NASA’s James Webb Telescope Opens Mirror on Earth for Last Time Before Orbiting the Sun

NASA’s James Webb Telescope Opens Mirror on Earth for Last Time Before Orbiting the Sun

The primary mirror of NASA's next generation James Webb Space Telescope (JWST) opened for the last time on Earth before the expected launch of the observatory on October 31, 2021.

As one of the final tests before the telescope is blasted into space aboard an Ariane 5 rocket from French Guiana in South America, engineers commanded the mirror to fully expand and lock itself into place, just like it will do once in orbit around the sun. The telescope will orbit the sun around a million miles away from Earth.

The successful completion of the test marks a key milestone in the lead up to the launch later this year. It was the last in a long series of checks that were designed to ensure that the telescope's primary mirror is ready to handle the telescope's long journey in space and a lifetime of discovery.