cooler for MIRI.

Securing a leading role on this prestigious NASA mission ensures that UK scientists remain at the forefront of global space science research. As the successor to Hubble, Webb is expected to generate even more astonishing images of our Universe, inspiring uptake of STEM subjects and the next generation of UK researchers and engineers.

MIRI was the first instrument to be delivered to NASA, in May 2012. Since delivery, it has been integrated and tested with the other science instruments and the telescope. MIRI are the other instruments for Webb are now with spacecraft prime contractor Northrop Grumman in California, ready to be integrated with the spacecraft.

Webb will look further back in time than any other telescope - to 400m years after the Big Bang. MIRI will ‘see’ faint infrared (IR) light invisible to the human eye and will peer far into the past observing very distant galaxies and newly forming stars and planets. MIRI uses IR because unlike visible light, it can penetrate the dense dust clouds which surround newly forming stars and planets.

Webb will also study the atmospheres of exoplanets identified by the PLATO science mission – necessary to understand their potential for hosting life.


To study these distant objects the telescope will use infrared light and must be cooled to within a few tens of degrees above Absolute Zero or - 273°C. This is to prevent radiation from the telescope and its instruments swamping the astronomical signals. To achieve this Webb will have a huge multi-layer sunshield which is the area of a tennis court.

To capture the very faint signals Webb’s main telescope mirror is 6.5m diameter, the largest ever flown in space and is gold-coated to optimise its ability to reflect infrared light. Its 18 segments will fold up inside the rocket for launch, then unfold in space.

Webb’s Integrated Science Instrument Module (ISIM) will house four instruments:

  • MIRI (Mid Infrared Instrument)
  • NIRCam (Near Infrared Camera)
  • NIRSpec (Near Infrared Spectrograph)
  • FGS (Fine Guidance Sensor)

UK involvement

The UK (UK Space Agency since 2011 and STFC) has invested almost £20M in the development phase of MIRI and has continued to support essential post-delivery testing, integration, calibration and characterisation activities by the UK MIRI team at NASA’s Goddard Space Flight Centre, Johnson Space Centre and more recently at prime contractor Northrop Grumman in California. This work is critical to understanding the instrument behaviour in operations and optimising the interpretation fo the science data which will eventually be returned from the mission.

STFC’s UK Astronomy Technology Centre contributes the Instrument Science Leadership though Prof Wright, along with the optical design/ engineering and calibration sources. Other UK institutes involved in MIRI are:

  • Rutherford Appleton Laboratory (thermal engineering and instrument assembly integration and testing);
  • Airbus Defence & Space UK (Consortium project management, Product Assurance co-ordination and System Engineering lead);
  • University of Leicester (Mechanical Engineering and Ground Support Equipment)
  • University of Cardiff (Calibration unit elements)

University College London’s Mullard Space Science Laboratory contributed to NIRSpec’s on board calibration system and a Staffordshire-based company, Tekdata Interconnections Ltd, manufactured the cryogenic harness - wiring to link the subsystems together on the spacecraft.

For more information, visit the NASA and ESA websites.

Published 16 April 2014
Last updated 21 December 2018 + show all updates
  1. Mission content updated.
  2. First published.