An exoplanet hunter and first-light detector on NASA's next-generation space telescope is ready to do science, six months after the observatory launched to space.

The $10 billion James Webb Space Telescope is completing commissioning by testing its four cutting-edge instruments and their various modes, which will enable Webb to study both distant galaxies and closer-up objects in the Milky Way or solar system.

Now one of those instruments is ready for operations as Webb officials prepare to release the observatory's first operational images on July 12.

Live updates: NASA's James Webb Space Telescope mission.

Related: How the James Webb Space Telescope works in pictures.

As a result of these contributions, Canadian researchers have a guaranteed share of the science on Webb, which will face a steep competitive proposal process throughout the observatory's projected 20 years of operations.

The last NIRISS mode to be fully ready for science was "single object slitless spectroscopy." This mode allows the instrument to separate incoming light from a distant object, measuring the amount of light at specific wavelengths. .

— NASA's $10 billion James Webb Space Telescope launches on epic mission to study early universe.

— James Webb Space Telescope: The scientific mysteries no other observatory could unravel.

— James Webb Space Telescope: The engineering behind a 'first light machine' that is not allowed to fail .

The full list of Webb's first cycle of observations is available at this website (opens in new tab) from the Space Telescope Science Institute in Baltimore, which runs Webb operations!