E-Mail IMAGE: The process of deploying, moving, expanding and unfurling all of Webb's many movable pieces after they have been exposed to a simulated launch is the best way to ensure they... view more Credit: Credits: NASA/Chris Gunn For the last time while it is on Earth, the world's largest and most powerful space science telescope opened its iconic primary mirror. This event marked a key milestone in preparing the observatory for launch later this year. As part of the NASA's James Webb Space Telescope's final tests, the 6.5 meter (21 feet 4 inch) mirror was commanded to fully expand and lock itself into place, just like it would in space. The conclusion of this test represents the team's final checkpoint in a long series of tests designed to ensure Webb's 18 hexagonal mirrors are prepared for a long journey in space, and a life of profound discovery. After this, all of Webb's many movable parts will have confirmed in testing that they can perform their intended operations after being exposed to the expected launch environment.