Testing the James Webb Space Telescope's primary mirror

2016-11-08 - Two technicians stand in front of the huge primary mirror of the James Webb Space Telescope as it undergoes tests at NASA's Goddard Space Flight Center in Greenbelt, Maryland. The mirror is made up of 18 hexagonal mirrors that fit together like a giant puzzle. Each segment can be adjusted with millimetre precision to collect light for the observatory to create astronomical images. (Credit: NASA/Chris Gunn)