NASA Launches the James Webb Space Telescope

Edan Tasca

Last Christmas, NASA launched the James Webb Space Telescope (JWST). Named after NASA administrator James Webb, who ran the agency between 1961 and 1968, and who was instrumental in building the Apollo program, the telescope was built to provide enhanced sensitivity compared with the Hubble telescope.

The JWST is capable of registering objects up to 100 times as far as Hubble. The telescope’s primary mirror — the Optical Telescope Element — has a 6.5-meter diameter, which consists of 18 hexagonal mirror segments made from gold-plated beryllium. This allows JWST to cover an area of capture more than five times that of Hubble. In addition, the JWST observes in a lower frequency range than Hubble, which will allow it to collect a more broad spectrum of data.

The JWST is also a lot farther from Earth than Hubble, located 1.5 million kilometers from us. The telescope resides so far out, because it must be kept at a temperature of -223 degrees Celsius. Thus, it must be protected from the heat of the Sun.

The project began in 1996. The initial launch was planned for 2007. After many delays — including a major redesign in 2005 — construction was finished in 2016. The JWST was built via a partnership between NASA, the European Space Agency, and our very own Canadian Space Agency.

Canada’s main contributions to the project were its Fine Guidance Sensor (FGS) and Near-Infrared Imager and Slitless Spectrograph (NIRISS). The FGS allows the telescope to determine its position, track objects of interest, and aim its detectors with extreme precision. NIRISS, meanwhile, will capture the infrared light emitted by objects and gather information about, for example, the atmospheres of exoplanets and distant galaxies.

In exchange for Canada’s help in the project, Canadian scientists have been guaranteed up to 450 hours of observing time with the Canadian NIRISS instrument and Webb’s other instruments. Of those hours, 403 will be spent between studying a) the atmospheres of exoplanets to determine if they are habitable, and b) clusters of very old galaxies to understand how they evolve. The remaining hours will be devoted to studying rogue planets, brown dwarfs, and exoplanets.

Preliminary estimates had the total cost at about $500 million. However, over the years and across delays, the total is looking closer to $9.7 billion. The hope is that the JWST will be able to provide advanced analyses of the cosmos, in particular the oldest and farthest objects detectable. Studying these objects gives us clues about the early state of the universe and how, well, pretty much everything works.

The satellite will enter service this June. But given its launch date, this is looking like a pretty decent Christmas present!