The James Webb Space Telescope has successfully deployed the tripod that holds the observatory’s secondary mirror, in what is a critical milestone for the mission.
Webb launched on Christmas Day, but a lot has already happened, including the successful deployments of the observatory’s solar array and five-layer sunshield, the latter of which was completed just yesterday. Today, the Webb team shifted its focus to the secondary mirror, in what is the first in a series of deployments having to do with Webb’s optics.
The secondary mirror, measuring 2.4 feet (0.77 meters) wide, is located on the tips of three long booms and is one of the most important components of the $10 billion observatory.
Webb is a three mirror anastigmat telescope consisting of the large 21.3-foot-wide (6.5-meter) primary mirror, the secondary mirror, and a tertiary mirror. The primary mirror, using its 18 gold-plated segments, will collect incoming light from distant stars, galaxies, and exoplanets, and then reflect a focused beam to the secondary mirror. The beam will then bounce back toward the primary mirror and enter into the tertiary and fine steering mirrors. There, the precious light will finally reach the four scientific instruments situated behind the primary mirror.