James Webb Space Telescope

The James Webb Space Telescope (JWST), successor to the Hubble Space Telescope, is the most complex and powerful telescope ever built. The Webb telescope is slated to become the premier space observatory of the next decade, serving thousands of astronomers worldwide.

The Webb telescope will study every phase in cosmic history, ranging from the first luminous glows after the Big Bang to the formation of stellar systems capable of supporting life on planets like Earth and the evolution of our own Solar System.

The science goals for the James Webb Space Telescope can be grouped into 4 themes:

  • Search for the earliest stars and galaxies
  • Map the evolution of galaxies
  • Study the formation of stars and planets in the Universe today
  • Search for life in the Universe.


Artist’s impression of the James Webb Space Telescope. (Video © NASA)

Located 1.5 million kilometres from Earth in the dark and glacial cold of space, the Webb telescope will be able to detect and study objects thousands of times fainter than what can be seen with today’s telescopes. This enormous space observatory will have a mass of about 6,500 kg, a solar screen the size of a tennis court, and a primary mirror 6.5 metres in diameter, composed of 18 hexagonal segments, cooled to -233 °C (40 Kelvin). The telescope will be folded up inside the Ariane rocket that will launch it, and then open like a flower once in space.

Four instruments will be available aboard the James Webb Space Telescope, including the FGS/NIRISS.

This “2 in 1” Canadian instrument is the 2nd of 4 instruments on the Webb Telescope to be delivered. It consists of a Fine Guidance Sensor (FGS), used to precisely point the telescope, and a scientific instrument, the Near-InfraRed Imager and Slitless Spectrograph (NIRISS). Both were designed, built and tested by COM DEV International in Ottawa and in Cambridge, Ontario, with technical contributions from the Université de Montréal and the National Research Council of Canada and scientific guidance by the FGS research team. Canada’s contribution guarantees Canadian astronomers a share of observing time.

The FGS consists of two identical cameras that are essential for the Webb telescope to “see.” Their images will allow the telescope to determine its position, place its celestial targets precisely for its instruments, and remain pointed so that the telescope can collect high-sensitivity data. The FGS will guide the telescope with the amazing precision of one millionth of a degree.

The NIRISS will have unique capabilities for finding the earliest and most distant objects in the Universe’s history. It will also peer through the glare of nearby young stars to discover new exoplanets similar to Jupiter. It will be able to detect the thin atmosphere of small, habitable, earth-like planets, determine their chemical composition, and seek water vapour, carbon dioxide and other potential biomarkers such as methane and oxygen.

The FGS/NIRISS science team is jointly led by Dr. John Hutchings of the National Research Council of Canada (NRCC) and physics Professor René Doyon from the Université de Montréal, Director of the Observatoire du Mont-Mégantic and a member of the Centre de Recherche en Astrophysique du Québec (CRAQ).  The team includes astronomers from COM DEV, the National Research Council Canada, Saint Mary’s University, the Space Telescope Science Institute (STScI), the Swiss Federal Institute of Technology Zurich (ETH Zurich), the Université de Montréal, the University of Rochester and the University of Toronto.

The James Webb Space Telescope is an international collaboration by NASA, the European Space Agency and the Canadian Space Agency.

See the Canadian Space Agency site for more information.