Billed as the successor to the Hubble Space Telescope, the James Webb Space Telescope is the most complex and powerful telescope ever built. When launched in October 2018, the infrared-optimized telescope will be the premier space observatory of the next decade, serving thousands of astronomers worldwide. The Webb 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, to the evolution of our own Solar System. The science goals for the Webb can be grouped into four 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 the potential for life in the Universe.
To observe objects at great distances—billions of light years away—the telescope will be large enough to gather very faint light and cold enough to detect infrared light from these distant objects. The Webb will be stationed 1.5 million kilometres from Earth at the Second Lagrangian Point (L2), one of five areas distant from the Earth where the effects of gravity are nearly eliminated, allowing the telescope to orbit a semi-stable point and manoeuvre with minimal interference. This optimal location will reduce problems with stray heat and light and enable the designed sensitivity of this highly sophisticated space observatory.
The Webb is an international collaboration between NASA, the European Space Agency (ESA), and the Canadian Space Agency (CSA). The NASA Goddard Space Flight Center is managing the development effort. The prime contractor is Northrop Grumman; the Space Telescope Science Institute will operate Webb after launch.
The CSA has invested approximately $160.4 million since 1998 in the design, building and science support for Canada's contribution to the Webb, which consists of the observatory's Fine Guidance Sensor (FGS), and one of the telescope's four science instruments: the Near-InfraRed Imager and Slitless Spectrograph (NIRISS). Both were designed, built and tested by COM DEV International Ltd. in Ottawa and Cambridge, Ontario, for the CSA, with technical contributions from the Université de Montréal, the National Research Council of Canada, and the CSA. The CSA's contribution guarantees Canadian astronomers a share of observing time as a 5% partner.
The FGS, or guider, is an essential component for the success of the telescope. The guider consists of a camera that will allow the Webb to determine its position, place its celestial targets precisely for its instruments, and remain pointed so that the telescope can collect sharp images and high-sensitivity data. The guider must spot telescope drifts the size of a dime seen 1000 km away, 16 times per second, to keep the Webb working properly. The guider also can track moving targets accurately, for observations of objects within the solar system. It is sensitive enough to work anywhere in the sky, and has two fully redundant cameras, as insurance against failure.
NIRISS will have unique capabilities for finding the earliest and most distant objects in the Universe's history, by obtaining key spectra of all faint objects in its field of view. It will also peer through the glare of nearby young stars to discover new exoplanets, by providing the telescope's highest resolution images. It will have the powerful capability of detecting the thin atmosphere of small, habitable, earth-like planets transiting their parent stars, to determine its chemical composition, seeking water vapour, carbon dioxide and other potential biomarkers such as methane and oxygen.
The FGS-NIRISS science team is led by Professor René Doyon from the Université de Montréal, Director of the Mont-Mégantic Observatory, Director of the Institute for Research on Exoplanets (iRex), and 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; York University; the University of Rochester; Cornell University;and kthe University of Toronto.